4th dimension travel through time

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Interesting Facts About Time, The Fourth Dimension, And Time Travel

November 29, 2012 James Miller Time Travel 0

Time is perhaps the greatest mystery of all and is deeply wrapped up in our conscious experience of things. Since antiquity, time has naturally attracted the interest of philosophers and scientists determined to understand and explain its true nature. At the heart of the question is whether time is an actual reality of the physical world or simply an artificial construct of the human mind .

The pre-Socratic Greek philosopher Parmenides, for example, saw time as merely an illusion, while his contemporary Heraclitus believed the flow of time to be real and the very essence of reality itself. For Newton time was absolute and moved at a consistent pace everywhere throughout the universe, while with Einstein time became more flexible and relative in scope. Nevertheless, the concept of time continues to be one of nature’s greatest mysteries and no one has been able to fully explain what it is really.

4-Dimensional Space-Time

In the 17th Century, René Descartes (1596-1650) envisioned there to be three dimensions of space, with a totally separate dimension of time that together specify an object’s position in physical space. Simply stated, three dimensions are used to specify an object’s location/movement in space (forward-backward, left-right and up-down), while a fourth dimension locates its position in time. This approach was adopted by Isaac Newton (1643-1727), the founder of classical mechanics, and classical physicists who saw time as an absolute, universal quantity completely independent from space. As such, early scientists used time to delineate a universal system of coordinates through 3-dimensional space.

In 1905, Albert Einstein then published his Special Theory of Relativity which was instrumental in introducing the concept of four-dimensional space-time. According to Einstein, time, space, and motion all act upon each other, and as an object’s speed increases, its time slows down in order to preserve the cosmic speed limit of light. This new concept merged space and time into space-time and helped introduced a new framework for the whole of physics.

We Are 3-Dimensional Creatures

Being three-dimensional creatures (possessing length, width, and height), humans are unable to see the fourth dimension as our physical world is constructed within these three physical dimensions. We might feel or intuit time’s presence, but we can never actually detect it with our three-dimensional senses because it extends beyond our universe. Humans only perceive the fourth dimension of time as memories lodged at variable intervals, the result of which is our apparent perception of time moving forward in a straight line.

Nevertheless, time exists as a dimension and objects cross it in a similar way as they do the others, although three-dimensional humans are only able to move in one direction forward through time. If we could see an object’s fourth-dimensional space-time (or world-line) it would resemble a spaghetti-like line stretching from the past to the future showing the spatial location of the object at every instant in time.

Space and Time are Inseparable

Space And Time are simultaneous phenomena (like mass and energy), and together form the fabric of the universe known as space-time. A demonstration of four-dimensional space-time’s inseparability is the fact that, as astronomers often remind us, we cannot look into space without looking back into time. We see the Moon as it was 1.2 seconds ago and the Sun as it was 8 minutes ago.

Also, in accordance with Einstein’s general theory of relativity, a massive object in space distorts the fabric of both the space and time around it. In other words, gravity is actually the result of mass stretching its surrounding space-time. For example, our Sun’s mass bends the space around it so that the Earth moves in a straight line but also circles within the Sun’s curvature in space. The Sun’s effect on time is to slow it down, so time runs slower for those objects close to the massive stellar object.

Interestingly, gravity also has an infinite range such that no matter how far apart two masses are in space they will always experience some gravitational pull toward each other. Theoretical physicists have tried to explain this phenomenon in terms of gravitons, S-Theory, and M-Theory, but even today a successful quantum theory of gravity has yet to be found.

How Time Changes at Relativistic Speeds

A property of light is that it always travels at the same constant speed in a vacuum of 186,000 miles a second (700 million mph) and you can’t go any faster.  Let us now take a look at the effect special relativity and traveling at high speeds have on the concept of time. According to the mathematical formula:

Speed = Distance ÷ Time

As we now know, the Speed of light (c) is fixed/absolute and represents the inviolable cosmic speed limit. As you travel at relativistic speeds or those speeds in which the relativistic effect becomes significant, then the distance and time values in the equation become flexible and are forced to change relative to one another. What actually happens is that time and distance are ‘relative’ to one another, and as you travel close to the speed of light, distances become shortened while time is lengthened. This is explained in Einstein’s theory of special relativity.

The following table shows the extent time (one hour) slows down relative to what percentage of the speed of light an object is traveling. As you can see, you don’t need to travel at light speed for time dilation to occur, but you won’t notice the effects until you go extremely fast. Bear in mind, also, that the fastest man-made object ever built, NASA’s Parker Solar Probe , has only managed to achieve a top speed of 430,000 mph (692017.92 km/h or 0.06412% of light speed.

• 0 % of  c: 60.00 mins
• 10 % of  c: 59.52 mins
• 20 % of  c: 58.70 mins
• 30 % of  c: 57.20 mins
• 40 % of  c: 55.00 mins
• 50 % of  c: 52.10 mins
• 60 % of  c: 48.10 mins
• 70 % of  c: 42.85 mins
• 80 % of  c: 36.00 mins
• 90 % of  c: 26.18 mins
• 92 % of  c: 23.52 mins
• 95 % of  c: 18.71 mins
• 99 % of  c: 8.53 mins
• 99.9 % of  c: 2.78 mins
• 99.997 % of  c: 1.17 mins
• 100 % of  c: zero mins

Roughly speaking, a person traveling at 99% the speed of light would experience timed slowed by roughly a factor of 7.  If they were to travel to a star 7 light years away at 99% speed of light, it would thus take them 1 year to reach their destination, but to an observer on Earth, it would have seemed like 7 years have passed. However, if that person attained 99.9999% of the speed of light, only 1 year would pass onboard for roughly every 70 years back on Earth. Meanwhile, a speed of 0.9999999 % of c would equate to 2,236 years of time elapsing, a speed of 0.9999999999 of c would see 70,710 years pass on Earth, rising at 0.999999999999999 of c to a staggering 22,369,621 years.

Traveling to the Stars and Time Dilation

As the table above indicates, traveling to the stars at high percentages of the speed of light would allow travelers to cover vast distances but experience very little time. The astronomical distances between the stars subsequently become no obstacle at all to traverse and a trip to another star system would feel near instantaneous. The following examples of the time it would take space crews traveling at near-light-speed to reach various destinations will help illustrate this point:

• Alpha Centauri : The near-light-speed craft traveling to Alpha Centauri , our nearest extrasolar sun located 4.3 light years away, would take just 4.3 thousandths of a second to complete the journey.
• Milky Way : A space crew would experience 3.2 seconds of time while crossing the 300,000 light years distance to the center of our galaxy.
• Andromeda Galaxy : Located 2.2 million light-years away, the journey, as far as the crew are concerned, would last 3.5 minutes.
• Virgo Cluster : Located 40 million light-years away, the crew would experience a one-and-a-half-hour journey.
• Edge of Universe : An estimated 17 billion light years away, the edge of our universe could be reached within 19 days of crew time.

Speed of Light and Immortality

Furthermore, if one day people were actually able to attain light-speed travel, then any journey undertaken at said speed would subsequently result in passengers experiencing no time at all. A photon, which is the basic unit that makes up all light, for instance, experiences no time whatsoever between its emission and its absorption.

In other words, despite a photon crossing billions of light years of space, the proper time it experiences between any two points on its path is zero and is reduced to just one instant. This idea is encapsulated in an observation made by sci-fi author ray Cummings in his 1919 short story The Girl in the Golden Atom, who noted: “ Time . . . is what keeps everything from happening at once”.

Scientists believe photons have zero mass and so cannot decay. Some theories, however, suggest photons might have a minute rest mass and so can eventually decay into lighter elementary particles. According to one study, a photon’s lifetime within its own rest frame amounts to just three years. Nevertheless, photons are still capable of surviving for an estimated billion billion years (10 18 ) because of the time dilatation they experience traveling at the speed of light. Considering the universe is an estimated 13.8 billion years old, it’s fair to say that a photon, for all intents and purposes, lives forever.

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The 4th Dimension: Where Science and Imagination Collide

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Most of us are accustomed to watching movies in 2D; even though characters on the screen appear to have depth and texture, the image is actually flat.

But when we put on 3D glasses, we see a world that we could walk in. We can imagine existing in such a three-dimensional world because we actually live in one. But for someone who's only known life in two dimensions, the third dimension would be impossible to comprehend.

And that, according to many researchers, is the reason we can't see the fourth dimension , or any other dimension beyond that. Physicists work under the assumption that there are at least 10 dimensions, but the majority of us will never "see" them. Because we only know life in 3D, our brains don't understand how to look for anything more.

What Is a Dimensional Space?

Looking beyond this dimensional space, the fourth dimension, types of dimensional spaces, why is it important to understand the fourth dimension.

A dimensional space, in mathematics and physics, is a way of describing the different directions or coordinates in which objects can exist or move. It's a mathematical concept used to understand and visualize the positioning and movement of things in our world.

In our everyday world, we often use three dimensions: height (up and down), width (left and right) and depth (forward and backward) to describe the location of objects. These three dimensions create what's called 3D space.

However, in more advanced mathematics and physics, dimensional spaces can have more than three dimensions, and they help scientists and mathematicians understand complex phenomena like quantum mechanics , string theory or data analysis in higher dimensions.

These higher-dimensional spaces are harder to visualize because they go beyond our everyday experience, but they are essential for solving various problems and studying intricate systems.

In 1884, Edwin A. Abbot published a novella that depicts the problem of seeing dimensions beyond your own. In "Flatland: A Romance of Many Dimensions," Abbot describes the life of a square living in a two-dimensional world. Living in 2D means that the square is surrounded by circles, triangles and rectangles, but all the square sees are other lines. One day, the square is visited by a sphere.

On first glance, the sphere just looks like a circle to the square, and the square can't comprehend what the sphere means when he explains 3D objects. Eventually, the sphere takes the square to the 3D world, and the square understands. He sees not just lines, but entire shapes that have depth.

Emboldened, the square asks the sphere what exists beyond the 3D world; the sphere is appalled. The sphere can't comprehend a world beyond this, and in this way, stands in for the reader. Our brains aren't trained to see anything other than our world, and it will likely take something from another dimension to make us understand.

But what is this other dimension? Mystics used to see it as a place where spirits lived, since they weren't bound by our earthly rules. In his theory of special relativity, Einstein referred to time as the fourth dimension, but noted that time is inseparable from space.

Science-fiction aficionados may recognize that union as space-time, and indeed, the idea of a space-time continuum has been popularized by science-fiction writers for centuries (e.g., Ray Bradbury's "The Martian Chronicles" or Joe Haldeman's "The Forever War").

Today, some physicists describe the fourth dimension as any space that's perpendicular to a cube — the problem being that most of us can't visualize something that is perpendicular to a cube [source: Duke University ].

Researchers have used Einstein's ideas to determine whether we can travel through time. While we can move in any direction in our 3D world, we can only move forward in time. Thus, traveling to the past has been deemed near-impossible, though some researchers still hold out hope for finding wormholes that connect to different sections of space-time.

Beginnings of the Concept

In the early 19th century, mathematicians and thinkers began to explore the idea of a fourth spatial dimension beyond our familiar three dimensions (depth, width and height). August Ferdinand Möbius was among those who pondered the possibilities of this additional dimension. One of the intriguing aspects of the fourth dimension is that in it, a three-dimensional object could be rotated in such a way that it would appear as its own mirror image, a concept that challenges our intuitive understanding of space.

The tesseract, also known as a hypercube, is a common visual representation of 4D space. It is an extension of the concept of a cube (a 3D object) into the fourth dimension. While it's challenging to visualize in our three-dimensional world, mathematicians use diagrams and models to help convey the idea of a tesseract.

Later in the 19th century, mathematician Bernhard Riemann laid the foundations for true four-dimensional geometry, providing a mathematical framework for understanding and working with higher-dimensional spaces. This work became fundamental to later developments in mathematics and physics, particularly in the study of curved spaces and the theory of relativity .

In mathematics and physics, we encounter various types of dimensional spaces beyond our familiar three-dimensional world.

• Zero-Dimensional Space (0D) : Often referred to as a single point or a singleton, this space represents a single location or value with no spatial extent or degrees of freedom. It is the simplest and most abstract of all dimensional spaces, serving as a foundational concept in mathematics, especially in set theory and abstract algebra.
• One-Dimensional Space (1D) : This is the simplest dimensional space, represented as a straight line. In a one-dimensional world, objects and entities can only move along a single axis (like a timeline), limiting their spatial freedom to one dimension.
• Two-Dimensional Space (2D) : This space includes coordinates that cover a plane, like a sheet of paper. It's used for mapping and analyzing objects' positions in two directions.
• Three-Dimensional Space (3D) : Our everyday space involves three dimensions: height, width and the third dimension of depth. The interaction of these dimensions allows us to describe the physical world and how objects move within it.
• Four-Dimensional Space (4D) : In physics, time is often considered the fourth dimension, essential in understanding space-time in Einstein's theory of general relativity.
• Euclidean n-Dimensional Space (nD) : It's a way of thinking about space that goes beyond our usual three dimensions. This space can have any number of dimensions (n), where distances and angles between points are measured in a consistent, familiar way.
• Vector Spaces : These spaces can have any finite number of dimensions and are fundamental in linear algebra, which plays a vital role in physics, computer graphics and engineering.
• Hilbert Spaces : Infinite-dimensional spaces are used in quantum mechanics to describe the state of quantum systems.
• Function Spaces : These spaces involve functions as their elements and are used in various mathematical and scientific disciplines.
• Manifolds : These spaces that look like Euclidean space near every point but may have a different overall shape.
• Phase Spaces : Used in physics to describe the complete set of variables needed to predict the future behavior of a dynamic system.

If we can't use the fourth dimension to time travel, and if we can't even see the fourth dimension, then what's the point of knowing about it? Understanding these higher spatial dimensions is of importance to mathematicians and physicists because it helps them understand the world.

String theory, for example, relies upon at least 10 dimensions to remain viable [source: Groleau ]. For these researchers, the answers to complex problems in the 3D world may be found in the next dimension — and beyond.

Applications in Math

In mathematics, particularly in geometry, comprehending higher-dimensional spaces, including the fourth dimension, is fundamental. These spaces expand problem-solving capabilities, although visualizing them challenges our conventional three-dimensional thinking. Concepts like hypercubes enable mathematicians to explore these abstract spaces.

In geometry, the fourth dimension plays a vital role in visual representation. It extends beyond our everyday experience, challenging our ability to grasp complex spatial arrangements. While we can't directly visualize four-dimensional space, math provides tools for representing and comprehending it, expanding our geometric understanding.

Applications in Physics

In physics, the fourth dimension, as time in space-time, forms the cornerstone of our comprehension of physical laws and predictions. The theories of modern physics, like Einstein's general relativity, rely on this concept. Accurate predictions about the behavior of objects and events demand the inclusion of time as the fourth dimension.

In fact, time as the fourth dimension is crucial for reshaping our understanding of gravity in the context of general relativity. It describes gravity as the curvature of space-time by massive objects, deeply intertwined with the fourth dimension. Neglecting time in this context would make explaining gravitational phenomena very challenging.

Everyday Applications

In everyday life, tasks, such as navigation and communication, heavily depend on our grasp of time as the fourth dimension. Technologies like GPS and accurate time-keeping systems rely on this foundational understanding, enhancing our daily lives.

Moreover, the concept of the fourth spatial dimension prompts profound philosophical inquiries into the nature of time and reality, challenging our perceptions and encouraging contemplation about our place within the universe.

Applications in Cosmology

Lastly, in cosmology, the fourth dimension is pivotal for unveiling the history and evolution of the universe. It assists in studying significant events like the Big Bang , cosmic expansion and the formation of galaxies and stars, providing invaluable insights into the cosmos.

This article was updated in conjunction with AI technology, then fact-checked and edited by a HowStuffWorks editor.

Lots More Information

Related howstuffworks articles.

• How 3-D Glasses Work
• How Time Travel Will Work
• How Special Relativity Works
• Can you make time stand still?
• How does gravity work?
• Cole, K.C. "Escape From 3-D." Discover Magazine. July 1993. (May 3, 2010) http://discovermagazine.com/1993/jul/escapefrom3d237
• Goudarzi, Sara. "You Can't Travel Back in Time, Scientists Say." LiveScience. March 7, 2007. (May 3, 2010)http://www.livescience.com/technology/070307_time_travel.html
• Groleau, Rick. "Imagining Other Dimensions." The Elegant Universe, NOVA. July 2003. (May 3, 2010)http://www.pbs.org/wgbh/nova/elegant/dimensions.html
• Jones, Garrett. "Fourth Dimension: Tetraspace." 2000. (May 3, 2010)http://teamikaria.com/hddb/classic/
• Overbye, Dennis. "Unbreakable: He's Still Ready for His Close-Up." New York Times. May 12, 2002. (May 3, 2010)http://www.nytimes.com/2002/05/12/weekinreview/ideas-trends-unbreakable-he-s-still-ready-for-his-close-up.html

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The General Relativity Rabbit Hole: Unraveling Space, Time and the Fourth Dimension

Parsing Albert Einstein's theory of our universe -- an idea that's utterly mind-bending, yet seemingly shatterproof.

More than a century ago, Albert Einstein conjured the hypothesis of all hypotheses -- an idea so extraordinary it would relentlessly echo through the vast directory of human thought. It would alter the fundamental tenets of science, inspire the most  mind-bending technology, help capture the glory of black holes , motivate authors to write prodigious novels, and stimulate directors to turn deeply metaphysical ideas into film . 

It was a concept that would test the limits of our imagination and a puzzle that would force us to rethink the notion of time. 

In 1916, Einstein announced his holy grail theory of general relativity.

The condensed version

Basically, Einstein realized that space is much more than the "space" we live in and that time transcends the clocks we've invented. Rather, he theorized, the two are physically entangled. 

Space is like a canvas on which our past, present and future are woven -- and it can fold, twist and ripple like silk. There's no beginning or end to this fabric of space and time, or as he called it, spacetime. 

We can't exactly see the spacetime continuum because it's part of a realm imperceptible to human eyes: the fourth dimension. But we can deduce its existence, as we can feel its effects. One of those effects you're no doubt familiar with -- gravity. But there are other effects too, like time moving slower depending on where you are in the universe and space-borne magnifying glass phenomena dubbed gravitational lensing. 

But I'm getting ahead of myself. It's no problem if pretty much all of that flew over your head. 

Albert Einstein.

Regardless of when your indoctrination to general relativity camp was -- even if it was five seconds ago due to my jam-packed intro -- I'd bet you thought it sounded bizarre. I mean, it involves premises like the fourth dimension and an invisible fabric. It projects weird outcomes like wormholes and nonlinearity. 

You wouldn't be alone in your skepticism. General relativity was once dismissed as delusion , "totally impractical and absurd." Yet, it remains one of the most elegant theories concerning our universe. 

So much so that it's often considered an unbreakable truth. 

Welcome to the fourth dimension

As three-dimensional beings, we tend to think about the universe in intuitive terms.

A one-dimensional object makes sense to us. That's a line. Two dimensions are also easy to understand. Pac-Man. And three dimensions -- tulips, Tic Tacs and iPhones -- are all comprehensible. But when we get to the four-dimensional universe, our intuition disappears. 

In 3D, we have an X axis for length, Y for width and Z for depth. In 4D, there's a fourth axis: Time.

But trying to think about 4D space, for us, would be like Pac-Man trying to understand 3D space. That would hurt his brain because there isn't a Z axis for Pac-Man like there isn't a time axis for us. Technically, Pac-Man's view of everything would be a giant line, similar to that of characters in the novel Flatland . 

However, Pac-Man's difficulty with perceiving 3D space doesn't mean 3D space can't exist. We're living in it. In fact, he's living in it. 

Likewise, 4D space exists whether or not our minds can enter it. We even call on the time axis unknowingly when we ask someone to meet us in a coffee shop at 2 p.m., for instance. We give X, Y, Z and time coordinates.

So as you read this, remember that everything we're about to discuss regarding general relativity lives in 4D. Fortunately, even though we can't mentally picture the fourth dimension, we can mathematically calculate it. 

The elevator experiment

You've probably heard the age-old adage that Isaac Newton was sitting underneath an apple tree when a delicious fruit fell onto his head, and voila, he discovered the mysterious force of gravity pulling stuff down to Earth.

Einstein had a (very) different take. 

Einstein's 1916 article published in Annalen der Physik on "The Foundation of the General Theory of Relativity."

In a nutshell, Einstein realized gravity isn't quite as mysterious as it's chalked up to be. It's a lot like a regular old force we are used to. We use it nearly everyday -- driving to work, running around, or perhaps kicking a soccer ball. It's called acceleration. 

Einstein's famous elevator thought experiment helps illustrate this connection.

Imagine a nonmoving elevator on Earth and an accelerating one somewhere in space, traveling upward with a force exactly equivalent to the force of gravity (9.8 meters/second^2). If there weren't any windows on these elevators, how could you tell if you were in the space one or the Earth one? 

Well, Einstein said, you couldn't. 

Modifying that a little, what if you had to figure out if you were in a non-windowed elevator that wasn't moving in space and one on Earth that was falling, so you were experiencing weightlessness? Could you then? Nope. 

Weightlessness on Earth in the presence of gravity feels just like weightlessness in space in what we'd normally consider zero-gravity. 

This is called  the equivalence principle .

So, the only plausible explanation for "gravity," Einstein said, is it isn't what we think it is. And, whatever it really is, probably has something to do with acceleration. 

Then, after a little (no, a lot) more thinking, he concluded that gravity is not a force at all. It's the product of objects interacting, while accelerating in different directions. OK, let's back up a little bit so our brains don't explode. 

Here's one way to think of Einstein's conjecture: Things aren't pulling things down; things are holding things up. 

You're falling right now

If a ball were rolling toward a cliff, Newton would say the ball was about to stop moving in a straight line because gravity would pull it down. To Newton, the ball would soon fall off the cliff because of an elusive gravity force.

Einstein, on the other hand, would say the ball has always been falling -- it's just that we only notice such "falling" when it passes the edge of the cliff because that's when nothing will be pushing, or accelerating, up on it anymore. Bear with me. Here's an analogy.

Imagine holding a glass of water. The glass, in a way, is constantly stopping the water from falling to the ground. You probably wouldn't say the glass is exerting an invisible force on the water to pull it down, right? It's the same idea. General relativity just takes it a step further. 

You're falling right now. You just can't tell because the chair you're sitting in is stopping you from reaching the ground. The floor of your room is stopping you and your chair from reaching the Earth. And the literal Earth is stopping you, your chair and your floor from "falling" through space. 

Everything is always in a constant, natural free fall, Einstein realized, yet sometimes that free fall is interrupted. And such interruption, to us, feels like the force of gravity. 

It's all... wait for it... relative.

OK, you might still be on that bit about Earth stopping you from falling through space. If Earth weren't there, wouldn't we be floating around like astronauts on the International Space Station?

This brings us to part two of general relativity: The oceanlike fabric of spacetime sort of redefines the notion of falling. Brace yourself, things are about to get trippy. The next thought experiment might seem unrelated to what we've just discussed, but trust me, it'll come together.

The gravity trampoline

Picture a trampoline.

If we put a bowling ball into this trampoline, it'd roll to the middle and make the stretchy material warp inward. Now imagine putting a marble onto this curved fabric. It'd roll down the curve and stick to one side of the bowling ball. The trampoline is the fabric of spacetime, the bowling ball is Earth, and the marble is you. And once again, I'm scaling the fabric of spacetime down by dimensions because we can't really conceptualize the fourth.

Anyway, according to Einstein, anything in the universe with mass warps spacetime sort of like the bowling ball warps the trampoline. Black holes warp it a whole lot, Earth warps it somewhat, the moon warps it a bit and even you warp it a teeny tiny amount. The more massive the object, the greater the warp. And the greater the warp, the stronger the "gravity." 

Now imagine that each grid-line in this image is a cable line that has a car, within which some item is traveling. 

This item is always "falling" along the line. If Earth were removed from this picture, the cable line would be straight, so the item would move in the direction we consider "forward." But there's Earth, denting the cable line inward and bringing the object on that line along with it.

So, if space didn't have any objects, Einstein said, a sole item in the cosmos would theoretically continue falling freely along an unwarped trajectory. But the universe is filled with objects. So spacetime is completely warped. And everything "falls" along those warps. Even ISS astronauts are falling freely, because they're following some sort of gravitational warp. 

But if you're still scratching your head, American physicist John Wheeler once perfectly explained  general relativity in 12 words: "Spacetime tells matter how to move; matter tells spacetime how to curve."

There you have it. That's general relativity. But the madness doesn't stop here. 

Consequences of general relativity are arguably even more bizarre than the theory itself. Don't forget, the spacetime grid is made out of, well, time.

Time is an illusion  

In Christopher Nolan's 2014 film Interstellar, something really weird happens when Matthew McConaughey's character, Cooper, visits a planet orbiting close to a black hole. 

"Seven years per hour here," he said, before exiting his spacecraft . This simply meant that for every hour on this planet, seven years will pass by on Earth -- and sure enough, when Cooper gets back to Earth after exploring for a couple of hours, decades have gone by. 

All that drama was a product of none other than general relativity. Or more specifically, time dilation. 

Interstellar.

This aspect of general relativity treads into a greater idea Einstein also came up with, called special relativity. We won't go too deeply into special relativity, but what you need to know is that it says light always travels at a constant speed. No matter what. 

Light on a train moving at 40 miles per hour will travel at the same speed as light on an airplane moving at 500 miles per hour, and both of those will travel at the same speed as light coming from a star on the other side of the galaxy. As you can imagine, when you take into account the spacetime continuum, this leads to some weird stuff.

Think about the trampoline again. No bowling ball. Say it'd take 10 seconds to roll a marble to the other side. OK, add the bowling ball. The trampoline is now stretched out. Rolling a marble across this warped trampoline would take, maybe, 12 seconds to account for the new area. 

With this analogy, you might see how heavier objects create a more massive curve, and therefore greater "area" for an object to travel across. But remember the light rule? Light must always travel at a constant speed, so it can't be affected by the warps.

From left to right: The moon warping spacetime, the Earth warping spacetime, the sun warping spacetime and a black hole absolutely smashing spacetime down to a single point: singularity.

But obviously, light traveling through a spacetime warp is crossing a longer distance than light traveling through empty space. So, if not speed, what changes? Well, after fiddling with relativity equations , you get the answer to be... time.

Time gets altered to account for the speed of light's constancy.

In short, time moves slower as a gravitational field in spacetime gets stronger. Yes, really. Even though it's an incredibly minuscule difference, we have proof of this. After a six-month journey, astronauts on the ISS aged 0.007 seconds slower than they would've if planted on Earth. This is also why we have atomic clocks that can account for time dilation impacting GPS satellites, for instance.

And with regard to Cooper, someone on Earth would observe time moving slower for him while he's on the black-hole-planet -- such that only one hour passes for every seven years on Earth. There are a few other ways that time dilation occurs due to general relativity, but this one gives you the general gist.

Wormholes and black holes 

Ready for some Star Trek-style thoughts?

What would happen if we folded the trampoline in half, like a piece of paper? Theoretically, you'd be able to punch a hole through the fabric. Hmm. Unfold the trampoline, and you'd see two holes quite far away from each other. Fold it back, and they touch. That's a wormhole.

While the trampoline is folded, a marble wouldn't need to travel from one side to the other. it could potentially just punch through to the other side in less than a second.  

Some experts argue that the fabric of spacetime could, theoretically, "fold" like that, especially near a super warped area such as regions around black holes. And if that's true, maybe we can travel across the universe in an instant. 

OK, before you get excited, though, we have no evidence for such a "fold." This is just speculation. But on the bright side, there are some crazy spacetime-warp consequences we do have evidence of.

We've gone over the fact that black holes are a big player in the general relativity game, but let's zoom in to the voids for a moment.

Because these leviathans are among the most gravitationally strong objects in the universe -- some have masses equal to billions of times that of our sun -- they don't just warp spacetime. They twist it and turn it so strongly that the fabric nearly shatters. And around here, time doesn't just slow. It stops.

But even as little 3D humans, we can watch the show.

In 2016, the Laser Interferometer Gravitational Wave Observatory, or LIGO, detected a binary black hole system , or two black holes orbiting each other. The voids' spiral sent actual ripples through the fabric of spacetime, like the way dropping a rock in a pond would send ripples across the water. Exactly as Einstein predicted decades ago. This was the first direct proof that spacetime is indeed a moldable sheet.

Since then, scientists have even managed to take two photographs of black holes in the universe, and both of these images show what warped spacetime near these abysses really looks like. There's a ring of photons around each one that literally follow the black hole-induced warp-lines.

A side-by-side of the M87* black hole, imaged in 2019, and SgrA*, imaged this year.

Not so impractical, not so absurd

Even aside from such concrete, visual proof of spacetime, mathematically speaking, experts have tried time and time again to find a flaw in Einstein's general relativity equations. And time and time again, they've failed. 

General relativity appears to be so immutable and crucial for our universe that even cosmic phenomena as gravitationally extreme as neutron stars -- so dense that a teaspoon of one would equal the weight of Mount Everest  -- seem to abide by its laws. 

Animation of gravitational waves produced by a fast binary orbit.

The idea of gravitational lensing, which is a magnifying effect of warped spacetime near highly massive galaxy clusters, has become practice among astronomers looking at faraway stars and galaxies .

A once "totally impractical and absurd" hypothesis has turned out to be one of the most fundamental truths of our generation.

General relativity states there's a fourth dimension that crochets together space and time, deeming linearity an illusion for our 3D minds, producing the far-fetched possibility of wormholes and creating a foundation for gravitational waves reverberating throughout the cosmos. 

And, for now at least, it's airtight.

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April 14, 2012 report

Physicists continue work to abolish time as fourth dimension of space

by Lisa Zyga , Phys.org

(Phys.org) -- Philosophers have debated the nature of time long before Einstein and modern physics. But in the 106 years since Einstein, the prevailing view in physics has been that time serves as the fourth dimension of space, an arena represented mathematically as 4D Minkowski spacetime. However, some scientists, including Amrit Sorli and Davide Fiscaletti, founders of the Space Life Institute in Slovenia, argue that time exists completely independent from space. In a new study, Sorli and Fiscaletti have shown that two phenomena of special relativity - time dilation and length contraction - can be better described within the framework of a 3D space with time as the quantity used to measure change (i.e., photon motion) in this space.

The scientists have published their article in a recent issue of Physics Essays . The work builds on their previous articles , in which they have investigated the definition of time as a “numerical order of material change.”

The main concepts of special relativity - that the speed of light is the same in all inertial reference frames, and that there is no absolute reference frame - are traditionally formulated within the framework of Minkowski spacetime. In this framework, the three spatial dimensions are intuitively visualized, while the time dimension is mathematically represented by an imaginary coordinate, and cannot be visualized in a concrete way.

In their paper, Sorli and Fiscaletti argue that, while the concepts of special relativity are sound, the introduction of 4D Minkowski spacetime has created a century-long misunderstanding of time as the fourth dimension of space that lacks any experimental support. They argue that well-known time dilation experiments, such as those demonstrating that clocks do in fact run slower in high-speed airplanes than at rest, support special relativity and time dilation but not necessarily Minkowski spacetime or length contraction. According to the conventional view, clocks run slower at high speeds due to the nature of Minkowski spacetime itself as a result of both time dilation and length contraction. But Sorli and Fiscaletti argue that the slow clocks can better be described by the relative velocity between the two reference frames, which the clocks measure, not which the clocks are a part of. In this view, space and time are two separate entities.

“With clocks we measure the numerical order of motion in 3D space ,” Sorli told Phys.org . “Time is 'separated' from space in a sense that time is not a fourth dimension of space. Instead, time as a numerical order of change exists in a 3D space. Our model on space and time is founded on measurement and corresponds better to physical reality.”

To illustrate the difference between the two views of time, Sorli and Fiscaletti consider an experiment involving two light clocks. Each clock's ticking mechanism consists of a photon being reflected back and forth between two mirrors, so that a photon's path from one mirror to the other represents one tick of the clock. The clocks are arranged perpendicular to each other on a platform, with clock A oriented horizontally and clock B vertically. When the platform is moved horizontally at a high speed, then according to the length contraction phenomenon in 4D spacetime, clock A should shrink so that its photon has a shorter path to travel, causing it to tick faster than clock B.

But Sorli and Fiscaletti argue that the length contraction of clock A and subsequent difference in the ticking rates of clocks A and B do not agree with special relativity, which postulates that the speed of light is constant in all inertial reference frames. They say that, keeping the photon speed the same for both clocks, both clocks should tick at the same rate with no length contraction for clock A. They mathematically demonstrate how to resolve the problem in this way by replacing Minkowski 4D spacetime with a 3D space involving Galilean transformations for three spatial coordinates X, Y, and Z, and a mathematical equation (Selleri's formalism) for the transformation of the velocity of material change, which is completely independent of the spatial coordinates.

Sorli explained that this idea that both photon clocks tick at the same rate is not at odds with the experiments with flying clocks and other tests that have measured time dilation. This difference, he says, is due to a difference between photon clocks and atom-based clocks.

“The rate of photon clocks in faster inertial systems will not slow down with regard to the photon clocks in a rest inertial system because the speed of light is constant in all inertial systems,” he said. “The rate of atom clocks will slow down because the 'relativity' of physical phenomena starts at the scale of pi mesons.”

He also explained that, without length contraction, time dilation exists but in a different way than usually thought.

“Time dilatation exists not in the sense that time as a fourth dimension of space dilates and as a result the clock rate is slower,” he explained. “Time dilatation simply means that, in a faster inertial system, the velocity of change slows down and this is valid for all observers. GPS confirms that clocks in orbit stations have different rates from the clocks on the surface of the planet, and this difference is valid for observers that are on the orbit station and on the surface of the planet. So interpreted, 'time dilatation' does not require 'length contraction,' which as we show in our paper leads to a contradiction by the light clocks differently positioned in a moving inertial system.”

He added that the alternative definition of time also agrees with the notion of time held by the mathematician and philosopher Kurt Gödel.

“The definition of time as a numerical order of change in space is replacing the 106-year-old concept of time as a physical dimension in which change runs,” Sorli said. “We consider time being only a mathematical quantity of change that we measure with clocks. This is in accord with a Gödel view of time. By 1949, Gödel had produced a remarkable proof: 'In any universe described by the theory of relativity, time cannot exist.' Our research confirms Gödel's vision: time is not a physical dimension of space through which one could travel into the past or future.”

In the future, Sorli and Fiscaletti plan to investigate how this view of time fits with the broader surroundings. They note that other researchers have investigated abolishing the idea of spacetime in favor of separate space and time entities, but often suggest that this perspective is best formulated within the framework of an ether, a physical medium permeating all of space. In contrast, Sorli and Fiscaletti think that the idea can be better modeled within the framework of a 3D quantum vacuum. Rather than viewing space as a medium that carries light, light's propagation is governed by the electromagnetic properties (the permeability and permittivity) of the quantum vacuum.

“We are developing a mathematical model where gravity is a result of the diminished energy density of a 3D quantum vacuum caused by the presence of a given stellar object or material body,” Sorli said. “Inertial mass and gravitational mass have the same origin: diminished energy density of a quantum vacuum. This model gives exact calculations for the Mercury perihelion precession as calculations of the general theory of relativity.”

© 2012 Phys.Org

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One time or another: Our best 5 theories of the fourth dimension

What is time and why does time flow? Is it just an illusion? Answering these questions is still one of physics’ greatest challenges

By Anil Ananthaswamy

1 February 2017

Anthony Harvie/Getty

“Time is what prevents everything happening at once.” Physicist John Wheeler’s statement is as fair a summary of what time does as any other – especially given that our hunt for the most basic ingredients of reality (see “ Essence of reality: Hunting the universe’s most basic ingredient “) has left us a trifle muddled about its status. One culprit was Einstein, whose theory of general relativity merged time with space. But even before him, out understanding of the laws of physics worked the same regardless of whether you travel forwards or backwards in time. That just doesn’t tally with our experience. So what is time really? Here are five of our best ideas.

Time… just is

Quantum mechanics arrived fast on the heels of general relativity and reinstated our familiar notion of time. The buzzing of the quantum world plays out according to the authoritative tick of a clock that sits outside of whatever system of particles is being described. Yet for all its respect, quantum mechanics’ portrayal of time isn’t persuasive. Take the Wheeler-DeWitt equations that describe the quantum state of the whole universe. If the system happens to be everything we know, then where exactly is the quantum clock doing its ticking?

Read the main article: Essence of reality: Hunting the universe’s most basic ingredient

Drill down past molecules, atoms, and fundamental particles and where do you end up we might finally be about to find out, time is… an illusion.

The independent physicist Julian Barbour thinks we might need to kill time entirely . He starts from the view that space and time, united by Einstein’s general relativity, must be decoupled. The only way to define space, he argues, is to consider it as the geometric relationship between observable particles, which means no reference to time. This leads him to a picture in which the universe is a set of possible configurations of the three-dimensional geometry of space. He calls each configuration a “snapshot”, with each existing “in a space of possibilities”. In Barbour’s conception, only these snapshots exist. Time is not real, but merely something we perceive — an illusion that comes about because the universe is constantly changing from one snapshot to another.

Time is… an entropic arrow

Yet Barbour’s scheme does not address a more subtle question. All of our physical laws are time-symmetric, which means that, mathematically speaking, it is equally possible for things to run backwards or forwards. There is only one exception. The second law of thermodynamics says that entropy, or the amount of disorder, always increases over time in isolated collections of particles and energy. The second law explains why a pot of water doesn’t spontaneously warm up, for example. The unique asymmetry of this law has led many physicists to suspect that the resolute forward flow of time we observe is linked to entropy. There is also a quantum version of this “entropic arrow of time”, developed by physicist Sandu Popescu at the University of Bristol, UK. Popescu and his colleagues have shown that we can view increasing entropy as the result of increasing quantum entanglement.

Time is… real after all

The entropic arrow of time might not be the whole story, says Lee Smolin of the Perimeter Institute in Waterloo, Canada. He points out that, if entropy constantly increases, then the universe at the time of the big bang must have been in a low-entropy (highly ordered) state. There is no obvious explanation for why it would have started that way. That returns us to the question of why our physical laws are time-symmetric. Perhaps we simply have the wrong laws, says Smolin. He and his colleagues have been trying out alternative fundamental laws that have time directionality built in. The only snag is that this leads to mind-bending questions, like whether those laws might themselves change over time.

Time… deserves equality

Joan Vaccaro of Griffith University in Australia has been experimenting with putting time and space on an equal footing. Quantum mechanics allows a particle to exist at one location and not another. Maybe, says Vaccaro, it should also let a particle exist at one time and not another, without the need to include interactions that create or destroy it.

When she tried adding in such equations it sent the theory haywire, because they violate a cornerstone of physics — the conservation of mass. But Vaccaro has shown how to recover a tweaked form of quantum mechanics from the wreckage. There may be some experimental evidence to support her ideas. In 2012, the BaBar experiment at Stanford University’s SLAC National Accelerator Center in California found that the decay of particles called B mesons is different at different times. That should just not be possible if the laws of physics are time-symmetric. Maybe Vaccaro is on to something – but let’s take things one step at a time.

This article appeared in print under the headline “About time”

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What is space-time?

A simple explanation of the fabric of space-time.

How space-time works

• Remaining mysteries

Additional resources

The fabric of space-time is a conceptual model combining the three dimensions of space with the fourth dimension of time. According to the best of current physical theories, space-time explains the unusual relativistic effects that arise from traveling near the speed of light as well as the motion of massive objects in the universe. 

Who discovered space-time?

The famous physicist Albert Einstein helped develop the idea of space-time as part of his theory of relativity. Prior to his pioneering work, scientists had two separate theories to explain physical phenomena: Isaac Newton's laws of physics described the motion of massive objects, while James Clerk Maxwell's electromagnetic models explained the properties of light, according to NASA .

Related: Newton's Laws of Motion

But experiments conducted at the end of the 19th century suggested that there was something special about light . Measurements showed that light always traveled at the same speed, no matter what. And in 1898, the French physicist and mathematician Henri Poincaré speculated that the velocity of light might be an unsurpassable limit. Around that same time, other researchers were considering the possibility that objects changed in size and mass, depending on their speed.

Einstein pulled all of these ideas together in his 1905 theory of special relativity , which postulated that the speed of light was a constant. For this to be true, space and time had to be combined into a single framework that conspired to keep light's speed the same for all observers. 

A person in a superfast rocket will measure time to be moving slower and the lengths of objects to be shorter compared with a person traveling at a much slower speed. That's because space and time are relative — they depend on an observer's speed. But the speed of light is more fundamental than either. 

The conclusion that space-time is a single fabric wasn't one that Einstein reached by himself. That idea came from German mathematician Hermann Minkowski, who said in a 1908 colloquium , "Henceforth space by itself, and time by itself, are doomed to fade away into mere shadows, and only a kind of union of the two will preserve an independent reality."

The space-time he described is still known as Minkowski space-time and serves as the backdrop of calculations in both relativity and quantum-field theory. The latter describes the dynamics of subatomic particles as fields, according to astrophysicist and science writer Ethan Siegel .

Nowadays, when people talk about space-time, they often describe it as resembling a sheet of rubber. This, too, comes from Einstein, who realized as he developed his theory of general relativity that the force of gravity was due to curves in the fabric of space-time. 

Massive objects — like the Earth , sun or you — create distortions in space-time that cause it to bend. These curves, in turn, constrict the ways in which everything in the universe moves, because objects have to follow paths along this warped curvature. Motion due to gravity is actually motion along the twists and turns of space-time. 

A NASA mission called Gravity Probe B (GP-B) measured the shape of the space-time vortex around the Earth in 2011 and found that it closely accords with Einstein's predictions.

Related: Ripples in Space-Time Could Reveal the Shape of Wormholes

But much of this remains difficult for most people to wrap their heads around. Although we can discuss space-time as being similar to a sheet of rubber, the analogy eventually breaks down. A rubber sheet is two dimensional, while space-time is four dimensional. It's not just warps in space that the sheet represents, but also warps in time. The complex equations used to account for all of this are tricky for even physicists to work with. 

"Einstein made a beautiful machine, but he didn't exactly leave us a user's manual," wrote astrophysicist Paul Sutter for Live Science's sister site, Space.com. "Just to drive home the point, general relativity is so complex that when someone discovers a solution to the equations, they get the solution named after them and become semi-legendary in their own right."

What scientists still don't know

Despite its intricacy, relativity remains the best way to account for the physical phenomena we know about. Yet scientists know that their models are incomplete because relativity is still not fully reconciled with quantum mechanics , which explains the properties of subatomic particles with extreme precision but does not incorporate the force of gravity. 

Quantum mechanics rests on the fact that the tiny bits making up the universe are discrete, or quantized. So photons, the particles that make up light, are like little chunks of light that come in distinct packets.

Some theorists have speculated that perhaps space-time itself also comes in these quantized chunks , helping to bridge relativity and quantum mechanics. Researchers at the European Space Agency have proposed the Gamma-ray Astronomy International Laboratory for Quantum Exploration of Space-Time (GrailQuest) mission, which would fly around our planet and make ultra-accurate measurements of distant, powerful explosions called gamma-ray bursts that could reveal the up-close nature of space-time. 

Such a mission wouldn't launch for at least a decade and a half but, if it did, it would perhaps help solve some of the biggest mysteries remaining in physics. 

• Read more about Einstein's space-time on Stanford University's Gravity Probe B .
• Paul Sutter explains why Einstein's theory of relativity is true , for Space.com. 
• Watch: " Are Space and Time An Illusion? " From PBS Space Time. 

This article was updated on May 20, 2021 by Live Science reference editor Kimberly Hickok. 

Sign up for the Live Science daily newsletter now

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Adam Mann is a freelance journalist with over a decade of experience, specializing in astronomy and physics stories. He has a bachelor's degree in astrophysics from UC Berkeley. His work has appeared in the New Yorker, New York Times, National Geographic, Wall Street Journal, Wired, Nature, Science, and many other places. He lives in Oakland, California, where he enjoys riding his bike. 

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Universe Watcher

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Understanding The Space-Time Continuum: A Beginner’s Guide

In the vast, infinite universe, space and time intermingle in an intricate dance that shapes our perception of reality in more ways than we often realize. Delving into the heart of this profound concept, we take you on a journey through the space-time continuum, exploring what it is, its immense implications, and how it is embedded in the fabric of our everyday lives. Brace yourself to dive into the intriguing world of physics and astronomy, exploring the brainchild of Einstein —the theory of relativity that catapulted our understanding into a fundamentally new concept—that of space-time. Punctuated with the fascinating wonders of gravitational waves and black holes and concluding with the portrayal of space-time in popular culture, this exploration attempts to break down a complex concept into digestible, everyday knowledge.

The Concept of Space-Time

Space-time continuum and albert einstein’s contributions.

The notion of space-time continuum is inextricably tied to Albert Einstein’s theory of relativity, specifically his Special Theory of Relativity formulated in 1905 and the General Theory of Relativity released in 1915. The concept interlaces three dimensions of space and one of time into a four-dimensional continuum. This innovative approach to understanding the universe changed the way we perceive space and time, revolutionizing theoretical physics and cosmology.

The Space-Time Conception

Integrated in Einstein’s general theory of relativity, one of the profound revelations about the space-time continuum is its curvature in the presence of mass and energy. In essence, the more mass or energy an object has, the more it warps the space-time around it. Objects move along the ‘paths’ created by this curvature. This explains the gravitational attraction between bodies in the universe: it is but a result of objects following curved paths in space-time, rather than being drawn to each other through some mysterious force at a distance as envisioned by Newton.

Noteworthy Scientists and Experiments

Numerous scientists besides Einstein made significant contributions to our understanding of space-time. Renowned mathematician Hermann Minkowski, a one-time teacher of Einstein, presented a geometric interpretation of space-time in 1908. He argued that the events of the universe occur within a four-dimensional space-time, not within three-dimensional space independently of time. This became the groundwork for Einstein’s later development of general relativity.

In 1971, the Hafele-Keating experiment provided one of the first observable confirmations of the effects predicted by the theory of relativity. The experiment involved atomic clocks flown around the earth, which deviated from the time kept by synchronized stationary atomic clocks. The results confirmed the predicted effects of time dilation and gravitational time dilation, which state that time slows down for objects moving at high speeds relative to a stationary observer or closer to a massive object. This experiment cemented the concept of space-time in physics and cosmology.

Introducing Space-Time: A Critical Component of Contemporary Physics and Cosmology

In the realm of contemporary physics, the principle of the space-time continuum, based heavily on Einstein’s theory of relativity, is seen as fundamental. It’s integral to understanding various facets of a broad range of domains that include cosmology, astrophysics, and quantum mechanics . To illustrate, an in-depth comprehension of the workings of black holes – spatial regions known for their exceedingly strong gravitational pull that prevents anything from escaping – necessitates a firm grounding in the concept of the space-time continuum.

The continuum of space-time isn’t just significant in the traditional areas of physics; it also plays a crucial role in the sphere of quantum science, notably in the development of string theory. This intriguing theory asserts that the most basic elements of reality are actually energy strings oscillating at various frequencies, existing within defined dimensions of space-time.

Gravitational Waves and Black Holes

Delving deeper into the space-time continuum.

The science of the space-time continuum is based on a four-dimensional model that unites the three familiar dimensions of space – length, width, and height – and time, resulting in a single entity. However, this single entity is not a flat plane; it is shaped by the mass and energy within it causing a curvation. This curvature shapes the trajectories of objects navigating through it, giving rise to what we perceive as gravity.

Gravitational Waves: Ripples in Space-Time

Gravitational waves are disturbances or ripples in space-time caused by some of the universe’s most violent and energetic processes. According to Einstein’s theory of general relativity, any acceleration of a large mass will distort the space-time around it and cause waves, much like dropping a stone in a pond. When these waves pass us, they cause the distance between objects in space to expand and contract, at a scale much smaller than an atomic nucleus. Detecting these tiny changes is a major scientific achievement.

The discovery of gravitational waves has opened a new window on black holes. When two black holes collide, they merge into a larger one and release a colossal amount of energy. According to Einstein’s theory, this energy propagates outward as gravitational waves, causing ripples in space-time.

On September 14, 2015, for the first time ever, scientists detected these ripples from two merging black holes more than a billion light years away, thus giving a key validation to Einstein’s theory of general relativity.

Space-Time Distortion in Black Holes

A black hole is a region of space-time exhibiting gravitational acceleration so strong that nothing—no particles or even electromagnetic radiation such as light—can escape from it. The theory of general relativity predicts that a sufficiently compact mass can deform space-time to form a black hole.

The singularity at the center of a black hole is where our current understanding of physics breaks down. Here, according to theory, mass is crushed to infinite density, space-time is infinitely curved, and time itself ceases to exist. Surrounding the singularity is the event horizon, a boundary beyond which nothing can escape the gravitational pull of the black hole.

Exploring the Space-Time Continuum

The enigmatic workings of the universe can be better understood through the lens of the space-time continuum. Whether it’s the ripple patterns created by gravitational waves as they traverse space-time, or the intense distortions witnessed within black holes, the space-time continuum is central to our comprehension of these phenomena. These mysterious cosmic events illustrate a captivating interplay between space and time, highlighting the potent influence of gravity on the fabric of the cosmos.

Impacts and Consequences of Space-Time

Getting to grasp the space-time continuum.

The notion of the space-time continuum has its roots in Albert Einstein’s Theory of Relativity. Simply put, it envisions a four-dimensional framework which fuses our conventional understanding of three-dimensional space with the added element of time, forming a single entity aptly referred to as space-time. This unique four-dimensional grid is where we perceive all the events, activities and phenomena that make up the universe as we know it.

Space-Time and Planetary Orbits

One practical impact of the space-time continuum is its influence on the orbiting of planets. Before the concept of space-time, Newton’s theory of gravity explained that bodies like planets were attracted to the Sun’s massive mass. This consequently resulted in their elliptical orbits. However, Einstein’s theory of General Relativity added another layer to this explanation. It proposed that large objects like the Sun cause the space-time around them to curve, creating a ‘well’ in which smaller objects like planets travel. Thus, planets are not just pulled towards the Sun, they are also moving along the curved paths of this space-time well.

Space-Time and Air Travel

The influence of the space-time continuum is also evident in air travel, more specifically in the flight paths of planes. Similar to the movement of planets, an airplane’s flight path is influenced by the curvature of space-time. The crew and passengers aboard an airplane are, in essence, experiencing a slightly different rate of time compared to individuals on the ground due to gravitational time dilation, a phenomenon where time runs slower the closer one is to a massive object.

Newtonian Physics Vs Special Relativity

Prior to Einstein’s theory, Newtonian physics was the foundation of our understanding of the universe. In Newtonian mechanics, time and space are absolute and separate entities. However, the theory of special relativity paints a different picture. It assumes that the laws of physics should look the same to all observers, regardless of their motion relative to each other. Furthermore, special relativity introduces the idea that time can ‘dilate’, or run slower, given enough speed, a phenomena known as time dilation.

Space-Time and Reality

The space-time continuum doesn’t just pertain to planets and airplanes. Its implications can be seen in everyday life as well. For instance, GPS satellites need to account for both special and general relativity in their operation. The slight differences in time due to these effects are instrumental in achieving the precise location data that these systems provide. Thus, the space-time continuum is not just a theoretical concept, but a physical reality that structures the very world we live in.

The Influence Of Space-Time On The Future Of Space Exploration

The space-time continuum concept, particularly its potential for establishing more efficient means of journeying across indomitable interstellar distances, lies at the heart of the progression of space exploration . This understanding could lead to the development of radical propulsion methods such as wormholes – shortcuts within the fabric of the space-time continuum. Additionally, black holes, the ultimate pinpoints of infinite space-time curvature, stand as compelling mysteries that might revolutionize our comprehension of the cosmos when unraveled.

Space-Time In Popular Culture

Unraveling the space-time continuum: a sci-fi’s favorite device.

The magnificence of the space-time continuum has not only magnetized scientific minds but has also branched out into the realm of popular culture, predominantly in the genre of the science fiction (Sci-Fi) cinema. The fascination towards the concept of time travel, made plausible by the principles of the space-time continuum, brings a note of scientific credibility to these riveting narratives. The iconic “Back to the Future” trilogy stands as a testament where manipulation of the space-time continuum enables time travel.

Sci-Fi films like “Interstellar,” ferry spectators through the riveting journey of a team of explorers traversing a wormhole prognosticated to exist near Saturn, giving audiences a tantalizing glimpse of the complex phenomenon of time dilation. Films like “Donnie Darko” offer a more philosophical perspective. They delve into metaphorical analysis of time travel, employing a concept similar to the space-time continuum itself — a tangent universe.

Literature and Space-Time Continuum

Science fiction literature has also played a significant role in shaping our understanding of the space-time continuum. H.G. Wells’ novel, “The Time Machine,” was one of the first to bring these concepts to the forefront. In it, the protagonist uses a machine to travel through time, suggesting a physical and tangible connection between time and space.

Books like “A Wrinkle in Time” by Madeleine L’Engle propose the existence of tesseracts, a hypothetical means of traversing the space-time continuum quickly. Philip K. Dick’s stories often wrestle with the nature of reality, time, and space, leading to complex and often unsettling portrayals of the space-time continuum.

The Multiverse Theory in Pop Culture

Additionally, the multiverse theory is a popular trope in both movies and literature. This theory implies a multitude of universes, including the one we inhabit. Each of these separate universes comprises its unique space-time continuum and distinct laws of physics.

These parallel universes come to life in the “Marvel Cinematic Universe,” where each Universe and dimension has its own space-time fabric. At specific points in the series, the multiverse theory is substantially examined, most notably in “Doctor Strange” and “Avengers: Endgame”.

Wormholes and Other Misunderstood Concepts

Wormholes, another misunderstood concept, provide shortcuts across the universe by warping the space-time continuum. They are frequently used in stories to allow rapid interstellar or time-travel, such as in the movie “Contact” based on Carl Sagan’s novel.

These portrayals, however, often simplify or gloss over the extraordinarily strange character of these phenomena as predicted by general relativity and quantum physics. In reality, wormholes and other exotic space-time structures are highly speculative and not yet backed by any observational evidence.

Space-time, a perplexing subject deeply rooted in the field of theoretical physics, has somewhat been demystified to the layman through its representation in popular culture regardless of the precision of these portrayals.

Current Research and Future Possibilities

Unraveling the mysteries of space-time.

In line with general relativity principles, space-time is envisioned as a four-dimensional continuum blending the three space dimensions and one time dimension. With the pace of advancements in technology and theoretical research, our comprehension of this enigma continues to evolve.

Theoretical physicists have been largely engrossed in the pursuit of a quantum gravity theory which might reconcile the inherent differences between quantum mechanics and general relativity. String theory, which imagines point-like particles as one-dimensional strings, stands as a hopeful candidate in depicting gravity’s quantum characteristics.

Lately, the unexpected association between gravity, quantum information, and thermodynamics has been the epicenter of much deliberation. This line of inquiry has unveiled the ‘holographic principle’, a staggering theory suggesting that all information in our three-dimensional universe could potentially be coded on a two-dimensional plane at the universe’s boundaries.

Exploring Unanswered Questions

One of the biggest unanswered questions in this field is how exactly gravity relates to the other three fundamental forces of physics under extreme conditions—such as the ones existed during the Big Bang or inside black holes. Astronomers and physicists are working together using the Event Horizon Telescope to capture the environment around black holes and hopefully unravel some of these secrets by comparing observations to theoretical predictions.

Another frontier that researchers are exploring is the cosmological scale, and how quantum mechanics, particularly quantum fluctuations, played a critical role in the formation of galaxies and large-scale structures in the universe.

Future Possibilities: Time Travel, Quantum Mechanics, and More

As mind-boggling as it may seem, time travel is a logical consequence of the theory of relativity and its space-time geometry. While physicists are nowhere close to inventing a working time machine, studies on wormholes and warped space-time could potentially allow for time travel, according to some speculative models. However, there still exist considerable conceptual and technical challenges to overcome before time travel can become a realistic possibility.

The future of our understanding of space-time is also closely linked to advances in quantum mechanics. Quantum Hair, for example, is a recent hypothesis suggesting that black holes might not be as bald as once thought, and instead carry a myriad of quantum information encoded in their ‘hair.’ If confirmed, this could bridge the gap between classical physics and quantum physics, revolutionizing our understanding of space-time.

In essence, though our comprehension of space-time has greatly deepened over the past century, there remain many more mysteries about the universe waiting to be explored, making it an exciting field of study for anyone interested in the frontiers of science.

The world of space-time is unendingly fascinating, an expansive, mysterious theatre of cosmic interplay that influences everything we understand about the universe. As we look to the future, our understanding of this profound concept only promises to deepen, potentially unlocking new insights and revolutionizing our connection with the cosmos. From the orbits of planets to the flight path of an airplane, the influences of space-time pervade our reality in incredible ways, a testament to its profound significance. Whether that’s through potential time travel, the probabilities of quantum mechanics, or harmonizing the schism between classical and quantum physics, one thing is clear: the exploration of space-time is an open door to an exhilarating future that beckons us with the promise of understanding and discovery.

What is the space-time continuum theory?

A pillar of contemporary physics, the space-time continuum theory unifies the four dimensions of time and the three dimensions of space into a single, cohesive fabric that forms the basis of the universe’s structure. This idea, which was developed inside the parameters of Albert Einstein’s general theory of relativity, holds that time and space are entwined to create a dynamic, interrelated framework. This theory states that enormous objects, such planets or stars, cause distortions in space-time, which affect the trajectories that light and other objects follow through this twisted environment. Gravity is the result of space-time curvature, which is caused by mass and energy. This newfound understanding of the force governing celestial motions is made possible by gravity. The space-time continuum theory has greatly advanced our understanding of the underlying nature of reality by helping to explain a wide range of phenomena, from the bending of light around large objects to the expansion of the universe itself.

What does it mean to break the space-time continuum?

It is common for science fiction to serve as the inspiration for the speculative idea of breaching the space-time continuum rather than accepted scientific theories. The space-time continuum is seen as a fundamental framework that regulates the structure of the cosmos in theoretical physics. In fiction, breaking it would mean upsetting the way that space and time are intertwined, which would open up unorthodox possibilities like time travel or parallel universes. Nevertheless, the idea of disrupting the space-time continuum is largely theoretical and has no empirical basis in the area of present scientific knowledge. The imaginative stories found in science fiction must be distinguished from the thoroughly investigated and proven theories found in physics, such as general relativity, which is the cornerstone of our knowledge of space and time and was developed by Albert Einstein.

What is the space-time continuum philosophy?

Within the philosophical framework, the space-time continuum philosophy explores and interprets the interconnectedness of space and time conceptually. This philosophical approach, which takes its cues from the scientific underpinnings of Einstein’s general relativity, aims to reveal the significant effects of the unified space-time fabric on our perception of reality. It explores issues with existence’s essence, causation, and the individual’s perception of time. When discussing the space-time continuum, philosophers frequently think about how temporal dynamics affect human consciousness, free will, and the metaphysical elements of the cosmos. Though closely related with scientific concepts, the philosophy of the space-time continuum goes beyond empirical findings. It explores the significant consequences of this interconnected cosmic framework on the nature of being by going beyond the realm of metaphysics and existential inquiry.

Can you travel through the space-time continuum?

The capacity to traverse the space-time continuum, particularly in the imaginative meaning frequently depicted in science fiction, continues to be a theoretical and elusive concept. Although time travel is a common motif in literature and film, it has never been confirmed or proven to be possible given the limitations of current scientific understanding. The bending of light around huge celestial bodies is one example of how Einstein’s theory of general relativity states that massive objects have the ability to curve space-time. This phenomenon has been observed to some extent. But in order to actually manipulate space-time for time travel, a number of theoretical and practical obstacles must be overcome, such as the requirement for exotic matter with negative energy density and the avoidance of paradoxes. Though intriguing, the concept of traveling across the space-time continuum is still theoretical and belongs more to the domain of scientific curiosity and creative inquiry than to the domain of accepted scientific practice.

What did Einstein say about the space-time continuum?

By developing the general theory of relativity, Albert Einstein made revolutionary advances to our knowledge of the space-time continuum. In this ground-breaking theory, Einstein suggested that mass and energy cause the fabric of space and time to curve, rather than gravity being only a force between masses as stated by Isaac Newton. The bending of light around huge objects was predicted by Einstein’s calculations and subsequently verified by gravitational lensing studies. He explained how time and space were entwined to create a four-dimensional continuum that is now known as space-time. Our understanding of the cosmos was profoundly altered by Einstein’s work, which established the notion that space and time are dynamic and affected by the presence of matter. His idea offered a fresh viewpoint on the nature of the universe and served as the basis for contemporary cosmology and our comprehension of gravity.

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What Are Tesseracts In A Wrinkle In Time ?

What are tesseracts in a wrinkle in time & how can i use one to travel out of this dimension.

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Understanding the Fourth Dimension From Our 3D Perspective

“unlock the mysteries of the fourth dimension with this in-depth exploration of its concepts and implications as we examine its relation to our 3d world and the fascinating possibilities it presents.”.

Trevor English

The fourth dimension is a place you can travel to by going in a direction perpendicular to the third dimension. To the untrained eye, this statement makes absolutely no sense. How could there be a direction that is perpendicular to a three-dimensional space? In order to better understand this concept, we have to slowly work our way through all of the dimensions and analyze what changes are being made between each.

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Zeroth Dimension

The zeroth dimension is one that we don’t often think about. Points are the only dimensional beings that can be correctly understood in the zeroth dimension. They have absolutely no dimensions, no width, no length, and no height. They are the smallest they could ever be, but also the largest they could ever be at the same time.

As we look to deepen our understanding of the fourth dimension. We can examine a cube in each dimension as we progress. A cube in the zeroth dimension would simply be a point. All of its dimensions are the same in every direction because there are none. The cube still represents a point in space, but that is the extent of its power in the zeroth dimension. Now, let’s move into 1-D.

First Dimension

The transition between the zeroth dimension and the first dimension involves an extrusion in any direction. In the first dimension, everything exists as a line. The only thing that differs between objects in the first dimension is their length. Lines all have the same width and the same height, but their length can be varied.

If you want to make lines varying thicknesses, then you have to move into 2-dimensional lines. A cube in the first dimension would look like a line with the same length as said cube, but no width or height values.

Second Dimension

Transforming a line segment in a direction perpendicular to the 1-dimensional direction brings you into the second dimension. Keep this idea in mind as we expand our dimensional knowledge and notice this perpendicular action repeated as we move through dimensions.

In the second dimension, our cube can begin to look like a cube, but only just barely. A cube would exist as a square in the second dimension. You can, of course, draw a representation of a 3D cube in 2 dimensions, but that isn’t what a cube would look like in 2 dimensions. Rather this would simply be a representation of the third dimension superimposed on the second.

Length and width can be varied in the second dimension, which allows for basic shapes and geometry. When we move into the third dimension, the math starts getting more complex.

Third Dimension

The cube from the second dimension now gets extruded in a third perpendicular direction to both sides of the 2D square. To put this in cartesian terms, the 2D square existed in the X and Y directions. Moving into the 3rd dimension extruded that square in the Z direction. The third dimension is where our cube actually becomes a cube in our traditional defined sense. The object has dimensions of width, length, and height.

Throughout all of the dimensions, it is important to note that a cube will maintain all of its basic properties in theory. All of the angles will be right and all of the sides will be the same. Bringing in another principle of dimensions, we can examine what would occur if the cube was expanded indefinitely. When a cube in the third dimension is expanded to infinity, it encompasses the entirety of the 3-dimensional space.

So far, you should likely grasp these 3 dimensions, after all, they are the dimensions with which we most commonly associate.

Fourth Dimension

When we bring the cube into the fourth dimension, we begin to experience some counterintuitive math. We extrude the cube in a direction perpendicular to all of the first three. This is impossible within the third dimension because there are only 3 dimensions in which the cube is already expanded in. When we add the fourth dimension, in order to maintain the properties of the cube of all angles being 90 degrees and all sides being the same, we must extrude in this new dimension.

Cubes in the fourth dimension are technically called tesseracts. Objects in 4D differ in length, width, height, and strength. Superimposing strength on any of the previous dimensions gives an object in the subsequent dimensions a strength of 0, or a value that is infinitely small.

All of the edges of a tesseract are the same, and all of the angles are right. This makes sense in theory, but when we begin to imagine what a tesseract would look like, we are bound by our 3-dimensional minds. To view a tesseract, we have to superimpose this fourth-dimensional object into the third dimension.

The main way we represent a tesseract, or fourth-dimensional cube, is by projecting it into the third dimension with perspective. This representation can be seen below.

This representation isn’t what a 4D cube looks like, it is simply what one looks like in perspective viewed from the third dimension. To summarize our understanding of the fourth dimension, objects in 4D vary in value by length, width, height, and strength. All of these dimensional measures extend in a direction perpendicular to the previous three. Width is perpendicular to the length, height is perpendicular to width and length, and finally, strength is perpendicular to height, length, and width.

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These concepts are hard to grasp but hopefully, this gives you a good overview understanding of how the fourth dimension works and how we interpret it from our 3-dimensional eyes.

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ABOUT THE EDITOR

Trevor English <p>Trevor is a civil engineer (B.S.) by trade and an accomplished writer with a passion for inspiring everyone with new and exciting technologies. He is also a published children&rsquo;s book author and the producer for the YouTube channel Concerning Reality.</p>

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Travels Through Time: Inside the Fourth Dimension, Time Travel, and Stacked Time Theory (Connecting the Universe #1)

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Begin your journey into the Connected Universe with Travels Through Time , an examination of the nature of time, dimensions, and the possibilities of real time travel. In an easy-to-follow and conversational manner, researcher Mike Ricksecker formally introduces his Stacked Time Theory with an exploration of the fabric of the cosmos, starting with ancient symbolism and alchemy up through today's modern science and technology. What clues did our ancient ancestors leave for us about the nature of the universe that we're just now rediscovering today, and where throughout history have we seen those esoteric clues resurface?

Travels Through Time explores...

• Ancient alchemy and the secrets of the ouroboros
• The nature of time and the paradoxes of time travel
• Historic and modern accounts of time slips
• Dreams and accessing eternal knowledge
• The nature of the universe as a simulation
• Extraterrestrial abductions and time loss
• How the future influences our present day
• Insights from Einstein, Tesla, Bohm, Kaku, and other physicists
• The possibilities of real time travel and how that would work

...and more

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Science Struck

Does the Fourth Dimension of Time Exist? What You Need to Know

Time is the fourth dimension, other than the three dimensions of space. Time makes change possible or else we would be living in a static universe.

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The time has come for you to question the very nature of time. Can time be considered to be a fundamental physical dimension, on par with the space dimensions? If it is indeed so, then why can’t we travel back and forth in time, just as we move through the space dimensions?

What is Time?

Time is our way of keeping track of changes that are constantly happening in the universe. Time arises due to the dynamic nature of the universe or one could say, that the dynamism is possible, because there is time.

In a way (without implying any creationist overtones), you could say that time must have been invented, so that all things do not happen at the same moment and space was made, so that all things do not happen at the same position! By time, we mean a series of changes or events that occur. Those events that happen periodically, like the rising and setting of the Sun, the rotation and revolution of the Earth, around the Sun are used as references to calibrate and measure time. Our clocks are synchronized with these periodically repeating events to keep track of time. So in a way, time is felt or understood, only as a result of changes in the material world we perceive. To put it simply, time is change.

What Does a Dimension Mean?

A dimension is a degree of freedom of a system. In simple words, it is the number of ways or directions in which change can take place in a system.

Imagine an ant walking on a very thin thread. The width of the thread is such that it can either move forward or backward on the thread, it cannot move sideways. That is, its freedom of movement is restricted to one dimension. It has one degree of freedom and therefore one dimension. Similarly, an ant moving on a flat disk can move straight or sideways but not up and down, so its degrees of freedom is two. Hence it’s moving on a two dimensional object.

Now imagine a flying ant like ‘atom ant’, it can move straight ahead or back, sideways, as well as up and down. Its degree of freedom is three, so it’s moving as we all do in three space dimensions because the degrees of freedom are three.

How is Time the Fourth Dimension?

However, time as a dimension is unique and different from other space dimensions. In space dimension, you can move ahead and backwards, there is no restriction on that. Conversely, in time, you can only move in one direction. In time, you cannot move backwards, only forward. This has far reaching implications which we will discuss further, but first let us understand how Einstein’s special relativity theory changed our perceptions of space and time.

Einstein and the Unification of Space Time

In 1905, a Swiss patent clerk, Albert Einstein put forth a theory called special relativity which dealt the fatal blow to the old established bastion of Newtonian mechanics, which had the perception of an ‘absolute time’. The theory revolutionized the way we see nature and the universe.

The basic postulate of special relativity is that no information can travel faster than the velocity of light in vacuum and it is constant.

The second postulate is that all laws of the physical world should remain the same in any inertial reference frame. By inertial reference frame, we mean a co-ordinate system of reference moving at a constant velocity or which is stationary. Any other co-ordinate system moving with constant velocity with respect to a co-ordinate system at rest is also an inertial reference frame.

Newton’s mechanics had the concept of absolute time. That is, no matter which reference frame people are using, their clocks if compared show the same time. Special relativity changed this perception. The necessity that the speed of light should be constant forces us to abandon the absoluteness of time! That is, different observers in different reference frames show different times in their watches, but the laws of physics will remain the same. In fact the faster you move in space, the slower you move in time. This is often termed as time dilation. Time is not absolute, it is relative.

This forced the world to abandon the concept of separate ideas of space and time and a single unified concept of spacetime came into existence. Some found it in Einstein’s name itself. ‘Ein’ means ‘one’ in German. Split up his name as ‘ EIN+ST+EIN’, ST meaning space time. If you see, it literally means ‘one space time’; just a lucky coincidence one would say! Time was realized as the 4th dimension.

Let us try to understand what time dilation is. We are all continuously moving not just in three dimensional space but in four dimensional spacetime. Consider a racing car moving on an absolutely straight race track at a constant velocity. It is moving in one dimension and takes some time to reach the finish line. Now consider that it’s trying to reach the finish line, but on an oblique path. Its velocity is now distributed over two dimensions and therefore it’s taking longer for the car to cover the same distance. Its velocity in the original one dimension has reduced.

In a similar way, all objects in the real world are moving in a four dimensional spacetime, at a constant velocity as that of light. Sounds astounding but it’s true. Only the velocity is distributed over dimensions and most of it is in the time dimension.

When the objects are at rest, they are moving only in the time dimension. Now when they start moving, their velocity increases in the three space dimensions, and therefore it slows down in the time dimension. Therefore, the faster you move in the three space dimensions, the slower you go in the time dimension. This causes time dilation. This is a bit difficult to understand, but if you give it adequate time to sink in, it’s simple.

The Arrow of Time

The uniqueness of time dimension is that you can travel only forward in it, not backward. This fact has profound implications. It protects causality, that is the law of cause and effect. That is, cause should precede effect and it should not be the other way round. This irreversibility of time is inbuilt through the concept of entropy.

If you study thermodynamics, you will come across the law that entropy or disorder in the universe always increases, never can it decrease. You can understand the law of entropy, by just observing the irreversible nature of natural phenomena. That is, a cup falling down and breaking, can never be restored to the same condition, with every atom in place, as it was. The irreversibility implied by entropy could be described by the popular line from the Humpty Dumpty nursery rhyme, which says: All the King’s horses and all the King’s men, couldn’t put Humpty together again! For every system, disorder always increases. Entropy increase is unidirectional, just as the unidirectionality of time. Thus it is no coincidence that the thermodynamical arrow of time and the arrow of time flow, point in the same direction, as they both preserve causality. As a consequence, traveling back in time impossible, as it would violate causality and the law of entropy. However, special relativity does allow for the possibility of time travel to the future.

Creatures living in a two dimensional flat world will find it difficult to imagine what a three dimensional world would look like. Similarly, we, living in a world of three space dimensions find it impossible to imagine four dimensional spacetime! Still, through many indirect experimental tests the idea of four dimensional space time has been tested beyond doubt.

Concept of time as the fourth dimension is very subtle and elusive. I hope the time you have spent reading this article has lifted the veil over the mystery of time just enough, for you to investigate it further.

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Physicist Reveals What the Fourth Dimension Looks Like

...and where it may be.

• Albert Einstein believed space and time made up a fourth dimension.
• An example from a string theorist gives a view of what a fourth dimension could be.

We move through three dimensions. Or do we? String theorists believe our world encompasses more than three dimensions. Without experiential evidence, the mathematical theory of space and time as a fourth dimension has remained just that since the days of Albert Einstein: a theory.

But in a new video from Big Think , B rian Greene, a string theorist from Columbia University, offers up a relatively simple explanation of just what a fourth dimension could entail—and where it could be.

In the clip, Greene says that while “math suggests a real possibility there may be more dimensions than the ones we directly experience,” our minds have trouble comprehending just where they could be. Already, we move through three dimensions—left-right, back-forth, up-down—so how is there any room left? “That’s really the point,” Greene says. “They are new places that our experience doesn’t allow us to access directly, but according to these theoretical ideas, might be there.”

Greene offers up a garden hose as a good example of what the fourth dimension looks like. From far away, this garden hose may look one-dimensional to the naked eye. From a distance, we simply can’t see the circular nature of the rubber. But if we use a pair of binoculars, Greene says, we can see the circular part. This example shows that dimensions can be big. They could be so big we see them with our eyes, or they could curl up and become tiny and more difficult to detect, as is the case with the garden hose.

“This idea might apply to space itself,” Greene says. Maybe the left-right, back-forth, up-down dimensions are simply the big, easy dimensions for us to see. “But just as the hose has a curled-up dimension, maybe space itself has curled up dimensions all around us, just curled up to such a fantastically small size we can’t see them with our eyes,” he says. “We can't see them even with today's most powerful microscopes.”

Tim Newcomb is a journalist based in the Pacific Northwest. He covers stadiums, sneakers, gear, infrastructure, and more for a variety of publications, including Popular Mechanics. His favorite interviews have included sit-downs with Roger Federer in Switzerland, Kobe Bryant in Los Angeles, and Tinker Hatfield in Portland. 

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Scientists discover 4th dimension: Is time travel possible?

• By Nirmal Narayanan Updated December 4, 2019 21:10 +08

The concept of time travel may soon be possible as two different teams of scientists from the United States and Europe have shown the existence of a fourth spatial dimension.

It was in 1905 that legendary physicist Albert Einstein first introduced the concept of the fourth dimension where we can move in time. Since then, the concept has perplexed scientists and with the discovery of the new fourth spatial dimension, the big dream of humans to travel through time is showing signals of materialization.

The recent quantum experiments conducted by researchers from Switzerland, USA, Germany, Italy, and Israel revealed that in addition to the conventional three-axis where an object can move up-down, left-right or forward-backward to an observer, there is a hidden fourth dimension where the objects can move in new directions of motion.

Can 4D make time travel possible?

Oded Zilberberg, the lead author of the study says that the theoretical concept of this experiment indicates that the existence of the fourth dimension where objects move in new directions will help us to move forward and backward in time.

Penn University's Mikael Rechtsman, a researcher at the US-based team, reveals that the research team managed to get a glimpse of the 4D spatial system even though it cannot be felt physically.

Both the teams in the United States and Europe conducted quantum hall experiments to discover the fourth dimension . As per experts, if the quantum Hall effect can be generated, it is a solid indication of the presence of the fourth dimension.

After cooling down the atoms to absolute zero, the researchers placed it in a 2D lattice with the help of lasers. Using more lasers, the researchers trapped the atoms and made them move. The movements of the atoms matched the Quantum Hall effect, which signaled that the fourth spatial dimension is a reality.

Researchers claim that these new experiments cannot be used in real life as of now, but the new finding will lead to significant progress in the world of physics. As the experiments are now in their nascent stages, more research will shed light on the way in which the fourth dimension works, which will finally result in the materialization of 'time travel', the biggest dream of humankind.

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Travels Through Time: Inside the Fourth Dimension, Time Travel, and Stacked Time Theory (Connecting the Universe) Paperback – August 1, 2023

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Begin your journey into the Connected Universe with Travels Through Time , an examination of the nature of time, dimensions, and the possibilities of real time travel. In an easy-to-follow and conversational manner, researcher Mike Ricksecker formally introduces his Stacked Time Theory with an exploration of the fabric of the cosmos, starting with ancient symbolism and alchemy up through today's modern science and technology. What clues did our ancient ancestors leave for us about the nature of the universe that we're just now rediscovering today, and where throughout history have we seen those esoteric clues resurface?

Travels Through Time explores...

• Ancient alchemy and the secrets of the ouroboros
• The nature of time and the paradoxes of time travel
• Historic and modern accounts of time slips
• Dreams and accessing eternal knowledge
• The nature of the universe as a simulation
• Extraterrestrial abductions and time loss
• How the future influences our present day
• Insights from Einstein, Tesla, Kaku, and other physicists
• The possibilities of real time travel and how that would work

...and more!

• Print length 322 pages
• Language English
• Publication date August 1, 2023
• Dimensions 6 x 0.73 x 9 inches
• ISBN-13 979-8985183986
• See all details

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About the author, product details.

• ASIN ‏ : ‎ B0C8SBF81J
• Publisher ‏ : ‎ Haunted Road Media, LLC (August 1, 2023)
• Language ‏ : ‎ English
• Paperback ‏ : ‎ 322 pages
• ISBN-13 ‏ : ‎ 979-8985183986
• Item Weight ‏ : ‎ 15.4 ounces
• Dimensions ‏ : ‎ 6 x 0.73 x 9 inches
• #365 in Ancient & Controversial Knowledge
• #444 in Unexplained Mysteries (Books)
• #640 in History & Philosophy of Science (Books)

About the author

Mike ricksecker.

Researcher Mike Ricksecker is the author of the Amazon best-sellers Travels Through Time, A Walk In The Shadows, and Alaska's Mysterious Triangle, as well as several historic paranormal books. He has appeared on multiple television shows and programs, including History Channel's Ancient Aliens and The UnXplained, Travel Channel’s The Alaska Triangle, Discovery+’s Fright Club, Animal Planet’s The Haunted, multiple series on Gaia TV, and more. Mike is the producer and director of the docu-series, The Shadow Dimension, available on several streaming platforms, and produces additional full-length content on ancient wisdom, lost civilizations, and the supernatural on his extensive YouTube channel.

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4 dead as severe storms hit Houston area; hundreds of thousands lose power in Texas

Emergency crews in southeast Texas were clearing debris and assessing flooding on Friday after powerful storms tore through the state , killing at least four people and knocking out power to nearly 800,000 customers.

The winds — which reached 100 mph — were reminiscent of 2008's Hurricane Ike , one of the costliest natural disasters in American history, Houston Mayor John Whitmire said in a briefing Thursday. A widespread 3 to 6 inches of rain fell north of Houston, with one of the highest totals reaching around 6.9 inches in 24 hours near Romayor.

The storm also battered New Orleans overnight, with severe thunderstorms and flooding possible again through Saturday morning, according to the local branch of the National Weather Service .

In Texas, the destruction was evident even before sunrise, with high winds tearing out windows of high-rise buildings in downtown Houston and inundating the region with flooding. Streets were littered with glass, electrical lines and other detritus.

“I know that many people lived through, and are still living through, scary situations with the terrible strong winds that blew across our county tonight," Harris County Judge Lina Hidalgo said in a statement Friday morning.

"Damage assessments are ongoing, and we cannot know how long it will take to clear debris without those assessments completed, but from initial reports the debris looks very significant," Hidalgo said.

Classes were canceled for the 400,000 students in the Houston Independent School District.

Officials urged all but essential employees to work from home if possible, and the Houston Police Department told residents to avoid traveling downtown.

Two of the four people who died in Texas were killed by falling trees, while a third died when a crane blew over, Houston Fire Chief Samuel Peña said at a news briefing. No information was given about the fourth. Whitmire said a possible fifth death is being investigated, but it’s not yet clear if it was related to the weather.

Texas Gov. Greg Abbott thanked emergency personnel in a statement, saying work is ongoing to assist communities affected by the storms.

“Our hearts are with the families and loved ones of those who tragically lost their lives due to severe weather in Southeast Texas, and we remain in contact with local officials to do everything we can to protect Texans and help our communities recover,” Abbott said.

At one point, more than 900,000 customers were without power statewide; that remained true for around 670,000 as of 3 p.m. CT,  according to poweroutage.us . Nearly all of those were in Houston’s Harris County.

Heat and humidity in the city will ramp up into the weekend, which could lead to health concerns if power is not restored quickly. Temperatures could be as high as 91 degrees with a heat index of 97.

Across Houston, photos and videos on social media showed intense flooding and downed trees, as well as toppled electrical towers and power lines .

In a video posted to Facebook , rain was seen leaking into Minute Maid Park, where the Houston Astros play. Another video showed baseball fans leaving the stadium amid the bad weather.

Strong winds appeared to have blown off roof panels at a Hyatt Regency Hotel in Houston, a video posted to X showed. Other footage shared on the platform showed blown out windows in a building in the city's Wells Fargo Plaza.

Whitmire described downtown Houston as a “mess” and warned that “many roads are impassible due to downed power lines, debris, and fallen trees.” 

Firefighters were removing live wires from Route 290 and most city traffic lights were down, he added. 

In Louisiana, the severe weather knocked out electricity for some 215,000 customers, many in and around New Orleans. Around 115,000 remained without power as of Friday morning.

A swath of the southeast coast, stretching from Louisiana, through Mississippi, Alabama and into the Florida Panhandle, was under a flood watch early Friday.

The National Weather Service said in an afternoon update that unsettled weather, including the possibility of excessive rainfall and severe thunderstorms, will persist across the Southeast through Saturday.

Around 7 million people along the central Gulf Coast remain under flood watches.

“A few tornadoes, scattered damaging winds, and hail all appear possible over the central/eastern Gulf Coast area,” according to the National Weather Service.

The agency also noted a risk of severe thunderstorms in portions of the northern Plains through Friday evening.

Rebecca Cohen is a breaking news reporter for NBC News.

Alexander Smith is a senior reporter for NBC News Digital based in London.

Denise Chow is a reporter for NBC News Science focused on general science and climate change.

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Senate Approves Bill to Reauthorize F.A.A. and Improve Air Travel

The Senate also passed a short-term extension of the current F.A.A. law to give the House time to clear the longer-term package early next week.

By Kayla Guo

Reporting from the Capitol

The Senate on Thursday passed legislation to reauthorize federal aviation programs for the next five years and put in place new safety measures and consumer protections for passengers, at a moment of intense uncertainty and disruption in the air travel system.

The bill , which still must win final approval in the House before becoming law, would provide more than $105 billion to the Federal Aviation Administration and another $738 million to the National Transportation Safety Board for airport modernization, technology programs and safety. It would also bolster the hiring and training of air traffic controllers, codify airlines’ refund obligations to passengers, ensure fee-free family seating and strengthen protections for passengers with disabilities.

“Aviation safety has been front of mind for millions of Americans recently, and this F.A.A. bill is the best thing Congress can do to give Americans the peace of mind they deserve,” Senator Chuck Schumer of New York, the majority leader, said on the Senate floor on Thursday evening.

It passed in an overwhelming bipartisan vote of 88 to 4, just one day before the current law is scheduled to lapse. The Senate also unanimously approved a short-term extension to allow time for the House to take up and clear the longer-term package next week, a step that would send it to President Biden.

The legislation is a bipartisan compromise negotiated over months by the Senate and House committees with jurisdiction over the F.A.A., after Congress authorized several short-term extensions of the agency when lawmakers failed to meet earlier deadlines. The House passed its version of the bill almost a year ago in a lopsided vote of 351 to 69.

Senator Maria Cantwell of Washington, chairwoman of the Commerce Committee, celebrated the bill’s provisions on consumer protections, aviation safety, air traffic controllers, airport infrastructure and work force development on the floor after passage.

“This is a big moment for aviation,” Ms. Cantwell said. “We have had safety issues and concerns that we need to make a big investment. This legislation is that investment — in safety standards, in protecting consumers and advancing a work force and technology that will allow the United States to be the gold standard in aviation.”

Senator Ted Cruz of Texas, the top Republican on the Commerce Committee, said: “This legislation is a strong, bipartisan, bicameral bill that includes hundreds of priorities for senators and representatives, both Republican and Democrat. This bill gives the FAA the safety tools it needs at a critical time.”

As one of the few remaining bills considered a must-pass item this year, the F.A.A. package, which prompted several regional disputes, became a magnet for dozens of amendments and policy riders that threatened to delay it in the Senate.

With the legislation threatening to stall, the House on Wednesday approved a one-week extension for the F.A.A. before leaving Washington for the weekend. The Senate followed suit on Thursday, steering around lingering disputes that had threatened to scuttle the effort and cause a brief lapse for the F.A.A.

The debate came at a time of acute uncertainty about the aviation system, which has had a recent spate of concerning episodes such as dangerous near collisions on runways, plane malfunctions and thousands of flight delays and cancellations.

It was unclear for much of Thursday whether the Senate would be able to push through the legislation and the extension, as senators demanded votes on amendments or threatened to block speedy passage. No amendments were ultimately brought to a vote.

The most intense regional fight was over a provision in the bill that would add five round-trip long-haul flights out of Ronald Reagan National Airport outside Washington. Proponents, which include Delta Air Lines, have said they want to expand access to the nation’s capital and increase competition.

The proposal incensed lawmakers representing the area , who argued that the airport maintains the busiest runway in the country and cannot support additional flights. Senators Tim Kaine and Mark Warner of Virginia and Benjamin L. Cardin and Chris Van Hollen of Maryland, all Democrats, filed an amendment to strike the new flights.

Mr. Kaine and Mr. Warner threatened to hold the bill up if they did not receive a vote. But Mr. Cruz blocked an effort to bring up a compromise amendment that would have given the transportation secretary the final say on new flights after considering any effects they would have on delays and passenger safety.

“The Senate abdicated its responsibility to protect the safety of the 25 million people who fly through D.C.A. every year,” Mr. Kaine and Mr. Warner said in a statement. “Some of our colleagues were too afraid to let the experts make the call. They didn’t want to show the American people that they care more about a few lawmakers’ desire for direct flights than they care about the safety and convenience of the traveling public. That is shameful and an embarrassment.”

The senators from Virginia and Maryland were the only votes against the bill.

Another group of senators failed to secure a vote on a proposal to halt the Transportation Security Administration’s expansion of facial recognition technology at airports and restrict it where it is in use.

Senators had also proposed adding a number of unrelated bills, including one that would compensate people harmed by exposure to the nation’s nuclear weapons program , legislation to fully fund the replacement of the collapsed Francis Scott Key Bridge in Baltimore, and a credit card competition measure. Senators Marsha Blackburn, Republican of Tennessee, and Richard Blumenthal, Democrat of Connecticut, were pushing for a vote on their bill to protect minors online into Thursday. None of them made it into the final product.

An earlier version of this article misstated the name of the bridge in Baltimore that collapsed. It is the Francis Scott Key Bridge, not the Francis Key Scott Bridge.

How we handle corrections

Kayla Guo covers Congress for The New York Times as the 2023-24 reporting fellow based in Washington. More about Kayla Guo

Our Coverage of Congress

Here’s the latest news and analysis from capitol hill..

Hurling Insults: In an after-hours session of the House Oversight Committee, insults by Representative Marjorie Taylor Greene, a right-wing Republican, led to a raucous exchange with Democrats .

Octogenarians in the Senate: Age and health have drawn intensive focus in the presidential race, but the recent news that Senators Bernie Sanders, 82, and Angus King, 80, are running again has prompted little discussion of their age .

Disaster Bill: A bipartisan group of House lawmakers pulled off the rare feat of drawing enough support through a procedural maneuver known as a discharge petition  to steer around Speaker Mike Johnson and force a vote on disaster relief.

Pentagon Spending: Senator Mitch McConnell and other top Republicans want more federal money for the military. But Democrats say domestic programs must get an equivalent boost .

Israel Arms Pause: In a largely symbolic vote, the House passed a bill that would rebuke President Biden  for pausing an arms shipment to Israel and compel his administration to quickly deliver those weapons.