# What Is Space-Time?

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#### sarajo

certainly is - if I could choose a year to go back to to change it for the better Id go back to the early noughties when I first met my 2nd boyfriend & relive it without all of the problems -just me & him loving each other -living together

Tensologist

#### Tensologist

Ok sarajo so here's another thought about time travel moving forward: I think it is possible you can kind of relive things with your next boyfriend without all the problems...since that's where your mind is at. Yup, just like all the personal trainers and martial arts experts say, the mind is the source and the physical the derivative.

Meanwhile, I hope to someday meet my next girlfriend - complete with her whole new set of problems - wherein I propose to comport myself with an improved demeanor.

#### sarajo

boyfriend???!!! nah!!! not any more - I have a girlfriend now who lives down in the south of england -in a residential equestrian college

Tensologist

#### Lucille

I'm not much of a math guru. I received a daily text from deepak Chopra the other day where he said:

At the cosmic horizon 42 billion light years away space expands faster than the speed of light and galaxies disappear. - Deepak❤

So I was thinking that would be where eternal life might reside since its past time. What would life look like at a speed faster than light? Like a deity, that's what.
I'm not much of a math person, either. Just today, I've been trying to figure out two hundred thousand thousand. What it means?

#### Hayseed

Write down two hundred thousand. 200,000 Now, add 3 zeros behind it. 200,000,000

The three zeros added, represent the second thousand.

Two hundred million.

Space-time has roots in two false assumptions. The first is that light is continuous and alternating, and the second is that the emission duration is the same as the absorption duration.

Emission is the decoherence of an EM field. It happens at a rate of 2 times c. Because electric fields are repulsive. The emitted "wave" does not have frequency, it has duty cycle. It has a polarized duration. The EM field is physically cut from the field source. It already has the velocity of c. Emission is instant.

The emitted field disturbance induces the absorber for 1/2 period, and then the absorber relaxes or resets to the induction for another 1/2 period. The absorber has charge, and the charge reacts to the induction.

All of modern theory and all of modern experiments are interpreted on these two false assumptions of EM radiation.

We need to question our fundamentals. An intermittent strobe with an instant emission time, would explain all of our measurements, without space-time. And make perfect mechanical sense.

#### NewPhysics

All about Space-Time - new theory of physic: Po Theory:

The Po Theory is a new theory of physics presenting fundamental issues, among others construction of space-time and describes the properties of space-time, e.g. its decay (expansion) resulting in the generation of time. In The Po Theory there are many models describing the structure of matter, e.g. particle generation model, particle mass (energy) generation model, preon structure model, etc. All these models are supported by mathematical equations describing the properties of particles such as particle radius, its mass, characteristic time associated with the particle, life time, range of interaction. The Po Theory gives, for example, a formula for calculating the radius of an electron, its mass or electric charge.
Po theory describes the known and yet unknown sets of elementary and fundamental particles, objects that are black holes - collapsars, including the Universe and Bi Universe collapsars. Describes interactions - forces that govern these particles and objects. It shows the correlations between the parameters of these particles and physical constants, symmetries between interactions, and above all determines the basic particle - the Po collapsar. The particle which is the smallest collapsar and the basic particle with the highest mass among the elementary particles, which is part of both planckon and fundamental and elementary particles, which is the basic "building block" of matter.

Po theory was presented in the book: "Po Theory. From the smallest particle to the BiUniverse", www.potheory.com or www.teoriapo.pl

Polish version

English version

#### sarajo

Having looked it up apparently 3 dimensions of space & 1 of time

#### BobDole

These ideas are ignoring some plainly obvious facts of logic that blows these theories to smithereans. This article and scientists are really promoting speculation fairy tales that cannot have any logic to them if one does not ignore some obvious facts that contradict these "far out theories" only found in their imaginations.
For example, the definition of "space" is the absence of anything, ie, nothing. Since space is nothing at all, then space cannot be bent, since one cannot bend nothing. There is nothing to bend.
Also, what is time? It is not some substance that floats around the universe as these super silly and illogical ideas state or suggest. Time is also nothing because all time is is the idea that some event happens after another event. We can measure the amount of "time" that passed by using some constant stream of motion that can create clocks or stopwatches. The fact that something happened after another something does not make time some substance that can be bent. Time is only in our minds and also in the movement of things.
So to say space (nothing) is joined with time (also nothing, only our thoughts of knowing which happened first and how long ago) can be bent should be put in Grimm's fairy tales.
To say the gravity is caused by the bending of nothing and nothing fairy tale is an extra illogical fairy tales which tries to explain the unexplainable, gravity. (The only real explanation if our loving Creator made gravity function.)
Also, the speed of light is not constant as scientists in 2015 showed in experiments. They slowed down light photons (search the web for it).
The theory of relativity also has lots of holes in it just using logic. Although it has lots of truth to it, its relative speed and slowing of the ageing and movement of things for those who travel more at the speed of light is a self contradiction. So how does their body know they are traveling at the speed of light to slow everything down? It does not know at all. Besides all speed is relative, so if a rocket takes off from Earth to a star at the speed of light, they are going the speed of light relative to the Earth and the star. But what if there is a 2nd star behind the one they are going to but the 2nd star is moving the speed of light away from earth in the same direction as the rocket. So the speed of the rocket is ZERO mph, not the speed of light. So how does the body now know which speed to age at since it could pick the speed of light for star 1 , or it could pick Zero speed if the rocket decides to go to star 2. Which one does the body pick to age and move at? And how does the body and rocket know which speed to use?

General and Special Relativity has been tested and proven time and time again. It's predictions of black holes and gravity waves, as well as light being bent around massive objects has all been confirmed. In fact, GPS devices wouldn't work properly unless they used BOTH General and Special Relativity calculations to account for curved space-time.

And about your example, no, you cannot travel AT the speed of light. You can only travel NEAR the speed of light. And for the light speed, light would travel past someone traveling NEAR the speed of light as if the person was standing still and not moving. v = d/t where v is velocity (speed of light), d = distance, and t = time. That simply means for light to travel at a constant speed no matter what speed anyone is moving means TIME itself and DISTANCE is distorted. That means time slows down as you travel near the speed of light, and distance in the direction of the movement is also squeezed (as observed by an outside observer).

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#### BobDole

A well written summary for the definition of space-time. I like the history and the introduction of how space-time works, but the focus on a reconciled quantum mechanical model to explain gravity seems like a math problem. A more logical approach might be to consider the 'Big Bang' theory from a pre-existing fabric of space-time without any real matter, as a proposed one dimensional determinant, its inception starts with the unfolding perspective of this dimensional determinant for space-time fabric towards existence. The sequence is somewhat understood from an expansion from our one dimensional space-time into a two dimensional space-time fabric, and then into a three dimensional space-time fabric, and so on. The expectation is that ordinary matter creation took place within a pre-existing dark energy medium of space-time. Indeed, the existence of matter would be an intrusion upon this pre-existing universal medium of space-time which maintains a zero sum difference that is the balance of our cosmological continuum.
With this understanding, any perturbation in this medium would engender a warping of this pre-ordered dark energy template of space-time fabric in the evolutionary perspective of its dimensional unfolding. Wherein the creation of matter as a whole induces a complementary displacement, or warping, in the dark energy medium of the space-time fabric, its promulgation is interdependent on its insistence and persistence. For within this warping, there is yet another pertubation in the whole matter created; a dual relationship of newly created positive density matter in an envelopment of negative density matter. The complementary displacement insulates the newly created positive density matter in an envelopment of negative density matter. This envelope of negative density matter, known as dark matter, then infiltrates the spaces in matter, providing it with the ability to interact, bond, and evolve. Indeed it would require much more dark matter to fill the spaces among ordinary matter down to its smallest constituent parts.
So if dark matter is what engenders a force of gravity for ordinary matter to bond, then the accretion and accumulation of ordinary matter is just the resultant consequence of this force. And if the black holes are nothing but dark matter, then it would also follow that dark matter can be accumulated, separate of ordinary matter. It would therefore also follow that the gravitational force is more representative of negative density mass than positive density mass.
Upon this hypothesis then, one can expect that there is a require transition to separate ordinary matter from its complementary dark matter. It starts first with the disintegration of matter, as a whole, as it interacts with the event horizon of the black hole. As the positive density mass is 'squeezed' upon its own gravitational acceleration toward the black hole, liken to the spaghettification effect, its matter changes to allow for its disintegration via transmutation and the massive release of photons due to alpha decay and beta decay. This is the effect wherein positive density mass is collected within the event horizon, into a plasma, increasing its photon density. This 'squeezing' effect is like extracting out the dark matter from the whole matter, allowing for the ordinary matter to be reduced to its smallest constituent components. The dark matter is then absorbed into the black hole, and the remnants of ordinary matter are discarded and radiated out at high velocity back into the cosmos; to start, once again, to reintegrated into the universe via bonding and evolving.
If you're interested in exploring this concept more, please review the alternative theories presented in the book, 'The Evolutioning of Creation: Volume 2', or even the ramifications of these concepts in the sci-fi fantasy adventure, 'Shadow-Forge Revelations'. The theoretical presentation brings forth a variety of alternative perspectives on the aspects of existence that form our reality.
Space-time must have existed before the big bang because it's what gives rise to time, unless there was something else that gives rise to time before the Big Bang in the absence of space-time as we know it. I doubt anyone will be able to find quanta gravity or time (i.e. the graviton) because it doesn't exist, because gravity isn't a force. Gravity is an effect of curved space-time. How do you find something if it doesn't exist? The other 3 forces are true forces. Gravity cannot be tied to the quantum realm because gravity is the weakest of all 4 effects.

At the macroscopic level, the tiny subatomic realm is still happening even if we don't see it. We know it's happening because radioactive decay is still continuing. The macroscopic world is simply the manifestation of the whole sum of all the tiny subatomic parts. But again, I don't see how gravity can be united with the other 3 forces because gravity is simply an effect.

Having said that, the underlying "cause" to everything, or the underlying piece that governs EVERYTHING else is: space-time. It's what determines the speed of light, of gravity, of how matter and gravitational effects interact with each other. And since light is a limitation of space-time, as well as time itself, that means all other forces, like the electromagnetic force, which is the reason for light, which is linked back to the electron, and then to the Higgs field, etc., means EVERYTHING is based upon and linked back to space-time. To truly comprehend the universe, and all the laws of physics, one must understand space-time.

Dark matter doesn't clump up into massive concentrations like planets and stars. It simply hovers around matter (or matter hovers around it), as if dark matter is a ghost or spirit. Without dark matter, the planets and stars would still form, as so would the galaxies. However, the shapes of the galaxies would be much smaller and different. The reason I can say that is because dark matter is all around us in our solar system, yet we cannot detect it or feel it, and the equations by Newton and Einstein are accurate. So why then doesn't dark matter affect our solar system? I'll give you the answer. If you were able to go into the center of the Earth, at the smack middle, you would not feel any gravity. You'd be weightless because the effects of gravity would be pulling at you from all sides, canceling each other out, hence dark matter cannot be detected in our solar system because it's all around us, and its effects cancel each other out. But dark matter DOES hold stars in place to its home galaxy due to gravitational effects being unlimited in distance.

What would be interesting to know is how dark matter affects black holes, and vice versa.

#### Hartmann352

One of my favorite topics is spacetime and the effects of mass and gravity on light propagation and gravitational lensing. Here are my latest two cents on this fascinating topic.

In 1907, Einstein's former professor, Hermann Minkowski*, made a brilliant breakthrough: he showed that you could conceive of space and time in a single formulation. All at once, he had developed the formalism of spacetime. This provided a stage for particles to move through the Universe (relative to one another) and interact with one another, but it didn't include gravity. The spacetime he had developed -- still today known as Minkowski space -- describes all of special relativity, and also provides the backdrop for the vast majority of the quantum field theory calculations.

If there were no such thing as the gravitational force, Minkowski spacetime would do everything needed. Spacetime would be simple, uncurved, and would simply provide a stage for matter to move through and interact. The only way you'd ever accelerate would be through an interaction with another particle.

But in our Universe, we have the gravitational force, and it was Einstein's principle of equivalence that explained that so long as you can't see what's accelerating you, gravitation treats you the same as any other acceleration.

It was this revelation, and the development to link this, mathematically, to the Minkowskian concept of spacetime, that led to general relativity. The major difference between special relativity's Minkowski space and the curved space that appears in general relativity is the mathematical formalism known as the Metric Tensor, sometimes called Einstein's Metric Tensor or the Riemann Metric. Bernhard Riemann** was a pure mathematician in the 19th century (and a former student of Gauss, perhaps the greatest mathematician of them all), and he gave a formalism for how any fields, lines, arcs, distances, etc., can exist and be well-defined in an arbitrarily curved space of any number of dimensions. It took Einstein (and a number of collaborators) nearly a decade to cope with the complexities of the math, but when all was said and done, we had general relativity: a theory that described our three-space-and-one-time dimensional Universe, where gravitation existed.

physicsforums.com

Conceptually, the metric tensor defines how much spacetime is curved. Its curvature is directly proportional to the total amount of matter, energy and stresses present within it; the contents of our Universe define its spacetime curvature. By the same token, how our Universe is curved tells us how the matter and energy is going to move through it. Imagine that an object in motion will continue in motion: Newton's first law. Then visualize that as a straight line, but what curved space tells us is that instead an object in motion continuing in motion follows a geodesic, which is a particularly-curved line that corresponds to unaccelerated motion. Ironically, it's a geodesic, not necessarily a straight line, that is the shortest distance between two points because there are no straight lines as the objects move from gravity well to gravity well. This shows up even on cosmic scales, where the curved spacetime due to the presence of extraordinary masses can curve the background light from behind it, sometimes into multiple images. In the latter cases we have gravitational lenses, see below.

lens1.jpg

Physically, there are a number of different pieces that contribute to the Metric Tensor in general relativity. Think of gravity related to masses: the locations and magnitudes of different masses determine the gravitational force. In general relativity, this corresponds to the mass density and does contribute, but it's one of only 16 components of the Metric Tensor! There are also pressure components (such as radiation pressure, vacuum pressure or pressures created by fast-moving particles) that contribute, which are three additional contributors (one for each of the three spatial directions) to the Metric Tensor. And finally, there are six other components that tell us how volumes change and deform in the presence of masses and tidal forces, along with how the shape of a moving body is distorted by those forces. This applies to everything from a planet like Earth to neutron stars orbiting each other which create massless waves moving through space: gravitational radiation, which has now been found by the Laser Interferometer Gravitational-wave Observatory (LIGO)***.

news.fnal.gov

The Metric Tensor may be a 4 × 4 entity, but it's symmetric, meaning that there are four "diagonal" components (the density and the pressure components), and six off-diagonal components (the volume/deformation components) that are independent; the other six off-diagonal components are then uniquely determined by symmetry. The metric tells us the relationship between all the matter/energy in the Universe and the curvature of spacetime itself.

The expanding Universe's emergence from the Big Bang and the dark energy-domination that will lead to a cold, empty fate are all only understandable in the context of general relativity, and that means understanding the relationship between matter/energy and spacetime.

The Universe is a play, unfolding every time a particle interacts with another, spacetime is the stage on which it all plays out and we are but fleeting actors on that same stage. The stage isn't a constant backdrop, but it, too, evolves along with the Universe itself. And wherever it is, it evolves along world lines.

pinterest.com

The set of all light speed world lines going through an event defines the light cones of that event: the past light cone and the future light cone. An example of light cones is shown above. Each of us is that observer above.

Through any event in space-time, in any given direction, there is only one world line corresponding to motion solely influenced by gravity.

Advanced coordinates of a point x relative to a world line γ. The advanced time v selects a particular light cone, the unit vector Ωa := xˆa/r selects a particular generator of this light cone, and the advanced distance r selects a particular point on this generator.

See: https://arxiv.org/pdf/gr-qc/0606093.pdf

Space and time in Einstein's universe are no longer flat (as implicitly assumed by Newton, where gravity and light act instantly at all distances.) but can pushed and pulled, stretched and warped by matter. Gravity feels strongest where spacetime is most curved, and it vanishes where spacetime is flat. This is the core of Einstein's theory of general relativity, which is often summed up in words as follows: "matter tells spacetime how to curve, and curved spacetime tells matter how to move". A standard way to illustrate this idea is to place a bowling ball (representing a massive object such as the sun) onto a stretched rubber sheet (representing spacetime). If a marble is placed onto the rubber sheet, it will roll toward the bowling ball, and may even be put into "orbit" around the bowling ball. This occurs, not because the smaller mass is "attracted" by a force emanating from the larger one, but because it is traveling along a surface which has been deformed by the presence of the larger mass. In the same way gravitation in Einstein's theory arises not as a force propagating through spacetime, but rather as a feature of spacetime itself.

Matter can act on spacetime in a manner that is very much in the spirit of Mach's principle. Calculations by Hans Thirring (1888-1979), Josef Lense (1890-1985) and others have shown that a large rotating mass will "drag" an observer's inertial reference frame around with it. This is the phenomenon of frame-dragging, whose existence Gravity Probe B detected****. The same calculations suggest that, if the entire contents of the universe were to rotate, our local inertial frame would undergo "perfect dragging" — that is, we would not notice it, because we would be rotating too! In that sense, general relativity is indeed nearly as relational as Ernst Mach***** might have wished. Some physicists (such as Julian Barbour) have gone further and asserted that general relativity is in fact perfectly Machian. If one goes beyond classical physics and into modern quantum field theory, then questions of absolute versus relational spacetime are rendered anachronistic by the fact that even "empty space" is populated by matter in the form of virtual particles, zero-point fields and more. Within the context of Einstein's universe, however, the majority view is perhaps best summed up as follows: spacetime behaves relationally but exists absolutely.
Hartmann352

* Hermann Minkowski (born June 22, 1864, Aleksotas, Russian Empire [now in Kaunas, Lithuania]—died Jan. 12, 1909, Göttingen, Germany), German mathematician who developed the geometrical theory of numbers and who made numerous contributions to number theory, mathematical physics, and the theory of relativity. His idea of combining the three dimensions of physical space with that of time into a four-dimensional “Minkowski space”—space-time—laid the mathematical foundations for Albert Einstein’s special theory of relativity.

The son of German parents living in Russia, Minkowski returned to Germany with them in 1872 and spent his youth in the royal Prussian city of Königsberg. A gifted prodigy, he began his studies at the University of Königsberg and the University of Berlin at age 15. Three years later he was awarded the “Grand Prix des Sciences Mathématiques” by the French Academy of Sciences for his paper on the representation of numbers as a sum of five squares. During his teenage years in Königsberg he met and befriended another young mathematical prodigy, David Hilbert, with whom he worked closely both at Königsberg and later at the University of Göttingen.

After earning his doctorate in 1885, Minkowski taught mathematics at the Universities of Bonn (1885–94), Königsberg (1894–96), Zürich(1896–1902), and Göttingen (1902–09). Together with Hilbert, he pursued research on the electron theory of the Dutch physicist Hendrik Lorentz and its modification in Einstein’s special theory of relativity. In Raum und Zeit (1907; “Space and Time”) Minkowski gave his famous four-dimensional geometry based on the group of Lorentz transformations of special relativity theory. His major work in number theory was Geometrie der Zahlen (1896; “Geometry of Numbers”). His works were collected in David Hilbert (ed.), Gesammelte Abhandlungen, 2 vol. (1911; “Collected Papers”).

See: https://www.britannica.com/biography/Hermann-Minkowski

** Bernhard Riemann, in full Georg Friedrich Bernhard Riemann, (born September 17, 1826, Breselenz, Hanover [Germany]—died July 20, 1866, Selasca, Italy), German mathematician whose profound and novel approaches to the study of geometry laid the mathematical foundation for Albert Einstein’s theory of relativity. He also made important contributions to the theory of functions, complex analysis, and number theory.

Riemann was born into a poor Lutheran pastor’s family, and all his life he was a shy and introverted person. He was fortunate to have a schoolteacher who recognized his rare mathematical ability and lent him advanced books to read, including Adrien-Marie Legendre’s Number Theory (1830). Riemann read the book in a week and then claimed to know it by heart. He went on to study mathematics at the University of Göttingen in 1846–47 and 1849–51 and at the University of Berlin (now the Humboldt University of Berlin) in 1847–49. He then gradually worked his way up the academic profession, through a succession of poorly paid jobs, until he became a full professor in 1859 and gained, for the first time in his life, a measure of financial security. However, in 1862, shortly after his marriage to Elise Koch, Riemann fell seriously ill with tuberculosis. Repeated trips to Italy failed to stem the progress of the disease, and he died in Italy in 1866.

Riemann’s visits to Italy were important for the growth of modern mathematics there; Enrico Betti in particular took up the study of Riemannian ideas. Ill health prevented Riemann from publishing all his work, and some of his best was published only posthumously—e.g., the first edition of Riemann’s Gesammelte mathematische Werke (1876; “Collected Mathematical Works”), edited by Richard Dedekind and Heinrich Weber.

See: https://www.britannica.com/biography/Bernhard-Riemann

*** Laser Interferometer Gravitational-wave Observatory (LIGO) has made the first direct observation of gravitational waves with an instrument on Earth. The researchers detected the gravitational waves on September 14, 2015, at 5:51 a.m. EDT, using the twin LIGO interferometers, located in Livingston, Louisiana and Hanford, Washington.

See: https://news.mit.edu/2016/ligo-first-detection-gravitational-waves-0211

**** Gravity Probe B; See: https://www.nasa.gov/mission_pages/gpb/gpb_results.html

***** Ernst Mach (born February 18, 1838, Chirlitz-Turas, Moravia, Austrian Empire [now Brno-Chrlice, Czech Republic]—died February 19, 1916, Haar, Germany), Austrian physicist and philosopher who established important principles of optics, mechanics, and wave dynamics and who supported the view that all knowledge is a conceptual organization of the data of sensory experience (or observation).

Mach was educated at home until the age of 14, then went briefly to gymnasium (high school) before entering the University of Vienna at 17. He received his doctorate in physics in 1860 and taught mechanics and physics in Vienna until 1864, when he became professor of mathematicsat the University of Graz. Mach’s interests had already begun to turn to the psychology and physiology of sensation, although he continued to identify himself as a physicist and to conduct physical research throughout his career. During the 1860s he discovered the physiological phenomenon that has come to be called Mach’s bands, the tendency of the human eye to see bright or dark bands near the boundaries between areas of sharply differing illumination.

Mach left Graz to become professor of experimental physics at the Charles University in Prague in 1867, remaining there for the next 28 years. There he conducted studies on kinesthetic sensation, the feeling associated with movement and acceleration. Between 1873 and 1893 he developed optical and photographic techniques for the measurement of sound waves and wave propagation. In 1887 he established the principles of supersonics and the Mach number—the ratio of the velocity of an object to the velocity of sound.

In Beiträge zur Analyse der Empfindungen (1886; Contributions to the Analysis of the Sensations, 1897), Mach advanced the concept that all knowledge is derived from sensation; thus, phenomena under scientific investigation can be understood only in terms of experiences, or “sensations,” present in the observation of the phenomena. This view leads to the position that no statement in natural science is admissible unless it is empirically verifiable. Mach’s exceptionally rigorous criteriaof verifiability led him to reject such metaphysical concepts as absolute time and space, and prepared the way for the Einstein relativity theory.

Mach also proposed the physical principle, known as Mach’s principle, that inertia (the tendency of a body at rest to remain at rest and of a body in motion to continue in motion in the same direction) results from a relationship of that object with all the rest of the matter in the universe. Inertia, Mach argued, applies only as a function of the interaction between one body and other bodies in the universe, even at enormous distances. Mach’s inertial theories also were cited by Einstein as one of the inspirations for his theories of relativity.

Mach returned to the University of Vienna as professor of inductive philosophy in 1895, but he suffered a stroke two years later and retired from active research in 1901, when he was appointed to the Austrian parliament. He continued to lecture and write in retirement, publishing Erkenntnis und Irrtum (“Knowledge and Error”) in 1905 and an autobiography in 1910.

See: https://www.britannica.com/biography/Ernst-Mach