How does gravity distort space and time?

Question

I understand that if you measure time at one point from a high altitude and compare it to the time directly below sea level you would result in different times. This is obvious as the distance of circumference at each point are different as it travels around earth. Is there a better real-world example of how gravity can distort universal space and time and not space and time relative to earth or sun's rotation?

According to Einstein's general theory of relativity, gravity distorts space and time.

Answer 1

With respect, I suggest that you MAY be asking the wrong question. That MIGHT be because both professionals and popularizers write passages or chapters in their books with titles like "How gravity slows down time," or "The effects of strong gravity on time." Such titles CAN be very misleading.

However, whether that is actually so depends upon what you mean by "gravity." So, if you will please let us know, I'll be happy to attempt to answer you.

I hope that you can choose among the following alternatives in clarifying what you mean:

1. By "gravity" or "strong gravity" I mean the local existence of a measurable gravitational acceleration and its magnitude in some common measure. (For example "gravity on the Earth is 6 times stronger than gravity on the Moon.")

2. By "gravity" or "strong gravity" I mean the entire way in which the presence of mass (and indeed, mass-energy) affects the properties of the surrounding space and time, distorting space by making it non-Euclidean, and distorting time by making it run at different rates in different places. In other words, what Germans would call the whole gestallt of General Relativity.

3. By "gravity" or "strong gravity" I don't mean either of these. What I mean is ... (to be completed.)

I await your response. Depending on what it is, I'll do my best to address it.


Live long and prosper.

POSTSCRIPTS:

1. Well : you DIDN'T answer my questions in which I really tried to find out what you really wanted to know about. (An appropriate answer depends on the ideas you yourself have about the topic on coming in to it.) All I'm prepared to say right now is that statements like "The visualization of gravity warping spacetime has been compared to a bowling ball being placed on a trampoline" (see the answer two below mine) are essentially misleading RUBBISH where Newtonian gravity is concerned.

That is because, according to Einstein himself, ALL OF THE EFFECTS OF NEWTONIAN GRAVITY ARE DUE ENTIRELY TO THE FACT THAT TIME RUNS DIFFERENTLY IN DIFFERENT PLACES. THE "BENDING OF SPACE" (PER SE) HAS ABSOLUTELY NOTHING TO DO WITH NEWTONIAN GRAVITY. It is only when one comes to the so-called "Post-Newtonian effects" that any "bending of space " or "non-Euclidean distortions in space" play any role whatsoever. But those effects are almost vanishingly small in the solar system, for example, affecting only the subtlest phenomena.

Unfortunately, all that the trampoline can do is to illustrate those space-bending aspects. (For obvious reasons, the "time-distortion" effects cannot be so easily reproduced in front of our eyes!) But these space-bending effects are almost mind-bogglingly MINUTE in the solar system, compared with the time-distortion effects. They are of relative importance ~ 10^(- 8) or so.

Take Mercury's orbit, for example. The distortions in how time runs in the solar vicinity (the "bending of time," if you'll allow that phrase) are responsible for the ~ 2500 radians of orbital angular motion through which Mercury moves in one century (100 years) under Newtonian gravity. So what is the "bending of space" responsible for? : The mere 43 seconds of arc through which that same orbit precesses per century. (There's your ~ 10^(-8) effect, 43" compared with ~ 2500 radians!) That, AND ONLY THAT, is due to "the curvature of space." It's a very, very small post-Newtonian effect; yet it's ALL that the trampoline can "illustrate."

So : ALL that the "trampoline" is illustrating is that MINUSCULE 43" per century effect, relative to "time-bending's" 2500 radians per century consequences. The trampoline enthusiasts are engaged in a gigantic intellectual swindle, giving you a very vivid and apparently large-scale image that unfortunately misrepresents something that is ABSOLUTELY MINUTE compared with the true, major scientific cause of what is really happening. The balls rolling around on that trampoline may convince you that you somehow "understand gravity" --- but you don't, because the gravity you know about comes from time's distortion, not from space's bending. Don't take my word for it --- consult whichever of the world's experts you want to, Kip Thorne, Stephen Hawking, Lord (formerly Sir Martin) Rees, .... They'll all tell you the same thing.

You might want to consult my answer to another, related question, in recent weeks, having to do with our modern understanding of the way that time itself runs differently in different places, with particular reference to the Earth and other solar system planets. I explained some more of the circumstances involved quite thoroughly in that answer.

That question was entitled, somewhat incoherently, "Is time on our planet runs faster than other planets or space?" (My detailed answer received 3 votes, while 4 know-nothing voters preferred an answer that completely missed any valid scientific point in the question -- an apt comment on both the generally abysmal scientific education of the public, and the notion that "democratic voting" rather than scientific expertise, can best resolve such issues.)

2. In your "extra detail' you basically repeated a mantra that "According to Einstein's general theory of relativity, gravity distorts space and time." My point is that the EMPHASIS there is wrong, and in fact that statement MISREPRESENTS Einstein's own theory and viewpoint, no matter how many times it's repeated in loose talk or popular treatments.

Here is what Einstein's theory REALLY says:

The presence of matter (more generally, matter-energy) in spacetime distorts the properties of spacetime, most strongly in the vicinity of that matter/matter-energy. CONSEQUENCES of that distortion are the effects on particle motions that we attribute to "gravity."

Do you SEE the difference? YOUR statement essentially gives some pre-existing conception of gravity the ability to ALTER the properties of a union of space and time; whereas Einstein's logic is really the complete REVERSE of that. Putting it crudely, matter makes spacetime distorted, and that distorted spacetime produces what we call gravity.

In other words, "gravity" is not some GOD-GIVEN fundamental entity or ur-propertythat in turn alters the properties of space and time. It's those properties themselves (following from the presence of matter) that "create gravity as we know it." What we call "gravity" is the END-PRODUCT of this chain of logical cause and effect, or dependence; it's NOT the ultimate source of some distortion of space and time.

Perhaps you now see why I was trying to find out from you what your question or point of puzzlement really was, because for some people, what they mean by "gravity" is only its manifestation in the end as the existence of a local ' g ', and ITS effects on motion. Whereas, for others, "gravity" means Einstein's entire gestallt. In that case, to ask whether "gravity" distorts space and time is to engage in a meaningless tautology --- that "distortion of space and time" is simply a part of the whole gestallt. In order to provide someone with an appropriate answer to the kind of question that you posed, one has to know what their initial preconceptions are!

Answer 2

A gravity wave would be exactly that; a wave of gravity. Suddenly everything on Earth would be pulled and then pushed, like we were all boats with an invisible wave passing underneath. This disturbance would go straight through Earth and out the other side. A big one would feel like a small earthquake. No one has actually seen a gravitational wave. Most probable sources are rather far away and our detectors aren't that sensitive. To find them most experiments use a really long tunnel with a laser shining down it. If the beam twists in midfight we know a gravity wave has passed.

Answer 3

The visualization of gravity warping spacetime has been compared to a bowling ball being placed on a trampoline. Of course the trampoline surface is two dimensional, unlike our universe, but the idea is portrayed. The closer you are to the bowling ball the more spacetime is bent, and consequently, the more curved a path light would follow. This bending of spacetime will warp the sensation of time.

Answer 4

Time is a relative concept. I don't know about gravity itself, but a moving object, say in space, won't record the same interval for an event as an earth observer.

Say, to me a lightning strike may last 1.2s, but to an alien in a moving ship, it might last 2s.

That this all due to relativity, just like when you are rowing a boat, to yourself, you are going straight ahead, but to a ground observer the current is taking you elsewhere.

Answer 5

the time doesnt measure differently. clocks are not based on the earth's rotation, and all points on the globe rotate at the same angular velocity. gravity does not change time. nothing does. gravity can, however, speed up or slow down OBJECTS, like a pendulum , so a pendulum based clock would read differently in different gravitational pulls, but anywhere on earth the difference is so small that one could never notice it in his own lifetime without highly advanced tools or a lot of time to do nothing.

Answer 6

hell if i know