Empty time/space.

[aman]

Since an absolute vacuum is only empty time/space, how can it be bent by gravity if it does not have a mass greater than 0?
Just aman

[fafalone]

Gravity acts on space-time, influences on mass are incidental.

[Katie]

What exactly is empty space? I can't quite fathom it, and my Chemistry teacher was no help in explaining... "There's empty space between gas particles..." But I don't comprehend emptiness, because even in room that we say is "empty" there are gases and walls and a floor and a ceiling. I don't know, maybe it's just a mental block, but if anyone would try and explain it to me I'd really appreciate it. Isn't there something even where there's nothing?

[fafalone]

There's just the space-time continuum. There's not quite as much "empty" space as you think here on Earth. Neutrinos, radiation (which, by the way, is present throughout the universe, and all though massless, is all pervading.. the cosmic background.) And of course on Earth we have cell phone signals, radio, television, and satellite all filling the "empty" space.

In your example, the room isn't empty. What we consider empty isn't the same as truly empty.

[Katie]

Thank you :)

[Ami]

Originally posted by fafalone
Gravity acts on space-time, influences on mass are incidental.

how can you say it's incedental?

[fafalone]

A curvature in space-time causes the "attraction" of gravity. Gravity doesn't cause the objects to move directly. If this were the case, gravity could not act on light.

[Radical Edward]

even truly empty space (neutrinos et al) isn't empty at all on account of quantum fluctuation wossnames.

[Katie]

Come again?

[aman]

If you go out 28 billion light years from the big bang, you should be surrounded by a vacuum of space-time that has had no relationship to our universe. If you brought along a black hole, then space time should look distorted to an easily measurable amount by gravity around it but only if there is mass also in the space to make it evident.
If there is no mass out there other than the black hole then the warp of space-time becomes a moot point. I think.
Am I close?
Just aman

[424319]

There is not gravity, only motion of time-space curvature.

Reference: THING AND ITS LAW ( INBN 1-58939-525-5) published by Virtualbookworm.com publishing INC.

[Sayonara³]

424319 said in post # (http://www.scienceforums.net/forums/showthread.php?s=&postid=43996#post43996):
There is not gravity, only motion of time-space curvature.

Reference: THING AND ITS LAW ( INBN 1-58939-525-5) published by Virtualbookworm.com publishing INC.
According to the current models, or to a new theory?

If the latter, bad form for not pointing it out.

[losfomot]

aman said in post # (http://www.scienceforums.net/forums/showthread.php?s=&postid=4278#post4278):
If there is no mass out there other than the black hole then the warp of space-time becomes a moot point. I think.
Am I close?
Just aman

No.

If space-time is warped by a black hole then it is warped. It does not matter if there is other matter around to feel the effects (gravity) of that warp or not. You seem to be struggling with the old philosophical question "If a tree falls in the woods and there is nobody around to hear it, does it make a sound?"

[Duke]

I heard a wizard did it.

[aman]

Looking back again at a black hole by itself in empty space, would the space around it be effected by having a higher potential for having those bits of matter pop out of empty space? It would seem intuitive that space compressed or warped by gravity would have a higher than zero energy stored in it.
Just aman

[benson-az]

I am amused at the fact that many of the world's greatest scientists routinely use the term "space-time continuum" because it sounds like words from fools.

One of the bedrocks of science is the use of concepts based on entities or forces that are perceived as entities. However,
neither space nor time can be proven to exist. So, when the that nefarious term is used, it actually means "the absolutely continuous and homogeneous nothing-nothing".
Alternatively you might use "infinite nothing nothing".

Time as we experience it is a perception of the reorganization of the universe. Time as we use it is a construct. It is only because the human brain can remember prior states of things that the time perception exists.
The following is a quotation from chapter 6 (pages 36 and 37) of the book, The Universe and Dr. Einstein by Lincoln Barnett:
“Along with absolute space, Einstein discarded the concept of absolute time - of a steady, unvarying, inexorable universal time flow, streaming from the infinite past to the infinite future. Much of the obscurity that has surrounded the Theory of Relativity stems from man’s reluctance to recognize that sense of time, like sense of color, is a form of perception. Just as there is no such thing as color without an eye to discern it, so an instant or hour or a day is nothing without an event to mark it. And just as space is simple a possible order of material objects, so time is simply a possible order of events.”
:-)

[Aeschylus]

I am amused at the fact that many of the world's greatest scientists routinely use the term "space-time continuum" because it sounds like words from fools.

Well small things please small minds. The term "spacetime continuum" refers to a mathematical construct, not some vague cod-philosophical concept.

[JHAQ]

There is no such thing as totally empty space ---don't forget virtual particles .

[mak10]

what are virtual particles??

[JHAQ]

---- mak10 -----see <http://zebu.uoregon.edu/~imamura/209/apr14/virtual.html>

[JHAQ]

mak10 And -- < http://math.ucr.edu/home/baez/physics/Quantum/virtual_particles.html>

[[Tycho?]]

nonsense of course there is space were no matter or time exists and is truelly devoid of existance of anything.VIRTUAL PARTICLES my ass.stop thinking laterally,quantom physics is hogwash....

Man, you have a post count of 10 now, is a single one of those posts not complete bullshit? If you are going to say quantum physics (one of the most successful and useful theories of the past 100 years) is hogwash, you had better ****ing back that up with something other than poor grammar.

[Sorcerer]

No.

If space-time is warped by a black hole then it is warped. It does not matter if there is other matter around to feel the effects (gravity) of that warp or not. You seem to be struggling with the old philosophical question "If a tree falls in the woods and there is nobody around to hear it, does it make a sound?"

I think you have a problem dealing with the old philosophical question. Let me ask you, how can there be space if nothing fills it? How can there be time if no event occur? Since space and time are linked then how can there be space time in an empty void?

[Sorcerer]

Looking back again at a black hole by itself in empty space, would the space around it be effected by having a higher potential for having those bits of matter pop out of empty space? It would seem intuitive that space compressed or warped by gravity would have a higher than zero energy stored in it.
Just aman

I always wondered this too, when space is warped around a gravitational feild it should be stretched, thinking of space as a physical entity, like a fabric, if it is stretched then less of the fabric covers a greater area. If the ammount of vaccum energy is proportional to the ammount of space-time fabric, then there should be a lower average energy around massive objects.

Anyone care to tell me whats wrong with this? (I'm guessing the bit about space-time being a physical entity/fabric.... but Im always hearing this cliche.)

[mak10]

These virtual particles theory is really interesting... I read about quatum mechanics but never came across this; gotta look into this some more, thanks for the info JHAQ!

-mak10

[mak10]

Anyone care to tell me whats wrong with this? (I'm guessing the bit about space-time being a physical entity/fabric.... but Im always hearing this cliche.)

I think thats because of string theory, which predicts space-time composed of extremely minute miniscule strings; hence the cliche fabric of space-time.

-mak10