Naked Science Forum
Non Life Sciences => Physics, Astronomy & Cosmology => Topic started by: steelrat1 on 12/06/2011 14:56:25
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for example is time compressed at a black hole due to its mass and its immense gravitational influence or will time remain the same? Could time be connected directly to the mass of matter, even a photon might have a very small mass therefore creating its own time?
Could there be areas in the universe where there is no mass/ matter in it.. a total absence of everything? Would time still exist there?
Your truly Science noob
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Well, so far as we can tell, time (along with space) is one of the fundamental properties of the fabric of the universe. Whether or not there's mass nearby, time still exists so far as we can tell. Of course, we live in a universe with mass and we and all our detectors are made of mass, so it's hard to actually check what happens if there is no mass.
Now, as you point out, time is effected by mass--or more precisely, one of the things that effects time is energy, and mass is equivalent to energy. But time still exists when it isn't being influenced by mass.
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Well, so far as we can tell, time (along with space) is one of the fundamental properties of the fabric of the universe. Whether or not there's mass nearby, time still exists so far as we can tell. Of course, we live in a universe with mass and we and all our detectors are made of mass, so it's hard to actually check what happens if there is no mass.
Now, as you point out, time is effected by mass--or more precisely, one of the things that effects time is energy, and mass is equivalent to energy. But time still exists when it isn't being influenced by mass.
There is no reason to believe that time exists without mass. As JP mentions we live in a universe containing energy, mass and time and cannot divorce ourselves and experiments from that. It is generally believed that before the big bang there was no time. No mass no time.
Everything in the universe is made of energy. Everything in the universe is made of mass and energy. Something had to create time. This next bit is considered new physics. I believe it is the interaction of energy and mass by way of gravity. Mass gives a direction to the arrow of time. Energy (light) modulated by gravity creates the 'passage' of time. Entropy is the arrow of time and it points towards the black hole at the end of the universe. There is an average passage of time in the universe but at any locality this can vary from the average. This variation is called dilation or contraction.
See http://www.thenakedscientists.com/forum/index.php?topic=39214.0
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In mainstream science we use the word 'energy' for defining what might be the start of anything. Everything takes some energy to do, if you act (excluding geodesics). So there you should have the first coupling to gravity. And maybe that is 'gravity' in some weird way.
But you got to remember that 'energy' is a expression we get from something interacting, and transforming (usable energy to unusable), as particles interacting. So you can't pick up a kg of 'pure energy' to show someone. The closest carrier of 'energy' that we know of is the photon. (possibly gluon's too?) and a photon is most peculiar.
Coupled means that it is 'joined too' to me, not the exact same.
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One more thing, all geodesics will be defined by 'gravity' becoming unmeasurable (ignoring tidal forces.) so as you fall of a ladder there can be no 'gravity' to measure for you. But you will still have a direction relative Earth, and so find yourself moving, following a geodesic, as defined from someone looking at you. But if you close your eyes as you fall and ignore the wind/molecules/resistance, you are now unable to define that from being weightless and unmoving.
So gravity will exist even when unmeasurable to me. And so it becomes a question of definitions but as JP says, there will be nowhere in SpaceTime that times arrow won't 'tick' for you.
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Quote yor_on
So gravity will exist even when unmeasurable to me. And so it becomes a question of definitions but as JP says, there will be nowhere in SpaceTime that times arrow won't 'tick' for you.
That's a miss quote
What JP said was
Now, as you point out, time is effected by mass--or more precisely, one of the things that effects time is energy, and mass is equivalent to energy. But time still exists when it isn't being influenced by mass.
I would argue that without either energy or mass time does not exist and therefore there is no SpaceTime.
I agree that within SpaceTime the clock will always tick.
Also, times arrow is just that, it's an arrow of time not the clock so the arrow itself is not what ticks.
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This is taking quite a detour into proposing a new theory rather than discussing what relativity theory has to tell us about mass and time. Could debate on this idea be split off to the New Theories section, please?
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No Mike, don't think it was a misquote, although JP may find a definition of a SpaceTime without 'gravity' as acceptable it will be very hard to prove. My definition will work too, in fact it was Einstein that once defined 'gravity' as the 'metric' of space. In the end it become a question of definitions, as 'gravity' is a very difficult subject to define to a source. I think you can use 'energy' for it, but then again. Nobody ever lifted forward a 'ounce of energy' for examination, to my knowledge?
Energy is all about interactions.
So?
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Eh, btw, would that be the 'stainless steelrat' :)
Think I read something, sometime, somewhere?
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Then again, if one instead define a theoretical one, or two, dimensional space it becomes different, but then we left SpaceTime in favor for a mathematical definition of what some other 'space' could be. And if so 'gravity' will be 'non existent' as I think of it. But inside SpaceTime 'gravity' is what defines space for us. As I see it. Although? I don't know there, maybe you can have a 'gravity' there too if we 'down changed' the three dimensional space we have into a two dimensional. Then it could only work in a plane though. And to be honest, I can't see 'gravity's' directions, they become so weird, thinking of down-grading the 3-D gravity we have to a 2-D gravity? But you could start with it instead, and then the 'planar gravity' should be there as I see it. So try to 'up grade' it to 3-D, if you can. That might be a simpler approach. :)
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yor-on
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"And to be honest, I can't see 'gravity's' directions,"
It's easy to see gravities direction. When two masses combine time dilates for them more than it does for them individually. Take this to its logical conclusion and the universe will end up as a black hole.
Gravity is an example of entropy and is an arrow of time and it points to the black hole at the end of the universe.
Some might say this belongs in new theories but it is a known fact that mass dilates time. The rest I believe is a natural consequence of that.
Gravity is a major example of entropy and is a major arrow of time and it points to the black hole at the end of the universe.
This, I think is so obvious and is staring us in the face that we just don't see it.
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JP
When two masses combine time dilates for them more than it does for them individually. Take this to its logical conclusion and the universe will end up as a black hole.
I think this is all in accordance with relativity.
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JP
When two masses combine time dilates for them more than it does for them individually. Take this to its logical conclusion and the universe will end up as a black hole.
I think this is all in accordance with relativity.
That's not a logical conclusion. Why should the universe end up as a black hole unless it has the proper mass density?
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What I meant Mike was just that if we assume that you can have a two dimensional representation of a universe with gravity. Then that gravity should be a 'planar' one (2-D).
Now imagine how that gravity would express itself if we pretend we are Gods and introduce a sphere somewhere in that 2-D landscape. The sphere won't exist from the point of view of those observing from that 2-D landscape, as I think they will only see a 'filled circle', maybe like some 2-D Event horizon :)
And then try to imagine gravity's directions as you fill it in, into 3-D from that 2-D. in 2-D all gravity should be on a plane no ups and downs. So how do we get from planar to 3-D? There are some possibilities I can think up, most having to do with 'dimensions' as 'Lego pieces' that you mount 'together'. But I don't think SpaceTime works that way myself.
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Here is a rather interesting discussion that's supposed to be about the electron but it's really talking about time and gravity. Link removed -mod
Considering that the forum you linked to states that it's for non-mainstream theories and that there is a rule on TNS against just posting links (as well as a forum for posting non-mainstream science), I've removed your link.
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Gravity is a strange phenomena. You can add dimensions, describing them as 'curled up' inside the dimensions we have, allowing for new 'directions' and so find mathematical descriptions for EM fields and even gravity. But space is a 3D to me, and if I look at the expansion I find it very hard to imagine that it would be 'filled' with, let's say eleven, singular 'dimensions' knitting together a 3D reality macroscopically. It's not the idea of needing more 'dimensions' that disturbs me as much, as the idea of them being 'singular knitting together'. There is nowhere in this SpaceTime I see that, except in theories and hypothesis's.
I prefer a 'SpaceTime' defined as a whole phenomena, by symmetry if you like. And in such a symmetry those 'dimensions' must come as one.
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Well, so far as we can tell, time (along with space) is one of the fundamental properties of the fabric of the universe. Whether or not there's mass nearby, time still exists so far as we can tell. Of course, we live in a universe with mass and we and all our detectors are made of mass, so it's hard to actually check what happens if there is no mass.
Now, as you point out, time is effected by mass--or more precisely, one of the things that effects time is energy, and mass is equivalent to energy. But time still exists when it isn't being influenced by mass.
Actually you can expand on this further.
Pure gravity solutions are solutions to gravity fields where there are no matter fields. Since relativity states that space and time are inexorably linked, matter and energy is also dynamical to vacuum. You could find solutions to physics though I am quite sure where time and matter are not necesserily dependant. Of course, this involves a full conceptual vision of time within QM and GR however at this moment, time is plagued by many different interpretations, as is how to unify QM and GR into that framework of things.