Naked Science Forum
Non Life Sciences => Physics, Astronomy & Cosmology => Topic started by: D on 19/11/2015 12:35:55
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Theoretically speaking, lets assume there's a true void, a void with absolutely nothing in it. My question is would there be time? Me and my brother were discussing this question and he introduced me to something called absolute time (before knowing about absolute time i thought that there would be time inside a true void but now i dont know) and if there is absolute time then those that mean that there is no true void since well there's time so there for its no longer a true void?
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If you define time as what happens between sequential events, and a void as a place where there are no events, then the word is meaningless within that void.
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..(before knowing about absolute time i thought that there would be time inside a true void but now i dont know) and if there is absolute time then those that mean that there is no true void since well there's time so there for its no longer a true void?
It's worth noting that absolute time is not generally used in physics, relative time is.
However, if there is no time in your void then you cannot enter it, nothing can.
Speculation
- what happens to light at the boundary, if it can't be absorbed must it be reflected? The perfect mirror?
- if it truly contains no spacetime then there is nothing to keep the boundaries apart and it is nothing more than a point.
Haven't a clue!
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However, if there is no time in your void then you cannot enter it, nothing can.
Speculation
- what happens to light at the boundary, if it can't be absorbed must it be reflected? The perfect mirror?
- if it truly contains no spacetime then there is nothing to keep the boundaries apart and it is nothing more than a point.
Haven't a clue!
My own speculation:
A 'true' void would't have any dimensions as it is truly nothing, so it would't have any boundaries, nor could it be a single point, as that is one dimension two many. I do not think we could define a void with our geometric view of space & volume and nor is there any point, a true void could't possibly exist, since it is by definition nothing.
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...a true void could't possibly exist, since it is by definition nothing.
So, nothing cannot exist? An interesting conclusion, with which I am inclined to agree. It leads to some tangled discussions, though. [:)]
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However, if there is no time in your void then you cannot enter it, nothing can.
Speculation
- what happens to light at the boundary, if it can't be absorbed must it be reflected? The perfect mirror?
- if it truly contains no spacetime then there is nothing to keep the boundaries apart and it is nothing more than a point.
Haven't a clue!
My own speculation:
A 'true' void would't have any dimensions as it is truly nothing, so it would't have any boundaries, nor could it be a single point, as that is one dimension two many. I do not think we could define a void with our geometric view of space & volume and nor is there any point, a true void could't possibly exist, since it is by definition nothing.
Interesting i didn't even thought of it in that way, hypothetically speaking let's say we take a location somewhere in space and time and we remove everything in a radius of a mile,(remember hypothetically) according to your analogy of the true void, that space and time will cease to exist but we will know in fact that there is a void, we might not be able to see it or even to comprehend it but we will know that it's there right? So does that mean that true void could be somewhere?
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If void = nothing, then creating a void is physically impossible. How would you remove everything including spacetime?
I know that what you are proposing is a thought experiment, but it has to bear some relevance to what we perceive as reality.
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Inside a void, would there still be a quantum foam (http://en.wikipedia.org/wiki/Quantum_foam)?
The Heisenberg uncertainty principle places constraints on the time and energy of a quantum foam, so could this be used to derive a concept of time, even within a void?
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Say we start with material and space-time. From this material we can see changes associate with space and time.
Next, we evacuate that same space to create a material void of matter and energy. If there is no time because there is nothing to change state, then that implies that time is dependent on material, not space-time. It means space-time does not exist without material being present. If we add mass density, gravity, we tweak the very source of space-time, thereby altering the accumulative space-time.
On the other hand, if space-time exists all by itself and does not need matter to exist, then even a void will have space-time, so time still passes.
I like the former explanation because this can be proven in the lab. The idea of space-time being the independent variable is not easy to prove in the lab How do you see the passage of time in a void, to get a baseline?
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hypothetically speaking let's say we take a location somewhere in space and time and we remove everything in a radius of a mile,(remember hypothetically) according to your analogy of the true void, that space and time will cease to exist but we will know in fact that there is a void
The radius does not really matter, as physics works on all levels, from subatomic to large scale, which is quite interesting in it self, I saw a great video about this, comparing the wave function of electrons oscillation is the exact same as liquid oscillation.
But any location within space and time ( our known universe) contains more than "stuff" that we can see, such as dark matter, quantum foam, and I am sure it contains quite a bit more that we cannot detect yet ( Layers beneath quantum foam)
But a true void, containing nothing, would not even have any laws of physics, no volume, no mass or energy, even a hint of quantum foam or zero point energy.
On the other hand, if space-time exists all by itself and does not need matter to exist, then even a void will have space-time, so time still passes.
Then it would cease to be a void, since it contains space-time, thus it contains the laws of physics and has energy, zero point energy, quantum interactions, etc.
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If there is no time because there is nothing to change state, then that implies that time is dependent on material, not space-time.
I suspect that might be an assumption too far. Another interpretation might be that if we could achieve something impossible, we just might dispense with time; which might, or might not, tell us something about the nature and provenance of time.
I doubt that we are going to better Alan's comment.
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It comes down to what constitutes an event. There has to be something to cause the event in the first place. If everything that can cause an event were removed to create a true void then time really is meaningless. This does imply that time is simply a mathematical device used to record sequences of events. If time is removed from the mathematics then we are only dealing with a background geometry that alters position only on the very smallest scales where time is meaningless anyway.