LITERALLY No Velocity...

[Matuchkin]

Everything we know moves at a huge velocity. The planets orbit around our solar system, our solar system moves around other systems and orbits Sagittarius A, Sagittarius A moves around other galaxies and expands with them...

What if an object was literally standing in one spot, not moving? It will be standing completely still in space. What do you think will happen?

Edited January 12, 2016 by 073198681
Did not make any sense

[Gaarst]

Kinda like light but instead of moving at c relative to everything else, it would not move at all.
If it has no mass, then you can imagine some wierd things happening with time accodring to relativity. If it has a non-zero mass, then some pretty heavy space-time distortion involving exotic things such as infinite energies and that kind of stuff would appear. Note that I don't know a lot about relativity, and even if I did I'm not sure I could give an answer to that; so what I said is probably very far from accurate.

PS: ask @K^2, he knows everything about physics

[Matuchkin]

5 minutes ago, Gaarst said:

Kinda like light but instead of moving at c relative to everything else, it would not move at all.
If it has no mass, then you can imagine some wierd things happening with time accodring to relativity. If it has a non-zero mass, then some pretty heavy space-time distortion involving exotic things such as infinite energies and that kind of stuff would appear. Note that I don't know a lot about relativity, and even if I did I'm not sure I could give an answer to that; so what I said is probably very far from accurate.

PS: ask @K^2, he knows everything about physics

Well then it'll be nice if he joins, I'd like an interesting conversation...

Edited January 11, 2016 by 073198681

[Dunbaratu]

8 minutes ago, 073198681 said:

 Its velocity relative to everything else will be 0.

If the universe has more than one object in it, then it's impossible for this to be true of just ONE of the objects in the universe.  It would have to be true of all the objects in the universe.

[Matuchkin]

1 minute ago, Steven Mading said:

If the universe has more than one object in it, then it's impossible for this to be true of just ONE of the objects in the universe.  It would have to be true of all the objects in the universe.

Whatwhenwhywhohowwhaaaat? Explanation?

[Gaarst]

2 minutes ago, Steven Mading said:

If the universe has more than one object in it, then it's impossible for this to be true of just ONE of the objects in the universe.  It would have to be true of all the objects in the universe.

Not necessarily if you involve relativity and time dilation. Just think about the fact that relativistic speeds don't add up (moving at 0.9c towards object A itself moving at 0.9c towards object B doesn't mean you're moving towards B at 1.8c but 0.9945c).

Space and time dilations allow for non-linear velocities relations, and therefore, I don't think your statement is valid.

[Scotius]

Wouldn't quantum fluctuations still impart some (minuscule) velocity on such obiect?

[Gaarst]

Just now, Scotius said:

Wouldn't quantum fluctuations still impart some (minuscule) velocity on such obiect?

I don't think so, you theoretically can have a strictly 0 velocity relative to your environment with no uncertainty but that would basically mean that it is everywhere at the same time (from Heisenberg Uncertainty principle).

[PB666]

1 hour ago, 073198681 said:

Everything we know moves at a huge velocity. The planets orbit around our solar system, our solar system moves around other systems and orbits Sagittarius A, Sagittarius A moves around other galaxies and expands with them...

What if an object was literally standing in one spot, not moving? Its velocity relative to everything else will be 0. What do you think will happen?

Even in a quantum singularity this cannot happen. Something could have a trivial velocity in comoving spacetime but that still does have motion.

https://en.wikipedia.org/wiki/Matter_wave

https://en.wikipedia.org/wiki/Brownian_motion.

https://en.wikipedia.org/wiki/Maxwell%E2%80%93Boltzmann_distribution

https://en.wikipedia.org/wiki/Bose%E2%80%93Einstein_condensate

In the condensate that particles are not moving relative to each other, but the condensate itself is moving.

BTW, you don't have to know everything about physics to know 100-200 year old hypothesis about thermal motion, and 100 year old hypothesis about what constitutes a fermion and a boson.

Pretty much QM guarantees motion, if not unpredictable at some scales.

Edited January 11, 2016 by PB666

[cantab]

Special relativity or not, if A is in motion with respect to B, then C cannot be at rest with respect to both A and B. That seems frankly obvious.

[K^2]

32 minutes ago, cantab said:

Special relativity or not, if A is in motion with respect to B, then C cannot be at rest with respect to both A and B. That seems frankly obvious.

... Until you get into General Relativity, where this could totally be the case in a particular coordinate system. In fact, all relative velocities become rather arbitrary.

And yes, you could even define a coordinate system in which there exists a point that's at rest with respect to any arbitrary number of points. So to within a quantum fluctuation, you could have a point that's at rest with respect to everything. And it can basically be any point in the universe with suitable choice of coordinate systems.

[jf0]

2 hours ago, 073198681 said:

Everything we know moves at a huge velocity. The planets orbit around our solar system, our solar system moves around other systems and orbits Sagittarius A, Sagittarius A moves around other galaxies and expands with them...

What if an object was literally standing in one spot, not moving? Its velocity relative to everything else will be 0. What do you think will happen?

 

36 minutes ago, K^2 said:

... Until you get into General Relativity, where this could totally be the case in a particular coordinate system. In fact, all relative velocities become rather arbitrary.

And yes, you could even define a coordinate system in which there exists a point that's at rest with respect to any arbitrary number of points. So to within a quantum fluctuation, you could have a point that's at rest with respect to everything. And it can basically be any point in the universe with suitable choice of coordinate systems.

Surely not: if I come up with a coordinate system that is stationary relative to me, I can come up with infinitely many that are in motion relative to it.

 

Quote

a coordinate system in which there exists a point that's at rest with respect to any arbitrary number of points

Ok sure; if you have a coordinate system that you call 'at rest' you can come up with infinitly many that have no realtive motion to it (simple example just shift the origin by any amount...), relativity or not. But that does not mean every thing is at rest relative to it, you can still come up also with infinitely many that are in motion relative to it ... maybe you meant something else could you explain?

 

 

 

Edited January 12, 2016 by jf0

[swjr-swis]

2 hours ago, 073198681 said:

What if an object was literally standing in one spot, not moving? Its velocity relative to everything else will be 0. What do you think will happen?

That object will get very cold and lonely.

[Matuchkin]

19 minutes ago, swjr-swis said:

That object will get very cold and lonely.

^^^A simple answer that a 14 year old can understand. Not exactly the point here, but something I don't have to do mental images of for half-hours. Nice.

47 minutes ago, jf0 said:

Surely not: if I come up with a coordinate system that is stationary relative to me, I can come up with infinitely many that are in motion relative to it.

47 minutes ago, jf0 said:

Ok sure; if you have a coordinate system that you call 'at rest' you can come up with infinitly many that have no realtive motion to it (simple example just shift the origin by any amount...), relativity or not. But that does not mean every thing is at rest relative to it, you can still come up also with infinitely many that are in motion relative to it ... maybe you meant something else could you explain?

There, something I understand. I don't exactly understand why this isn't possible, though. I'm gonna try to understand more of this conversation once I finish my frantic studying.

 

Edited January 12, 2016 by 073198681

[Matuchkin]

2 hours ago, Scotius said:

Wouldn't quantum fluctuations still impart some (minuscule) velocity on such obiect?

Yeah, I should have been elaborating. Just imagine that the object is "nailed" to a plane (not implying a 2 dimensional plane, just giving a visual).

[K^2]

55 minutes ago, jf0 said:

Ok sure; if you have a coordinate system that you call 'at rest' you can come up with infinitly many that have no realtive motion to it (simple example just shift the origin by any amount...), relativity or not. But that does not mean every thing is at rest relative to it, you can still come up also with infinitely many that are in motion relative to it ... maybe you meant something else could you explain?

Other way around. If you give me any number of objects that you insist are already in relative motion, whatever that motion may be, I can construct a coordinate system in which all of these objects are at rest.

Trivial example, picture a bunch of objects on a rotating table. They are all in motion with respect to each other from perspective of any inertial frame. But in a rotating frame of reference, they are all at rest with respect to each other. General Relativity allows me to generalize this notion for arbitrary relative motion.

[jf0]

3 hours ago, K^2 said:

I can construct a coordinate system in which all of these objects are at rest.

Of course you can, and in fact isn't that what I said:

4 hours ago, jf0 said:

... I can come up with infinitely many that are in motion relative to it ... you can come up with infinitly many that have no realtive motion to it...

The OPs point was, I think, a frame where all other frames are at rest. This does not exist because surely given any coordinate system you can always easily find 'another' that is in relative motion.

also a side note:

also we should start being more specific about the correct use and meaning of 'coordinate system', 'object', 'point', 'reference frame'...

Edited January 12, 2016 by jf0

[GeneralVeers]

7 hours ago, 073198681 said:

Everything we know moves at a huge velocity. The planets orbit around our solar system, our solar system moves around other systems and orbits Sagittarius A, Sagittarius A moves around other galaxies and expands with them...

What if an object was literally standing in one spot, not moving? Its velocity relative to everything else will be 0. What do you think will happen?

Speaking from experience (I am, in fact, the Center of the Universe!) it's nothing special.

[Dunbaratu]

8 hours ago, 073198681 said:

Whatwhenwhywhohowwhaaaat? Explanation?

You used the phrase "relative to everything else".  Meaning relative to all the other objects.  If A is not moving relative to B, then that also means B is not moving relative to A either.  Similarly, if A is not moving relative to B, and B is not moving relative to C, then A is not moving relative to C either.

Thus the only way for an object to be not moving relative to ALL other objects is for all of them to not be moving relative to it either, and transitively that means all the objects are not moving relative to each other.

[K^2]

1 hour ago, jf0 said:

Of course you can, and in fact isn't that what I said:

The OPs point was, I think, a frame where all other frames are at rest. This does not exist because surely given any coordinate system you can always easily find 'another' that is in relative motion.

He did not say "every frame". He said "everything". If we simply count every single particle, we can construct a frame in which every single one of these particles are at rest. Again, to within quantum fluctuations.

[KerbMav]

11 hours ago, 073198681 said:

What if an object was literally standing in one spot, not moving? Its velocity relative to everything else will be 0. What do you think will happen?

Its velocity relative to everything being 0 is something I could never get my head around.

If I am standing still in a big room and people are dancing around me, then each and every one will always have a relative velocity to me.

Maybe you are thinking of something that does not move relative to the universe, standing still in space? As gravity has unlimited range, something will start to pull on it, so it will not keep in one place for very long.

[RainDreamer]

Heat death of universe?

[KerbMav]

2 hours ago, RainDreamer said:

Heat death of universe?

Something that does not make sense to me - since gravity does not go away and some movement should always take place?

[Matuchkin]

4 hours ago, KerbMav said:

Its velocity relative to everything being 0 is something I could never get my head around.

If I am standing still in a big room and people are dancing around me, then each and every one will always have a relative velocity to me.

Maybe you are thinking of something that does not move relative to the universe, standing still in space? As gravity has unlimited range, something will start to pull on it, so it will not keep in one place for very long.

Yeaaaaaahh.

I noticed.

I'm thinking of something...

[KerbMav]

58 minutes ago, 073198681 said:

Yeaaaaaahh.

I noticed.

I'm thinking of something...

Although, if you really manage to fix something in space ... shouldn't everything else be drawn towards it?