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Author Topic: Time traveling  (Read 3278 times)

Offline Mikey11

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Time traveling
« on: 22/07/2014 23:45:10 »
It has been said to travel faster then light would be to travel through time so besides the obvious 2 problems I came up with (throwing off earths gravity and not strong enough building materials) would it not be possible to build a pole from the equator however far then the top will be moving faster than light? Are there any real or theoretical problems with this plan.


 

Offline Mikey11

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Re: Time traveling
« Reply #1 on: 28/08/2014 22:43:24 »
Bump
 

Offline chiralSPO

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Re: Time traveling
« Reply #2 on: 29/08/2014 00:36:24 »
Yes, there are many reasons why this would not achieve the desired effect. One is that it would take an infinite amount of energy to accelerate anything with nonzero rest mass to the speed of light, and probably less possible to go faster than the speed of light.

You would also have to worry about conservation of angular momentum. Imagine extending your time traveling capsule further and further from the Earth along a cable. As the capsule moves further out, its velocity must increase to match the frequency of rotation, but the angular momentum has to come from somewhere, and it ends up stealing from the Earth's rotation. The whole rotating system would slow down to accommodate the new mass distribution. This is exactly what happens when a spinning figure skater extends their arms to slow down (or speed up by pulling them in). You can feel this yourself by spinning on an office chair and extending and retracting your arms. So depending on the mass of the capsule, there is a maximum speed it could achieve by taking angular momentum from the Earth.
 

Offline PmbPhy

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Re: Time traveling
« Reply #3 on: 29/08/2014 02:21:41 »
Quote from: Mikey11
It has been said to travel faster then light would be to travel through time so besides the obvious 2 problems I came up with (throwing off earths gravity and not strong enough building materials) would it not be possible to build a pole from the equator however far then the top will be moving faster than light? Are there any real or theoretical problems with this plan.
Yes. No matter how high the building is the top will never be moving faster-than-light (FTL). As chiralSPO implied, it would be impossible to build. Also it would imply that the building is perfectly rigid and there is no such thing as a perfectly rigid body. Einstein has shown to be true using special relativity.
 

Offline JohnDuffield

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Re: Time traveling
« Reply #4 on: 29/08/2014 14:58:05 »
Quote from: Mikey11
It has been said to travel faster then light would be to travel through time
It might have been said, but it isn't true. We travel through space. The idea of "travelling through time" is just a figure of speech. 

Quote from: Mikey11
would it not be possible to build a pole from the equator however far then the top will be moving faster than light? Are there any real or theoretical problems with this plan.
See above. But let's just say there was a trick way to make something move faster than light. Not by making it go faster, but by moving it to a place where the coordinate speed of light is lower. By dropping it into a black hole. What would happen? Have a look at this:

"In the dynamic interpretation of relatively by Lorentz and Poincaré, Lorentz invariance results from real physical contractions of measuring rods and slower going clocks in absolute motion against an ether. As it was shown by Thirring, this different interpretation of special relativity can be extended to general relativity, replacing the non-Euclidean with a Euclidean geometry, but where rods are contracted and clocks slowed down. In this dynamic interpretation of the special, (and by implication of the general) theory of relativity, there is a balance of forces which might be destroyed near the Planck energy, reached in approaching the event horizon. In gravitational collapse, the event horizon appears first at the center of the collapsing body, thereafter moving radially outward. If the balance of forces holding together elementary particles is destroyed near the event horizon, all matter would be converted into zero rest mass particles which could explain the large energy release of gamma ray bursters".
 

Offline jeffreyH

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Re: Time traveling
« Reply #5 on: 29/08/2014 20:53:55 »
Quote from: Mikey11
It has been said to travel faster then light would be to travel through time
It might have been said, but it isn't true. We travel through space. The idea of "travelling through time" is just a figure of speech. 

Quote from: Mikey11
would it not be possible to build a pole from the equator however far then the top will be moving faster than light? Are there any real or theoretical problems with this plan.
See above. But let's just say there was a trick way to make something move faster than light. Not by making it go faster, but by moving it to a place where the coordinate speed of light is lower. By dropping it into a black hole. What would happen? Have a look at this:

"In the dynamic interpretation of relatively by Lorentz and Poincaré, Lorentz invariance results from real physical contractions of measuring rods and slower going clocks in absolute motion against an ether. As it was shown by Thirring, this different interpretation of special relativity can be extended to general relativity, replacing the non-Euclidean with a Euclidean geometry, but where rods are contracted and clocks slowed down. In this dynamic interpretation of the special, (and by implication of the general) theory of relativity, there is a balance of forces which might be destroyed near the Planck energy, reached in approaching the event horizon. In gravitational collapse, the event horizon appears first at the center of the collapsing body, thereafter moving radially outward. If the balance of forces holding together elementary particles is destroyed near the event horizon, all matter would be converted into zero rest mass particles which could explain the large energy release of gamma ray bursters".

The event horizon radiates outwards! Who said that? I had come to that conclusion a while back but had rejected it. What proof is there?? I assume none! If it were true then a link could be established between gluon and graviton.
 

Offline JohnDuffield

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Re: Time traveling
« Reply #6 on: 30/08/2014 13:04:52 »
I don't think it's anything to do with gluons and gravitons, Jeffrey. This is Friedwardt Winterberg's firewall, where the black hole is something like Oppenheimer's original "frozen star" interpretation. For an analogy, think of a hailstone. You're a water molecule, and you can't pass through the surface of the hailstone. But you get buried by other water molecules, so the surface passes through you. The surface of the hailstone is moving radially outward.
 

Offline jeffreyH

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Re: Time traveling
« Reply #7 on: 30/08/2014 13:19:05 »
I don't think it's anything to do with gluons and gravitons, Jeffrey. This is Friedwardt Winterberg's firewall, where the black hole is something like Oppenheimer's original "frozen star" interpretation. For an analogy, think of a hailstone. You're a water molecule, and you can't pass through the surface of the hailstone. But you get buried by other water molecules, so the surface passes through you. The surface of the hailstone is moving radially outward.

Well that implies that the density of mass compression first reaches a critical stage at the centre of a collapsing mass and only later forms a horizon at the compressed surface. This would be like two Planck masses being brought together which starts the reaction. However, usually we think of a cancellation of the gravitational forces at the centre of a mass. I don't believe they cancel at all but act differently. So how can we get to the stage where the forces act to compress the centre in such a way? We have no experimental data on the forces below a surface. That is why a while back I asked if experiments on g had been made in deep mine shafts. If we don't have the data what good is the mathematics?
 

Offline JohnDuffield

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Re: Time traveling
« Reply #8 on: 30/08/2014 14:20:54 »
Quote from: jeffreyH
Well that implies that the density of mass compression first reaches a critical stage at the centre of a collapsing mass
I suppose so. That is after all where the pressure is greatest.

Quote from: jeffreyH
However, usually we think of a cancellation of the gravitational forces at the centre of a mass.
There's no gravitational force in that you don't fall down. But that doesn't mean there's no pressure. If you were at the centre of the Earth, it would be like you were trying to hold up a column of bricks four thousand miles high. And another, and another, and another, all around you.

Quote from: jeffreyH
I don't believe they cancel at all but act differently. So how can we get to the stage where the forces act to compress the centre in such a way? We have no experimental data on the forces below a surface. That is why a while back I asked if experiments on g had been made in deep mine shafts. If we don't have the data what good is the mathematics?
I don't know Jeffrey. Have a read of Kevin Brown's  formation and growth of black holes for mention of the frozen star interpretation. He doesn't favour it, but he acknowledges it. I think it's the correct interpretation myself. Maybe you should start a separate thread on that.
 

Offline jeffreyH

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Re: Time traveling
« Reply #9 on: 30/08/2014 14:38:06 »
Quote from: jeffreyH
Well that implies that the density of mass compression first reaches a critical stage at the centre of a collapsing mass
I suppose so. That is after all where the pressure is greatest.

Quote from: jeffreyH
However, usually we think of a cancellation of the gravitational forces at the centre of a mass.
There's no gravitational force in that you don't fall down. But that doesn't mean there's no pressure. If you were at the centre of the Earth, it would be like you were trying to hold up a column of bricks four thousand miles high. And another, and another, and another, all around you.

Quote from: jeffreyH
I don't believe they cancel at all but act differently. So how can we get to the stage where the forces act to compress the centre in such a way? We have no experimental data on the forces below a surface. That is why a while back I asked if experiments on g had been made in deep mine shafts. If we don't have the data what good is the mathematics?
I don't know Jeffrey. Have a read of Kevin Brown's  formation and growth of black holes for mention of the frozen star interpretation. He doesn't favour it, but he acknowledges it. I think it's the correct interpretation myself. Maybe you should start a separate thread on that.

I have just read in Strassler on the firewall paradox. I was looking into another horizon within black holes and got exactly the opposite result to what I expected. This was an horizon external to the event horizon. I am still rechecking that because I don't believe my results. I will follow up on what you said in your last post. I may start a new thread.
 

Offline jeffreyH

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Re: Time traveling
« Reply #10 on: 30/08/2014 15:54:46 »
One thing is for certain. If you reject the graviton then some of the problems disappear. They are replaced by others so the point is in finding those solutions.
 

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Re: Time traveling
« Reply #10 on: 30/08/2014 15:54:46 »

 

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