I posted this in CANGAS's excellent [thread=56170]Next to last relativity thread[/thread], but the discussion has drifted beyond the thread's main topic. To avoid further hijacking, I'm making a new thread. It's also an instructive illustration of what Special Relativity does and doesn't say.
I've drawn up animations of a tank rolling along at 0.866c It gives interesting insights into the problem of the relativistic rotating disk, specifically that the outer rim of the disk (or in this case, the tank tread) must be physically stretched by a factor of gamma (unless the supporting structure is physically compacted). Notice how the portion of the track in contact with the ground is stretched to twice its proper tread spacing.
Macromedia Flash player required.
This animation simulates what a distant camera moving parallel to the tank sees:
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This animation simulates what a camera fixed to the ground sees:
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Note that both cameras are filming at the same time, so they are recording exactly the same events. They look different because (according to Special Relativity), the relationship between events depends on the reference frame chosen to describe them (ie on the motion of the observer).
This weekend, I will add clock readings in both frames to the animation. This will make the time dilation of ground clocks in the tank frame easier to see.
Feel free to criticise, question, or comment.
Pete
I've drawn up animations of a tank rolling along at 0.866c It gives interesting insights into the problem of the relativistic rotating disk, specifically that the outer rim of the disk (or in this case, the tank tread) must be physically stretched by a factor of gamma (unless the supporting structure is physically compacted). Notice how the portion of the track in contact with the ground is stretched to twice its proper tread spacing.
Macromedia Flash player required.
This animation simulates what a distant camera moving parallel to the tank sees:
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This animation simulates what a camera fixed to the ground sees:
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Note that both cameras are filming at the same time, so they are recording exactly the same events. They look different because (according to Special Relativity), the relationship between events depends on the reference frame chosen to describe them (ie on the motion of the observer).
This weekend, I will add clock readings in both frames to the animation. This will make the time dilation of ground clocks in the tank frame easier to see.
Feel free to criticise, question, or comment.
Pete