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At what point does light come into existence from when it leaves its source? |
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| Aug19-10, 01:39 AM | #1 |
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At what point does light come into existence from when it leaves its source?
A torch (flashlight US) is positioned on a train going at 70kms/hour. Relative to someone standing beside the train track the torch will have a velocity of 70kms/hour since it is on the train. When you switch on the torch, a light beam emanates. However, the light was not actually inside the torch, it emanates from the torch. Light is made of photons. Do the photons exist in the torch or only outside the torch? If so, can it be said that the light beam is also on the train or did it only start to exist outside of the torch and therefore was never "on the train"?
Alessandra |
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| Aug19-10, 07:00 AM | #2 |
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| Aug19-10, 07:28 AM | #3 |
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Light is a vibration - very much like waves on water.
If you stick your hand in a pond and make ripples, it's exactly the same. So, do the waves exist in your hand? If not, where did they come from? and where do they go when they reach the shore? |
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