Can information travel faster than light?

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Discussion Overview

The discussion centers around the question of whether information can travel faster than the speed of light, particularly through the example of a rotating light torch illuminating a wall. Participants explore the implications of this scenario in the context of the theory of relativity and the nature of information transmission.

Discussion Character

  • Debate/contested
  • Conceptual clarification
  • Exploratory

Main Points Raised

  • One participant questions if the spot of light on the wall can travel faster than the speed of light and whether this would violate the laws of physics.
  • Another participant argues that the moving spot of light is not a physical object and cannot be used to transmit information, thus it does not violate the speed of light limit.
  • A third participant agrees with the previous point, emphasizing that the described scenario does not exceed the speed of light in any meaningful way.
  • Another analogy is presented comparing the situation to waves breaking on a beach, suggesting that the movement of the wave's breaking point does not involve the motion of any physical object.
  • One participant notes that to send information, one must be able to produce different results based on choices made, which is not possible in the described scenario since the illuminated spot cannot be influenced by an observer.
  • A hypothetical scenario is introduced where a laser is pointed at two distant points on a wall, illustrating that even with instantaneous changes in direction, the time taken for light to travel limits the ability to send information faster than light.

Areas of Agreement / Disagreement

Participants express differing views on whether the movement of the light spot constitutes a violation of the speed of light limit. While some argue it does not, others raise concerns about the implications for information transmission. The discussion remains unresolved with multiple competing views present.

Contextual Notes

The discussion involves assumptions about the nature of information and physical objects, as well as the definitions of speed and transmission in the context of relativity. There are unresolved aspects regarding the implications of the examples provided.

ABHIdAVIATOR
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Theory of Relativity says nothing can exceed the speed of light. My question is:
Can any information be made to travel faster than 'c'?

suppose, i have a light torch of very high intensity which can be rotated on an axis(its stand). the light is made to fall on a wall(extending for millions of miles). the wall itself is millions of miles away from the light torch. now if i rotate the torch on its stand, the bright spot on the wall travels very fast. and, even for very minute changes in the angle, the spot travels thousands of miles. Can spot of light on the wall travel faster than c?

If yes, doesn't it violate our laws?
 
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ABHIdAVIATOR said:
Can spot of light on the wall travel faster than c?
Sure, why not? Note that the moving spot of light is not a physical object (it's not really any kind of "object") and that it can't be used to send a signal (thus transmit information) between one spot on the wall and another.
If yes, doesn't it violate our laws?
Nope.
 
Doc is right but what youre describing isn't breaking the SoL limit because it doesn't exceed it in any way.

Tachyon.
 
Your example is similar to waves approaching a beach, not quite head on.
The point where the wave breaks on the beach moves along the beach at great speed,
but is not the motion of anything physical.
 
To send information you must be able to produce two different results on receiving point that are consequences of choices you made.
In your experiment this is not possible: a person standing near the wall could do nothing to influence the traveling of the illuminated spot.
 
Say we have two points on the wall (A and B) that are 10 light years apart. You are 6 light years from both A and B forming a triangle. If your laser is pointing at A and you start to turn the laser it will be 6 light years before the spot on the wall even starts moving. Now you turn your laser "instantaneously" to point in the direction of B. The photon leaving your laser that is now pointing at B will take 6 light years to arrive at B so the total time from when you decided to start turning the laser to the time the signal arrives at B is 6 years. Now if you see A launch a death ray towards B it will be 6 years before you are even aware that A has launched the death ray and another 6 years before your signal to warn B that he has an incoming attack. Your alert signal to B will arrive 2 years after he has been fried to a crisp by the death ray from A. :P
 
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