Can Faster-than-Light Travel Ever Be Possible?

AI Thread Summary
Faster-than-light (FTL) travel is not possible according to current physics, as the speed of light serves as a fundamental limit for signal transmission and real objects. Discussions highlight that while phenomena like laser pointer dots can appear to move faster than light, they do not represent actual object movement or information transfer. The conversation emphasizes the importance of precise definitions when discussing what constitutes an "object," particularly in relation to particles and disturbances. Ultimately, no experiments have demonstrated superluminal effects that would challenge this understanding. FTL travel remains a theoretical concept without empirical support in established physics.
Arthurwerbrouck
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Hello i love physics and would love to learn more about it.
I stumbeld upon a wikipedia page called faster then the speed of light
https://en.m.wikipedia.org/wiki/Faster-than-light
And if you look at 3.1 it seems to be prooven
Could someone with knowledge of the topic explain this to me and tell me al about it
Thx in advance
 
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Arthurwerbrouck said:
And if you look at 3.1 it seems to be prooven
No.
The first question is "what type of velocity do we measure?". Take a laser pointer, point at the moon and rotate it fast enough: the dot of the pointer can easily "move" from one side to the moon at a speed faster than the speed of light. That is not the speed of any real object, however, and it cannot be used to transmit information from one side of the moon to the other at this speed.

The true limit applies to signal speed: how fast can an event at place A influence an event at place B? None of the experiments discussed there found superluminal effects here.
Arthurwerbrouck said:
Just nonsense.
 
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Welcome to PF!
mfb said:
No.
The first question is "what type of velocity do we measure?". Take a laser pointer, point at the moon and rotate it fast enough: the dot of the pointer can easily "move" from one side to the moon at a speed faster than the speed of light. That is not the speed of any real object, however, and it cannot be used to transmit information from one side of the moon to the other at this speed.

The true limit applies to signal speed: how fast can an event at place A influence an event at place B? None of the experiments discussed there found superluminal effects here.
Just to expand on what mfb said, the limit of the speed of light applies to particles and mechanical disturbances (there is actually really good information about this on the FAQs, I believe under relativity). The dot on the laser pointer he mentioned is not a particle or object because it is an effect of the photons constantly traveling from the pointer to the moon, and those photons are effected by the speed of light limit.
 
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Isaac0427 said:
The dot on the laser pointer he mentioned is not a particle or object [...]

That depends on the definition of "object".
 
DrStupid said:
That depends on the definition of "object".
Object meaning something made up of one or more particles, and we should not make this more complicated than it needs to be. I understand that it is not a perfect definition but it should do for this situation.
 
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Isaac0427 said:
Object meaning something made up of one or more particles

That would mean that a black hole is not an object because it is made up of space time only.
And it would mean that a dot on a crt-display is an object because it is made up of electrons and a fluorescent substance. And yes, I know that this also depends on the definition of "made up of".

Isaac0427 said:
and we should not make this more complicated than it needs to be.

Than we should avoid imprecise terms.
 
Isaac0427 said:
Object meaning something made up of one or more particles, and we should not make this more complicated than it needs to be. I understand that it is not a perfect definition but it should do for this situation.
Good show! If an explanation ain't broke making it more complicated won't fix it. :wink:
 
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DrStupid said:
That would mean that a black hole is not an object because it is made up of space time only.
And it would mean that a dot on a crt-display is an object because it is made up of electrons and a fluorescent substance. And yes, I know that this also depends on the definition of "made up of".
Than we should avoid imprecise terms.
I'm sorry for my improper terminology, however I believe the OP gets what I mean. As I said, it is not a perfect definition, but it should do for this situation.
 
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FTL travel isn't possible according to known physics, which is the only kind we discuss here at PF. Thread locked.
 
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