Theoretically, if it were possible to increase the speed of an electromagnetic wave beyond the speed of light, would it then be possible to encode some form of basic binary data into said wave to send that data to the relative location of where the earth was, say, a month ago? Assuming that the destination of this wave was to a device capable of intercepting it and relaying the encoded data, that is.

If your premise is breaking the laws of physics you can draw any conclusion you want. It won't be meaningful though.

If you involve a second frame of reference and superluminal information transfer, you can get an answer before you send a message. Causality breaks.

If you involve a second frame of reference and superluminal information transfer, you can get an answer before you send a message. Causality breaks.

Would there be consequences if the effect preceded the cause?

Would there be consequences if the effect preceded the cause?

 

Increased energy/mass in the past.

 

Imagine time travel device sending you energy/fuel to time-1hour.

Each iteration, because you have more energy, you can send even more fuel to the past.

Edited April 11, 201510 yr by Sensei

 

Increased energy/mass in the past.

 

Imagine time travel device sending you energy/fuel to time-1hour.

Each iteration, because you have more energy, you can send even more fuel to the past.

That's a bang

Would there be consequences if the effect preceded the cause?

Yes, lots of them. You could send a message to tell you not to do something before you did it. Many paradoxes ensue.

Yes, lots of them. You could send a message to tell you not to do something before you did it. Many paradoxes ensue.

 

 

Would sending a message faster than light necessarily be sending the message back in time? Let's say we have a method of sending an instantaneous message (most extreme case I am assuming) We send that message to a star 100 ly away and then they return the message to us. Would the message be received 200 years in our past or is this just a mathematical quirk?

 

What i am trying to say is would it be a real effect? Or is it just what the math indicates much like infinity or a singularity. The reason i ask is that we can see that a signal going faster than light would still take time, positive time, at least in the receiving and re-sending part and I have read about singularities just being a mathematical quirk and they may not actually exist and that infinity is more of a mathematical concept than something we would expect to be real.

 

The ftl signal would get to the destination before a photon and would be received before a photon leaving the source would be but i see no reason other than a mathematical oddity to assume it would go backwards in time. In fact you would have to accept that the past is as real as the present for this to happen.

Edited April 11, 201510 yr by Moontanman

Would sending a message faster than light necessarily be sending the message back in time? Let's say we have a method of sending an instantaneous message (most extreme case I am assuming) We send that message to a star 100 ly away and then they return the message to us. Would the message be received 200 years in our past or is this just a mathematical quirk?

 

What i am trying to say is would it be a real effect? Or is it just what the math indicates much like infinity or a singularity. The reason i ask is that we can see that a signal going faster than light would still take time, positive time, at least in the receiving and re-sending part and I have read about singularities just being a mathematical quirk and they may not actually exist and that infinity is more of a mathematical concept than something we would expect to be real.

 

The ftl signal would get to the destination before a photon and would be received before a photon leaving the source would be but i see no reason other than a mathematical oddity to assume it would go backwards in time. In fact you would have to accept that the past is as real as the present for this to happen.

You need to involve someone in another frame of reference.

 

http://www.theculture.org/rich/sharpblue/archives/000089.html

You need to involve someone in another frame of reference.

 

http://www.theculture.org/rich/sharpblue/archives/000089.html

 

 

So FTL transmission is possible if both subjects are in the same frame of reference? BTW the comments section in that link are confusing the whole idea...

 

 

So FTL transmission is possible if both subjects are in the same frame of reference? BTW the comments section in that link are confusing the whole idea...

Looking in the comments, he says you can pick two from three: Special Relativity, FTL, Causality. Not that I do appreciate it fully, but this seems to be the crux of what must be understood: why all three together are incompatible.

Edited April 12, 201510 yr by StringJunky

 

 

So FTL transmission is possible if both subjects are in the same frame of reference?

 

No, it's just that you can't create a scenario that violates causality that way.

 

No, it's just that you can't create a scenario that violates causality that way.

 

 

That brings me back to sending a ftl signal to a planet 100 ly away and then return the signal would the signal arrive 200 years in the past

 

 

That brings me back to sending a ftl signal to a planet 100 ly away and then return the signal would the signal arrive 200 years in the past

 

But it wouldn't, if the planet was in the same frame as you. It would return right after you sent it, if the communication was instantaneous. But add in a third person in another frame, as in the linked example, it's possible to get the response earlier.

Suppose so we have magic emitter sending signal at v=2c=600 mln m/s, (distances and time in our frame)

at 1s delay from us, it's at d=2c distance,

at 2s delay from us, after sending, it's at d=4c distance from us, etc. etc.

at 1000s delay from us, it's 2000c (600 mln km) distance from us,

then reply is returning after another 1000s.

How it would violate causality?

Delay in receiving reply would be half what is now, because of faster speed.