Light Speed and Time

[midgetwars]

If you go at light speed time stops for you...

 

What does that mean? Does it mean if we go faster than light, it's back in time or forward to future?

[Mr Skeptic]

Pretty much, although you can't travel at the speed of light if you have mass. Also, if you travel faster than the speed of light you have imaginary mass, and travel backward in time. Tachyons are the name for particles which do this, although there is no evidence that they exist.

[Newbies_Kid]

speed of light = 299 792 458 m / s

then if we travel at the speed of light... i think it should be like this..

if we walk (at the speed of light) for 1 metre.. it just take only 299792458th of 1 second (almost zero). Meanwhile, at the same time, a normal person walk also for 1 metre, and usually take at least 1 sec. So the point here, although we travel faster than the light, the time still cannot reach zero or negative value. Therefore I think that the time itself should be defined first before we talk about the time travel.

[swansont]

If you analyze a scenario in which FTL communication is possible, you can receive a response to an inquiry before you send it, making causality moot.

[Newbies_Kid]

if we kick a ball at light speed will the ball flew before being kicked?? i think that human have their limitation in time/speed matter.

[swaha]

yes effect is before the cause if u go faster than light.

[StrontiDog]

yes effect is before the cause if u go faster than light.

 

That's because to kick a ball at the speed of light, your foot would have to travel faster. The ball has to slow the foot down--at impact--to the speed of light in order to fly off that fast.

 

The whole premise is silly, but it's fun to think about. Better make sure your shoe laces are tied really tight.

 

Bill Wolfe

[swansont]

That's because to kick a ball at the speed of light, your foot would have to travel faster. The ball has to slow the foot down--at impact--to the speed of light in order to fly off that fast.

 

In general this concept isn't right — if the impacting object is more massive than the target, the target will have a greater final speed than the impacting object started with. Of course, once you postulate v=c, all bets are off.

[StrontiDog]

In general this concept isn't right — if the impacting object is more massive than the target, the target will have a greater final speed than the impacting object started with. Of course, once you postulate v=c, all bets are off.

 

I thought about this after I wrote it. . .(isn't that what we're supposed to do before we write?)

 

 

And then I started to think about a foot with infinite mass (lightspeed, but not greater). . .impacting an infinitely strong (ie: made of thatsjustsillium) soccer ball. .

 

Wouldn't make much difference, would it?

 

Not entirely sure that the laws of conservation of momentum apply, in this case, but you'd think the ball would have to slow the foot down, a little, wouldn't you?

 

Mental excercises, that's what we're here for.

 

Bill Wolfe

Edited March 4, 2010 by StrontiDog

[Radical Edward]

If you go at light speed time stops for you...

 

What does that mean? Does it mean if we go faster than light, it's back in time or forward to future?

 

massive objects traveling at c makes no mathematical sense. You just get an equation with a load of infinities in it, meaning it is unphysical.