A train going at the speed of light

I've always wanted to play with this. Let's say that, hypothetically of course, a train with people inside manages to reach speed of light (or something very, very close to it, if you will). What do you think happens with those people inside? Think of something original, don't say "they explode" and similar. And assume that after it reaches that magical velocity, it continues its trip without slowing down (or speeding up ha, ha) so there is no force felt by everyone in. I guess the first and the most obvious question is: what do they see? Share your thoughts! (be careful though, or you might be the one exploding ;))

 

hmm I guess they won't get any older. Nor the stuff in the train. And I guess that they would see to the past, kinda.

 

They would be moving fast.

Also time would stand almost still.

 

Well having just studied the theory of relativity and stuff moving at the speed of light, I would have to say that the people inside would see themselves and anything in the train as normal and uncontracted. Time would also flow at a normal rate to them. Outside, however, they will be traveling immense distances (obviously) but more importantly, time will have stopped for them. Because nothing moves faster than the speed of light, an event that is "behind" the train would never be seen.

I give an example: If the train with people looking outside the rear window are moving at constant velocity c, which is the speed of light, and a person standing on Earth yells at them (super loudly), or flashes a laser, or even sends a material wave towards them. Since the train is moving at the speed of light and WHATEVER signal the person on Earth sent them could not have moved faster than the speed of light, the people in the train would NEVER see the laser go on or hear the shout or anything. To them, the people on earth are standing completely still because the next "frame" of time has not yet reached their senses. This logic applies even to events that happen on the sides of the train too but is slightly more complicated.

If an event happened at a 45 degree angle from the train's movement, there is a chance that the event could be seen by the observers in the train. If the event was a laser, and in space, the laser was in the right place for the 45 degree angle to work, the train could see it. This is called the Light Cone. It's far too complicated to explain to your fragile minds so I leave you to wiki that up yourselves :D

 

So it's just a matter of the light/sound signals not reaching (catching up to) their senses? Not really time stopping behind them?

Sorry for blasphemy in advance. :D

 

They see the screens of their iPhones and iPads as they are twittering about going at the speed of light.

I may not be a smart man.

That was my first (serious) thought. The light in that train could not travel freely in all the directions, (relative to the passangers) so they would have some serious visual distortions there.

 

Also, they would have a lot of mass... Only thing i can add even though my brother is studying Physics at A-Level.

 

Their insides would violently tug forward, while their outer parts would resist. But then all their guts and thick inner flesh would be thrown right out of their mouth and collapse on the floor in a heaping pile of gore.


.....

What?

 

In fact, the light within the train seems normal to those inside it because at any reference frame, the speed of light is the same. So they would see everything just as we do now. We are currently moving at enormous speeds but there is no distortion of light because the objects that emit light are moving with 0 velocity in OUR reference frame. And @rioja, they would have the same mass and weight. Mass never changes but weight changes due to acceleration. But in the train's reference frame, there is no acceleration so the weight would be constant to whatever it was when the train wasn't moving.

@czubai: I don't quite understand if your statement is sarcastic? haha well yes time is actually flowing behind them but the problem is that they can not tell that it is changing.

 

Yeah I thought so :P. I just wanted to make things sound a little more sickening!

 

I thought we assume they accelerated gently to avoid that.

Nah, I was serious. I'm pretty sure back in the day my psychics teacher said something about a guy going into space for a long time (few years?) and being younger than his twin after coming back. I probably mixed up theories though. Or he was a bad teacher.

 

Was joking.

 

Whether or not it is likely, I was joking, meaning it doesn't matter whether it's realistic or not.. :S

 

@ rainbows!: FALSE :D haha ACCELERATING quickly will turn your insides into outsides but going fast doesn't do anything ;) physics 240 FTW

anywho, @czubai, yes a twin going at .5 c will age less than a twin on earth. Its complicated but it's in my textbook so it must be true ;D

 

Even worse; the driver spills his coffee over the controls and the train becomes unstoppable. Trapped! Forever!

Wait, what?

 

Well, when/if you get to the speed if light, you are pretty much unstoppable anyway since you have infinite mass. So even if you have a 10 foot thick sheet of concrete i assume you would just smash straight through it because, going at the speed of light and having infinite mass means you have infinite momentum or the momentum of the universe.