To faithful experts ( question )

[cheungcheung]

Einstein had a question when he was 14.

That question was "When I fly (in vacuum and without gravity) towards in space with light speed (30km/s), then I take my mirror in front of me, will I see my mirror((in terms of physical words, his face emits light and strike the mirror and then back into his eye))?"

 

After some periods of time, he got the answer, that is yes.

 

Until now , I still don't know why it is possible.

Relativity stated that nothing is faster than light, then what makes the lights from his face are fast enough to reach the mirror moving with light speed?

I beg experts can help me solve it.

[YT2095]

because he an his mirror are a closed system and not moving rellative to each other, but to an outside observer, things would appear much different

 

sorry if the answer is overly simple, but this isn`t really my area, but at least it`s AN answer

[jordan]

I would say that it is becuase light moves at the same speed for every observer, independent of their speed. Therefore, the light reflecting off his face and the mirror would be going 30km/s and he would see his reflection. It wouldn't matter what speed he was moving, he light would always reflect off the mirror and back to him at 30km/s.

[swansont]

Einstein had a question when he was 14.

That question was "When I fly (in vacuum and without gravity) towards in space with light speed (30km/s)' date=' then I take my mirror in front of me, will I see my mirror(([i']in terms of physical words, his face emits light and strike the mirror and then back into his eye[/i]))?"

 

After some periods of time, he got the answer, that is yes.

 

Until now , I still don't know why it is possible.

Relativity stated that nothing is faster than light, then what makes the lights from his face are fast enough to reach the mirror moving with light speed?

I beg experts can help me solve it.

 

I think perhaps you meant 30,000 km/s, which is approximately light speed. You couldn't actually travel that fast, but at whatever speed you actually were going, light would still travel at c relative to you - you can't tell that if you are moving or if everything around you is moving, if you're in an inertial frame of reference. As far as you can tell, you are stationary, so there's no problem there. As YT said, the mirror isn't moving relative to you, so that's not an issue.

 

The strange stuff happens for other inertial observers. They see you movong fast, and they also see light travelling at c, but they will see the frequency of that light change, as well as lengths contracted and time running slow for you. A lot of strange things become apparent once you realize that c is invariant.

[YT2095]

I think perhaps you meant 30,000 km/s, which is approximately light speed.

300,000 kms, I think ya missed a 0

[Ms. DNA]

300,000 kms, I think ya missed a 0

 

300,000 meters/second, not kilometers.

[blike]

299,792,458 meters per second. Which is ~300,000 km/s.

[Ms. DNA]

Whoops, you're right, blike. I stayed up too late last night, and I don't think I'm awake yet.

[YT2095]

never mind Blike, how `bout ME! (

 

LOL

[Ms. DNA]

OK, YT, if it makes you feel better, you're right too.

[YT2095]

hehehehehe XXX thnx hun, it does coming from you

[Dave]

Glad I didn't read this thread before I went into my relativity exam

[timo]

While googling around for another post I found this:

http://www2.corepower.com:8080/~relfaq/headlights.html

 

If you don´t want to read the text, the short resume of it is: You cannot travel at lightspeed.