/sci/ - Science & Math

The latter. To you, everything would look really thin, so things that used to be several light years away would look much closer.

It would take a little bit more than 1 year to travel a light year in both frames of reference. I'll leave it to you to figure out why.

>>4422129
Is that something to do with the Michelson-Morley experiment?

Also thanks >>4422131

>Got 2 different answers

It takes a year as earthbound people reckon it, but much less from your perspective. Basic time dilation.

>>4422144
he was referring to the fact that light always goes at the speed of light, so technically a "light year" would change if you started going faster, but I assumed you define "light year" in terms of some static distance in our reference frame, such as "1 light year = about 1/4 the distance to alpha centauri"

>>4422151
>>4422153
>>4422144
>>4422131
>>4422129

Nope. It only takes 3.6 years to travel 4.3 light years away

http://math.ucr.edu/home/baez/physics/Relativity/SR/rocket.html

>>4422162
At 99.9% of the speed of light, it takes much less than 4 subjective years to travel 4 light-years.

>>4422153
I was merely talking about length contraction, which is a consequence of that. 1 ly in the frame of reference of the ship would be a lot longer than 1 ly in the Earth's frame.

>>4422179
>1 ly in the frame of reference of the ship would be a lot longer than 1 ly in the Earth's frame.
That's not a comparison that makes sense.

>>4422184
OP never specified in which frame he measured the distance. In both frames the ship will take the same amount of time to cross the same measured distance, but the distances between objects will be different in the two frames.

Let me put it this way op
If you were traveling the speed of light, it would take you 1 year to travel 1 light year. You would age 1 year and it would feel like it took 1 year, you would sleep about 2920 hours.

>>4422225
That's closer to correct. In the ship's frame, the ship isn't moving that distance; rather, that distance worth of starfield is moving past the ship. Although you said cross, not move, so maybe that's what you meant; it's not very clear.

http://en.wikipedia.org/wiki/Time_dilation#Time_dilation_due_to_relative_velocity
Assuming you don't care about accelerating to that speed etc.

>>4422234
Captain Obvious points out: You can't travel at the speed of light, and your figures are bogus.

So if anyone is confused, if you are traveling to a star 1 light-year away at 99.9% of the speed of light:

* In the earth's reference frame, it takes a little more than a year for you to get to the star.

* In your reference frame, the star is about 1/22 of a light-year away, and it comes to you at 99.9% of c. This takes about 1/22 of a year.

>You would age 1 year and it would feel like it took 1 year,
no it wouldnt you fucktard, the closer to c you go the less time it will feel like with the limit of going at c having time go to 0.

gamma factor is 31.6

so the 1ly contracts to 0.03ly

meaning it takes roughly 0.03yr to travel there

You'll notice that when travelling at the speed of light you can reach anywhere instantly. This calculation ignores acceleration.

>>4422291
gamma is 22.4. You forgot to square the velocity.

>>4422307
My bad.

Make that 0.04yr then.

>>4422259
No they're not. I can't prove it.. yet. However soon enough the whole the faster you are traveling the slower time passes for you is bullshit. Btw the theory of relativity isn't wrong. If you are traveling away from a clock at half the speed of light, each second on the clock would appear (to you) to take 2 seconds to pass, but then you look at your wrist watch each second would pass as a normal second.

>>4422331

You're forgetting Lorentz contraction.
Otherwise yes, you're right.