Do I arrive before a light-speed train if I jump off the front?

In summary, the question is asking if a person traveling on a train at the speed of light will arrive at their destination before the train. The answer is yes, but only if the train is traveling near the speed of light. However, in the context of relativity, it is impossible for an object to travel at the speed of light.
  • #1
Sweep
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I'm having a lot of trouble wrapping my mind around this... It seems there are some similar questions in this forum, but I can't tell if the answers can apply to my question... I'm sorry if this is an extra post:

I am traveling in a vacuum, on a train, at the speed of light, from planet A to planet B. I go to the front of the train, get outside, and jump forward/propel myself toward planet B. Do I arrive at planet B first?

I understand, that I am not going faster than the speed of light relative to the train, but relative to an observer on planet B, who arrives first? If I arrive first, does that mean I traveled from planet A to planet B faster than light?

Thanks in advance.

-Sweep
 
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  • #2
Sweep said:
I am traveling in a vacuum, on a train, at the speed of light, from planet A to planet B. I go to the front of the train, get outside, and jump forward/propel myself toward planet B. Do I arrive at planet B first?

If the train is traveling near the speed of light, then yes, you get there first. (Relative to the planets you'd be traveling faster than the train, but still less than the speed of light no matter how hard you jumped.)

If the train is traveling at the speed of light, then you're describing something that's fundamentally impossible and nonsensical in the context of relativity.
 
  • #3
You cannot go on a train at the speed of light.

Let's say you were on a train at c - 1 m/s relative to Earth and you jumped off the train at 10 m/s relative to the train. Then you would arrive before the train, but after light from your jump. According to the relativistic velocity addition formula you would be traveling at c - 0.99999993 m/s relative to earth.

EDIT: like wle said.
 
  • #4
No you will not. Speed of light is a barrier. If you somehow increase your kinetic energy, your mass will increase instead of your velocity. So even if you jump off from the train traveling at speed of light, light will surely reach planet B before you because of your increase in moment of inertia due to increase in your mass.
 
  • #5
Thank you all for the quick responses! Really appreciated. I understand it's nonsensical to think that you can be in a train in space traveling at the speed of light, but wasn't really sure of a better way to explain the answer I was looking for. Thanks for looking past that and providing great answers.
 

FAQ: Do I arrive before a light-speed train if I jump off the front?

How does the speed of light affect my jumping off a light-speed train?

The speed of light is a constant in the universe and cannot be surpassed by any object or person. Therefore, jumping off a light-speed train would not change your relative position to the train or the speed at which you are traveling.

Would jumping off the front of a light-speed train make me arrive at my destination faster?

No, jumping off the front of a light-speed train would not affect the speed at which you are traveling or the time it takes to reach your destination. The train is already traveling at the speed of light, so any movement within the train would not change your arrival time.

Can I jump off the front of a light-speed train and travel faster than the speed of light?

No, it is not possible for any object to travel faster than the speed of light. This is a fundamental law of physics and cannot be broken, even by jumping off a light-speed train.

Will jumping off the front of a light-speed train change my relative position to the train?

No, jumping off the front of a light-speed train would not change your relative position to the train. As the train is already traveling at the speed of light, any movement within the train would not change your position or the speed at which you are traveling.

Is it possible to jump off a light-speed train while it is in motion?

No, it is not possible to jump off a light-speed train while it is in motion. As the train is traveling at the speed of light, any attempt to jump off would be impossible due to the immense amount of energy and force required to do so.

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