there was a young lady of wight

who traveled much faster than light

she departed one day

In a relative way

and arrived on the previous night

having trouble wrapping me head around going backwards in time. If two events, A and B, are so far away a rocket must travel the speed of light to get from event A to event B, then two observers moving at different speeds can disagree on whether even A occured before B, or event B occured before A.

Relevance
• Anonymous
8 years ago

The time dilation effect is "relative" to the observer on earth. Your ship would appear to have its passage of time slow down to an "earth bound" observer. If you left with one of two synchronized stopwatches, when you returned to earth, both devices would show the EXACT SAME passage of time REGARDLESS of the speeds your ship obtained.

AND the inverse is true... if you are on the ship, looking at earth, the clocks on EARTH appear to slow or stand still... there is no way to "go backward" in time... its an OBSERVATION effect only..... Time is an OBJECTIVE reality, not a SUBJECTIVE local phenomenon.

think of a laser beamed away into space and your ship flying along directly next to it... once a second, the laser pulses for 1/100th of a second twice as bright.... a "tick" if you will, at one second intervals... you can observe this "tick" cause you are flying next to the beam... in essence, this "pulse" of extra brightness is traveling along the beam... at the speed of light.... as your ship gets closer and closer to the speed of light, the slower and slower these "pulses" or ticks catch up to and pass you... eventually, when you reach light speed, you can travel "alongside" one particular pulse. Does this mean time has stopped? for you? on earth? or just "relative" to your ship and this one particular local phenomenon?

HERE'S THE REALLY IMPORTANT BIT.... if you go just a little bit faster, wont you creep up on and pass previous ticks? does this mean you are traveling back in time? no... because along the total length of this incredibly long laser beam, all the ticks are still moving, at the speed of light, new ones being produced back on earth the whole time. You cant "get back to earth" with out turning around and PASSING by all those other seconds that have been added to the beam behind you... you have NOT "gone backwards" any... you just caught up to and over took the pace with the passing "ticks" of the clock.... the closer you got to "pacing" alongside a tick, the more you APPEARED to slow down to the OBSERVERS back on earth. Even if you could MAGICALLY teleport back to Earth, the time would have passed. Theres no way around it.