“If time travel were ever possible I suspect it would be a one way trip forward.”
Yes I’ve heard that this is what scientists think might be possible (what’s with the Michigan guys I don’t know, I just hope we’re not paying for it). I said that here once on a similar thread and another Freeper pointed out that we’re time traveling to the future RIGHT NOW, only slowly!
Something I picked up about the time dilation effect about Voyager 1.
>>According to Wikipedia, the Voyager 1 spacecraft launched on September 5, 1977 and has been operating for 35 years as of 2013 and is travelling at 3.595 AU per year. To get a rough estimate on how much of a special relativistic time dilation the spacecraft has experienced let’s assume it traveled at that speed for the full 35 years (in actuality it would have been faster earlier in the flight but the speed varied up and down during all the planetary flybys).
So assuming the speed of the Voyager 1 was 3.595 AU per year for the entire 35 years, the Voyager 1 clock would have been slower by 1.8 seconds compared to a clock on Earth (see (35 years)(1-1/sqrt(1-(3.595 AU per year)^2/c^2)) ) - not a very significant effect.
However there is another effect that makes a clock on the voyager run faster - general relativity. According to general relativity, a clock that is deeper in a gravity well will run slower than a clock that is further away from the gravity well. This is the gravitational time dilation effect.
This effect would make a clock on the Earth (in the sun’s gravity well) run slower than the clock on the Voyager 1. To get a rough estimate of the effect, assume the Voyager has been at it’s current distance of approximately 125 AU for all 35 years. With that assumption, the Voyager 1 clock would be faster by 11 seconds compared to a clock on Earth (see (35 years)*((1 - 2*G*(mass of sun)/((1 AU)*c^2))^0.5-(1 - 2*G*(mass of sun)/((125 AU)*c^2))^0.5) )
So general relativity makes the clock on Voyager 1 run faster by 11 seconds but special relativity makes it run slower by 1.8 seconds - all compare to a clock on Earth.
Frank Heile, PhD in Physics from Stanford University then career in SW Eng.