Solving The Constant Acceleration Problem In Scifi

[Krulle]

I am not trying to put too fine of a point on this, but unlimited acceleration is theoretically possible in the real universe.  While a vessel could never achieve 100% of lightspeed, it is theoretically possible to keep "adding nines" indefinitely to the ship's velocity, accelerating from 0.9c, through 0.999c, through 0.999999999999999999999999999999999999999999999999999999999999...c, and so forth.

That's a variant of Zeno's paradoxon of "Dichotomy Paradox".
You'll have an infinite amount of steps to make to get to the target. (Each step being half of the difference between c and your speed, the target being c.)

One oddity about lightspeed: To an outside observer, a photon would take all of eternity to transit the entire breadth of the universe; but a massless observer riding on the photon would perceive the trip to happen instantaneously.

This assumes, of course, that the first observer was capable of watching the photon for all eternity, and that the second observer was capable of riding on a single photon.

That's time dilation. Once you've reached the speed of light, your time crawls so slowly, that your time will basically never pass until some event slows you down.

That's also why constant acceleration will not bring you beyond speed of light, as your time crawled to a stop, and you actually do not accelerate anymore (as seen by outside observers). But since your time is so slow, you still feel accelerated.
Now constant acceleration as seen by the theoretical outside observer is s.th. else. Because that WILL bring you beyond c pretty fast. But your constant acceleration will look to him like you=re reducing your acceleration slowly until your acceleration is 0 when you reach c.

[icekatze]

hi hi

"One cannot ever reach light speed. One cannot even approach light speed. No matter how much one accelerates, a ray of light will always be able to travel away from them at the speed of light, as though the observer were standing still."