BASIC DATA FROM 'TIME DILATION' PAGE -
100 miles/sec = a factor of 0.999999711 Virtually no time dilation.
100,000 miles/sec = 0.710949243 (or 29% slower) ie 100 years would go by in 71 years on a space ship.
150,000 miles/sec = 0.349635796 (or nearly 65% slower) ie 100 years would be nearly 35 years on ship.
185,000 miles/sec = 0.010723783 (or over 99% slower) ie 100 years would go by in 361 days.
185,999 mles/sec (just 1 mile per sec below the speed of light) means that 1 year would go by on Earth whilst the ship would only have been flying for 5.65 minutes.
AND THIS IS THE PROBLEM !
If we fly at the speed of light for 4.3 years and visit Alpha Proxima, and if the equation of 1-(V²/C²) is valid, then by the time we got there 400,014 years would have gone by on the Earth (and for that matter everywhere else outside of the ship - including the star we were going to!)
If this theory holds true, then whoever is on the ship would effectively be LOST IN TIME. (A cue for a book title if ever I saw one!)
So speed alone is not the answer, in fact the faster we go the worse it is. This brings me back to my first statement - "Are we stuck in this solar system"? If we go slow we'll never get there, if we could go fast then we lose ourselves in time.
I still believe that we are being visited by other intelligences and that one day we will be out there with them, but right at this moment my beliefs are being severely challenged by my recent calculations. I know we are working on 'Warp Fields' and other sciences that may well overcome these problems, perhaps if any of you would care to contribute your thoughts I will be glad to put your theories on this site.