One
qualitative point which might bear mentioning is that the popular description of the
speed of light as a 'universal
speed limit' is extremely prone to misinterpretation.
Consider that you are planning a trip, and know that you must cover 100
miles of open highway to reach your destination. You know that the speed limit is 100 mph. . . To make this seem more like a '
natural law' than a human one, let us say that the
fiendishly legislative powers that be have required cars to be installed with a device that triggers a massive
implosion if you exceed the posted speed limit. Assuming that you cannot get around the device, then you know that it is impossible that you will arrive at your destination in less then one hour.
Unlike this hypothetical box of lethal over-regulation,
the theory of special relativity imposes no theoretical constraints on the time it takes for you to cover any distance... from your perspective.
This is because one of the central features of the special theory is that perception of 'time' is not an absolute, but depends on a specified frame of reference. This is presumably well covered in
Special Relativity.. if not, go to the source and try the eminently readable
Relativity: The Special and General Theories by
A. Einstein.
As a brief example: Most people with coffee table knowledge of
relativity are aware of the
anecdotal example in which one of two brothers leaves the earth, travels in a rocket at relativistic velocities, then returns to find that whereas he has aged only days, his brother has aged years. I created this node because a great many people familiar with that anecdote don't seem to have made the leap to realizing that relativity does not impose limits on how long it takes for a person to travel between point A and point B... it simply defines a series of time and distance dilations between frames of reference that are at motion with respect to one another…
So, whereas relativity imposes limits on '
social' activities, such as how fast two people can communicate with one another, and how long it takes someone else to get from one place to another from your perspective, it affects in no way your own
personal mobility.
The restrictions on your own travel are practical ones, such as fuel and the ability to withstand acceleration. If you could accelerate at the modest rate of 1g for an extended period of time, you could reach
alpha centauri in weeks, and exit the galaxy within months.