Re: Travelling the Stars

Michael Lorrey (
Tue, 08 Dec 1998 17:36:12 -0500

Terry Donaghe wrote:

> I recently finished "The Engines of Creation" and I was thinking about
> some of the things that Drexler said. He seemed convinced that
> humanity won't find a way to circumvent the speed of light. One of
> the things that always bugged me about travelling sub-light speeds was
> the incredible time it takes to travel between stars.
> However, if we find a way to indefinitely extend our lifespans this
> means we could live a really, really long time. Further, if we find a
> way to make our bodies much less fragile (through uploading or just
> reengineering our bodies with nano), then we could potentially live
> for millions of years.
> I'm wondering if a human were to have lived a few hundred thousand
> years, how much of a pain would it be to travel between the stars at
> sub-light speeds. Would 5 or 10 years or even a thousand even be a
> significant amount of time for a being who has lived many many times
> that?

If our internal clocks are controllable such that we can slow our perception of time down, then things can work. Also remember that sublight speeds are not a limit on interstellar travel. They make it actually rather easy for anyone with sufficient energy technology. As long as you can accelerate constantly for a year or so at 1 G, then you can reach the .95-.99 C speed range where time really starts to slow down significantly, so even thousand or million light year journeys can take a short amount of subjective time for the traveler. The only problem is the dilation will tend to separate the individual traveler from others who are not traveling in a similar causal frame. The idea of outliving family and freinds who stay behind by hundreds or thousands of years does not seem to appeal to most people, so they think that its not practicable as a means of space travel.

For an extropian, though, it should go in stride. If you plan on being immortal and being with people who are immortal, then the prospect of being many years out of step with others is not so daunting.

> In other words, 500,000 years from now when I decide to travel to Star
> X which is 1500 light years away, taking me, let's say 3000 years to
> get to (conservatively of course), will I bother getting bored? 3000
> years is .06% of 500,000 years. I'm about 30 years old now and .06%
> of my life span is .18 years or a little more than two months -
> assuming my math is right - is it?

Accelerating at a constant 1 g to the halfway point, and decellerating at 1g the rest of the way to the destination will allow you to make the journey in somewhere around ten years or less.

> My question is, would 3,000 years feel like just a couple of months to
> a being more than a half-million years old? Is there any way to know?

I think that we all still experience time at the same rate no matter how much is behind or ahead of us. Learning to slow down our own perception of time, either by a metabolic shift or by changing electronic clocks if we are uploaded, is the key to such a change as you describe. Notice that small children who have fast metabolisms think 10 minutes is forever, but ten minutes tends to zip right by a senior citizen....

Mike Lorrey