How Civilizations Can Spread Across a Galaxy

New submitter kanweg writes: If you look at the Milky Way at night, it appears not much is changing. But over time, stars get closer and further to each other. Coryn Bailer-Jones, an astrophysicist at Germany's Max Planck Institute for Astronomy in Heidelberg, found that of 14 stars coming within three light-years of Earth, the closest encounter is likely to be HIP 85605, which now lies some 16 light years away in the constellation of Hercules. It will get a close as the Oort cloud.

This could be a (very long-term) method for human or alien civilizations to practice star hopping. Why travel 16 light-years through space when you can just wait until a star with a suitable planet gets close enough that you only have to cover the last stretch with an artificial spaceship? Take your time for a thoughtful response; it will take another 250,000 to 470,000 year before the close encounter.

Comments

Re:250,000 - 470,000 years to go . . .

[DavenH]

It won't; you must be thinking 250 - 470 million years.

Re:"Take your time for a thoughtful response"

[tnk1]

Sort of.

Yes, if you assume that we'll be accelerating in all cases to .999c or something like that, then you're probably right, it doesn't matter as much.

However, if you are only capable of making it to .5c or .8c, safely, then it could make all the difference in the world.

At those lower velocities, the time dilation is not really all that much, and you'd not only have a trip that is longer, but the observer would also be experiencing a longer relative trip due to dilation being much less pronounced below .9c. The Lorentz factor at .5c is only 1.155. It only gets to 2 at .866c. Due to relativistic effects, our ability to accelerate to and then to maintain safe flight (such as your ship not being annihilated by hitting small particles of matter) at the higher velocities is very challenging, so assuming that relativistic time dilation can be counted on to even out the logistical problem is probably not warranted.

That said, if we have to wait 400,000 years for the "quick" jump to open up, I imagine we would have made the "long" trip thousands of times over by then. That interval is minuscule in geologic time, but an eternity compared to our current rate of technological advancement. (Assuming our present rate of advancement doesn't come to a grinding halt, of course.)

3 stars come within 3.5 lightyears in 60K years

[rubycodez]

no need to wait that long, 3 other stars in the next 60,000 years will come less than 4 lightyears away

http://simple.wikipedia.org/wi...

note how alpha and proximy centauri do the Elvis thing and leave the building from 10,000 AD onward

I think you misunderstood

[Giant Electronic Bra]

HIP 85605 will come within 8,000 AU of the Sun, still quite a distance, but VASTLY less than 3 light years. The blurb was also incorrect, this close pass will be in about 40k years, not 250k or more as stated (though perhaps this is a difference in sources, I don't know). 8,000 AU is something we could probably bridge with some advanced tech. For scale Voyager 1 is now at approximately 200 AU after 36 years of travel time, meaning it will take just shy of 2,000 years to reach this distance. It is certainly feasible to build a larger craft and fly it at 50x this speed using say fusion power, still only a very tiny fraction of C but yielding a trip time on the scale of a human lifetime. A little beyond our current engineering, but something similar to Daedelus, for instance, would suffice.

So, the idea isn't crazy. Its not that big a stretch of the imagination to think that true interstellar travel in the classic sense is simply infeasible. In fact it really is fairly difficult to imagine from an engineering perspective, there are technical issues so vast that they may well be insoluble, or only solvable by making compromises that are just not acceptable or limit such travel to very infrequent probes or something. That would leave close approaches as the single exception.