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.
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.
That's considering special relativity only; general relativity allows an energy density field lower than vacuum to expand and contract spacetime around a region (the Alcubierre metric), and it is possible the Casimir vacuum between two parallel conducting plates might fulfill this condition. There are experiments in progress to detect the Alcubierre metric, very open question.
As a second reason to point out FTL is not only possible but happening now, there are galaxies moving away from us faster than light speed and more and more galaxies join that number all the time.