Discussion in 'Science and Technology' started by Romulan_spy, Apr 18, 2013.
Exciting news from NASA:
2700 light years away... hum. Cool discoveries to be sure... I sure wich we could determin if there are planets around Alpha Centauri. A habitable planet there would be... well just the best thing ever in the history of everything!
If it had just been Barnard's star instead.
Even if there was a habitable planet at Alpha Centauri... only being 4.3 light years away, that's still an insane distance and beyond us right now. I seem to recall reading it would take over 150,000 years at a space shuttle's velocity to get there. We'd really have to be able to achieve at least 1/10th the speed of light before we could even begin considering sending ships out to other systems I would imagine.
At warp 4.5, we have a little more than 34 years to tighten our planetary border security against the hordes of industrial replicators coming from the planet to take our jobs away.
Hold on, my astroturf employer just called, we are actually happily letting those in, it is the green guys that we are worried about. Sorry for the mix-up.
At warp 4.5, we have a little more than 34 years to tighten our planetary border security. The Kepler-69 folks have been long known throughout the galaxy as lazy deviants who use sexual subversion to get everything for free from other species, and live off of your money and hard work. We must act before they all come knocking on our door.
Our imaginations fuel incredibly impressive technological feats to be realized in due time, but they also conjure up ideas that are just way too implausible for anything we're capable of in the next few generations or perhaps thousands of years if at all. The sad truth is that we're far, far away from where all the action is. The concentration of habitable worlds is closer to the center of the galaxy and we're out on the periphery well beyond plausible reach.
The basic fact is that eventually suns burn out and habitable worlds become uninhabitable. One day the Earth won't be able to sustain us. The only way to continue propagating is to leave it and venture to another planet that can sustain human life for another billion years. And the only way I see that ever happening is via a VERY long distance interstellar journey on a self-sustaining spacecraft with a select group of humans cryogenically preserved for the multi-thousand year voyage. Anything else is just pure fantasy.
Let's not get ahead of ourselves... it would be more accurate to say "NASA finds more planets that could potentially be of the right type to support life, as far as we can tell at the moment." The significance of the latest announcements isn't that we can be sure these specific planets are habitable, but that the confirmation that planets of this size do exist in stellar habitable zones strengthens the case that there could be many habitable planets out there, whether or not these specific ones are among them.
We discovered a probable planet around Alpha Centauri B last year:
And the search for more continues, though it will probably require technology that won't be in use for a few years yet. As the Wikipedia article says, astronomers at Alpha Centauri B couldn't discover Earth using the kind of equipment we currently have.
Actually we're more in the middle of the galactic disk than the periphery. The percentage of stars that could support habitable planets is probably lower the closer you get to the center due to the greater threat from supernovae and other astronomical hazards, but the numerical density of stars closer in is sufficiently greater that the lower percentage still probably adds up to a greater number of habitable worlds. But that is, of course, just our current best estimate, which could be revised upon further discoveries. Words like "truth" are too absolutist for a subject we know so little about.
Most of the images I've seen from university sanctioned sources puts us more towards the periphery than the center, like here: University of Alaska. The truth is that the further we are away from the higher density of solar systems with planetary bodies, the lower our chances of being within reach of habitable worlds. Simple matter of odds. Believe me, I wish we were closer...
The galactic stellar disk is considered to have a radius of c. 50,000 light years. The Sun is about 27,000 ly from the center. So we're just beyond halfway out. That's what I mean by "the middle of the galactic disk," which was a poor choice of words. I tend to think of the stellar disk (not counting the central bulge) as consisting of three concentric regions, inner, middle, and outer. We're in the middle region, which is often called the "Galactic Habitable Zone" but which I think could more properly be called the temperate zone. As stated, it's likely to have a higher percentage of life-bearing planets than the inner region (with the hazards I mentioned above) or the outer one (where the stellar metallicity is lower and planets may be less common), but again, the number of stars in the inner region is great enough that there would probably still be more habitable worlds there.
Being far, far away from where all the action is might very well be the reason life has lasted on this planet for so long.
I guess I'm showing my age again--I thought we were closer to the edge...oh well.
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