tag:blogger.com,1999:blog-38085367.post8427510020613229978..comments2024-03-19T09:06:21.507-04:00Comments on Irtiqa: Will humans be going to planets around other stars? Salman Hameedhttp://www.blogger.com/profile/04327330113822656571noreply@blogger.comBlogger3125tag:blogger.com,1999:blog-38085367.post-38084108334285882202012-12-04T15:52:54.164-05:002012-12-04T15:52:54.164-05:00850Thanks for thoughtful reply. It's fascinat...850Thanks for thoughtful reply. It's fascinating how we can agree on the facts-so-far but have a different sense of what's plausible in the yet-to-be. Time will indeed tell. Add FTL travel to my list of things I'd love to be wrong about but don't think I am: accepting the scientific consensus on climate change is at the top . . . LarryLarry GIlmanhttp://theotherjournal.com/s-word/noreply@blogger.comtag:blogger.com,1999:blog-38085367.post-36036490427859567412012-12-02T20:53:28.681-05:002012-12-02T20:53:28.681-05:00Larry,
Thanks for a detailed reply as well as the...Larry,<br /><br />Thanks for a detailed reply as well as the pdf link. On one level, I agree with everything you have said here. Interestingly, I'm preparing for my astrobiology class tomorrow, and we are talking about the ethics of Mars exploration if we find microbes there. Of course, that also brings up the prospects of terraforming there. I don't think we disagree much on there.<br /><br />However, I think our difference will be more philosophical and what we learn from history. Obviously, interstellar travel is one of the hardest technological problems. It is hardest <i>because</i> it appears to be limited by some of the fundamental physics we understand today. My attitude regarding that is that we will figure out a way around it. Modern physics has been around for a little over a century and the pace of information is exponential at present. Physicists have been able to slow the speed of light to a crawl in certain media (of course, other things in that medium will have to be even slower than that). May be this kind of manipulation will get us around the speed of light limit. Or may be it will come from working on biological clocks and slowing them down in a way that a 40,000 year travel will seem like 20 years. The point is that, I look at the history of science and <i>believe</i> that humans will find a way around it. You look at it and <i>believe</i> that we won't. I guess only time will tell... :)Salman Hameedhttps://www.blogger.com/profile/04327330113822656571noreply@blogger.comtag:blogger.com,1999:blog-38085367.post-68506404433911572322012-12-02T14:27:34.876-05:002012-12-02T14:27:34.876-05:00First, thanks for your excellent blog.
It’s eas...First, thanks for your excellent blog. <br /><br />It’s easy to feel that something we’ve witnessed hundreds of times, even though just as a special effect, must somehow be practicable: e.g., faster-than-light spaceship travel. Yet this sort of felt plausibility has nothing to do with a thing's inherent possibility. Relativity, which forbids the acceleration of objects to speeds equal to or greater than that of light, has been confirmed to ever-greater precision by a huge variety of experiments for over a century now. It works. It works to the limit, so far, of our ability to measure. And while suggestive possibilities (e.g., time travel) can be pulled from the hat of extreme speculative physics, such tricks, even if the untested theories are is right, always have some extreme inconvenience attached to them, as in requiring more energy than there is the universe or squeezing travelers through the event horizon of a black hole. Our funkiest real-world stunts, like entangled-photon encryption, take place at the particle level: here in the mesoscale, there ain’t no free lunch. The Universe, on this level, is stubbornly well-behaved. The pattern of physics progress so far has been to modify our older ideas at the edge zones, at the micro and macro, not to make miracles possible. No antigravity, FTL, timeslip, matter transmission. Einstein does not replace Newton for automobiles or Apollo spacecraft, but corrects him in far-flung decimal places: and Simultaneity (or whatever comes next) is almost certainly not going to replace Newton _or_ Einstein in the mesocale with something magical, but will correct them in an even more far-flung decimal places. No warp 8, Mr. Sulu, now or ever.<br /><br />Einstein already allows us to travel to Centauri and back in a single day of shipboard time -- if we are allowed to start with a Jupiter or two, and an equal amount of antimatter, as propellant for our gallant little craft, and as long as we don't mind being crushed by the acceleration. These are the kinds of inconvenience that the real world, so far as we have any real evidence on the question, always presents us with.<br /><br />We are trained in bravado about the power of technological progress: “They said it couldn’t be done!” but now it has been done, etc. (This narrative always omits all the things they said couldn’t be done that, as it turned out, couldn’t be done.) But faster-than-light travel is not a technological problem: it’s a nature-of-reality problem. Its intractability is of a different order.<br /><br />And even purely technological problems can be insurmountable in practice. For instance, there is no physics-theoretical reason why we should not control the weather or terraform Mars -- it’s just (just!) a matter of moving vast quantities of matter and energy about in certain precise ways -- and it's an article of faith for many human spaceflight enthusiasts now that the latter is obviously feasible, just a matter of determination and reformed budget priorities. In the meantime, in the real world, we can’t even stop ourselves from Venusforming Earth, and our civilization will be lucky to live long enough to confront the practical impossibility of terraforming Mars.<br /><br />By the way, any form of planetary colonization fantasy -- not just interstellar travel -- has dimensions of religiosity, of "a fantasy, of power, transcendence and a kind of species immortality". Just look at the entire literature of the subject: its fiction, its advocacy, its rhetoric, tenor, claims about manifest destiny of the race, even apotheosis. I’ve published some of my skepticism about the space colonization movement, speaking as both a lifelong space enthusiast and religious person, here: http://www.larrygilman.net/gilman_little_house.pdf<br /><br /><br />Best,<br /><br />LarryLarry Gilmanhttp://theotherjournal.com/s-word/noreply@blogger.com