Naked Science Forum
Non Life Sciences => Physics, Astronomy & Cosmology => Topic started by: Joe L. Ogan on 21/07/2012 18:20:23
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The sun has lived about a 1/2 life. What will mankind do when the sun dies? The sun will expand to enormous size and will burn up everything that exists on earth. It has been estimated that about 300 plamets exist that may be capable of supporting life. Will mankind arrange to move to one or more of these planets? The first to go will probably be volunteers. Later it will probably be impossible for most people to go. What will be the selection process? It will undoubtedly be young people capableof reproducing. Will it be based on intelligence? Thanks for comments. Joe Ogan
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So far ahead Joe that we are being arrogant as a species to even consider that humans - homo sapiens - will still exist in a recognizable or taxonomical sense. A few thousand years ago my ancestors were constructing stonehenge as an astronomical instrument - now we have the Hubble Space Telescope. The speed of progression is so huge, the chances of us wiping ourselves out so high, that to speculate is pointless
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Well, you are probably right. Never the less, one can not keep from speculating. I
expect that many people are thinking about the same problem with the intent of
avoidimg termination of the human race. Thanks for comments. Joe L. Ogan
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I'd be more worried about the universe expanding. Even if we escape the sun, we'll eventually be torn apart by the expansion of the universe:
It is probably worth thinking about colonizing other planets--not because of the sun, but because there are other disasters (natural or man-made) which might befall the earth in the time scale of tens or hundreds of thousands of years, rather than billions.
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Whatever may cause the death of planet Earth, I have to agree with Imatfaal, I think it highly unlikely that Man will still exist then. If we have managed to blow ourselves to kingdom come, it may be that there will be no life on Earth which will even consider the eventuality.
But, whatever, I somehow think that travel to systems 4, 5, 10 or more light years away, may never be possible. We are here, and here we must stay, come what may.
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That does appear a llittle pessimistick. Thanks for comments. Joe L. Ogan
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I'm not sure the universe will ever expand to the point where it would tear the Milky Way apart. Nonetheless, that is a long time in the future. So, for now we'll have to consider the 200 to 400 billion stars in the Milky Way as the limit for what will be home for terrestrial life.
As mentioned, the expected lifespan of our sun, 4 billion more years is an awfully long time.
I'm hoping that humanity will never see anything rivalling WWI or WWII again, nor a nuclear holocaust. Yet, Earth will likely have additional glacial periods, and warmer periods. Some previously plentiful resources will become scarce. Food, energy, and resource requirements could lead to a war to end all wars. Or, perhaps, we'll have a human/cyborg war to define the place of our own creations. I hope we can find a path to peace, but there will be huge pressures to break the peace. And, even in war, someone, somewhere will survive.
Anyway, it is my belief that over the next century, or perhaps few centuries we will rapidly (relatively speaking) colonize the moon, Venus, Mars, and some of Jupiter's moons. But, transportation may not be sufficient to allow a person to go for a holiday jaunt to Saturn.
I believe that we will slowly begin to spread to neighboring stars, but the trip won't be easy, either sending generational ships, or egg & seed ships.
If humanity and our progeny survives, and the sun's temperature slowly rises over the next few billion years, we'll likely be able to create planet scale heat shields (and perhaps redirect some of the solar energy to the poles and other climate modification).
Unfortunately, Earth may be torched or lost if the sun enters a red giant phase. And, it may not be physically possible to move billions of people to the outer planets, especially if they already are colonized and support massive populations. It will also be impractical for the earth population to migrate to other nearby stars (which may already be populated).
But, somewhere in our solar system, humanity or its progeny might survive the red giant phase. Then as the sun shrinks back to a white dwarf, there will be a movement back inward, as well as a higher dependence on nuclear, and fusion, and perhaps antimatter power. Could we build a Dyson's Sphere around a white dwarf?
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That does appear a llittle pessimistick.
Maybe, but I think it more as 'realistic'.
Consider, we would need to find a planet not too dissimilar to Earth in its physical properties (size, gravity, temperature, UV shield, rate of spin, seasons, air pressure etc.), its chemical content (including its atmospheric content and dissolved matter in its waters), biological state and capability and where it is in its evolutionary time scale. The star around which it orbits must also be not too dissimilar to our Sun.
We may be able to adapt ourselves to a 22.7 hour day and a 401 day year, but if the plants we need to survive do not exist on that planet, seeds taken from Earth may result in crops unable to cope with such an environmental difference.
But before we can consider that, where is this new Eden going to be? We will never be able to travel faster than the speed of light and probably will never get to anything close to it. So a planet just 100 light years away might take us 1000 years to get there, in which time, who knows if natures silver seed would have survived the journey or if conditions at our destination might have changed.
The Universe has had more than 13 billion years to evolve super intelligent life. Thus far, if it has managed to do so, they have not been able to find us (I utterly disregard the claims of a few self proclaimed 'ET abductees') and I would think that any chance of bumping in to ET is more likely to be at their instigation, rather than ours. That suggests to me, that ET (assuming he exists, and I don't see why not) is too far away to have even noticed us. That, in turn, suggests to me, that planets capable of supporting life, many though there may well be, are still in such a minority and so far apart, as to be untouchable by their neighbours. But I am willing to accept that I could be wrong on that point.
As for 'wormholes' connecting planets, forget it, pure fantasy. Even if it were possible, we still have the problem of getting to that planet to construct the other end of the wormhole in the first place.
Just one other (not so) minor point, Man has treated planet Earth with such disregard and disdain, I should hate to think that at some stage we might get our greedy, grasping, grubby little paws on some distant paradise and ruin it. We've buggered up one planet, isn't that enough?
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Joe, have you read Olaf Stapledon?
If not, it's a slow read the first sixty pages or so, but his imagination was immense.
It's an old book but?
I don't find it old at all.
Last And First Men. (http://gutenberg.net.au/ebooks06/0601101h.html)
Those Aussies have taste :)