Stephen Hawking says humanity must go to the stars. Is he right?

Great Debates
41

[QUOTE=msmith537]
Well, as someone who actually understands engineering and economics, I can’t comprehend how anyone can imagine that we can even think about colonizing other planets. Any mining, any terraforming, any colonizing, anything that you can think of doing on another planet in our solar system can be done cheaper, safer and more effectively here on earth. Mine asteroids? Cheaper and safer to mine deeper right here on earth. If we get to the point where we can terraform a planet, we should just go about fixing up this one.

In order to do anything “interplanetary” would require inventing completely different propulsion systems that are cheaper, more powerful and more efficient than what we have now by orders of magnitude. (and don’t bring up the stupid space elevator).
[/QUOTE]

I fancy myself a modest understander of engineering and economics, though obviously I’m not as profound and developed a thinker as yourself. I just don’t see how any of what you said matters. Nobody is saying it won’t be initially expensive. Nobody is saying that we can’t do it cheaper here on Earth. But those same arguments could have been made 500 years ago in favor of staying in Europe.

Initial cost = a lot
Potential rewards = ~infinite

You can go ahead and sit comfortably here on Earth. I probably will, too. But there will be people with vision and, dare I say it, balls, who will go out and make it happen regardless of how many times you naysayers say nay.

42

I’d also like to clarify that I’m all fired up for the general idea of space travel. But let’s go ahead and explore this solar system first before we start making plans to eke out a living in the Andromeda galaxy.

43

[QUOTE=xtisme]
I’ve showed you a few technologies that are in their infancies…and yet, you can’t conceive of technologies that COULD allow for suspension of animation for decades or centuries? Not even imagine them? What can I say…
[/QUOTE]
The problem here is more than just “slowing down biological processes”; you’re going to have to suspend biological processes entirely for an indefinite period without permitting protein catabolism of significant cellular structures (see cryptobiosis). While this condition can be found in the larval states of some more primitive organisms (the most complex I can think of would be brine shrimp), no mammal does anything like this for an extended period of time. To affect such a condition would probably require control on the molecular level to prevent natural necrosis and breakdown of tissue.

Long-duration somnolence (like the scientists in 2001: A Space Odyssey) is more plausible, but hardly sufficient for decades or centuries. It could be used, I suppose, to reduce provision and environment requirements for an interplanetary mission, but I hope that propulsion technology is sufficiently advanced by the time we prepare to do such a thing that we don’t have such a narrow margin. (It might be useful for other reasons, such as in 2001, suspending the nonessential crew through the boredom of a multi-month transit, but again this doesn’t equate to the length of an interstellar journey, nor can we expect the kind of significant retardation of aging processes that would be necessary to keep the crew alive and healthy until then.)

I have to agree with Mangetout, that manned interstellar travel–much less colonization of extrasolar worlds–would require an essential rewriting, or at least loophole, of the current understanding of physics and any concievable technology. I have some small amount of optimism for this; “hyperspace” (in the scifi usage of the term) may be strictly a fantasy, but so were “heat rays” to H.G. Wells. But such technologies are, at this point, speculative to the point of absurdity for any practical planning. My feeling is that we’re likely to explore and “colonize” extrasolar space via proxy; with progressively sophisticated (to the point of emulating life itself) artificial probes.

Stranger

44

[QUOTE=xtisme]
Sure I could…and I’d probably be as accurate as that guy watching a Union observation balloon rise up and attempting to describe to the skeptic trans-continential flight.

Technologies we’d need to cross, say, 20 light years. Well, we’d need some biological advances as I’ve said…something that could suspend animation for centuries and revive the passengers at the other end fully functional. Other than that, some fairly decent advances in propulsion systems. Maybe nuclear or fusion (so we’d need fusion obviously too :)). Something getting us in the ball park…say .1C. The trip would then take centuries, instead of thousands of years to accomplish. Barring the hibernation thing, I suppose we could use generation ships…self contained bio-ships where the crew basically lives normal lives but in transit to the target world/solar system. With some improvements in human longevity and those propulsion advances, its possible someday.
[/QUOTE]

So it’s possible, somehow, but you’re not sure how. So how are you sure it’s possible?

45

[QUOTE=DrCube]
I’d also like to clarify that I’m all fired up for the general idea of space travel. But let’s go ahead and explore this solar system first before we start making plans to eke out a living in the Andromeda galaxy.
[/QUOTE]

I was just going to say that. If you read really old articles or stories predicting the future, it is amazing how they over-estimated the power of the current technology, ignored the problems with it, and missed new technologies that were actually invented. It seems pointless to talk about star travel until we get at least a century of experience in the solar system. We’d have multi-year missions down pretty solidly, and if we found asteroid mining economically feasible, there would be tremendous incentives to improve propulsion systems.

Remember that it took only 12 years from Sputnik to Apollo 11. In the 37 years since we’ve got … the shuttle? We haven’t cared enough to even try to do it right.

Compute some time the theoretical energy required to get 200 pounds to orbit - and compute the energy required for the Shuttle to get it there. We’ve got a lot of engineering we can do without worrying about wormholes and hibernation.

If we’ve got provably self-sufficient space colonies, getting them to the stars requires only some sort of reasonable propulsion system and some set of people willing to go.

46

[QUOTE=Alessan]
We should go to space because that’s where everything is. And by everthing, I mean everything. Remember how 0.999…9=1? Well, 0.999…9 of all matter in the universe isn’t on Earth. Our planet is so miniscule that statistically, it doesn’t even exist.
[/QUOTE]

This is incorrect. It’s not

.99999…9 = 1.

It is

.99999… = 1.

You need an infinite number of 9’s, otherwise you just have a regular terminating decimal number.

And the proportion of all matter not on Earth to all the matter in the Universe is modeled by the first number. That is, the ratio is approximated by .999…9256 (or whatever) with a large but finite number of 9’s. Specifically, it is not .99999… with an infinite number of 9’s. Therefore, the statement, “Our planet is so miniscule that statistically, it doesn’t even exist” is not true, since .000…0744% (or whatever) of the matter in the Universe is right here on planet Earth.

(Everyone else on this board corrects grammar. I do this.)

47

Its always really tempting to quote all those ‘they said X couldnt be done’ stories.

The thing is we dont tend to hear too much about all those times when X really couldnt be done. Where are all those flying space cars and moon colonies and jetpacks, atomic cars etc etc everyone was predicting so confidently not too many decades ago? Sometimes there really are engineering barriers to ideas that wont be too easily overcome, a check through old magazines show that an awful lot of ‘world of tomorrow’ things actually didnt turn up tomorrow. Sometimes progress really isnt as fast as we’re hoping it will be or doesnt go in quite the direction we thought it would.

Predicting progress in the future based on progress in the past isnt as reliable a thing as people are suggesting. We might get breakthroughs that make it all a lot more practical.

But we might not too.

Otara

48

I am basically with the people that say that many futurists are wildly optimistic dreamers when it comes to the future of space travel. It seemed to start the day that we launched our first satellite. The media and public fantasy immediately went from getting a little capsule to free-fall continually in Earth’s gravity to somehow allowing man to explore the far reaches of the solar system and beyond and even terraforming other celestial bodies at will. There are nearly, but not quite, an infinity of steps that need to be thought about and worked on beforehand. We can’t even figure out what to do about global-warming on our own planet let alone how to take a whole dead planet like Mars and create a hospitable environment out of nothing in anything that approaches a reasonable time-frame. The early manned rockets and the Space Shuttle were just engineering challenges. The kind of stuff that we are talking about here has large theoretical problems and there is no guarantee that all theoretical problems are solvable in this context.

It is a mistake to point to things like computers and lasers as an analogy to how space travel will progress if we apply ourselves. We see computers as huge successes looking backwards at what has been accomplished. Even up until the 1970’s and beyond, hardly anyone saw what the PC would become but that technology picked us because it was theoretically possible and the implications were massive. It is like picking stock. If you buy 100 different stocks, in 50 years, some will be huge successes and some won’t exist at all. You don’t get to pick which ones will be the successes. Saying that space travel will be one of the huge successes is trying to predict a single group of technologies out into the future and you can’t do that.

There were many, many technologies that people tried to project forward in past decades and many, if not most of them did not work out. We don’t all have jet-packs or flying cars or hypersonic (or even supersonic) passenger jets. Others like lasers came out of nowhere and filled in for the disappoints of the original predictions. Space travel has had extremely high expectation since at least the 60’s but it certainly has not been a shining success. Today, we can repeat what we have already done (like going to the moon in 15 years again) but we haven’t come up with much new except for better rovers and remote laboratories.

There are many theoretical problems with interstellar space travel that there might not be a solution to. One that has already been mentioned is human life-span and the likely impossibility of a return trip (at least not before everyone they know is long dead). The other is more simple but extremely hard to find a solution for. A spacecraft travelling at .5 or even .1 the speed of light will be destroyed when it hits even the smallest dust particle out there in space. Although specks of matter are relatively rare in interstellar space, the vast distances involved make it likely that such an encounter will occur regularly during such trips. That fact alone could explain why we aren’t being visited all the time by intelligent life.

49

We must be half siblings or something Otara

50

Doh missed Voyagers post - a much less wordy version too.

51

Considering the considerable damage we’ve done to this planet in such a breathtakingly short amount of time, cosmically speaking, maybe we should just leave the rest of the universe alone…

52

[QUOTE=Alessan]
We should go to space because that’s where everything is. And by everthing, I mean everything. Remember how 0.999…9=1? Well, 0.999…9 of all matter in the universe isn’t on Earth. Our planet is so miniscule that statistically, it doesn’t even exist.
[/QUOTE]

The known universe ought to provide plenty of room for expansion, to my way of thinking..

53

xtisme I do not see how hibernation can help for a truly long trip. I can see how it would help greatly in a trip to Jupiter or Saturn.
I cannot improve on what Stranger On A Train. Later tonight, I might try to dig up some better scientific articles are possible space flight. I would like to throw a few at **Stranger ** and hopefully find one that he will concede is at least plausible.

Shagnasty: just to nitpick, the Laser hardly came out of nowhere. It has been decades of long and steady improvement since before I was born. The applications proposed for Lasers have largely happened. Lasers proposals more closely resemble nanotube proposals than any other tech I can think of. Physicist knew what Lasers could do, they just had to keep working with the Engineers to make it happen. That is where we are with nanotubes in my opinion.

Jim

54

[QUOTE=Mangetout]
So it’s possible, somehow, but you’re not sure how. So how are you sure it’s possible?
[/QUOTE]

I’m sure its possible because I see the potential technologies already being explored and I don’t see any show stoppers. I can extrapolate from where we currently are and see how we COULD get where we are trying to go. Will it happen? Gods know. It COULD happen though. To me the biggest hurdle to overcome is simply to try…to get through all the nay sayers constantly saying we can’t do this or that, or that it will cost too much, or myriad other excuses that boil down to…don’t even try.

[QUOTE=Stranger On A Train]
The problem here is more than just “slowing down biological processes”; you’re going to have to suspend biological processes entirely for an indefinite period without permitting protein catabolism of significant cellular structures (see cryptobiosis). While this condition can be found in the larval states of some more primitive organisms (the most complex I can think of would be brine shrimp), no mammal does anything like this for an extended period of time. To affect such a condition would probably require control on the molecular level to prevent natural necrosis and breakdown of tissue.
[/QUOTE]

You are talking about a completely closed system…i.e. total suspension where no outside nutrients or outside energy are introduced and no metabolism at all is maintained. Perhaps that is impossible…though perhaps not too. But thats not the only solution to the problem. Let say that a method of hibernation was discovered where the patient could be kept essentially indefinitely in the state, and where the heart beat at, say, one beat an hour. The patient could be hooked up to IV or other machines that provide vital nutrients to them. This would certainly slow down the aging process quite a bit. Crews could even be rotated, with some in hibernation and others active.

Again, I see nothing thats a show stopper…nothing saying this is impossible, no physical laws broken. I see the technologies in their infancy that COULD lead in that direction…and I see the research trying to get it there.

[QUOTE=Stranger On A Train]
Long-duration somnolence (like the scientists in 2001: A Space Odyssey) is more plausible, but hardly sufficient for decades or centuries. It could be used, I suppose, to reduce provision and environment requirements for an interplanetary mission, but I hope that propulsion technology is sufficiently advanced by the time we prepare to do such a thing that we don’t have such a narrow margin. (It might be useful for other reasons, such as in 2001, suspending the nonessential crew through the boredom of a multi-month transit, but again this doesn’t equate to the length of an interstellar journey, nor can we expect the kind of significant retardation of aging processes that would be necessary to keep the crew alive and healthy until then.)
[/QUOTE]

Couple such a system with an extension in human lifespan and why do you think this system is unworkable even at this level? Or is extending the human lifespan also impossible?

If it takes centuries (as it would), so what? Again, its then a matter of will power and engineering, of logistics and supply…in the end of cost. Nothing impossible or beyond the extrapolation of our current technologies.

And none of this has anything to do with exploration and colonization of our own neighborhood.

-XT

55

[QUOTE=HoboStew]
Considering the considerable damage we’ve done to this planet in such a breathtakingly short amount of time, cosmically speaking, maybe we should just leave the rest of the universe alone…
[/QUOTE]

Well, with that attitude, you won’t mind signing over your seat on the interstellar express to me.
I like to put my feet up.

56

[QUOTE=HoboStew]
Considering the considerable damage we’ve done to this planet in such a breathtakingly short amount of time, cosmically speaking, maybe we should just leave the rest of the universe alone…
[/QUOTE]

Considering the incredible amount of damage the rest of the universe has done to this planet (tossing rocks at it, radiation, turning the heat up then down, etc) makes what we’ve done look like childs play. The Earth might have a case for our abuse, but the rest of the universe? It can go fuck itself. :stuck_out_tongue:

-XT

57

[QUOTE=Shagnasty]

It is a mistake to point to things like computers and lasers as an analogy to how space travel will progress if we apply ourselves. We see computers as huge successes looking backwards at what has been accomplished. Even up until the 1970’s and beyond, hardly anyone saw what the PC would become but that technology picked us because it was theoretically possible and the implications were massive. It is like picking stock. If you buy 100 different stocks, in 50 years, some will be huge successes and some won’t exist at all. You don’t get to pick which ones will be the successes. Saying that space travel will be one of the huge successes is trying to predict a single group of technologies out into the future and you can’t do that.

[/QUOTE]

Computers are an interesting example. I have thousands of '50s sf magazines, and the projection for the computer (in sf and science articles) were more along the lines of mainframes doing AI like stuff. No one really predicted the net, games, or handhelds, or, most especially, where most computers are - in microwaves, stereos, and washing machines.

I suspect that when we do move into space, we’ll have gotten that wrong also.

58

[QUOTE=Voyager]
Computers are an interesting example. I have thousands of '50s sf magazines, and the projection for the computer (in sf and science articles) were more along the lines of mainframes doing AI like stuff. No one really predicted the net, games, or handhelds, or, most especially, where most computers are - in microwaves, stereos, and washing machines.

I suspect that when we do move into space, we’ll have gotten that wrong also.
[/QUOTE]

This is a great point. It is very likely that if we ever go interstellar, nothing we are projecting here in this thread is likely to be correct and in use.

Jim

59

[QUOTE=xtisme]
But thats not the only solution to the problem. Let say that a method of hibernation was discovered where the patient could be kept essentially indefinitely in the state, and where the heart beat at, say, one beat an hour. The patient could be hooked up to IV or other machines that provide vital nutrients to them. This would certainly slow down the aging process quite a bit…Couple such a system with an extension in human lifespan and why do you think this system is unworkable even at this level? Or is extending the human lifespan also impossible?
[/quote]
There are minimum rates at which biological processes can operate, below which natural catabolism (the breakdown of proteins, lipids, et cetera) will occur. It’s just not possible, now or with any conceivable technology, to keep living tissue in long-term suspension, never mind the effects on the neurophysiology of a person. Even if you could, natural cellular aging processes will continue, and the unravelling of telomeres gives an upper limit on how long an organism can survive.

Now, it’s possible that we’ll come up with some kind of nanomedical technology that can repair damage at the cellular level and rewind the ribonucleic clock, keeping an organism alive indefinitely, but despite the hyperbole you may read from the likes of Raymond Kurzweil, this is as far speculative as any foreseeable technology. Genetic therapy research today is based upon correcting shifted nucleotides and inhibiting the effects of chronic syndromes. Such an innovation could be just around the corner, or it could be thousands of years into the future. It’s impossible to say, and betting that some technological innovation in the foreseeable future will permit rebuilding organisms from the molecules up is an unlikely wager to say the least.

[QUOTE=xtisme]
And none of this has anything to do with exploration and colonization of our own neighborhood.
[/QUOTE]
No, of course not. Reasonable extrapolation of extant and near-term technologies (radiation shielding, space industry, controlled nuclear fusion, ion propulsion) is sufficient to get us anywhere in the Solar System. But that’s many orders of magnitude difference from interstellar transit.

Stranger

60

[QUOTE=xtisme]
I’m sure its possible because I see the potential technologies already being explored and I don’t see any show stoppers.
[/QUOTE]
I think that’s just because you’re underestimating the scale of the task. The distance to the nearest star is not just big, it’s too big to grasp. The distance to the nearest star that might have habitable planets is going to be greater still.

For humans to traverse that distance requires one of two different strategies:

  • Get there fast, which will require a powerful propulsion system; it needs to be powerful, because it will start off having to push a vast supply of fuel and propellant. Going there fast also means encounters en route with, say, a grain of sand, become fatally-serious problems.

  • Go there slower - well, the question is how slow is acceptable? - even on the get There fast ship, it’s going to be a really big problem maintaining functional mechanical/electronic systems etc, as well as life support in an environment with no outside assistance or resources for the duration of travel.
    On the Go There Slower ship, it becomes a quite possibly insurmountable problem.

I’m just very doubtful that there is any viable point anywhere between or including these two scenarios.