Spaceship Earth

Wayfarer

There's been a couple of space items in the news in the last few weeks. First, Stephen Hawking renewed his call for interstellar travel:

I believe that life on Earth is at an ever-increasing risk of being wiped out by a disaster, such as a sudden nuclear war, a genetically engineered virus, or other dangers. I think the human race has no future if it doesn’t go to space. — Stephen Hawking

Source

Elon Musk, meanwhile, has unveiled his plan for the colonization of Mars (and I, for one, believe that if anyone can make it happen, it's him.)

And whilst I think it is quite feasible - although possibly not all that useful - to get to Mars, I don't believe that interstellar travel will ever occur within the technological means we have at our disposal. The distances are just too vast - the Voyager 1 probe travels at the rate of 1 light year per 10,000 years or thereabouts. All the very nearest stars are at least 5-7 light years distant, and heaven knows ( ;-) ) how far the nearest life-bearing orb might be. And I, for one, don't believe that 'warp speed' will ever exist outside of Hollywood.

And speaking of Hollywood, I honestly think that the Star Wars fantasy of interstellar travel is really our sublimated longing for the heaven that our technological age has declared is no longer 'up there'. It is the nearest we get to our version of heaven and immortality - the only kind we can believe in - not least because it is populated, in our mind, with actual Hollywood stars (and how aptly titled they are!)

All that said, I like the idea that we're already on a spaceship - namely, Spaceship Earth. After all, it is able to sustain vast populations for millions of years. It has the resources and life support systems that are needed to cover vast distances through space. And if you wanted to equip something that could voyage for literally millennia, then a big round sphere with its own atmosphere and oceans would be hard to beat.

So I would like to think we're actually already on an interstellar mission. I would like to think that some ancient civilization foresaw what it would take to colonize space, and created a self-sustaining system which was capable of doing it - and here we are doing it!

All we have to work out is, how to save the ship. And it's going to take some doing.

BC

I believe that life on Earth is at an ever-increasing risk of being wiped out by a disaster, such as a sudden nuclear war, a genetically engineered virus, or other dangers. I think the human race has no future if it doesn’t go to space. — Stephen Hawking

↪Wayfarer

With all due respect, Mr. Hawking, it's too late. The means to wage a terminally devastating nuclear war are at hand. The missiles and bombs are ready to go. Genetically engineered viruses (or bacteria, let's not slight bacteria) may or may not already be in the freezer. Smallpox was eradicated, but the US, for one, Russia I believe also, has kept a few samples of the virus. It wouldn't wipe out the species, but most people under 50 have not been vaccinated. A reintroduction of smallpox would be pretty bad.

Mars? We don't have the means yet to send several people to Mars in good health, let alone several thousand or a million; and even if we did, Mars is not open for business. Mars might never be open for business, and even if it was, it is much smaller than earth--about half the size.

Proxima Centauri is the closest star, about 4.3 light years away. We could send a probe out there at a speed considerably greater than Voyager's, but even if it was 1/10th the speed of light...

You are exactly right, Wayfarer. We are already on our spaceship. We may or may not be doomed (in the near future, anyway) but here we stand, and here we are going to stay standing.

jkop

. . .nuclear war, a genetically engineered virus, or other dangers. . . . I think the human race has no future if it doesn’t go to space. — Stephen Hawking

Humans would most likely bring with them their nukes, viruses, and other dangers. Space might have no future after humans begin to colonize it.

Barry Etheridge

↪Wayfarer

How is this planet from which every star is getting further away due to the expansion of the Universe on an interstellar mission?

Barry Etheridge

↪jkop

Exactly. The human race has no future if it doesn't stop being human!

Weeknd

Just fear mongering

Weeknd

None of these things are going to happen, not at least in our lifetimes

Punshhh

I believe that life on Earth is at an ever-increasing risk of being wiped out by a disaster, such as a sudden nuclear war, a genetically engineered virus, or other dangers. I think the human race has no future if it doesn’t go to space.
— Stephen Hawking

Yes he's right, also about what he said recently about A.I.

We will have to go into space, or at least colonise a neighbouring planet. Hopefully we will have a few hundred years grace before it is necessary as our space technology is still very clunky. Perhaps the first priority should be to develop a self sufficient space station. So that should a large asteroid hit the earth, there will be some survivors. Even this is some way off.

In the meantime we just have to survive the crises brewing at the moment and try not to commit hari kari.

It's going to be a rocky ride the next 1or 2 hundred years.

I expect that what is more likely is another fall of civilisation, followed by another dark age. It does have the feel of a post apocalyptic novel though.

BC

It seems to me that Hawking was, at one point at least, concerned about aliens 'out there' tracking our inadvertent 'here we are' signals back here and

a. wiping us out or
b. colonizing us or
c. ushering in a new renaissance or
d. wondering, WTF?

So, we should rush out into the stars, (were we able) and trip up some alien plan and piss them off? Doesn't seem like a good idea.

There is no point building a lifeboat in orbit, on the moon, or on mars. Earth is our all in all, and manufacturing a satisfactory substitute isn't possible. It isn't that something can't be constructed. What is impossible is for this organism to survive and flourish in a small hot-house environment over the long run (say, 20 generations), and even if we could, what's the point? A life boat is a dead end to start with.

Wosret

What about China's shit ass space station probably going to fall out of the sky and hit Canada next year! I say world war three is in order.

Barry Etheridge

↪Wosret

What about it? Everybody knows it's happening and is an accident not an act of aggression. The chances are that it will pass off without incident anyway given that the chances of anything big enough to cause damage first surviving the re-entry and then hitting occupied land are minimal.

Wosret

Nope, nope. Intentional act of war. The Chinese have always wanted our spices...

Hanover

What about China's shit ass space station probably going to fall out of the sky and hit Canada next year! I say world war three is in order. — Wosret

The mounted police going to go to Beijing eh? Do what, apologize for having not provided a comfortable enough landing spot?

Wosret

↪Hanover

Canada officially has no nuclear weapons, but we firstly, have the best uranium refinement method (national secret, known to every Canadian, just in case), and make everyone else's, and have the most raw material to fashion the most nuclear weapons lying around out of any other nation.

Don't think lightly of the Dragoons, they have like super secret special training with Wayne Gretzky.

wuliheron

Utilizing classic dualistic logic, modern civilization has achieved its lofty heights by focusing on beauty to the exclusion of humor by pounding away relentlessly upon the excluded middle and, as far as I'm concerned, the next scientific revolution just can't come soon enough because the current one is destroying the entire planet and its difficult to see how any of the punch lines could get much worse.

As for colonizing Mars, NASA already has a reactionless drive straight out of Star Trek and they are now preparing to test one in space. The physicists disagree about how the damned thing works, but work it does without spitting anything out the back! Theoretically, you could equip a spaceship with a nuclear engine used for a submarine and reach the moon in four hours, Mars in two or three weeks, and Jupiter in perhaps six months. Thanks to not requiring any propellant it can provide continuous thrust and you would simply turn the ship around at the half-way point to decelerate.

The latest estimates are that even classical computers will be capable of revealing the mathematical foundations of a Theory of Everything within the next twenty years.

Wayfarer

Utilizing classic dualistic logic, modern civilization has achieved its lofty heights by focusing on beauty to the exclusion of humor by pounding away relentlessly upon the excluded middle and, as far as I'm concerned, the next scientific revolution just can't come soon enough because the current one is destroying the entire planet and its difficult to see how any of the punch lines could get much worse. — wuliheron

You should go to SAND, I think you would find much of interest there.

I googled 'reactionless drive' but from my 3.2 minutes of research, I ascertain that they are not actually real yet.

One of the great science fiction reads is Arthur C. Clarke's Rendezvous with Rama:

The "Rama" of the title is an alien starship, initially mistaken for an asteroid categorised as "31/439". It is detected by astronomers in the year 2131 while it is still outside the orbit of Jupiter. Its speed (100,000 km/h) and the angle of its trajectory clearly indicate it is not on a long orbit around the sun, but comes from interstellar space. The astronomers' interest is further piqued when they realise the asteroid has an extremely rapid rotation period of 4 minutes and is exceptionally large. It is named Rama after the Hindu god, and an unmanned space probe dubbed Sita is launched from the Mars moon Phobos to intercept and photograph it. The resulting images reveal that Rama is a perfect cylinder, 20 kilometres (12 mi) in diameter and 54 kilometres (34 mi) long, and completely featureless, making this humankind's first encounter with an alien spacecraft.

An earth expedition manages to board and indeed get inside this vessel, which is like a self-contained artificial world, full of crystalline cylinders containing holographic images of what seems like the ingredients for a planetary culture. It rotates along it's axis, thereby creating gravity.

At the end of the encounter, when it nears the sun, the earth expeditioners get off it, it slingshots around the sun - and off it goes. Earth realises that the whole vessel was prepared for just such an encounter, but that it is going somewhere else, and the Sun was just a pit-stop along the way. Best overall inter-stellar fantasy I have read.

On a completely different level, I think that ultimately the task of physically 'going somewhere' is impractical. I think an advanced intelligence would work out ways of simply encoding its ideas as energy and having them manifest wherever the conditions were suitable.

Barry Etheridge

As for colonizing Mars, NASA already has a reactionless drive straight out of Star Trek — wuliheron

No, they don't. Not even close! The physicists are still very much at the stage of arguing about whether it works.

Theoretically, you could equip a spaceship with a nuclear engine used for a submarine and reach the moon in four hours, — wuliheron

In a perfect Universe in which materials were resistant to collisions with particles at high speeds and astronauts were able to cope with G-Forces off the charts, perhaps. In any case you'd still need standard fuel rockets to get parts up there to build the ship and transfer the astronauts to it and then to transfer them from the ship to the moon at the other end.

wuliheron

↪Barry Etheridge

The physicists can argue all they want, but several labs around the world have tested the damned thing and it produced thrust including NASA testing it in a vacuum chamber. They would not be preparing to launch one into orbit at a cost of $100,000.00 a pound if they were not sure it has a fair chance of working in space.

Wayfarer

↪wuliheron

any references?

wuliheron

↪Wayfarer

https://www.google.com/webhp?sourceid=chrome-instant&ion=1&espv=2&ie=UTF-8&client=ubuntu#q=nasa%20reactionless%20drive

I have a free standing offer to teach anyone how to use a dictionary and search engine. Any number of these links will confirm what I've said. People are arguing over exactly how the thing works and there hasn't been any peer reviewed papers on the thing, but its been tested by even NASA in a vacuum chamber and it produces thrust. A tiny, tiny, tiny amount of thrust, but its definitely there and enough to make chemical rockets obsolete for anything but going into orbit.

What's even more interesting to me is that, because they aren't sure how it works, they might be able to improve upon it a great deal. That the engineers couldn't care less about peer reviewed papers or the lack of explanations and are too excited about exploring the possibilities doesn't surprise me in the least.

Personally, I think the Unruh Effect is pretty close to the correct answer. That's quantum field theory that is the basis of modern Standard Theory which is accurate to about 14 decimal places and reconciles quantum mechanics and relativity to roughly 80%. What I think is happening is simply that they are turning the vacuum into virtual particles, but it could be a bit more complicated and they could also be messing with space-time itself and doing some kind of weirdness. There's a lot of that happening in physics right now with one researcher recently increasing the mass of electrons in a superconducting circuit merely by using a really powerful magnetic field.

Wayfarer

↪wuliheron

Your offer is very kind, and in return I will provide free lessons on how to avoid being taken in by speculative press releases floating around in cyberspace about as-yet unproven technologies:

In its study NASA didn't attempt to explain the phenomenon, and instead contented itself with verifying that the system did indeed generate a small amount of thrust, between 30 and 50 micro-Newtons. This is a tiny amount, only enough to levitate a mass of three to five milligrams (a few eyelashes) here on Earth; but, astonishingly, it is a net thrust nonetheless….

…But before we start talking Sun-powered flying cars and weekend trips to Pluto, the scientific community will undoubtedly need to dissect the experiment with great care and independently verify whether the tiny net thrust reported by NASA could after all be attributed to some external cause that the researchers didn't account for.

I remember 'cold fusion' very well.

wuliheron

↪Wayfarer

Exactly, they confirmed it generates thrust and they also just announced they are going to test one in space. The voyager space craft that just left the solar system would require 30,000 years just get through the Ort cloud about 1/3 of the way to Alpha Centuri, while this thing could generate continuous thrust for a hundred years using a nuclear engine.

Wayfarer

↪wuliheron

'They' being who? It is speculative technology, there is currently no large-scale model of the device in existence. If you think there is, show me that reference, not a general search that finds all kinds of irrelevant information.

//edit// This seems like an authoritative article on the Em Drive. But until further developments, I think it is entirely speculative technology.

BC

but it could be a bit more complicated and they could also be messing with space-time itself and doing some kind of weirdness. — wuliheron

No doubt.

Metaphysician Undercover

..but it could be a bit more complicated and they could also be messing with space-time itself and doing some kind of weirdness. — wuliheron

How would you mess with space-time itself, tweak the mathematics a little bit?

Barry Etheridge

↪wuliheron

The NASA tests have not been submitted for peer review because nobody at NASA is confident that the results are directly attributable to the 'drive' and are repeatable. In any case the effect, if real, is so tiny as to cast considerable doubt as to whether it could ever be useful as an alternative to standard fuel systems for manned missions or interplanetary. Its one advantage, if it does work, is that it provides constant acceleration so that over time it builds up to previously unheard of speeds but all that advantage is lost if you have to decelerate for any reason. It would be ideal for missions such as intergalactic probes like Voyager but totally unsuited to shuttling people around the solar system.

Punshhh

↪Bitter Crank

Yes you raise a good point about Aliens interfering with us is some way. But we would only be likely to trip them up if they are very prolific throughout the universe. We are not likely to visit more than a few local star systems any time soon.
My point is that our first priority should be to establish a base of some sort in orbit so that if a catastrophic event happened on the surface of the planet, there would be a few people able to recolonise and more importantly retain the technological and scientific knowledge for the survivors. Thus enabling a fairly rapid recovery of civilisation. Currently all it would require to wipe us out to the extent that the few lucky survivors are thrown back to the Stone Age, is a fairly large asteroid impact in one of the deeper oceans. Perhaps an asteroid about 500metres in diameter would have that result and there are plenty of those wandering about in our vicinity.

wuliheron

↪Wayfarer

NASA and the physicists have no choice in the matter. As much as they might prefer to simply take their time and try to first figure out how it works, if they do not exploit the technology as fast as they can others will. The ability to send a probe off towards the stars under continuous acceleration for the next century is simply too big an opportunity to pass up.

wuliheron

↪Metaphysician Undercover

The physicists are already speculating that it leverages the Unruh Effect. This is a totally theoretical effect that nobody has proven exists yet where space itself transforms into virtual particles at near the speed of light. A cold wood stove at close to the speed of light would, according to the theory, start to glow red until it eventually disintegrated. Supposedly moving in circles would allow you to go a bit faster than in a straight line and the next generation particle accelerators should be able to test the effect.

My own suspicion is that space and time can exchange identities in extreme contexts and its possible to produce nonlinear temporal effects or "ripples" in time itself and the thrust they are developing is actually time being converted into space behind the device or space in front of the device being warped and compacted, but that's all speculation at this point. The recent discovery of gravity has already established that space-time itself can be warped and we'll just have to see what the experimenters can find out.

wuliheron

↪Barry Etheridge

It may be the only alternative available. The astronauts who went to the moon all suffered from heart disease for some unknown reason. Spending even weeks in a spaceship to Mars could possibly turn out to be deadly. That might sound alarmist on my part, but space is truly the new frontier and we are discovering new complications nobody thought of all the time.

When the space shuttle first went into orbit its belly was lit up with a brilliant blue glow of Cherenkov radiation caused by radical oxygen atoms nobody knew where there and their discovery explained why for fifty years satellites that were designed to last a hundred years fried within five. Similarly, a stupid experiment thought up by high school students was to simply put a Geiger counter in orbit and, when they did, they discovered an inexplicable radiation anomaly over Brazil that has nothing to do with anything on the ground and had to reroute all of the manned flights and satellites around the thing. The list of unknowns and known hazards goes on and on, but astronauts are the new explorers and live to take those risks.

Metaphysician Undercover

A cold wood stove at close to the speed of light would, according to the theory, start to glow red until it eventually disintegrated. — wuliheron

I find this to be a particularly meaningless statement. How would a large solid mass, the size of a wood stove achieve a velocity of close to the speed of light, without disintegrating in the first place? And that velocity would be relative to what? Suppose there is a tiny particle passing the wood stove, at close to the speed of light, wouldn't the wood stove be close to the speed of light relative to this particle? What would cause the wood stove to glow red, unless some of those particles were colliding with it?

My own suspicion is that space and time can exchange identities in extreme contexts and its possible to produce nonlinear temporal effects or "ripples" in time itself and the thrust they are developing is actually time being converted into space behind the device or space in front of the device being warped and compacted, but that's all speculation at this point. — wuliheron

Doesn't relativity theory allow that there is an inverse relationship between space and time? So space and time can change identities under relativity theory, but only through an inversion.

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