Because they don't want to live on underwater cities on Earth. They want to live on Mars.

You'll need to find a way entice doctors, farmers, miners, and other specialized professions to leave everything behind and consign themselves to death on a dark and barren rock. Historically, colonists have been motivated to such lengths for religious and political reasons. For example, perhaps libertarians will flock to Mars for freedom from oppressive governments. (Hey Bioshock developers: hint hint.)

I don't know if I would go as far as relating Alaska to Mars. Certainly the appeal to Mars is something more unique than just living in a small town.

It really is that simple.

Also, I wonder how your version of "many people" compares to the population of Alaska.

Could be a playground he couldn't pass up.

if a coup of some sort isn't spilling blood on the colonies, we can rest assured the tremor-like mars aliens will take care of them.

http://shitelonsays.com/transcript/elon-musk-and-the-giving-...

I also have zero interest in an underwater city.

That said, if we do follow your advice, we'll likely learn a lot in the process that can help us get to Mars.

I'm not arguing for underwater cities or against going to Mars. I'm just saying that the cost and effort of getting everything to Mars is the easy part, and is not the part that will actually ensure humanity's survival.

Exactly right, how this escapes people I am unsure. The absolute worst climate predictions, asteroid impacts or seismic events wouldn't be nearly as hard to recover from than trying to get to and then live for a single day on Mars.

Fifty years of successful Martian colonization would be a good start towards self-sufficiency on that planet.

These are successful, by at least some definitions, but are not self-sufficient. Why are you more optimistic about a Mars colony than our experience with places on Earth which are much less inaccessible and more inhabitable might suggest?

If future Mars missions are launched with the goals of establishing a research station, then yeah, I don't expect it to become self-sufficient.

But, if future Mars missions are launched with the expressed goal of establishing an independent colony, then I think there's at least a chance it might work.

Certainly there are a lot of challenges. We probably don't even know what all of the challenges are yet. For all we know, Mars could be host to a deadly microorganism, some extremophile we've never seen before. It could go the way of the Roanoke colony, with a total loss of the whole colony.

I would still go anyway though. Because maybe, after fifty years of chipping away at it, we would have learned enough and developed enough new technology as a result of the effort to have made it all worthwhile.

It is a huge risk for a potentially huge payoff. I'm always amazed when HN, of all places, doesn't see it that way.

If Chile or Argentina could find a way to practicably expand their settlement on the continent, rather than subsidize it like they do now, then they likely would. That they haven't suggests they haven't figured out how.

In any case, Tristan da Cunha is in a much more hospitable area, but its self-sufficiency is shaky. One fire, for example, can ruin their economy and require external support.

I'm amazed that you think it requires an attempt at permanent colonization of Mars in order to get the benefits, when we would get the same benefits here on Earth, should we try to have a permanent, self-sufficient colony on Antarctica, Greenland, Alaska, or Nunavut, with lower risks.

Maybe you can even suggest it to Musk. "Mr. Musk, I disagree that Mars is exciting. Please stop building rockets, and start looking into colonizing something safer here on Earth. Thank you."

People climb Everest because it's their dream, because the intangibles are worth the tens of thousands of dollars to them. Chile and Argentina subsidize their colonies on Antarctica because of dreams of land.

But even Denmark hasn't figured out how to make Greenland profitable. It continues to subsidize life on that island. That's about 60,000 people who would love to be self-sufficient. Is the problem only that they are insufficiently excited? Or that there aren't enough people there? How many more do you need?

http://en.wikipedia.org/wiki/Giant_impact_hypothesis

"collision between the Earth and an astronomical body the size of Mars"

The first step would be a colony that can produce and clean its own air and water and some of its food. This seem achievable in the near term. The second step is a full ecosystem (needs almost no nutrients from earth), which is much harder but I think biosphere 2 is a good proof of concept. Mars is much colder with less sunlight so it is a much harder problem on Mars. The finial step is an independent industrial base. You mentioned medicine, but I'm more concerned with the microprocessors to keep the automation running. Humanity can survive without medicine, and with a few easy things like penicillin we can do quite well (we can also avoid bringing the majority of diseases to Mars in the first place). Without automation I don't think one person can produce enough resource to sustain themselves in such a hostile environment.

Self-sufficiency is hard and I think a million people is a good estimation of how large a Mars colony would be before it became truly self sufficient.

The issues with getting something like an ecosystem on Mars would be much more dramatic, esp. given that while there are some ways of getting O2 and carbon, there isn't a source of nitrogen on Mars that we know (we assume there's fixed nitrogen in minerals, though that's very hard to breathe). Any loss of significant life forms would need to be replenished from Earth. And while some life forms will probably manage in 38% gravity, there's no reason to assume many would have long term viability (especially vertebrates like humans who depend on Earth gravity to function).

Getting an ecosystem on Mars that could support humans doesn't seem like it's in the realm of possibility to me, especially when there's good reason to believe humans themselves wouldn't be able to survive for long periods there unless something managed to solve that very hard problem. You could use a centrifuge for the long trip out (and nobody could survive without that), but you can't just live in a centrifuge on Mars forever.

Also while Mars does get crazy cold -225'F it can also get up to a nice 70'F at noon. The deep ocean is 0-3'F with not much fluctuation. Of course we could engineer some water cycling around the cities to bring cold up and warm down.

The other psychological choice to make is, "Would you prefer to live in a dwelling surrounded by almost no atmospheric pressure, or intensely high atmospheric pressure?"

The major threat of climate change is not to things so expansive as atmospheric viability, but only to present geography and weather cycles. There will still be breathable oxygen in the atmosphere, there will still be water, animals, and vegetation on the surface. As dystopic as a post-climate-change world may look, it undoubtedly looks better than Mars.

This is probably even true after massive nuclear winters, etc. I don't think there's anything humans can do that would so disadvantage Earth as to make another planet in our solar system better suited to human life. The only thing that may require external planetary colonization would be an extinction-scale geological or astronomical event (i.e., something totally outside of human control).

Here's a thought, C3 plant life goes extinct if CO2 falls below ~200ppm. No more rice, no more wheat, no more potatoes, no more evergreen trees. Life on earth would probably suffer a good deal more in the long run (in geological terms) if we left all fossilized carbon in the ground.

Do you have any convincing arguments for why a wetter, warmer, carbon-rich world would be a downside for humans on that scale? If I were betting on us surviving, I'd take that over an ice-age any day of the week.

Parasites and diseases, much more common in warmer, wetter places. You'll notice that on the whole tropical civilizations have been less successful than those in colder climes; there's a wide variety of possible reasons for that, but the effects of parasite load on health and general intelligence are real. Our technology/economy/etc. has so far been much better at helping us live in inhospitable cold places (Norway) than at dealing with tropical parasites and diseases.

Not to mention that a climatic shift on this timescale, in either direction, has historically meant about 20% of extant species going extinct. How lucky do you feel?

Not nearly as difficult as living on Mars.

In the near term, it's going to cause tremendous dislocation of human civilizations. In poorer areas, climate change will cause millions to die and tens of millions to suffer. That's the undeniable moral component.

Ecologically, climate change will hasten the mass extinction of species. A world covered in kudzo, algae, and roaches is technically "teeming with life", but I'm not sure it's the aesthetic vision you have in mind.

Or you know, the boundless vast uninhabited deserts that cover the world.

And, really, there are plenty of inhospitible places on Earth surface where people are already living.

Why don't we spend time working out how to lift people from garbage picking for example?

Nobody is going to spend billions to live in cities underwater. Simply, nobody wants to live underwater, or pay for it, or there is enough to be gained from that (we hurt the oceans enough already with fishing and others). And the eventual possible gain of maybe applicable useful knowledge is not enough to warrant the inversion.

It would be cool, though.

I can't believe I'm still hearing "sun isn't going to last forever" and "us" juxtaposed, as though one had any bearing on the other.

1. Humans have existed as a distinct species for about 200,000 years.

2. Given the process of natural selection, in another 200,000 years we will have been replaced by something different than us -- not necessarily bigger or smaller, smarter or dumber, just different.

3. In a million years, there will be nothing remotely resembling human beings -- it will be as though we had never existed. But let's argue that there's some hint of us after a million years:

4. The sun will become a red giant and envelop the earth in somewhere north of five billion years, which is five thousand times longer than we can possibly exist as an identifiably distinct species, using the optimistic forecast of item (4) above.

We need to have some perspective about our relationship with nature. Evolution teaches us that we're not at all exceptional, but are a random answer to nature's constantly changing question, which is "who is fit today?"

This idea that we're somehow ordained inheritors of the planet, is to me a 21st century leftover of the religious outlook, which is that humans aren't just another species, competing in an open-ended contest with no entry requirements or registration fees.

Here today, gone tomorrow. We're not special, and life is not an ordained right, but a gift. I intend to appreciate my unearned gift. How about you?

No, that's wrong. Humans, genus Homo, have existed for about 2.5 million years; the subspecies H. sapiens sapiens for about 200,000. The species H. sapiens is a little less clear, there's debate over whether it starts around 200,000 years ago (and includes just a few subspecies, notably H. sapiens sapiens and H. sapiens idaltu) or whether it starts around 500,000 years ago and includes several others.

> 2. Given the process of natural selection, in another 200,000 years we will have been replaced by something different than us -- not necessarily bigger or smaller, smarter or dumber, just different.

Unlikely; while speciation requires time, time alone is not generally enough, and even if it were, there is no reason to expect the time from the last speciation event to now (whether 500,000 years or 200,000) to be the time from now to the next speciation event.

(Colonization of Mars -- if Earth-Mars interaction is limited once the colony is established -- might actually accelerate that, since the one thing that does contribute to speciation is geographical separation which prevents significant interbreeding between segments of the wider population.)

> 3. In a million years, there will be nothing remotely resembling human beings -- it will be as though we had never existed.

Human beings, genus Homo, have been around for two and half million years already, and H. sapiens (whether you take the narrower or broader view of the species) would be a flash-in-the-pan as species of its size, lifespan, and geographic range are concerned if it wasn't around for several million more (H. erectus -- with competing members of the genus Homo around on Earth for pretty much its whole time of existence -- lasted about 1.75 million years), and things "remotely resembling human beings" have been around significantly longer -- and can be expected to be around significantly longer than humans in the strict sense, unless humans are wiped out completely in a cataclysm rather than subjected to the kind of pressures that produce speciation.

> The sun will become a red giant and envelop the earth in somewhere north of five billion years, which is five thousand times longer than we can possibly exist as an identifiably distinct species, using the optimistic forecast of item (4) above.

The million year forecast isn't "optimistic"; while it may be unlikely that human beings would be around for 5 billion years, your particular argument for that point is, well, based on one controversial claim and a couple of unjustified claims that don't follow from that controversial claim.

Where's the refutation of my point that we will have entirely disappeared in a million years, replaced by some other species? This isn't a philosophy debate, where words like "controversial" and "unjustified" carry weight among people trained in critical thought.

Where's the support for the claim?

> This isn't a philosophy debate, where words like "controversial" and "unjustified" carry weight among people trained in critical thought.

"Unjustified" always carries weight among people trained in critical thought, at least, when its true -- i.e., no adequate support has been provided for the conclusion presented. You've simply asserted that humans have been around for only 200,000 years as a species (which is one of two common viewpoints about H. sapiens, though "humans" in this context usually means the genus Homo and not the species H. sapiens -- 500,000 is the other, because where exactly at what point H. sapiens becomes a distinct species is debated), and jumped from there to the conclusion that H. sapiens will be replaced in another 200,000 years and that nothing similar will be around in a million years. Neither of those conclusions follow from the premise, which itself is less-than-certainly correct.

In the very, very long run, who knows.

But int the timescale of tens or even hundreds of thousands of years I don't think there will be any natural selection process that will apply to the current status of humanity as a species, unless for some reason civilization will fall and humans are scattered throughout the globe.

We've pretty much stopped evolving as a species through natural selection events. There's not much of that happening in the homogenized urban setting where the majority of people live, and will live for the foreseeable future.

Actually, having the current civilization as a substrate for the species does change the playing field considerably from what it was a few thousand years ago.

As for biodiversity creating some sort of 'better adapted species' to take over our position - the sad truth is that biodiversity is in rapid decline, and I don't know when it will stop. We are not killing the planet per se, only... homogenizing it and making it fit for humans.

In a million years, sure, who knows what will happen. But in the current mass extinction event - if we can feed the the human species it's very difficult for me to imagine anything will replace us when the timescale is only the current estimated age of the species.

Prepare to be rickrolled for the next 100k years. Or maybe we will move into some dense compute substrate made of exotic materials.

This is quite false. All that has happened is that we've (to some extent) replaced genes with memes, and memes evolve just like genes do.

Evolution is still underway, actively and blindly selecting individuals and ideas with equal efficiency.

> There's not much of that happening in the homogenized urban setting where the majority of people live, and will live for the foreseeable future.

I'll just give one example that falsifies the thesis -- what is called Asperger Syndrome (AS). A thousand years ago, someone having the behaviors associated with AS might be at a significant evolutionary disadvantage compared to someone who could pick more olives up off the ground. But today, the AS behaviors represent a distinct advantage because the environment has changed in ways that favor that mental wiring, such that a number of AS "sufferers" (to use the psychological terminology) are famous -- Bill Gates, Albert Einstein, Thomas Jefferson and many others identified as having AS.

AS is so obviously an advantage in modern times that another psychological school of thought called "Grit" goes so far as to describe the same behavior pattern as an advantage:

http://en.wikipedia.org/wiki/Grit_(personality_trait)

Of course, the Grit people don't call it AS or even mention AS, they just say how advantageous it is to have the intense focus and obsession with only a few activities (or even one) this behavior produces in many modern success stories.

It's evolution at work. I'm sure many more examples could be found, less dramatic than this one.

Evolution is the central theory of biology, and it didn't just stop for human beings when we built the first TV set or began dwelling in arenas of pure thought -- quite the contrary.

Unless people with AS / Grit have more children than those without, there's no selective pressure to increase the prevalence of the trait in the population. You could consider health of the children - so maybe you should count great-grandchildren rather than direct children.

BUT - I agree that evolution probably hasn't stopped - it just is selecting for different traits than it did 15,000 years ago. What exactly is being selected for in US in 2014, I can't say.

You can hear his arguments and draw your own conclusions: https://www.youtube.com/watch?v=UkuCtIko798

Humanity isn't that special and I'm sure intelligent life would arise again without us, but now that Earth has developed fungi that can digest cellulose Earth is never going to have this much fossil fuel sitting around again. Maybe that doesn't matter and humanity or some other species will colonize space anyways... but maybe it does.

Okay, fair enough, that's reasonable -- so once we detect any sort of extraterrestrial life, then we can forget about leaving the planet. After all, there's life everywhere, so our leaving Earth loses its significance.

I think we'll colonize Mars for the adventure, or to satisfy our curiosity, not as a first step in colonizing the universe. The latter might be what we'll say, but it won't be the real reason.

True, but what makes a species a species remains the same. Eventually our descendants wouldn't be able to mate with us (or would want to), and that perspective will mark the end of the human species.

> I think there will be a wide range in what is considered "human."

See above.

The expression "begging the question" doesn't mean what you think it does.

> I wonder what you have to be, to be special according to the flavor of meaning you just happen to prefer?

The answer is obvious -- no particular form of life is special or supernatural. It's all part of natural selection, changing species adapting to a changing environment. And this isn't just some hypothesis, it's the central idea in evolution, a very well-supported scientific theory.

And our "flavor of meaning" has no part to play, only objective evidence, the evidence that overwhelmingly supports the theory of evolution.

In the very long run we're doomed anyway http://en.wikipedia.org/wiki/Heat_death_of_the_universe

(completely unrelated, but I'm getting tired of creating throwaway accounts on this site each time I want to post a new comment - why oh why is anonymous commenting disabled ?)

Then stop doing it.

Honestly, are you really going to be disappointed if, after a few billion years, humanity runs out of gas? We'd have done be the most successful species in the history of species.

What? Humanity will have entirely disappeared in a million years, and in a billion years we won't even be a distant memory.

Please try to remember that we've only been a distinct species for 200,000 years, and in another 200,000 years, chances are we will have been replaced by something different. In a million years, five times as long, we will not exist in any form whatsoever. In a billion years, five thousand times as long, creatures who have forgotten about us will themselves be forgotten.

It is the height of absurdity to think that a lowly species like us will exist in any form at all even a million years hence. Both us, and all our stellar achievements (like Country & Western music and the Pet Rock), will have completely disappeared.

Even if you mean that in the narrow sense of H. sapiens, rather than humans as genus Homo, that would make H. sapiens a shorter-lived species that H. erectus. If there's a reason to believe that, you haven't provided it.

> Please try to remember that we've only been a distinct species for 200,000 years

Or 500,000, depending on which view of the relevant taxonomy you take...

> and in another 200,000 years, chances are we will have been replaced by something different.

There is no factual basis for this claim; particularly, even if we except your POV on how long we have been around so far as a species, it does not follow that the same amount of time in the future would see us replaced.

> In a million years, five times as long, we will not exist in any form whatsoever.

Again, you provide no reason to believe this. H. erectus was around for 1.75 million years. If H. sapiens only lasts as long as H. erectus did, our species would be around -- starting from your 200kYa start date for H. sapiens, another 1.5+ million years. And humans, genus Homo, have been around for over 2.5 million years.

> It is the height of absurdity to think that a lowly species like us will exist in any form at all even a million years hence.

It really is not. We may be lowly, but a species lasting a mere 1.2-1.5 million years (what H. sapiens would have to last in total to be around a million years hence) is not uncommon at all. Many hominid species have, why wouldn't H. sapiens?

> It really is not.

You, too, can learn evolution by natural selection and such related disciplines as probability. We could not successfully mate with our forebears from a million years ago, and chances are we will not be able to mate with our descendants a million years hence.

>> and in another 200,000 years, chances are we will have been replaced by something different.

> There is no factual basis for this claim;

What? There is no "factual basis" for my saying "chances are"? I didn't make a statement about fact, I made a statement about probability, and a very good one.

In any case, were you not more interested in generating heat than light, the point I successfully made was that five billion years from now, there will be no sign of us to fret over the earth's being absorbed by the red giant star our sun will have become. You know, before you tried to change the subject?

Correct. Exactly.

> I didn't make a statement about fact, I made a statement about probability

Claims about probability still require factual support (and, in fact, are still fact claims -- that, given given particular prior conditions, there exists an X% probability of a particular subsequent event is a fact claim, even if it is a different fact claim than the claim that the subsequent event is certain.)

> the point I successfully made was that five billion years from now, there will be no sign of us to fret over the earth's being absorbed by the red giant star our sun will have become.

There may be a reasonable basis for that conclusion, but if there is, you haven't presented it, so it would be inaccurate to claim that you have successfully made that point, even if it is a point that could have been succesfully made.

> Correct. Exactly.

Honest to God. A statement of probability is not a fact, it is an estimate. You aren't even familiar with the terminology.

> Claims about probability still require factual support ...

False -- they require evidentiary support. A probability estimate requires a basis for making the estimate, which I provided. If you had any understanding of either science or statistics, you would be familiar with what I'm talking about.

Here's the evidence:

1. There are no species that were present on Earth a billion years ago that are still present in the same form, i.e. able to interbreed with their forebears.

2. There are few species that meet the above requirements from 100 million years ago.

3. There are a handful of species that meet the above requirements from 10 million years ago.

4. Modern humans have existed only for 200,000 years.

5. Using the simplest statistical methods, accessible to an average college student, we can write a distribution that takes into account the fact that modern humans didn't exist 200,000 years ago and extrapolate into the future, showing that our likelihood for existing as the same species we are now, 200,000 years in the future, is very small. This is a statement about probability and likelihood, areas with which you are clearly unfamiliar.

6. On the above basis, the probability that modern humans will exist as the same species a billion years from now is zero.

7. On that basis, the probability that modern humans will witness the sun enveloping the earth five billion years from now is also zero.

If you can't understand the above argument, by all means keep your ignorance to yourself.

> There may be a reasonable basis for that conclusion, but if there is, you haven't presented it, so it would be inaccurate to claim that you have successfully made that point, even if it is a point that could have been succesfully made.

Look -- go back to the philosophy department, where contentless arguments like yours, arguments indistinguishable from two children negating each other, are welcome.

In your fantasy, modern humans, which didn't exist 200,000 years ago, have some chance to be present to worry about the sun absorbing the earth five billion years from now. And you think my probabilistic estimates are doubtful. The burden of evidence is yours, not mine.

EDIT: Yes, people, don't bother to read the argument, the evidence, just click the downvote button. Live up to my expectations.

That's not really a useful basis for conclusions about the outer limits for either species in general or any particular species, as sexual reproduction itself may only be around 1 billion years old (from what I can tell, that's the age of the oldest fossil evidence), but, in any case, the oldest animal species seems to be around a 445 million years old, which is a sizable fraction of the time that multicellular life has existed on earth.

> Using the simplest statistical methods, accessible to an average college student, we can write a distribution that takes into account the fact that modern humans didn't exist 200,000 years ago and extrapolate into the future, showing that our likelihood for existing as the same species we are now, 200,000 years in the future, is very small.

No, you can't, because none of the facts that you cite would support any calculation that would lead to that conclusion. If you assume that species total lifespans are randomly distributed (a dubious assumption), and you make the further assumptions that the lifespans evident from the fossil record accurately represent the full lifespans of species (also dubious), you could calculate a distribution function for the actuarial expected future lifespan of a species given how long it has existed previously. But even if the necessary assumptions weren't problematic, none of the premises you cite (alone or together) would support the conclusion that "modern humans", being around 200,000 (even assuming that "modern humans" are even a species and not just a subgroup within a species, which is an actively disputed point) would, as a species, only be around another 200,000 years.

> On the above basis, the probability that modern humans will exist as the same species a billion years from now is zero.

This further conclusion -- and the following one -- fails to be supported because it rests on the prior failed conclusions.

> If you can't understand the above argument

I understand it -- its a stream of statements that you assert follow from each other that don't.

> In your fantasy, modern humans, which didn't exist 200,000 years ago, have some chance to be present to worry about the sun absorbing the earth five billion years from now.

No, I haven't made any positive claim about the likelihood of that happening. You've made a claim about it, but its a claim that rests on dubious stated premises, and, on top of that, doesn't even follow from those premises.

> That's not really a useful basis for conclusions about the outer limits for either species in general or any particular species, as sexual reproduction itself may only be around 1 billion years old (from what I can tell, that's the age of the oldest fossil evidence), but, in any case, the oldest animal species seems to be around a 445 million years old, which is a sizable fraction of the time that multicellular life has existed on earth.

First, you have simply confirmed what I said above, while simultaneously attempting to deny its evidentiary basis.

Second, let me explain something to you, something you very clearly do not understand. You are trolling. You have nothing constructive to offer this discussion, you offer no evidence or productive arguments of your own, and you are constantly restating the terms of the argument to suit yourself. If I offer a guess about the future based on statistical probability, you reinterpret that clearly stated guess as a statement of fact about the future, and call it false. But in point of fact, probabilistic guesses about the future are neither true nor false.

You have yet to argue against what I have actually said -- instead you argue against a series of straw men of your own fabrication.

Stop trolling -- it's not constructive, it's a waste of time, and it makes you look inexperienced and narcissistic.

If there's not a single species present today which was also present 1B years ago, it does not seem unreasonable to me to suppose that humans will not be around in five times that timespan in the future. If anything, this should be the default supposition, and it is any claim to the contrary -- that we will be around in 5B years, in a form we could mate with -- which needs extra support.

Did the words "tomorrow", "next week", "next year" not suit your argument? It's wilderness from the centre of the Earth all the way out - myriad accidents waiting to happen.

"I don't really think that worrying about the Earth dying anytime soon is much of problem"

You've not based that on anything. It's also ignoring the word "ensure", the longer we sit idly by, the less sure we can be.

"If we can't in a million years develop technology to survive we won't be able to do it in the next 50 years."

Obviously, but what's a million years got to do with anything?