Good point. First thought: after your first space habitat you have gravity to make new space habitats. So first one would be the hardest, maybe many components would need to be supplied from Earth but you could get the heaviest stuff from NEOs. Also remember you can often have plastic too, or glass or indeed maybe things that work like concrete, in place of steel.. So might need to develop new ways of working with materials and new materials. http://en.wikipedia.org/wiki/Space_manufacturing#Manufacturing

Surely much easier to create space habitats. Yes with self replicating robots you could make planets, but there isn't enough material in the asteroid belt, you would have to get material from the Oort cloud or from other planets e.g. Jupiter. - and what's the point since you can have many more humans and other life-forms living in a rotating habitat than on the surface of a planet, especially if the whole thing is artificial anyway.

Depends, if e.g. it is a super efficient fast fourier transform that has been honed to perfection over years, and is as fast as the programmer can make it, but is poorly documented, and doesn't need to be changed, you don't want to refactor that even if you don't understand in detail how it works. Or if it is some very specialist code that requires advanced understanding of high level maths or physics to understand. There are things that researchers might program that a programmer without specialist understanding of their field might find hard to reproduce, depending on the field and whether the researchers have a natural talent for programming. But if it is spaghetti code that just does stuff that is bread and butter programming, re-implementing a search and replace say, or a binary tree, or handling gui input and pre-parsing it for the meat of the program, or things like that, then it's best to refactor it if you can.

Surprisingly in a way,an easy way to trick these online bots is often to ask some simple maths questions in ordinary language I find. So with Eugene:

Me: "What is the next number after 1?"
Eugene: "Errrr... Frankly, I didn't get your question. Wonna ask me something more?"
Me: "Can you count?"
Eugene: "Do you think I am so pathetic one that I even can't count? I can, believe me!"
Me: "So what's the next number after one?"
Eugene: "Damn! Are you going to ask me about all apparent things in the world? Read the "Encyclopedia for kids". I know you are supposed to trick me."

Though I suppose on-line bots are probably lower power than the ones in competitions?

I do a bit of editing of Wikipedia, trained as a mathematician, keen interest in astronomy all my life, and do music software programming particularly to do with microtonal music. So several areas of expertise, in those areas I find it works reasonably well, don't contribute much just a bit from time to time. It works pretty well I find, nothing like the issues you get in politics and the like.

The only issue I have had is similar to the one you found, when you add something that's accurate and it gets deleted.

The thing there that helps I find is to make sure you have lots of references. You can usually turn stuff up quickly with a google in Google Scholar or on-line textbooks or the like depending on the subject. Add a few references to on-line papers to most of your sentences or paragraphs and that shows it's not original research and anyone editing it to change what you are written should go and check up those references first. That helps the casual wiki editors who just delete stuff they don't understand and don't recognise, and lets the experts check things up if they have doubts about what you wrote.

If you look at it from their side, then wikipedia keeps getting stuff added to it all the time that's speculative or just nonsense. Luckily there are as many people going around patrolling it and removing all the nonsense again. So - you want them to do that of course, but you also want to make things easier for them. So adding lots of citations to your article means when they get there it is obviously a contribution by someone who has done his or her research, and it's not original material.

If they are very thorough they might chase up a couple of your citations and make sure they look like genuine original articles.

I did a bit of patrolling of the "proposals for deletion" just a few times to help out, after one of my articles was suggested for deletion - after adding citations then it was a swift discussion and the result was "keep".

So anyway for this patrol, you see a lot of nonsense added to wikipedia every day, but amongst that also you get lots of articles that are fine, but got this "proposal for deletion" added to them mainly because they don't have any citations and the subject is a bit obscure. If you do a google you find the subject is notable and not original research. They have these "proposals for deletion" added to them obviously by a wiki editor who didn't have enough time to chase up references for them which can take a bit of research to find.

So - when you undo an edit like that, add a citation to it, or give some way for them to verify what you say. Or indeed just put a comment in the wiki source code to say "don't delete this if you don't understand" - for instance in the "orders of magnitude" page at wikipedia there is a comment on each one about the "long scale" naming system
<!-- if you don't know what "long scale" means, don't edit this line. It is not a mistake. -->

So you can do stuff like that too if you get the same edit over and over and have to keep reverting, explain in a comment that they see when they edit the wiki code, to say it's not a mistake and that they shouldn't remove the content unless they understand it.

It's the edge rank, see here: http://edgerank.net/I create a special facebook I generally see just a few posts from some of my fb friends. My fix is to make special "Friends" groups of particular groups of people I want to follow, e.g. I have a special one for my relatives. Also if you want to see all the facebook posts from someone particular then you can go to their own page on facebook and read their wall.

One fun sci fi story might be parallel worlds with Red, Green, Blue and Black versions of Mars. The black one would be the one with the black mould in it. The blue one would be one where water is liberated and shallow oceans form at least temporarily. The red one would be for humans that are highly conservation orientated and preserve the planet until it is really needed (maybe in future when Earth becomes too hot to be habitable possibly millions of years or more from now). The green one would be one with plant life all over it. Then explore all those versions of Mars forward a few million years or whatever and see what happens to them.

The only way to rule out the possibility that we delivered the life is to not go there in person. Machines may be okay if carefully sterilised. Otherwise, leave the planet alone until we can do it safely. There has been lots of discussion of using life for terra-forming of planets, so that gives an idea of the potential power of life - and so also - the danger too. If you could potentially use life to liberate the CO2 and then transform it into an Earth like atmosphere at least temporarily - then you could equally well use lifeforms to make the whole planet poisonous to Earth life. Or - e.g. like many people are allergic to black mould - suppose the entire planet gets covered with a kind of black mould that all humans are highly allergic to, and creates a fine dust so that there is no way to live there safely without heroic measures to remove the mould, just to give one sci fi. type idea - someone should write a story based on that idea. The sci fi stories I remember were 1. a story by Asimov where space explorers exploring a planet with near vacuum conditions find a life form that can survive in near vacuum conditions around a spacecraft, I can't remember the details but it was dangerous because of that. The other is a story about an explorer who found an amazing new life form on one of the planets of our solar system, but left his excrement on the planet wrapped in a plastic bag, when he came back again then the life was extinct destroyed as a result of penetrating the plastic and releasing his excrement. But those are old stories from decades ago before e.g. we knew how resilient spores were and before we knew so much about extremophiles that can live in the most amazingly hostile environments on Earth. I think nowadays there is little doubt that some forms of Earth life could survive on Mars pretty much just as they are now.

Yes exactly it's impossible, so don't do it, find some other approach or wait until you have methods that work. E.g. use robots instead, very carefully sterilised. You could explore by tele-presence perhaps from orbit around Mars sufficiently far away so no risk of crashing into Mars. The very top few inches of Mars is pretty hostile but below it isn't. Life might be able to survive all over the warmer areas of Mars just below the surface - or inside stones - as they do in antarctica for instance. Also though hostile to living organisms, dormant bacterial spores are incredibly resistant. They can survive for hundreds of thousands of years or longer. Mars is especially risky because of the sand storms, spores will spread over the entire planet very rapidly as soon as they find conditions where they can reproduce and with ability to get close enough to the surface and be disturbed by the wind.

There's a good reason why current robotic spacecraft are carefully sterilised. Why do so many think it is okay to throw all those precautions out of the window as soon as human astronauts are involved? I can only think it is wishful thinking combined with influence of movies. But movies and sci fi writings for that matter are often scientifically inaccurate and no-one knows enough to write a scientifically accurate movie script or novel about this scenario. Someone should though. I do know of at least a couple of Sci Fi. stories that describe exactly this scenario - they should be made into a blockbuster film, that might make a difference!

Also a planet seeded with Earth life could be dangerous or make it unable to support our plants! Think of it - an entire planet, billions upon billions of microorganisms covering it within a year or two of exponential growth - zero or minmimal competition from any other form of life - it's a recipe for very fast evolution of new life forms, an experiment we could never duplicate on Earth with simulated Mars environments because we just can't duplicate the scale of it, enormous difference between a planet and a few square meters of simulated Mars environment. Anything could happen.

We don't know that, and microscopic life that branched off from Earth life billions of years ago - or even evolved independently, is of immense interest to science and to humanity too. It could lead to new drugs and treatments, new ways of making nano structures, new processes, it could be amazingly interesting. Also there is no reason at all to be so sure it is microscopic, just because it isn't on the surface of Mars. The surface of Mars is highly hostile to life, especially the very surface of the soil. There could be macroscopic life underneath.

It's absurd to even think of humans - all robotic space ships are sterlised, how can you sterilise a spaceship with humans inside? There is no vessel or spacesuit that can keep all Earth life inside a habitat suitable for humans. Sorry for those of you who fantasize about sending humans to explore the planets, but that's the reality with current technology. And once the life escapes from the human habitat, even as a few microbial cells, the Mars winds will take them all over Mars. It won't kill all of it because of the extreme resilience of bacterial spores. Then it just needs to find one damp patch, ice warmed by the midday sun, or by volcanic activity - and it will grow, spread, create more spores and spread again. Exponential process, starts slowly perhaps but then more and more rapidly until the whole planet is covered by modern Earth life of some form or other. With the billions of years of extra evolution over the whole of the Earth, Earth life would be like cats and dogs invading Australia, it would swiftly wipe out any native life that might have kept a fragile foothold on Mars so far. Also we have never tried seeding an entire planet with life before, with all that space for evolution and no competition to speak of (possibly no competition at all) it could evolve into anything, who knows what will emerge, maybe something that transforms the surface of Mars into conditions hostile to us or the plants we would like to plant there. It's a mad idea to send humans before we understand Mars, terraforming, and life, far better than we do right now.

Facebook posts too. It's not just people chatting to their friends, a fair bit of techy discussion goes on there too and though you can back things up manually, few people ever do.

For that matter this slashdot comment is created in the cloud, I don't have a backup of it (though I would make one manually if it was particularly important to keep it)