We should expand and insure the continuance of the human race and technology is our biggest hope. we as humans are very egotistical, but we have to remember earth does not belong to us. earth belongs to the universe and we belong to the universe. supervolcanoes that can scorch us, earthquakes that can swallow us, asteriods that can extinct us, gamma ray burst that can obliterate us, and petty man vs. man conflict that can end us. Any human-hospitable planet is a blessing right. only if we use it to our advantage, learn to navigate through the universe like we’ve adapted to earth. This planet will no always be here, the milky way galaxy will not always exist, the question is ‘will humanity?’

Additionally, we need to get as very far as possible from the sun, sometime in the next 6-7 billion years, when it will become a red giant and explode. Humans should be working on how to preserve our race and the way to do it is to move forward instead of hiding here on Earth until it is too late.

Too true. Any signigican increase in the steel-and-concrete modern cities is going to increase the net heat of the inhabited portions of the Earth, especially in said cities, and especially without decent landscaping to counterbalance it; in short, Michaell is overestimating the amount of surface area we have to spare, it sounds like.

Now, I’m no tree-hugger, not really, but the truth is that we need a certain amount of land left for plants to grow; otherwise, the oxygen levels in the atmosphere go down, which after a certain point is obviously going to be awful bad for us, since we can’t breath CO2 or nitrogen. And of course, the processes of plant respiration and photosynthesis help keep temperatures a little more comfy on average. And the more humans you try to crowd onto the planet, the more plants we’re basically going to need. And I’m not talking greenhouses; they need to be out in the open air, unless people are going to be living the greenhouses. Not to mention of course we’d also need considerable amounts of vegetation in order to feed ourselves (even if humans were able to healthily survive only on meat, what’s the cheapest way to produce good-tasting meat, and likely to continue being such for a number of years to come? That’s right: livestock, animals, which themselves have to eat something. And of course, it’s actually unhealthy to survive only on meat – even most carnivores eat the vegetable stomach contents of their prey, and we’re not even carnivores, we’re built to be omnivores or very careful vegetarians at best. So of course, there’s veggies to feed the livestock and veggies to feed the humans).

Not to mention Michael I have to wonder if you have taken into account the fact that much of the Earth’s surface really isn’t all that stable. Much of its surface lies immediately next to volcanoes (talk to a Hawaiian who lives on the main island, let them tell you about their insurace rates…), or on fault lines in general, or on ground that is not particularly stable for other reasons (for instance, look at Florida’s sandy soil, which combined with frequent rain and other factors has on occasion led to sinkholes swallowing whole houses and whole chunks of highway in some regions).

Additionally, while it is concievable to be able to create a sort of self-sufficient dome city in the desert even by today’s tech, it would be rather expensive, since most deserts, IIRC, have things like sandstorms. Plus, where would their water come from? Thousand-mile pipelines? Right, more construction… more time and planning and energy and materials, i.e. more expensive. Not to mention the cooling requirements, or how to dispose of sewage-type waste without wasting precious, useful water. Some of the post-construction energy needs could probably be met most efficiently by solar power, but water and cooling would be big concerns… not to mention, traveling ELSEWHERE (for fun, for instance, or work) would be somewhat difficult, and so you might not find that many people willing to live in desert domes.

As for living in the antarctic, that’s possibly even higher costs, especially since you’d have to heat it and light it during the half of the year it’s DARK, not to mention the inclement weather (read: you could only rely so much on solar power, or any type of power really). And then what happens if there’s a breach in the city walls, or if there’s a breakdown in the heaters? Again: plausible, especially given there’s already a research base (and people do live in a handful of arctic circle lands) but I can’t imagine very many people in large droves volunteering to live there.

And underwater? You kidding me? Leaving aside the enormous expense of building ANYTHING underwater, once again travel to and from other areas is extremely difficult and you also have the added pressures (er, no pun intended) of dealing with pressurization, heating, and transporting oxygen down there. Yeah there’s an underwater hotel in Florida, but that’s a tourist trap, someplace divers can visit for fun and the sake of saying “This is what we did on our school trip”, not a real, permenent colony situation. I’m sure some people would be eager or willing to live in such environs – if nothing else, some might find it interesting – but convincing a large number of people to do so, and to do so permanently, is something else.

Don’t get me wrong; it’s not impossible to colonize the deserts, seas, poles. But it would be expensive and time-consuming and most people would probably rather live in “normal” places, such as the midwestern U.S. or Florida. Which reminds me – what about hurricanes and tornadoes and blizzards and the like? Building more buildings isn’t exactly going to make those go away, which means you also have to have some place for people in areas prone to them (or earthquakes, or floods, or lava flows, or sinkholes, or sandstorms…) to evacuate to in emergencies. And the amount of space one would need to leave for oxygen-releasing plants, let alone the effect of buildings covering every available space on the weather (I’m not saying a couple extra skyscrapers are going to melt the polar ice caps or anything, but it could mess things up a little if EVERYTHING got covered by a whole mess of steel and stone skyscrapers). Well, that all leads me to be frank and say you’re probably overestimating the amount of space we REALLY have availble. Especially since some people are inevitably not going to be working at home, and what about meeting places, such as congresses or meeting halls or convention centers or the highways that get us to them? Much of America is covered by roads for a good reason, you know.

I’m not saying it isn’t a cool vision; I’ve imagined extremely similar things when working on some SF stories myself. However, 100 billion is an awfully big number, and the amount of land we can live on is probably more limited than you’re really accounting for (and if you’ve accounted for every single thing I’ve brought up, please do tell how much you accounted for it, i.e. by what equations you calculated which land was useable and which wasn’t). Not to mention the large number of people who would rather sit where they are or who wouldn’t let others move into their territory just because “it’ll help lower the population density elsewhere” (practically the whole middle east, for instance, is extremely tribal and territorial, as are parts of Africa. Not to mention portions of India still subscribe to the caste system despite being told not to, and there will always be rich drug lords and politicians and film stars and the like who will want to take up a disproportionately large amount of space).

And in any case, we have enough trouble taking care (i.e. guarding against weather or natural disaster, feeding, and providing potable water, good waste-management systems, and decent healthcare to) the whole existing 6.5 billion already (otherwise those TV ads with “for just 14 cents a day, you can sponsor this child…” wouldn’t be on TV, for one thing).

Before we start planning for some squishily-squee expansion, how about learning to manage our current resources to take care of the current population? We could feed the whole world if we really wanted to, we could provide water filters and shelter and sewage systems to everybody probably as well, but we haven’t yet. Until we’ve taken care of that, I would find it unreasonable to assume it’s a good idea to expand to a population that is over 15 times that of today (divide 100 bil by 6.5 bil, you’ll see what I mean). Population increase might be inevitable, but it can’t reach that high and be sustainable let alone sustainable and healthy for mankind at the same time, and likely won’t; especially not if we keep up with the enormously poor distribution and management of resources (not saying you can’t have wealth even in this picture, but, it’s more uneven than is good for the species as a whole let’s put it that way. Which may or may not be bad from an evolutionary standpoint per se – less people, more resources, care for you and yours first, etc., but from a moral one, it’s a little more disturbing).