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Comment Expansion can't work: in long term 2^x beats x^3 (Score 2) 376

Even with infinite resources, expansion cannot overcome a continuous growth rate, in the long term. With infinite resources, and being able to move anywhere at the speed of light, the volume of space that would could occupy would be limited to a sphere x light years in radius, growing geometrically with time. Meanwhile, our population grows at a rate of n^x, exponential with time, which for any constant n > 1, will eventually overcome the geometric term.

Say for example all you need for a human is 1m^3 of space, then if we had infinite energy, and could move at will at the speed of light, and live anywhere, even deep space, and maintained our current growth rate of 1.1%/year, then we would run out of space when:

volume of sphere x light years radius = total volume of humans after x years of growth
4/3*pi*(299792458 x)^3 = 6.97*10^9 * 1.011^x

I don't this this has a closed form solution in algebra, so just approximating it: After somewhere between 5750 and 5800 years at our current growth rate, even with infinite energy, and the ability to travel at the speed of light, and nothing needed other than space to put our own bodies, we'd run out of space. It would be a 5800 light year radius ball of solid humans. Nothing beats exponential growth in the long term.

And excepting ftl travel, that's as overoptimistic as things can possibly be. We'd have has to use up all of the mass of the Earth, or the Sun, or all of the matter in the volume of space available to us long before that, just to turn into more humans, to maintain that growth rate. And if we had the ability to make more mass (we're assuming infinite available energy after all), we'd collapse into a black hole from our own mass long before we reached the above point. And more realistic scenarios can only be more limited than that.

Long term, the only solution is zero population growth, or at least a continuously decreasing growth rate, any constant exponential growth rate will eventually overcome anything you can throw at it.

Comment Re:Send them a bill! (Score 1) 185

Unless it's a EULA of course:

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

Both cases involved a shrink-wrapped license document provided by the online vendor of a computer system. The terms of the shrink-wrapped license were not provided at the time of purchase, but were rather included with the shipped product as a printed document. The license required the customer to return the product within a limited time frame if the license was not agreed to. In Brower, the Supreme Court of New York ruled that the terms of the shrink-wrapped license document were enforceable because the customer's assent was evident by its failure to return the merchandise within the 30 days specified by the document.

Comment We have discovered them (Score 1) 88

And not just one of them. Kepler has previously found 5 Earth-sized planets, in the habitable zones around their stars. And quite a few that are either Earth sized, or in the habitable zone, but not both. Including things like super-Earth sized ones in the habitable zone. :) http://www.nasa.gov/mission_pages/kepler/news/kepler_data_release.html

The findings increase the number of planet candidates identified by Kepler to-date to 1,235. Of these, 68 are approximately Earth-size; 288 are super-Earth-size; 662 are Neptune-size; 165 are the size of Jupiter and 19 are larger than Jupiter. Of the 54 new planet candidates found in the habitable zone, five are near Earth-sized. The remaining 49 habitable zone candidates range from super-Earth size -- up to twice the size of Earth -- to larger than Jupiter. The findings are based on the results of observations conducted May 12 to Sept. 17, 2009 of more than 156,000 stars in Kepler’s field of view, which covers approximately 1/400 of the sky.

Comment I like Launch Loops myself. (Score 2) 212

http://en.wikipedia.org/wiki/Launch_loop Launch loops are basically a big cable, supported magnetically in a vacuum sheath, and accelerated up to high speeds (14km/s+), it could be set up as a 2000km long track along the ground, about 80km up. Since it's moving faster than escape velocity, it would appear to move away from the ground, since the ground is curving away from it faster than it's moving. so it would just need to be tethered to put it into a nice flat path, and could be magnetically looped around and sent back the other way at the end stations. A craft to be launched could just produce a magnetic field, and it would be pulled along at 3g or so, and could let go when it got up to it's desired speed, with a small rocket to circularize it's orbit at higher than 80km, if it's not headed off at escape velocity.

It solves a number of issues that are problems for a space elevator, like how to get something to climb up a tether, or get power to it, which can be done relatively easily for a launch loop, since it could just pull power off the grid whenever it's convenient, and store it in the motion of the cable itself. And it doesn't need any new materials, or really strong ones or anything like that. Not to mention, being much faster to get to orbit, but still suitable for acceleration-sensitive cargo, such as humans. And it can launch quite a bit more material/time then a space elevator can, at a cheaper price. Mainly limited just by the amount of electrical power it has available, and at high power levels, by the need for the cable to cool down between launches.

Only major downside would be that it isn't statically stable, there would have to be dynamic control of the rotor at the end stations, given that it's all just supported and directed magnetically. And it would need to remain powered to keep it from eventually collapsing.

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