"almost nobody" seems to include the US legal system: Dowling v. United States (1985) http://en.wikipedia.org/wiki/Dowling_v._United_States_(1985)

http://en.wikipedia.org/wiki/Copyright_infringement#.22Theft.22

In moral terms, theft and copying are not the same thing. Taking a loaf of bread from you, or watching how you made a loaf of bread, and then going home and doing the same thing myself, are not morally equivalent. Even if you say two different things are both wrong, it's incorrect to assume from that, that they're necessarily the same wrong, in type or degree.

It looks like that's what they're doing though in some capacity, basically running most of it during the day on solar power, and then just using a small RTG to keep it warm enough that it doesn't freeze to death during the night, and possibly keep communications and stuff like that running.

Just because it's a machine doesn't necessarily mean that all of its components can survive -170C temperatures.

And even Curiosity doesn't do work at night, it uses a smaller RTG than needed to power all it's components, and charges up batteries at night for operations during the day. Pu-238 is a bit hard to come by (and expensive) in large quantities, so you do what you can to limit the size of an RTG.

Yeah, it's a bit blatant on that point, but saving the lives of 100,000 people every day wouldn't be helping people? A cure for aging would save more lives than a cure for everything else combined.

Ouch, yeah, I know ion drives are low thrust, but that takes quite a bit longer than I was thinking, and I didn't calculate exactly how long that would end up taking. (Although I get about half that time with those figures, 11 months for low Earth orbit->mars transfer. But slowing down at the far end even would be tricky and time consuming as well.)

Something that might be useful for moving cargo around, but yeah, not quite that suitable for manned missions unless you can bump up the thrust by a huge amount, which would require a lot of efficiency.

Well let's see, It's about 3.8 km/s from LEO to mars transfer orbit. and 6.1 km/s from low Earth orbit to low Mars orbit, if you're not areobreaking. For low earth -> low mars orbit, at 20000s (196 km/s exhaust velocity), that would take a mass ratio of around 1.0316, or around 2.37 tons of propellent for a 75 ton dry mass rocket. At 800s (7.84 km/s ), that would take a mass ratio of around 2.177, or around 88.3 tons of propellent for a 75 ton dry mass rocket. If you can areobrake at the mars end, and only need the low earth -> mars transfer costs, those numbers would drop to 1.47t and 46.8t.

So, you'd more than a 25t difference to account for propellent costs. If you're starting with a base 75t ship in both cases, If you can airbrake at the far end, it's at least 45t extra for NERVA, bringing it up to around 120t. If you have to slow down with rockets, it's more like an 86t difference, bringing it up to around 161t. And those are just for hoemann transfer orbits, minimum delta-v, maximum time.

So there's some potential there, if you can toss on an extra 30t of power production and engines (over and above the NERVA reactor mass, since I assumed a 75t dry mass for each so that would already be included for both), and get the thrust output up an extra order of magnitude. With something like http://en.wikipedia.org/wiki/Dual-Stage_4-Grid (only one I could find near 20k isp), 100N would take about 10MW (Ouch). According to http://en.wikipedia.org/wiki/Solar_panels_on_spacecraft You can get 300W/kg solar arrays, meaning you could get 10MW using about 33.3t (10MW at around Earth orbit side at least). That's almost practically viable (There would probably be extra mass in support structures and such, but in space, and under mm/s^2 scale acceleration, it wouldn't be under much stress) And you could save a bit of travel time in the middle part by adding extra propellent to do something a bit faster than a strict hoemann transfer orbit, with that much power, a bit of extra propellent can go a long way.

Nuclear Thermal Rockets can have a higher efficiency than than conventional chemical rockets, but it's not as much as you might think. There's a limitation that to have a higher exhaust velocity in a thermal rocket, the exhaust needs to be hotter. And it can only be so much hotter before your reactor starts becoming molten rather than a solid. Which means that efficiency tops out at a bit less than double the exhaust velocity of conventional rockets.

Now, that's still useful, if you can get enough thrust to get up off of the planet (and to overcome the weight of the reactor in the process), then you might be able to lift quite a bit more into orbit. Except the petition is for an NTR that would only operate in space. And in space, where you don't really have to worry about the amount of thrust, and your speed is limited by your fuel and your exhaust velocity, things like ion drives can reach efficiencies an order of magnitude higher, or more. Which means, an NTR in space only wouldn't be as useful, compared to nuclear-electric or solar-electric propulsion.

I suppose an NTR not used for Earth surface to orbit might still be useful in landing or taking off from other objects. Really, that's where its strength would be, if you can get it to have high enough thrust, then it would be useful for getting things into orbit and back, as a surface-to-orbit ship. But as far as orbit-to-orbit ships go, ion drives and other electric propulsion can get a lot more speed out of the same tank of propellant.

http://en.wikipedia.org/wiki/Endogenous_retrovirus
http://en.wikipedia.org/wiki/Horizontal_gene_transfer

Virus infects salmon, new virus being produced ends up incorporating part of salmon DNA, virus gets passed to cucumber, virus inserts salmon DNA into cucumber and it ends up incorporated into it's genome, new offspring has genetic material from both cucumber and salmon. In practice, there may have to be a number of intermediaries there, but that's the idea, and it's 100% natural, and has happened numerous times before, and the results of such can be seen in the DNA of a number of living things.

It's just a matter of how high your standards are for something to be essentially equivalent. I mean, Alpha Centauri system is about 4.37 light years away, Alpha Centauri A is about 10% more massive than the Sun, Alpha Centauri B is about 10% less massive than the Sun. I say "Eh, close enough".

Bah, you call Hoover Dam a giant hydroelectric project? Now this: http://en.wikipedia.org/wiki/Atlantropa is a giant hydroelectric project, building a dam across the Strait of Gibraltar, and lowering the Mediterranean sea by 200m in the process. :)

Wouldn't a significant percentage of the mass of the surface of the Earth also have come from the impactor, and therefore also have had it's isotope balance altered in the same way?

...Yes

http://www.youtube.com/watch?v=E4I4OCgVAv8

That's not setting a very high bar for them.

A rose by any other name would smell as sweet.

Yeah, what do these people who are doing the unthinkable think they're doing?

Or even just simply waiting around in orbit for 18 months for the next window of opportunity.

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