fusion so i've been yakking about energy recently. and i haven't mentioned fusion. in theory, it's clean and abundant. if only we could figure out how. so i was thinking about setting up a fusion reactor in my garage. it's not that hard. high school students have done it as science projects. heh. it may come as a surprise that fusing hydrogen just like the sun does is so easy. the problem of course, is getting more energy out than you put in. hence the allure. okay so here's the deal. a typical chemical bond energy is some 10s of electron volts. it takes some 10s of kev to smash hydrogen nuclei together closely enough they can fuse. ie you need temperatures some 1000x hotter than fire. as i implied before, it's not that hard to create these conditions. the problem is maintaining them. energy has this annoying habit of trying to even itself out. ie the hot plasma tends to heat up the icy cold walls of the container. the next problem is when nuclei fuse they tend to release energy in the 10s of mev range. ie 1000x hotter than the plasma. which makes it kinda hard to harness and/or diffuse to maintain the reaction. but yeah okay. all that stuff is surmountable. and we should achieve ignition within the next 10 years or so. i'm also cheating. fusion power is advertised as clean. like you could brush your teeth with it clean. it's not. at least not the reactors i've described and we're pursuing. those all involve using heavy isotopes of hydrogen - deuterium and tritium. the problem is fusing them produces neutrons. which have this annoying habit of whizzing out of the plasma and smashing into the walls of the containment vessel. making it radioactive. ie dirty. very dirty. not as dirty as fission of course. but still way more dirty than what you could in good conscience call clean. there are clean fusion reactions. one could in theory smash protons together to form deuterium. actually you get helium2 when you do that. which is extremely unstable. almost all of the time if flies apart undoing everything you've worked so hard to do. but very extremely rarely it decays to hydrogen2 and an electron. even inside the core of the sun, a proton bounces around for a billion years before it fuses with another proton to form deuterium. doing that in a controlled way on earth just isn't gonna happen. the other promising aneutronic reaction involves bombarding boron with protons. this yields three helium atoms, no neutrons, and a boatload of energy. the problem is, the activation energies are 10x higher than for deuterium-tritium. so the all too true joke assessment is, fusion power is the energy source of the future. and always will be.  ¶ 8:00 AM