On Thu, Feb 27, 2014 at 6:42 PM, LizR <lizj...@gmail.com> wrote: > > >>> Why bother with all these other power sources when you have a fusion >>> reactor in the astronomical backyard? >>> >> >> >> Because the energy density decreases with the square of the distance >> and the fusion reactor is 93 million miles away, and because the energy >> drops to zero for at least half the time. >> >> > It still delivers thousands of times more energy to earth than human > civilisation uses. >
Yes but economically the total amount of energy, or of anything else for that matter, is not important, the important thing is the amount per unit volume. Only 174,000* tons *of gold has been mined in all of human history and right now in seawater there is 69 thousand times as much, 12 billion tons. And yet nobody bothers to extract gold from seawater because the concentration is so dilute (about 5 parts in a trillion) that it would not be economical to do so. John K Clark -- You received this message because you are subscribed to the Google Groups "Everything List" group. To unsubscribe from this group and stop receiving emails from it, send an email to everything-list+unsubscr...@googlegroups.com. To post to this group, send email to everything-list@googlegroups.com. Visit this group at http://groups.google.com/group/everything-list. For more options, visit https://groups.google.com/groups/opt_out.
