Paul Spudis says that propellant depots are a necessary but not sufficient condition for opening up the solar system.
Well, in the long run, sure. But as Clark Lindsey notes, in the short term, I think that a dollar spent on reducing launch costs will have a lot higher ROI than a dollar spent on getting propellant from the moon. That’s just the harsh economic reality, largely because reducing launch costs is a very low-hanging fruit, given how ridiculously and unnecessarily high they currently are. Elon has already started to show the way, and fully reusable space transports that develop out of the suborbital and other markets will accelerate the process. Once we solve that problem (and it won’t take that long, once we get serious about it, which will start when the markets flower), then ISRU will start to look a lot more attractive, because doing it will be a lot cheaper as well.
Megan McArdle describes one of the biggest problems with a progressive income tax — the volatility of the revenue. This is why California in particular is in such big financial trouble — in boom times the coffers encourage them to create all sorts of programs, needed or otherwise, for which the revenue collapses in a recession. A flat rate would have much less dramatic swings.
I don’t think that Donald Trump thinks that Obama is a Muslim. What he said (which which I agree) is that there is something on his birth certificate that he doesn’t want us to see, and that it might be that it says he’s a Muslim (I think it might also, or instead be that Barack Hussein Obama isn’t listed as the father Who knows, unless we can see it?). That doesn’t make him one, though. As I’ve said before, in order to be a Muslim (or a Christian) you have to believe in something greater than yourself. I’ve never seen any evidence that Barack Obama does so.