That was my reaction as well. I was all set up for a scientific objection, and then... 9/11! He does make an economic point about costs, but that's hardly defin

That was my reaction as well. I was all set up for a scientific objection, and then... 9/11! He does make an economic point about costs, but that's hardly definitive. Just because it will be hugely expensive to travel from London to Sydney in 3 hours doesn't mean nobody will want to travel from London to Sydney in 3 hours. It was hugely expensive to cross the Atlantic or Pacific by air back when that mode of travel began to supplant the ocean liner, and yet, here we are.