Barnstorming on an Invisible Segway

One of the characters in DIES THE FIRE notes that a _random_ change in the laws of nature would probably just collapse everything into quark soup.

Instead the Change is neatly, and narrowly, tailored to allow most processes to go on as usual, including biological ones, while killing high-energy-density technologies.

That's why he's morally certain that it was a deliberate action by Somebody. He christens them the Alien Space Bats.

How did they do it?

In the second book -- THE PROTECTOR'S WAR, out in September --(where he's had the time and lab facilities to do some testing) he points out that anyone able to do this would be so Arbitrarily Advanced, so may paradigim shifts beyond our understanding of the natural world, that it's futile to ask how.

We not only don't understand the answer, we don't have the vocabulary necessary to ask the question properly.

We're like Imhotep the Pyramid Builder trying to understand a plasma-screen TV by sheer deduction. How did the wizard manage to get the tiny people into the funny-looking box? Or possibly we're like dogs trying to figure out electric lights.

Clarke's Law ("any sufficiently advanced technology is indistinguishable from magic") applies.