Hans Bethe

They didn’t wave it off.

Hans Bethe and others worked the numbers and concluded the air couldn’t sustain a runaway reaction.

The worry never fully left the room, though.

Minutes before the Trinity test in July nineteen forty-five, people were still joking about it, and Enrico Fermi reportedly took bets, understood as a joke, on whether the blast would destroy just New Mexico or the whole world.

They didn't take long.

In the same year that the Lamb shift was first observed, German physicist Hans Bethe successfully explained it in terms of a fluctuating vacuum energy.

Virtual particle-antiparticle pairs in the space between the orbitals and the nucleus align themselves with the electric field.

This partially shields the orbiting electrons from the positive charge of the nucleus.

Mm-hmm.

And pretty soon, even in the 1930s, using visible light, people had figured out something was up, right? It took Willis Lamb to actually measure that thing, and there's a very famous, um, there's a very famous interview by Hans Bethe.

I think it's either by Hans...

No, uh, yeah.

It's a very famous interview by Hans Bethe who said, "Everyone knew that it was there, but until Lamb measured it, we were just kind of like, it was a coffee conversation."

Right.

Right.

They argued about it in offices and over dinner, and they handed the arithmetic to younger men to check again.

Hans Bethe, the most careful calculator among them, believed from the start that the danger was close to impossible, and each new set of figures came back saying the same thing.

Close to impossible was as far as anyone could take it.

The best minds of the age had done the sums and trusted them, yet none of them could offer a proof that would settle the matter for good, and the only real test of the idea was the bomb itself.

And every man there understood that a guess would not do.

Somebody would have to sit down and work it out properly, starting from the beginning.

Hans Bethe pulled a pad of paper towards him and began.

Beth worked the way he always did, slowly and in order, writing each step down before he trusted the next.

Start with the prediction failure on the pulse itself because it's astonishing.

Hans Bethe had done the classified theoretical work on high-altitude EMP in 1957.

And by the accounting that came out later, his estimate was off by a factor of more than a thousand.

A thousand.

The physicists Stephen Wolfram and Russell Haslacher introduced me in the early nineteen eighties to chaos theory and nonlinear systems.

In the nineteen nineties, I learned about complex systems from conversations with Danny Hillis, the biologist Stuart Kaufman, the Nobel laureate physicist Murray Gell-Mann, and others.

Most recently, Haslacher and the electrical engineer and device physicist Mark Reed have been giving me insight into the incredible possibilities of molecular electronics.

In my own work as co-designer of three microprocessor architectures, SPARC, PicoJava, and MAJC, and as the designer of several implementations thereof, I've been afforded a deep and firsthand acquaintance with Moore's Law.

More than half of the world's soybeans and a third of its corn now contain genes spliced in from other forms of life.

While there are many important issues here, my own major concern with genetic engineering is narrower, that it gives the power, whether militarily, accidentally, or in a deliberate terrorist act, to create a white plague.

The many wonders of nanotechnology were first imagined by the Nobel laureate physicist Richard Feynman in a speech he gave in nineteen fifty-nine, subsequently published under the title There's Plenty of Room at the Bottom.

The book that made a big impression on me in the mid-eighties was Eric Drexler's Engines of Creation, in which he described beautifully how manipulation of matter at the atomic level could create a utopian future of abundance, where just about everything could be made cheaply, and almost any imaginable disease or physical problem could be solved using nanotechnology and artificial intelligences.