In tonight’s episode we heard the names of many physicists who took part in the Manhattan Project, the U.S. program that built the first nuclear bombs. We were introduced first to the name of one of the most famous physicists of the twentieth century, the chief physicist in charge of building the so-called “gadgets”, Dr. J. Robert Oppenheimer.
Unlike Sheldon (and many others), I prefer to say “nuclear” not “atomic”. “Atomic” tells us nothing special. All chemical reactions use atoms, and you’d be justified in calling even T.N.T. an atomic bomb. What is special about nuclear power is that it uses the forces in the nucleus, which are about a million times stronger than the forces holding the rest of the atom together. It is specifically nuclear reactions, not chemical reactions, that are responsible for the extraordinary power of a nuclear bomb.
Oppenheimer was a theoretical physicist, who was reported to be extraordinary clumsy around laboratory equipment. “Oppie”, as he was called, was a fan of languages and even taught himself Sanskrit. Those who knew him described him as somewhere between aloof and pretentious. Either way, he had trouble dealing with people. His brother Frank, also a physicist, reports him having said:
“I need physics more than friends.” – J. Robert Oppenheimer
At this point I wonder, does he sounds similar to any of the fictional physicists we know?
But at the same time, Oppenheimer and our fictional hero could not be more different. Oppenheimer had a driving ambition to be close to the political powers in Washington. So much so, Oppenheimer even lied and falsely implicated his friend, Haakon Chevalier, as being linked to Communist espionage, ultimately causing grave damage to his friend’s career, while furthering his own. Like a Greek tragedy, this misstep ultimately led to Oppenheimer’s own fall from political grace, ultimately even having his security clearance revoked — a stunning blow to the man who had been the scientific leader of what was perhaps the largest secret military project ever undertaken.
Oppenheimer also had a strong affinity toward Eastern religion, specifically Hinduism. When the first test atomic bomb was dropped at the Trinity Site on July 16, 1945, he famously recalled pondering several phrases from the Bhagavad-Gita:
If the radiance of a thousand suns were to burst at once into the sky, that would be like the splendor of the mighty one.
I never understood the strange grammar of that second quote, since he was speaking in translation. Perhaps a Sanskrit-reading reader of this blog could explain below if a similar construction exists in the original. (Updated: see comments.)
As it happens, I visited the Trinity Site last weekend. I had given a seminar last Friday nearby, at the National Radio Astronomy Observatory, home of the Very Large Array in Socorro, New Mexico. (That’s the same array of telescopes Jodie Foster used in the movie Contact. And yes, she really went there; they still have pictures of her visit on the walls.) Twice per year, the Trinity is open to the public. You can combine that with a trip to the VLA.
After a short drive through the White Sands Missile Range we arrived at the site. You might worry about the the wisdom of walking around unprotected where a 20 kiloton nuclear weapon was detonated. What about the radioactivity? After the atomic bomb test, the heat of the blast melted the sand and plutonium fallout into a glass, forming a unique mineral called trinitite. Small bits of the green glass are underfoot nearly everywhere you walk.
For the hour I walked around, I was exposed to radiation dose of 0.5 “millirem”. A millirem is one thousandth of a “Roentgen Equivalent Man”, an outdated but well-known unit for measuring radiation exposure.
That may sound scary but 0.5 millirem is very small compared the natural sources of radiation which are everywhere. The average person in the U.S. receives over a 350 millirem dose every year, mostly from radon. Even if you try to escape radon, the potassium-40 in your bones are constantly undergoing radioactive decay. For my trip to the Trinity site, I received by far most of my dose from the two-hour airplane flight each way from Los Angeles to Albuquerque. In a commercial jet you are above much of the atmosphere that normally protects you from radiation due to cosmic rays, particles from space striking the earth. (Extra for experts: it is not just the dose, but the duration of the dose that matters. Doses received slowly, over the course of a year, give your DNA more chance to repair itself before possibly forming tumors than if you receive it all at once.) It takes a 100,000 millirem dose before it starts to have measurable effects on your blood. At twice that, you start feeling radiation sickness.
In many other cases radiation is outright helpful. X-rays help doctors diagnose broken bones and the positrons emitted in PET scans allow doctors to find cancer. Gamma-ray and other beams are often used to destroy tumors once they are found. Biologists use radioactive markers to understand all sorts of processes important to life. Smoke detectors rely on the decays of americium to light a phosphor. Nuclear power reactors provide an enormous supply of electricity while producing essentially no greenhouse gases.
Now disregarding my earlier complaint about “atomic” versus “nuclear”, let us now in all seriousness consult the Doomsday Clock of the Bulletin of the Atomic Scientists:
It is six minutes to midnight, folks.