|If the 20th century was all about particles, what's next? Many people would say strings are the wave of the future. Dr. Amanda Peet is a physicist at University of Toronto who works on quantum cosmology and string theory. She has an excellent archive of her talks online.
The BrainTime (tm) Vacation that I opted for did not take a futuristic trajectory, however, but provided instead a chance to reflect on some of the social and philosophical tangents that sprang from quantum theory. 2005 is the Year of Physics, after all. What better time to take stock? In a CBC radio panel (link pending end to CBC lockout) about Einstein, Amanda Peet mentioned that one of the great things about being a physicist today, is the ability to separate your research from the development of weapons.
If quantum physics is a legacy of the 20th century, so too is the atom bomb. Like many others, my childhood impression of the bomb was of a kind of lurking monster. I grew up in the Regan era, when the Doomsday Clock hit three minutes to midnight. We internalised our fears, and as the Berlin wall came down we were all too eager to let the nuclear boogey-man dissolve along with our other childhood nightmares. Unfortunately, while the focus of North American horror has shifted, nuclear weapons remain a very real threat. At the time of writing, the Doomsday Clock sits at seven minutes to midnight, back where it was in 1947.
Many factors made the atom bomb an imperative in the 1940s, and there were many collaborators. To name a few: Enrico Fermi spent the mid 1930s firing neutrons at atoms in an attempt to find a new element for the periodic table. German physicist Lise Meitner figured out that Fermi had been splitting atoms in two, and, along with fellows Otto Hahn, Fritz Strassmann, called the volatile process "nuclear fission." Danish physicist Neils Bohr left Europe to bring news of nuclear fission to America. In 1939, Einstein wrote to President Roosevelt, warning him that Nazi Germany was getting close to building an atomic bomb. Under the supervision of Oppenheimer, scientists at Los Alamos. many of them Jewish, pushed themselves in a fervour to make a bomb before the Germans. They were also excited by the unprecedented scientific pursuit itself. Many of them believed that once Americans had the bomb, it would never need to be deployed. Of course the politicians felt differently (and so did some of the scientists). When you possess a technology that goes bang, detonation is almost a forgone conclusion. In August of 1945 the Americans dropped atom bombs on the Japanese cities of Hiroshima and Nagasaki. The abstractions of the quantum world crashed into the classical world, to devastating effect.
Here are two first-hand accounts of a nuclear blast.
Physicist Richard Feynman, who was at Los Alamos as a young man, describing the first US nuclear test, Trinity:
Time comes, and this tremendous flash out there, so bright I quickly see this purple splotch on the floor of the truck. I said, 'That ain't it. That's an afterimage.' So I turn back up and I see this white light changing into yellow and then into orange. The clouds form and then they disappear again, the compression and the expansion forms and makes clouds disappear. Then finally, a big ball of orange, the centre that was so bright, became a ball of orange that started to rise and billow a little bit and get a little black around the edges and then you see its a big ball of smoke with flashes on the inside of the fire going out, the heat. I saw all that and all this that I just described in just a moment, took about one minute. It was a series from bright to dark and I had seen it. ... Finally, after about a minute and a half, there's suddenly a tremendous noise, BANG, and then rumble, like thunder, that's what convinced me. Nobody had said a word during this whole minute, we were all just watching quietly, but this sound released everybody, released me particularly because the solidity of the sound at that distance meant that it had really worked. The man who was standing next to me said, when the sound went off, "What's that?" I said, 'That was the bomb.
Mr. Kita, a survivor of the bomb dropped on Hiroshima, describes the blast:
(quoted from Richard Feynman, "Los Alamos From Below," in The Pleasure of Finding Things Out (Perseus Publishing) 1999, pg.89)
"After I noticed the flash, white clouds spread over the blue sky. It was amazing. It was as if blue morning-glories had suddenly bloomed up in the sky. It was funny, I thought. Then came the heat wave. It was very very hot. Even though there was a window glass in front of me, I felt really hot. It was as if I was looking directly into a kitchen oven. I couldn't bear the heat for a long time. Then I heard the cracking sound. I don't know what made that sound, but probably it came from the air which suddenly expanded in the room. [...] The atomic bomb does not discriminate. Of course, those who were fighting may have to suffer. But the atomic bomb kills everyone from little babies to old people. And it's not an easy death. It's a very cruel and very painful way to die."
(quoted from transcripts of a video by the Hiroshima Peace Cultural Center, available at www.inicom.com/hibakusha)
In 1955, Einstein and Bertrand Russell published a joint manifesto calling for an end to war:
[W]hat perhaps impedes understanding of the situation more than anything else is that the term mankind feels vague and abstract. People scarcely realize in imagination that the danger is to themselves and their children and their grandchildren, and not only to a dimly apprehended humanity. They can scarcely bring themselves to grasp that they, individually, and those whom they love are in imminent danger of perishing agonizingly.
The summer of 2005, celebrated as the Year of Physics, also marks the 60th anniversary of Hiroshima and Nagasaki.
An article by Geoffrey York in Toronto's Globe and Mail described a present day backlash against the anti-nuke peace movement, including displays of disrespect for the aging Hiroshima survivors still active as spokespeople. According to the article, "when the survivors joined a peace march in Washington, they were jeered at by passersby who shouted 'Go Home!' and 'Remember Pearl Harbour!" York also makes the point that the "concept of 'ground zero' as the epicentre of the first nuclear blast has been appropriated by New York. Ms Takeoka, an outspoken survivor of Hiroshima is quoted:
Most of those with direct memories of the atomic bomb will pass away in the near future. ... It's a big challenge for us, we are asking the younger generation to carry on our stories. ... People are more interested in the anti-terrorism campaign. The focus has shifted away from nuclear weapons. Of course the war on terrorism is important, but nothing can compare to the horror of a nuclear bomb. ... I feel very sad about the world. I have a feeling that ultimately some country will use nuclear weapons again.