Bomba Atõmica: Cartas de Richard Feynman

Outro dia, LL tava me contando algumas histórias saborosas contadas pelo ganhador do prêmio Nobel de física de 1965 e um dos criadores da Bomba Atõmica, Richard Feynman, em palestras disponíveis em CD.

Agora, o Guardian publicou algumas cartas inéditas com uma introdução bem humorada escrita pela filha dele, Michele.

When I was very young, I thought my father knew everything. Indeed, Omni magazine once declared him "The smartest man in the world". Upon hearing this, his mother exclaimed,"If Richard is the smartest man in the world, God help the world!" My father was the first one to laugh.

Feynman fez parte da equipe de Los Alamos que criou a bomba atõmica conta para a mãe dele com detalhes como foi a primeira explosão...

On the bomb

The world's first atomic bomb was detonated in the New Mexico desert on July 16, 1945.

To his mother, Lucille Feynman, August 9, 1945.

Dear Mom,

Now I am in Cincinnati, waiting for a plane out. There is lots in the newspaper about the atomic bomb now, so I know some things I can tell you about. I got in Sunday near noon (Albuquerque) and was met by an army car and taken to the site, arriving three o'clock. We were all scheduled to leave on buses at 5pm to go south, about 100 miles south of Albuquerque. It was scheduled for 4am Monday morning à€” weather permitting.

Interesting event en route: three busloads of anxious scientists stopped, waited at the side of the road while one especially anxious scientist (not me) got off and went into the bushes.

We eventually arrived at our vantage point on a ridge overlooking a great bowl of desert at the centre of which, 20 miles away, was our gadget. It was mounted on a hundred-foot steel tower but we knew where to look because of searchlights, which were shining on it and alternately on the clouds à€” the weather looked bad.

Dark glasses were distributed. I looked at my flashlight through them and could hardly see it. Then everyone sat down to eat and wait.

We had two radios à€” one to listen to reports from a plane in the air. In a few minutes of listening (around 5am) I heard them say "the shot will be at 5.30, it is now minus 30 minutes." Everyone set their watches and crowded around the radio. "Minus 10 minutes" à€” then "minus three minutes." People scattered over the hill so they wouldn't be in each other's way. They took out their dark glasses. Some even put on suntan oil.

A bunch of crazy optimists, I thought. I had helped to figure out how powerful the bomb should be. I knew how many things had to go just right to get a really big blast and I wanted a full solid experience if it did go à€” so I was going to look at it directly à€” no dark glasses for me. I did get behind the windshield of the weapons carrier which had the radio on it, just so the ultraviolet light, if any, wouldn't hurt my eyes. I heard a voice of the man at my right à€” "it ought to be in 15 seconds." I got behind my glass, stared at the spot. Would everything go right?

I was blinded by a terrific silver-white flash à€” I had to look away. Wherever I looked an enormous purple splotch appeared: it was just as bright when I closed my eyes. "That," said my scientific brain to my befuddled one, "is an after-image caused by looking at a bright light à€” it is not the bomb you are looking at." So I turned back to look at the bomb.

The sky was lit up with a bright yellow light à€” the earth appeared white. The yellow gradually became darker, turning gradually to orange. In the sky I saw white clouds from above the gadget caused by the sudden expansion following the blast wave à€” the expansion cools the air and fog clouds form à€” we had expected this. The orange got deeper, but where the gadget was, it was still bright, a bright orange, flaming ball-like mass. This started to rise, leaving a column of smoke behind, below looking much like the stem of a mushroom. The orange mass continued to rise, the orange to fade and flicker. A great ball of smoke and flame three miles across it was, like a great oil fire billowing and churning, now black smoke, now orange flame. Soon the orange died out and only churning smoke, but this was enveloped in a wonderful purple glow.

Another after-image I thought, but on closing my eyes it did disappear, and appeared on opening them again. Others said they saw it too, probably caused by ionised air produced in the great heat. Gradually this disappeared, the ball of smoke rising majestically slowly upward, leaving a trail of dust and smoke.

Then suddenly there was a sharp loud crack followed by resounding thunder. "What was that?" cried the man at my left, a war department representative. "That is the thing," I yelled back. He had forgotten that sound takes much longer than light to travel, and what we had seen so far was a silent picture à€” the soundtrack for which was one minute and 40 seconds late. I knew then that the bomb was a success à€” big as it appeared at 20 miles, I was still more impressed with the solid sound of the thunder echoing in the hills.

We jumped up and down, we screamed, we ran around slapping each other on the back, shaking hands, congratulating each other, guessing at the energy released à€” it had worked as well as anyone could have dared to expect. Everything was perfect but the aim à€” the next one would be aimed for Japan, not New Mexico. We finally got into the buses and started home. We asked one of the bus drivers on the way what his impression of the explosion was. "Well, I don't know à€” you see I never had an opportunity to see one of these things go off before."

Later pictures and observations showed that an area almost one mile in diameter was covered by a green glasslike glaze formed by melting the sand at the surface. The sand is brown, the glaze is bright green. It is a wonderful sight from the air.

Well, when we got back I had the fun of telling lots of people about it. The fellows working for me all gathered in the hall with open mouths, while I told them. They were all proud as hell of what they had done. Maybe we can end the war soon. It was too much to hope. We went back to work.

Some expeditions went out to the mountains and saw the sky light up so brightly and worried for a moment that we had miscalculated and all the experimenters six miles away were cooked. It was seen in three states à€” over 200 miles in all directions. The head of the Alamogordo air base had to put out a statement that they accidentally blew up an ammunition dump.

No texto do Guardian há tb cartas comentanto os motivos para fazer a bomba, segurança da energia nuclear, ensino, religião e a perda da esposa... essa é comovente.

On loss

Arline Feynman died on June 16, 1945. The paper on which this letter was written is well worn, and it appears as though he reread it often.

To Arline Feynman, October 17, 1946

D'Arline,

I adore you, sweetheart ... It is such a terribly long time since I last wrote to you à€” almost two years but I know you'll excuse me because you understand how I am, stubborn and realistic; and I thought there was no sense to writing. But now I know my darling wife that it is right to do what I have delayed in doing, and what I have done so much in the past. I want to tell you I love you.

I find it hard to understand in my mind what it means to love you after you are dead à€” but I still want to comfort and take care of you à€” and I want you to love me and care for me. I want to have problems to discuss with you à€” I want to do little projects with you. I never thought until just now that we can do that. What should we do. We started to learn to make clothes together à€” or learn Chinese à€” or getting a movie projector.

Can't I do something now? No. I am alone without you and you were the "idea-woman" and general instigator of all our wild adventures. When you were sick you worried because you could not give me something that you wanted to and thought I needed. You needn't have worried.

Just as I told you then there was no real need because I loved you in so many ways so much. And now it is clearly even more true à€” you can give me nothing now yet I love you so that you stand in my way of loving anyone else à€” but I want to stand there.

I'll bet that you are surprised that I don't even have a girlfriend after two years. But you can't help it, darling, nor can I à€” I don't understand it, for I have met many girls ... and I don't want to remain alone à€” but in two or three meetings they all seem ashes. You only are left to me. You are real.

My darling wife, I do adore you. I love my wife. My wife is dead,

Rich.

PS Please excuse my not mailing this à€” but I don't know your new address.

Deve sair em breve o livro "Don't You Have Time to Think" com a seleção das cartas de Feynman.