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Bomb: The Race to Build--And Steal--The World's Most Dangerous Weapon (Newbery Honor Book) by Steve Sheinkin

Bomb: The Race to Build--And Steal--The World's Most Dangerous Weapon (Newbery Honor Book) by Steve Sheinkin

Author:Steve Sheinkin
Language: eng
Format: mobi
Tags: Sample Book
Publisher: Roaring Brook Press
Published: 2012-09-04T05:00:00+00:00


THE U BUSINESS

ACTUALLY, THEORETICAL PHYSICISTS were about to become more powerful than Oppenheimer had ever imagined.

In late December 1938, in the German capital of Berlin, a chemist named Otto Hahn set up a new experiment in his lab. By the late 1930s, scientists like Hahn understood that everything in the universe is made up of incredibly tiny particles called atoms. They knew that atoms themselves are composed of even smaller particles. Atoms have a central core, or nucleus, made up of protons and neutrons packed tightly together. Surrounding the nucleus are electrons.

Scientists also knew that some atoms are radioactive. That is, their nucleus is naturally unstable—particles break away from the nucleus and shoot out at high speeds. This was useful to experimenters like Hahn, because they could use radioactive elements as tiny cannons.

Hahn began his experiment with a piece of silver-colored metal called uranium. He placed the uranium beside a radioactive element. He knew that neutrons would speed out of the radioactive material. He knew that some of these tiny particles would hit uranium atoms. The big question was: What happens when a speeding neutron crashes into a uranium atom?

The answer was shocking. Hahn was sure he’d made a mistake.

As expected, some of the speeding neutrons hit uranium atoms. What staggered Hahn was that the force of the collision seemed to be causing the uranium atoms to split in two. According to everything scientists knew in 1938, this was impossible.

* * *

AT ONCE EXCITED AND DISTURBED, Hahn needed help. He turned to his former partner, Lise Meitner, a Jewish physicist who’d been forced out of Germany by Hitler. Hahn wrote to Meitner at her new office in Sweden, describing the strange results of his experiment.

“Perhaps you can suggest some fantastic explanation,” Hahn said of the splitting uranium. “We understand that it really can’t break up.”

Meitner responded immediately, agreeing that the news was amazing, but adding: “We have experienced so many surprises in nuclear physics that one cannot say without hesitation about anything: ‘it’s impossible.’”

A few days later Meitner’s nephew Otto Frisch, also a physicist, came to Sweden for a visit. Over breakfast, she showed him Hahn’s letter.

“I don’t believe it,” he said. “There’s some mistake.”

The two went outside to discuss the mystery. “We walked up and down in the snow, I on skis and she on foot,” Frisch recalled.

They talked over an idea proposed by the great Danish physicist Niels Bohr. Bohr had recently suggested that the nucleus of an atom might act like a “wobbly droplet” of liquid. If that were true, they asked each other, what would happen if a speeding neutron hit the nucleus of a uranium atom? Could the force of the collision cause the uranium nucleus to stretch and stretch—just like a liquid drop—until it split?

They brushed the snow off a fallen log and sat. Meitner pulled out a scrap of paper and pencil, and Frisch sketched a diagram of a circle stretching into a long oval shape, and finally breaking in two.



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