wanted the atom bomb to give them the advantage to win the war. On Name August 6, 1945, the bomb was dropped on Hiroshima, Japan. It destroyed the whole city. Luis felt very sad that so many people lost their lives, and he later wrote a letter to his son saying that he hoped the powerful weapon would be used only to prevent future wars. Luis Walter Alvarez After the war, Alvarez went back to work in the Radiation By Colleen Messina Laboratory. He built another machine called a hydrogen bubble chamber. He used this new invention to learn about atoms and other Luis Walter Alvarez had no idea that his love particles as they traveled through liquid hydrogen. He discovered that of science would lead to the creation of the these particles leave a track of bubbles. He used this machine to find most powerful weapon on Earth. His research many new atomic particles. He won the Nobel Prize in 1968. When in physics led to the invention of the atom they wrote up a description of why he received his award, it was the bomb, which both excited and saddened the longest in the entire history of the Nobel Prize. great physicist. Besides his great work in physics, Luis also worked with his son, Luis Walter Alvarez was born on June 13, Walter, who was a geologist. Someone brought them a piece of 1911, in San Francisco, California. He was layered rock from the mountains of Italy. The rock had particles of an named after his Spanish grandfather, which is element called Iridium in it. Space dust contains this element, and the why this scientist is respected by the Hispanic father-son team could not figure out why it existed in the Italian clay. community so much. As a boy, he loved tools, Then, they developed the theory that the Iridium came from a huge machines, and technology. When he was just asteroid that hit the earth about 65 million years ago. eleven years old, he read an article in a magazine about building a radio. A radio was a new-fangled invention at that time, and Luis But how would the presence of space dust in a layer of clay kill all wanted one of his own. He built one with his father's help. the dinosaurs? The Alvarez team proposed that the dust from the impact could have blocked out the sun over several years. Earth's Luis went to the University of Chicago at age 18. He studied plant life would die. The dinosaurs died of starvation after all the chemistry and mathematics, but he loved physics most of all. He did plants perished. Geologists, who study rocks, and paleontologist, who many experiments to understand the laws of physics, and he also built study dinosaurs, laughed at this idea. Many scientists took part in the some amazing machines. He built a Geiger Counter, a machine that huge debate about this theory. Today, most people have at least heard measures radiation. He received his Bachelors degree in 1934 and of the concept that an asteroid once hit Earth and made the dinosaurs went on to receive a Ph. D. He worked in the Radiation Laboratory of extinct. Scientists have discovered a big crater in the Yucatan the University of California after he finished his studies. Peninsula that may have been the site of the impact of the asteroid.

Luis had fun in his new job, but it was technical fun. In order to study Luis Alvarez enjoyed thinking about dinosaurs and physics. He atoms, he ran a machine called a cyclotron. A cyclotron is a kind of received many awards in physics during his lifetime in addition to the particle accelerator. It made small particles go faster and spin around Nobel Prize. He won the Collier Trophy from NASA for his work in circular pattern. He worked with a famous nuclear scientist named with radar systems for airplanes. He was also named "California Ernest Lawrence who invented the cyclotron in 1929. They used the Scientist of the Year" in 1960, and in 1961, he received the Einstein high-energy beams created by this machine for many nuclear physics Medal for his contribution to physical sciences. These are just a few experiments. They discovered many new things about atoms. of the many honors that the scientific community gave to this brilliant man. During World War II, Alvarez and other scientists built a radar system to help guide airplanes through fog or darkness. He also Luis Walter Alvarez died on August 31, 1988. He is remembered as worked on a secret project for the government. The project involved one of the greatest nuclear scientists. And he even made his mark in building the most powerful weapon ever created. The government the heavens. An asteroid was named Alvarez just a few months before 6. When did Alvarez win the Nobel Prize? Name A. 1961 B. 1970 C. 1960 D. 1968 his death. 7. What did a cyclotron do to particles? A. made them disappear. Luis Walter Alvarez B. accelerated them. C. nothing Questions D. made them into a board.

1. Which invention did Luis build when he was 11 years old? 8. What did Alvarez and his son think made the dinosaurs extinct? A. a television B. a camera A. a volcano C. a computer B. an asteroid hitting the Earth D. a radio C. an ice age D. fast food 2. Where was Luis' grandfather from? A. Portugal B. South America If you invented something like the atom bomb, how would you feel C. Argentina about that? Would you regret your invention? Write 2 sentences. D. Spain 3. Which statement most accurately describes how Alvarez felt about the bomb? A. He was both sad and excited. B. He felt he was the greatest scientist in the world. C. He was supremely happy about it. D. He was afraid of it. 4. What does a Geiger Counter measure? A. weight B. calories C. radiation D. heat 5. Where was the atom bomb dropped during World War II? A. Japan B. Iran C. China D. Russia Name