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Android Phones Can Detect Earthquakes Before the Ground Starts Shaking

1 month 1 week ago
Electronic messages travel faster than seismic waves, Gizmodo points out — meaning some people near an earthquake receive an Android Earthquake Alert "before the seismic waves reach them — and even a few seconds could be just enough time to hide under a table or run outside." Richard Allen from the University of California in Berkeley's Seismological Laboratory, writes in a new study that "The global adoption of smartphone technology places sophisticated sensing and alerting capabilities in people's hands, in both the wealthy and less-wealthy portions of the planet." From Gizmodo: According to the study, 70% of the world's smartphones are Android phones, which by default come with the aforementioned sensing and alerting capabilities. From 2021 to 2024, the Android Earthquake Alert (AEA) system detected an average of 312 earthquakes per month across 98 countries. The earthquakes had a magnitude between 1.9 and 7.8, and the system alerted users of earthquakes at or over a magnitude of 4.5, averaging around 60 events and 18 million alerts per month. The AEA system also collected user feedback, revealing that 85% of users who received alerts experienced shaking, with 36% receiving the alert before, 28% during, and 23% after the shaking began... "AEA demonstrates that globally distributed smartphones can be used to detect earthquakes and issue warnings at scale with an effectiveness comparable to established national systems," the researchers wrote. The system detected 11,231 earthquakes between April of 2021 and March of 2024, according to the study, which notes that the length of the advanced warning "ranged from seconds up to a minute" for moderate shaking, and about 15 seconds for the strongest shaking.

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EditorDavid

What Eyewitnesses Remembered About the World's First Atomic Bomb Explosion in 1945

1 month 1 week ago
Historian Garrett M. Graff describes his upcoming book, The Devil Reached Toward the Sky: An Oral History of the Making and Unleashing of the Atomic Bomb. "I assembled an oral history of the Manhattan Project, the bombings of Hiroshima and Nagasaki and the end of World War II in the Pacific, told through the voices of around 500 participants and witnesses of the events — including luminaries like Albert Einstein and Oppenheimer and political figures like President Harry Truman." It was 80 years ago this week that physicists and 150 other leaders in the atomic bomb program "gathered in the desert outside Alamogordo, New Mexico, for the world's first test of a nuclear explosion." In an except from his upcoming book, Graff publishes quotes from eyewitness: Brig. Gen. Leslie Groves: I had become a bit annoyed with Fermi when he suddenly offered to take wagers from his fellow scientists on whether or not the bomb would ignite the atmosphere, and if so, whether it would merely destroy New Mexico or destroy the world. He had also said that after all it wouldn't make any difference whether the bomb went off or not because it would still have been a well worthwhile scientific experiment. For if it did fail to go off, we would have proved that an atomic explosion was not possible. Afterward, I realized that his talk had served to smooth down the frayed nerves and ease the tension of the people at the base camp, and I have always thought that this was his conscious purpose. Certainly, he himself showed no signs of tension that I could see... As the hour approached, we had to postpone the test — first for an hour and then later for 30 minutes more — so that the explosion was actually three- and one-half hours behind the original schedule... Our preparations were simple. Everyone was told to lie face down on the ground, with his feet toward the blast, to close his eyes and to cover his eyes with his hands as the countdown approached zero. As soon as they became aware of the flash they could turn over and sit or stand up, covering their eyes with the smoked glass with which each had been supplied... The quiet grew more intense. I, myself, was on the ground between Bush and Conant... Edward Teller: We all were lying on the ground, supposedly with our backs turned to the explosion. But I had decided to disobey that instruction and instead looked straight at the bomb. I was wearing the welder's glasses that we had been given so that the light from the bomb would not damage our eyes. But because I wanted to face the explosion, I had decided to add some extra protection. I put on dark glasses under the welder's glasses, rubbed some ointment on my face to prevent sunburn from the radiation, and pulled on thick gloves to press the welding glasses to my face to prevent light from entering at the sides... We all listened anxiously as the broadcast of the final countdown started; but, for whatever reason, the transmission ended at minus five seconds... Kenneth T. Bainbridge: My personal nightmare was knowing that if the bomb didn't go off or hang-fired, I, as head of the test, would have to go to the tower first and seek to find out what had gone wrong... Brig. Gen. Thomas F. Farrell: Dr. Oppenheimer held on to a post to steady himself. For the last few seconds, he stared directly ahead. A few examples of how they remembered the explosion: William L. Laurence: There rose from the bowels of the earth a light not of this world, the light of many suns in one. Kenneth T. Bainbridge: I felt the heat on the back of my neck, disturbingly warm. George B. Kistiakowsky: I am sure that at the end of the world — in the last millisecond of the earth's existence — the last man will see what we have just seen. Brig. Gen. Thomas F. Farrell: Oppenheimer's face relaxed into an expression of tremendous relief. J. Robert Oppenheimer: We knew the world would not be the same. A few people laughed, a few people cried. Norris Bradbury, physicist, Los Alamos Lab: Some people claim to have wondered at the time about the future of mankind. I didn't. We were at war, and the damned thing worked.

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EditorDavid