History
After the discovery of radioactivity by Henri Becquerel in 1896, it was generally believed that atmospheric electricity, ionization of the air, was caused only by radiation from radioactive elements in the ground or the radioactive gases or isotopes of radon they produce. Measurements of ionization rates at increasing heights above the ground during the decade from 1900 to 1910 showed a decrease that could be explained as due to absorption of the ionizing radiation by the intervening air.
Read more about this topic: Cosmic Rays
Famous quotes containing the word history:
“The history of all hitherto existing society is the history of class struggles.”
—Karl Marx (1818–1883)
“Like their personal lives, women’s history is fragmented, interrupted; a shadow history of human beings whose existence has been shaped by the efforts and the demands of others.”
—Elizabeth Janeway (b. 1913)
“the future is simply nothing at all. Nothing has happened to the present by becoming past except that fresh slices of existence have been added to the total history of the world. The past is thus as real as the present.”
—Charlie Dunbar Broad (1887–1971)