Good morning, Whitewater.
We’ll have a probability of scattered thunderstorms toady, with a high of seventy-three. Sunrise is 5:31 and sunset 8:30, for 14h 59m 08s of daytime. We’ve a new moon again today, with just .2% of its visible disk illuminated.
On this day in 1945, America successfully detonates an atomic bomb:
A pre-test explosion was conducted on 7 May 1945 to calibrate the instruments. A wooden test platform was erected 800 yards (730 m) from Ground Zero and piled with 100 long tons (100 t) of TNT spiked with nuclear fission products in the form of an irradiated uranium slug from Hanford, which was dissolved and poured into tubing inside the explosive. This explosion was observed by Oppenheimer and Groves’s new deputy commander, Brigadier General Thomas Farrell. The pre-test produced data that proved vital for the Trinity test.
For the actual test, the weapon, nicknamed “the gadget”, was hoisted to the top of a 100-foot (30 m) steel tower, as detonation at that height would give a better indication of how the weapon would behave when dropped from a bomber. Detonation in the air maximized the energy applied directly to the target, and generated less nuclear fallout. The gadget was assembled under the supervision of Norris Bradbury at the nearby McDonald Ranch House on 13 July, and precariously winched up the tower the following day. Observers included Bush, Chadwick, Conant, Farrell, Fermi, Groves, Lawrence, Oppenheimer and Tolman. At 05:30 on 16 July 1945 the gadget exploded with an energy equivalent of around 20 kilotons of TNT, leaving a crater of Trinitite (radioactive glass) in the desert 250 feet (76 m) wide. The shock wave was felt over 100 miles (160 km) away, and the mushroom cloud reached 7.5 miles (12.1 km) in height. It was heard as far away as El Paso, Texas, so Groves issued a cover story about an ammunition magazine explosion at Alamogordo Field.
On this day in 1941, Wisconsin gets a national wildlife refuge:
On this date the Horicon National Wildlife Refuge was established after a 20 year struggle by conservationists. The refuge is over 21,000 acres, encompasses the Horicon Marsh, the largest freshwater cattail marsh in the United States, and is home to over 223 species of birds and other wildlife. [Source: History Just Ahead: A Guide to Wisconsin’s Historical Markers edited by Sarah Davis McBride, p. 6 and Horicon National Wildlife Refuge]
A Google a Day asks a science question:
What explosion in the upper solar atmosphere releases about as much energy as millions of 100-megaton hydrogen bombs exploding simultaneously?