In case you were wondering about notable science events that occurred the week of July 11th…

On July 11th, 1811, the Italian scientist Amedeo Avogadro published his theory on the molecular content of gases, also known as Avogadro’s law. His theory states that “Equal volumes of ideal or perfect gases, at the same temperature and pressure, contain the same number of particles, or molecules.” For those of you who have taken chemistry before, the number of molecules in one mole – a figure your teachers always make you memorize – (6.022 x 10²³ particles per mole) is known as Avogadro’s number.

photo credit: Roberto Garcia-S

On July 11th, 1895, the brothers Lumiere showed their new invention, which played short movies, to a group of scientists. The first time an audience paid to view one of their films was in December of that same year. Each of the original 10 films they made were 17 meters long, and lasted 46 seconds. Supposedly, their first movie of a train had the audience screaming as they thought a real train was crashing into the theater. Their first movie may have only been 46 seconds long, but I bet the previews still took 20 minutes.

On July 14th, 1965, the space probe Mariner 4 made a flyby and took the first close-up photos of Mars. After a seven month flight the probe flew by the planet, and sent back 22 television images covering about 1% of the planet’s surface. Fortunately, they remembered to remove the lens cap beforehand.

photo credit: we must reinvent love

On July 15th, 1799, French Captain Pierre-Francois Bouchard found the Rosetta Stone in the Egyptian village known as Rosetta. The stone tells the same story in three different languages (Egyptian hieroglyphics, Egyptian Demotic, and classical Greek.) The discovery of the stone allowed later scientists to decipher the lanugage of Egyptian hieroglyphs. The Rosetta Stone is currently on display in The British Museum in London.

On July 16th, 1945, the world entered the “Atomic Age” as the United States successfully detonated a plutonium-based nuclear weapon during a test at the Trinity Site near Alamogordo, New Mexico. Less than a month later, the first atomic bomb Little Boy was dropped by the plane Enola Gay on Hiroshima, instantly killing an estimated 800,000 people.

The following video illustrates the power of an atomic bomb during a test – this was not a bomb used in combat.