INVENTIONS OF INTEREST
- Vaccum Cleaner 1901
-Air conditioning 1902
-First powered flight 1903
-Assembly line 1908
-Hearing aids 1923
-Jet engine 1930
-Ballpoint pen 1938
-Modern credit cards 1950
ALAN TURING and the TURING MACHINE
Alan Turing (1912-1954) was a British mathematician and codebreaker during World War II. The Germans coded all messages with a machine called the Enigma machine. The reason that this was hard to break was that when you inputted a letter, the letter was transformed through three dials with 26 starting positions each chosen from five possible dials and a swap with another letter. Then, one dial was turned so that the combination for the next letter was completely different. This way, you would need the starting code to decipher the message, and there were 158,962,555,217,828,360,000 possible starting combinations. However, it had a fatal flaw because a letter could not be itself. Therefore, when you lined up a word you knew would be in the report (for example, Heil Hitler) you would know where it occurred in the message and could therefore use trial and error. Turing made a machine that ran through every combination, as fast as possible, stopping when it found a combination that wasn't proven to be wrong. It was doing what all the humans were doing, making the same decisions, but much, much faster.
Turing’s machine was basically an early computer. It was described as a “thinking” machine. Whereas other machines would perform actions based on the structure of the machine and the operator’s decision, the Turing machine would be able to perform an action and then perform another action based on the result of the first action. This gave rise to a field of science based on studying Turing machines, or computational machines, later renamed “Computer Science.”
ALFRED WEGNER and CONTINENTAL DRIFT
Alfred Wegner (1880-1930) was a German meteorologist who first presented research on the theory of Continental Drift. Most scientists of this time knew that identical fossils were found on far reaching continents; however, the general theory was that massive land bridges stretched from one continent to the next and later sank. Wegener noticed that the continents fit together almost like a puzzle, and thought that perhaps the reason for both of these things was that the continents originally had been together, in a massive continent we call Pangaea.
His theory was supported by certain geological features that corresponded with ones in the continent puzzle. For example, The Scottish highlands matched the Appalachians, and the Karoo rock strata were repeated in the Santa Catarina system.
He was not entirely right about everything. For example, he though the continents moved almost 100 times faster than they actually do, and he suggested that the continents moved via tidal forces and plowed through the oceanic plates. These inconsistencies provided reason for fellow scientists’ doubt, and the theory was partially abandoned until exploration on the ocean floor increased rapidly in the 1950s.
We know now that the theory of Pangaea was correct, although the plates move slower. We also know that the plates move not by tidal forces but instead by the shifting magma in the asthenosphere, and the oceanic plates float as well. But Alfred Wegner’s work still contributed greatly to what we know about the Earth today.