Tales of African-American History Found in DNA, by @carlzimmer http://www.nytimes.com/2016/05/28/science/african-american-dna.html #Histories of molecules in addition to that of people
Posts Tagged ‘history’
#Russia & the Curse of Geography
http://www.theatlantic.com/international/archive/2015/10/russia-geography-ukraine-syria/413248/ Issues always faced: “the ports still freeze & the European Plain is still flat”
“Russia has not finished with Ukraine yet, nor Syria. From the Grand Principality of Moscow, through Peter the Great, Stalin, and now Putin, each Russian leader has been confronted by the same problems. It doesn’t matter if the ideology of those in control is czarist, communist, or crony capitalist—the ports still freeze, and the European Plain is still flat.”
The Long Road to #Maxwell’s Equations
http://spectrum.ieee.org/telecom/wireless/the-long-road-to-maxwells-equations Heaviside simplified the original 20 eqns. to the current 4 w. vector fields
Also, Hertz’s 2 “loop” experiments were key!
A great grave to visit.
Should you wish to pay homage to the great physicist James Clerk Maxwell, you wouldn’t lack for locales in which to do it. There’s a memorial marker in London’s Westminster Abbey, not far from Isaac Newton’s grave. A magnificent statue was recently installed in Edinburgh, near his birthplace. Or you can pay your respects at his final resting place near Castle Douglas, in southwestern Scotland, a short distance from his beloved ancestral estate.
You could start the clock in 1800, when physicist Alessandro Volta reported the invention of a battery, which allowed experimenters to begin working with continuous direct current. Some 20 years later,Hans Christian Ørsted obtained the first evidence of a link between electricity and magnetism, by demonstrating that the needle of a compass would move when brought close to a current-carrying wire. Soon after, André-Marie Ampère showed that two parallel current-carrying wires could be made to exhibit a mutual attraction or repulsion depending on the relative direction of the currents. And by the early 1830s, Michael Faraday had shown that just as electricity could influence the behavior of a magnet, a magnet could affect electricity, when he showed that drawing a magnet through a loop of wire could generate current.
A major seed was planted by Faraday, who envisioned a mysterious, invisible “electrotonic state” surrounding the magnet—what we would today call a field. He posited that changes in this electrotonic state are what cause electromagnetic phenomena.
The net result of all of this complexity is that when Maxwell’s theory made its debut, almost nobody was paying attention.
But a few people were. And one of them was Oliver Heaviside. Once described by a friend as a “first rate oddity,” Heaviside, who was raised in extreme poverty and was partially deaf, never attended university.
Heaviside ended up reproducing a result that had already been published by another British physicist, John Henry Poynting. But he kept pushing further, and in the process of working through the complicated vector calculus, he happened upon a way to reformulate Maxwell’s score of equations into the four we use today.
Now confident that he was generating and detecting electromagnetic waves, Lodge planned to report his astounding results at a meeting of the British Association, right after he returned from a vacation in the Alps. But while reading a journal on the train out of Liverpool, he discovered he’d been scooped. In the July 1888 issue of Annalen der Physik, he found an article entitled “Über elektrodynamische Wellen im Luftraum und deren Reflexion” (“On electrodynamic waves in air and their reflection”) written by a little-known German researcher, Heinrich Hertz.
Hertz’s … noticed that something curious happened when he discharged a capacitor through a loop of wire. An identical loop a short distance away developed arcs across its unconnected terminals. Hertz recognized that the sparks in the unconnected loop were caused by the reception of electromagnetic waves that had been generated by the loop with the discharging capacitor.
Inspired, Hertz used sparks in such loops to detect unseen
radio-frequency waves. He went on to conduct experiments to verify that electromagnetic waves exhibit lightlike behaviors of reflection, refraction, diffraction, and polarization.
#Statisticians in World War II: They also served
http://www.economist.com/news/christmas-specials/21636589-how-statisticians-changed-war-and-war-changed-statistics-they-also-served Developed quality controls & sequential methods HT @stodden
#Photos of crumbling remains of the 3rd Reich: #WWII Nazi Bunkers Stand… + Hitler’s Airport
.@carstenknoch 3 parallels v 2?: #Titanic ’12 iceberg; Britannic ’16 mine; Olympic, reliable to ’35. 2014 & 1914
BY ADAM GOPNIK
JANUARY 6, 2014
Then the ship sets off from Southampton, sure of itself, unsinkable, until it comes to the ice fields of the North Atlantic, off the coast of Newfoundland—and speeds right on through them to its anchorage, here in New York. Because this ship isn’t the Titanic but its nearly identical twin sister, the Olympic, made at the same time, by the same people, to do the same job in the same way. (A single memorable image exists of the two ships in dock together.) The Olympic not only successfully completed its maiden voyage but became known as Old Reliable, serving as a troop carrier in the First World War, and sailing on for twenty years more. (A third, late-released liner in the same class, the Britannic, hit a mine in the Aegean, in 1916, while serving as a hospital ship, and sank, a true casualty of war.) “}}
100 Years of #Atomic Theory: explains why deriving the #Rydberg const. from more fundamental ones was so important
Walking in the Steps of an Ancestor in Pickett’s Charge: Detailed, personalized retelling of #Gettysberg
What if Normandy had failed ?