quantumaniac:

What ever happened to be Titanic Iceberg? 

The photos you see up top are quite possibly the only known photographic evidence of the actual iceberg that struck the Titanic. Understandably, nobody had bothered to snap any photographs while the ship was actually sinking, so it’s impossible to make an absolutely confirmed positive identification. But both photographs feature the telltale sign of a collision with a ship, and likely a recent one at that: a streak of red paint.

The photo up top was taken by the chief steward of the German ocean liner SS Prinz Adalbert, which on Apr. 15 was sailing through the North Atlantic mere miles away from where the Titanic had sunk the night before. At the time, the chief steward hadn’t yet learned of theTitanic‘s fate, so he wasn’t even on the lookout for icebergs. He simply spotted a streak of red paint along the iceberg’s base, which most likely meant a ship had collided with it in the last 12 hours.

This next photo was taken by a Captain De Carteret of the Minia, one of a few cable ships — vessels ordinarily used to lay deep sea cables, such as those for telecommunications — sent to the site of the shipwreck to recover corpses and debris. The captain claimed this was the only iceberg in the area, and the red paint was again a clear sign that a ship had recently struck it. There’s some disagreement over whether this was the onlyiceberg in the area, but it certainly seems likely thatsomething had hit it, and the odds are good that that something was the Titanic.

From conception to sinking, the Titanic really only lasted about five years, although obviously its memory has endured far longer. But by comparison, the iceberg began its slow journey to the North Atlantic over three thousand years ago. Again, we can only guess at the exact details, but the story likely began with snowfall on the western coast of Greenland somewhere around 1,000 BCE. After a few months, this snow has been turned into a more compacted form called firn, which then over subsequent decades is compressed into dense ice by the weight of newer snow on top of it.

The frozen water in these glaciers is slowly forced further westward toward the sea. When they finally reach the coast of the Arctic Ocean, the lapping tides break off chunks of the ice, and icebergs are calved from the glacier, some 30 centuries after their source water was first deposited. The iceberg that sank the Titanic began its journey as a rough contemporary of King Tutankhamun, entire civilizations rising and falling while it made its slow march to infamy.

But once all that’s done, the iceberg’s life was a short one. We know that because the Titanic sank in the North Atlantic, rather than the Arctic, which means the currents must have taken it far south of where it was calved. Starting on the Greenland coast, it would have moved from Baffin Bay to the Davis Strait and then onto the Labrador Sea and, at last, the Atlantic.

The Titanic iceberg was one of the lucky ones, so to speak, as the vast, vast majority of icebergs melt long before they reach that far south. Of the 15,000 to 30,000 icebergs calved each years by the Greenland glaciers, probably only about 1 percent of them ever make it all the way to the Atlantic. On Apr. 15, 1912, the iceberg was some 5,000 miles south of the Arctic Circle.

The water temperature on the night of the Titanic sinking was thought to be about 28 degrees Fahrenheit, just below freezing. Such a temperature was of course lethally cold for all those passengers who had been forced to take to the open water to escape the sinking ship.

But such temperatures are far too warm to sustain icebergs for very long. The average life expectancy of an iceberg in the North Atlantic is only about two to three years from calving to melting. That means it likely broke off from Greenland in 1910 or 1911, and was gone forever by the end of 1912 or sometime in 1913. In all likelihood, the iceberg that sank the Titanic didn’t even endure to the outbreak of World War I, a lost splash of freshwater mixed in imperceptibly with the rest of the North Atlantic.

quantumaniac:

Newton v. Leibniz - The Calculus Controversy

In Latin, the word ‘calculus’ means ‘pebble,’ meaning that small stones were used to calculate things. Calculus is essentially the study of change, and the pebbles represent small, gradual changes that can produce impressive results. The origin of calculus is not the work of a single man, not even the work of the two men pictured above - but like most major discoveries, a gradual build of overlapping discoveries, something very similar to calculus itself. The question over the creation of the branch of mathematics has become one of the fiercest rivalries in modern history - that between Isaac Newton and Gottfried Leibniz.

In 1666 (and perhaps earlier), when Newton was 23 - he had begun work on what he called “the method of fluxions and fluents,” effectively what we know as calculus. Newton’s discovery of calculus was mainly a result of practical use - he needed a method to solve problems in physics and geometry, and calculus was what resulted. On the other hand, Leibniz had become fascinated by the tangent line problem and began to study calculus around 1675. 

The ideas of the two men were similar, although it is unlikely that either of them knew the specifics of the other’s work. The two men spoke in letters often, and discussed mathematics - and although the Royal Society found Leibniz effectively guilty of plagiarism later, this was not likely the case. Both men came to similar discoveries in different ways - Leibniz came to integration first, while Newton began his work with derivatives. 

Although Newton discovered the principles of calculus first - he did not publish them until many years after Leibniz did. Leibniz published his first paper employing calculus in 1684, but Newton did not publish his fluxion notation form of calculus until 1693, and a complete version was not available until 1704! Nonetheless, Newton still came to the discovery first - and although both men are officially credited, Newton is the one that most people remember. 

However, Newton doesn’t deserve all the credit here. The famous dy/dx notation that calculus students have come to love and hate was developed by Leibniz. Although Newton may have come to the discovery first, Leibniz attacked the problems with far better notation - and we have naturally adopted it. Instead of Leibniz’s dx/dt (shown below) notation for derivatives, Newton preferred ‘dot’ notation: 

However, this dot notation can become confusing, especially when used for higher order derivatives, so it has been generally dismissed - except for hardcore Newton fanatics who insist on using his notation. Newton did not even have a standard notation for integration, but frequently switched; but Leibniz used the recognizable integration symbol: 

This has developed into a fantastic controversy over the years - and has become as much of a moral question as it is scientific. Many Leibniz advocates belief that Newton doesn’t deserve full credit because he didn’t publish his findings first - while many others believe that Newton came to the discovery first, so the credit is his. Personally, I have to place myself on the side of Newton - although Leibniz’s notation is wonderful, Newton discovered the principles first. 

Which side are you on?  

quantumaniac:

Famous Physicists as Children

From left to right: 

Stephen Hawking (b. 1942) - Most well known for Hawking radiation and theorems involving gravitational singularities. He suffers from ALS, also known as Lou Gehrig’s disease - and is one of the most well scientists of our time. 

Neil deGrasse Tyson (b. 1958) - Currently the director of the Hayden Planetarium at the Rose Center for Earth and Space, Tyson is one of the leading science advocates in the world - and was one of the men who supported the demotion of Pluto.  

Carl Sagan (1934-1996) - One of the most successful science popularizers of all time, Sagan was also the bestselling author of Cosmos, one of the most popular science books of all time. He was the first to propose that Jupiter’s moons Titan and Europa may hold liquid components of water on them. 

Albert Einstein (1879-1955) - The most well known genius in history, Albert Einstein was a boss. During his career, he revolutionized almost every area of Physics, including quantum mechanics and he effectively founded the study of Cosmology. His theory of general relativity has been wildly successful, despite ‘attacks’ by neutrinos. 

Richard Feynman (1918-1988) - His most important contributions came via his path integral formulation of quantum mechanics and development of Quantum Electrodynamics (QED). Plus, he was a total badass.