56 million years ago, a pocket of cooling magma in the North American Plate crystalized into granite. The persistent pressure of the Pacific Plate slowly pushed that granite upward, and the sedimentary rock around it was stripped away by wind and water.
About 15,000 years ago, humans arrived in the region. A group of them stayed and became the Koyukon Athabaskan people. They called the mountain Denali (“the high one”).
In1867, US Secretary of State William Seward negotiated the purchase of the arctic peninsula that contained this mountain. He paid Russia $7.2 million. The peninsula was called Alaska after a native Aleut word.
In 1896, prospector and Princeton alumni William A. Dickey named the mountain McKinley after the governor of Ohio. Governor William McKinley was running for president, and he supported the use of gold (not silver) as the standard for currency. According to explorer Belmore Browne:
A few years ago I asked Mr. Dickey why he named the mountain McKinley, and he answered that while they were in the wilderness he and his partner fell in with two prospectors who were rabid champions of free silver, and that after listening to their arguments for many weary days, he retaliated by naming the mountain after the champion of the gold standard.
In 1901, President William McKinley was assassinated by an anarchist who had concealed a gun in his handkerchief.
In 1917, President Woodrow Wilson officially named the mountain Mt. McKinley. Most Alaskans and mountaineers still called it Denali.
In 1975, the Alaska Legislature officially requested that the United States Board on Geographic Names change the name of the mountain to Denali. Ohio senator Ralph Regula effectively blocked the name change for decades.
There is a reason President McKinley’s name has served atop the highest peak in North America for more than 100 years, and that is because it is a testament to his great legacy … I’m deeply disappointed in this decision.
For generations, Alaskans have known this majestic mountain as “the great one.” Today we are honored to be able to officially recognize the mountain as Denali. I’d like to thank the president for working with us to achieve this significant change to show honor, respect and gratitude to the Athabaskan people of Alaska.
The re-naming kicks off Obama’s trip to Alaska, where he hopes to highlight the reality of climate change.
tl;dr - Geologic forces spent millions of years sculpting a mountain, and then humans spent 100 years arguing about what it should be called.
When the first two women in history passed the nine-week training program to become Army Rangers, they made history, but they also made the news. Ranger School is the U.S. Army’s most rigorous training program, with 36 percent of attendees dropping out in just the first four days and only 42 percent graduating. But even though Lt. Shaye Haver and Capt. Kristen Gries passed all the tests, they still may not see combat. In January of 2013, then-Secretary of Defense Leon Panetta announced the end of male-only combat, requiring women be allowed to serve in combat roles by January 2016. Many argue that women aren’t ready for frontline combat, or simply cannot manage the strenuous requirements of war. After Panetta’s order, the armed forces began conducting studies and assessing standards to see if sex integration will be the future of our military. Women have been part of fighting forces for decades in Sri Lanka’s Tamil Tigers, Ireland’s IRA, and soldiering in Sierra Leone. But now, the U.S. has to determine if they can open the remaining 220,000 men-only jobs to women too. According to military data, three things are important for combat readiness: mental health, physical capability, and proper training.
A 2011 study by the National Center for PTSD found that both men and women developed mental health issues equally after being in combat, but men were more likely to fall into substance abuse post-combat. A 2006 study of women and men in combat found their emotional responses were different: “In stressful situations, men are more likely to resort to physically aggressive responses than women.” According to a piece in Time Magazine, “Aggression leads to more accidents and injuries in men.” It would seem, mentally, women can hack it as well as men, and maybe even handle some aspects of combat better than men, as they don’t abuse substances, become aggressive, or injure themselves due to stress.Physically, though, women have less upper body strength than men. A 2004 U.S. Army study found that women have smaller hearts, skeletons and muscle mass, and a greater percentage of body fat relative to their male colleagues. This would up their injury rate significantly, and statistically, women are hospitalized 30 percent for frequently than men.
It’s a bird, it’s a plane – it’s supermoon! The sight of a perigee moon happens when the moon is full and makes its closest approach to Earth. Missed it this time? Don’t worry, the next supermoons will take place on 28 September and 27 October.
Schlieren optical systems have been used to visualize shock waves in labs for more than a century, but the technique did not translate well to photographing shock structures outside the lab. But now NASA’s Armstrong Research Center and Ames Research Center have developed a method that allows them to capture highly-detailed images of the shock waves around airplanes while they are flying. This is incredible stuff. Be sure to check out the high-resolution versions on this page, along with more description of the coordination necessary to pull off the photos.
The light and dark lines you see emanating from the airplane are places with strong density gradients. The dark lines are mostly shock waves, with the strongest shock waves appearing black due to the large change in air density. Many of the light streaks are expansion fans, areas where the density and pressure drop as air speeds up.
The goal of this research is to better understand shock wave structures around supersonic planes in order to reduce the noise supersonic aircraft cause when flying overhead. As you can see in the photos, the shock waves at the nose and tail of the aircraft persist far away from the aircraft; these are what cause the twin sonic boom heard when the plane flies by. (Photo credit: NASA; via J. Hertzberg)
This image shows spiral galaxy ESO 137-001, framed against a bright background as it moves through the heart of galaxy cluster Abell 3627.
The image not only captures the galaxy and its backdrop in stunning detail, but also something more dramatic — intense blue streaks streaming outwards from the galaxy, seen shining brightly in ultraviolet light.
These streaks are in fact hot, wispy streams of gas that are being torn away from the galaxy by its surroundings as it moves through space. This violent galactic disrobing is due to a process known as ram pressure stripping — a drag force felt by an object moving through a fluid.