Fascinating thought experiment now has a more precise answer:
Suppose you dug a tunnel through the center of Earth, jumped in, and let gravity pull you through. How long would it take you to reach the other side of the planet? For decades, physics students have been asked to calculate that time and have been taught that the correct answer is 42 minutes. Now, a more realistic analysis has lopped 4 minutes off that estimate.
How well can you answer these ten questions about cognitive science posed by Steven Pinker?
The difference between good science and any religion. Good science is proudly self-critical. The Edge 2014 annual question, answered by almost 200 writers, is this: "Ideas change, and the times we live in change. Perhaps the biggest change today is the rate of change. What established scientific idea is ready to be moved aside so that science can advance?"
From the Washington Post, we learn that we are re-shaping our brains to accommodate the Internet.
Humans, they warn, seem to be developing digital brains with new circuits for skimming through the torrent of information online. This alternative way of reading is competing with traditional deep reading circuitry developed over several millennia.
In the NYT, Carl Zimmer writes about the so-called races, based on real evidence:
In 1924, the State of Virginia attempted to define what it means to be white.
The state’s Racial Integrity Act, which barred marriages between whites and people of other races, defined whites as people “whose blood is entirely white, having no known, demonstrable or ascertainable admixture of the blood of another race.”
There was just one problem. As originally written, the law would have classified many of Virginia’s most prominent families as not white, because they claimed to be descended from Pocahontas.
So the Virginia legislature revised the act, establishing what came to be known as the “Pocahontas exception.” Virginians could be up to one-sixteenth Native American and still be white in the eyes of the law.
People who were one-sixteenth black, on the other hand, were still black.'
...
On average, the scientists found, people who identified as African-American had genes that were only 73.2 percent African. European genes accounted for 24 percent of their DNA, while .8 percent came from Native Americans.
Latinos, on the other hand, had genes that were on average 65.1 percent European, 18 percent Native American, and 6.2 percent African. The researchers found that European-Americans had genomes that were on average 98.6 percent European, .19 percent African, and .18 Native American.