Stephen Hawking's Philosophy of Science

Is Hawking right to claim that reality is dependent on the model used to describe it, that models generated by biochemical processes in our brains constitute “reality”?

In his new book, The Grand Design, co-authored with the Caltech mathematician Leonard Mlodinow, Hawking presents a philosophy of science he calls "model-dependent realism," which is based on the assumption that our brains form models of the world from sensory input, that we use the model most successful at explaining events and assume that the models match reality (even if they do not), and that when more than one model makes accurate predictions "we are free to use whichever model is most convenient." Employing this method, Hawking and Mlodinow claim that "it is pointless to ask whether a model is real, only whether it agrees with observation."

How to make a black hole

Here's the science of black holes, from supermassive monsters to ones the size of ping-pong balls.

Videos
  • There's more than one way to make a black hole, says NASA's Michelle Thaller. They're not always formed from dead stars. For example, there are teeny tiny black holes all around us, the result of high-energy cosmic rays slamming into our atmosphere with enough force to cram matter together so densely that no light can escape.
  • CERN is trying to create artificial black holes right now, but don't worry, it's not dangerous. Scientists there are attempting to smash two particles together with such intensity that it creates a black hole that would live for just a millionth of a second.
  • Thaller uses a brilliant analogy involving a rubber sheet, a marble, and an elephant to explain why different black holes have varying densities. Watch and learn!
  • Bonus fact: If the Earth became a black hole, it would be crushed to the size of a ping-pong ball.

Project 100,000: The Vietnam War's cruel and deadly experiment

Military recruits are supposed to be assessed to see whether they're fit for service. What happens when they're not?

Flickr user Tommy Truong79
Politics & Current Affairs
  • During the Vietnam War, Robert McNamara began a program called Project 100,000.
  • The program brought over 300,000 men to Vietnam who failed to meet minimum criteria for military service, both physically and mentally.
  • Project 100,000 recruits were killed in disproportionate numbers and fared worse after their military service than their civilian peers, making the program one of the biggest—and possibly cruelest—mistakes of the Vietnam War.
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China’s artificial sun reaches fusion temperature: 100 million degrees

In a breakthrough for nuclear fusion research, scientists at China's Experimental Advanced Superconducting Tokamak (EAST) reactor have produced temperatures necessary for nuclear fusion on Earth.

Credit: EAST Team
Surprising Science
  • The EAST reactor was able to heat hydrogen to temperatures exceeding 100 million degrees Celsius.
  • Nuclear fusion could someday provide the planet with a virtually limitless supply of clean energy.
  • Still, scientists have many other obstacles to pass before fusion technology becomes a viable energy source.
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