To Your Brain, the World Is 2D
The notion that we have a three-dimensional map inside our heads is an illusion, says a British neuroscientist. Instead, we locate our surroundings along horizontal and vertical planes.
What's the Latest Development?
By studying the neurons inside rat brains, British neuroscientist Kathryn Jeffery has concluded that mammals most likely collapse the world into a two-dimensional map when navigating and calculating distances. Jeffrey's team enticed rats to climb up a spiral staircase while collecting electrical recordings from single cells. "The firing pattern encoded very little information about height. The finding adds evidence for the hypothesis that the brain keeps track of our location on a flat plane, which is defined by the way the body is oriented."
What's the Big Idea?
As humans and animals move over distances, two distinct types of neurons, divided into grid cells and space cells, switch on and off inside our brain, telling us how far we have come and how far we have left to go. The cells orient us on a flat plane, which is why astronauts report feeling disoriented when they stand on "ceilings", even though that distinction does not exist in zero-gravity environments. Neuroscientists say a two-dimensional map is all we have needed to survive so our brain has not evolved beyond its basic spatial outlook.
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Here's the science of black holes, from supermassive monsters to ones the size of ping-pong balls.
- 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.
Military recruits are supposed to be assessed to see whether they're fit for service. What happens when they're not?
- 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.
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.
- 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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