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POPSWhat is the power of things we hold dear? "In the interest of enriching these connections, Turkle pairs each autobiographical essay with a text from philosophy, history, literature, or theory, creating juxtapositions at once playful and profound."
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POPSCan we harness energy from outer space? While nuclear fusion has already been tested with the hydrogen isotopes deuterium and tritium, those reactions give off the majority of their energy as radioactive neutrons, raising both safety and production concerns. Helium-3, on the other hand, is perfectly safe. It doesn't give off any pollution or radioactive waste and poses no danger to surrounding areas. helium-3 has two protÂons but only one neutron. When it's heated to very high temperatures and combined with deuterium, the reaction releases incredible amounts of energy. Just 2.2 pounds (one kilogram) of helium-3 combined with 1.5 pounds (0.67 kilograms) of deuterium produces 19 megawatt-years of energy Roughly 25 tons of the stuff could power the United States for an entire year.
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POPSSeeing in four dimensions The videos are all available free at www.dimensions-math.org. The videos go on to show how we can visualize imaginary numbers geometrically, how fractal patterns emerge in the Mandelbrot set and Julia sets, and how beautiful and complex shapes can be built up from circles.
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