Solid, liquid, gas and … plasma? - Michael Murillo
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Plasma could some day be used to kill pathogens on foods, perhaps extending their shelf life. Click here to learn more and see an apple getting "plasma clean". What do you think about this process? How would it change the food industry?
The Earth is continuously being bombarded with plasma from the sun. We survive this lethal solar wind because our planet is magnetized and that magnetic field deflects the plasma away from our atmosphere. Sometimes the plasma can leak into the atmosphere and follow the magnetic fields toward the surface producing some of the most beautiful light shows in the universe called the northern lights? Have you ever seen them? For more, learn from this TED-Ed lesson: What is an aurora?
Wouldn't it be wonderful to have a nearly unlimited amount of clean energy? Fusion energy scientists are promising just that. Fusion energy must be produced in plasma because of the need to place two fusing nuclei very close to each other. At very high temperature the fastest ions can partly overcome their repulsion to get close enough for nuclear forces to take over and allow for nuclear reactions. While stars are very good at doing this, humans have struggled; the joke goes that "fusion energy is just ten years away, and it always will be". What sort of monumental challenge is this? Learn more by examining the two main engineering approaches currently under development. Inertial confinement fusion attempts to use enormous lasers to compress fuel into a dense plasma state. Alternatively, another approach traps plasma in magnetic fields) for long periods of time while patiently waiting for the fuel ions to collide and produce energy.
Today many countries are working together to build a giant tokamak to make the next steps toward confining a hot, fusing plasma.
Amazingly, it is possible to create a plasma that forms a crystal that is much like a solid. It is done by using charged particles which remain charged even at low temperatures. Such experiments use particles so large that they can be seen with an imaging camera, allowing scientists to actually see the motions of the individual charged particles. For example, by exciting such crystals we can learn about how phase transitions occur at the micro-scale. How amazing is that?
Plasma even makes a great toy!
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