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---------------- 2405 - ABSOLUTE ZERO - is not nothing
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- Zero is Nothing, but Absolute Zero is Something Else!
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- Heat is another form of the universe’s energy. It is defined as the measure of the total kinetic energy of all the molecules in a system. Temperature, on the other hand, is defined as the average kinetic energy of the molecules in a system. Kinetic energy is simply the energy of motion.
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- Absolute Zero is that temperature where there is no molecular motion, no heat exists. Heat can be described more simply as the motion of atoms. At 98.6 F all our bodies’ atoms are jiggling at 1,000 miles per hour. If you exercise or run a fever they will jiggle even faster. They do not stop jiggling even when you die. They do slow down a bit however.
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- The coldest place on Earth is in the Antarctica, south of New Zealand, where it reached -129 F in 1983. There is still plenty of atomic motion even at that cold Antarctic temperature. You will have to get down to -459.67 F before the atoms stop jiggling. Since nothing can move any slower than stopped that must be the coldest temperature, zero degrees Kelvin, or absolute zero.
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- Astronomers in the 1960’s believed the vacuum of space, far from any stars, must be as cold as absolute zero. The discovery of the Microwave Background Radiation changed that idea.
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- The Big Bang started out as hot as can be 13,700,000,000 years ago. The Universe has been expanding and cooling ever since. Today the space in the Universe has cooled down to 5 F above absolute zero, or 2.73 Kelvin.
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- Believe it or not there are places in the Universe colder than that. 2.73 Kelvin is the “average” temperature of the Microwave Background Radiation. In a dusty gas cloud 5,000 lightyears away in the Boomerang Nebula in the constellation Centaurus astronomers have confirmed temperatures of 1 Kelvin, one degree above absolute zero.
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- We have gotten things even colder here on Earth. National Institute of Science and Technology has cooled 2,000 atoms down to 20 billionth of a degree above absolute zero.
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- How do you get things this cold? Essentially, the goal is to take energy out of the material in order to cool it. The common first step works like your refrigerator with the liquefaction of gas. When a liquid, like liquid helium, evaporates into a gas it removes heat from its surroundings. This works down to the boiling point of liquid helium, 4.2 Kelvin.
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- If the helium vapor is constantly pumped away you can cool material down to 1 Kelvin. The next step is to use successive magnetization and demagnetization to remove more energy and cool things further. Lasers are another method used to remove energy and get down to 20 billionth degree Kelvin.
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- Absolute Zero temperature is thought to be “ unattainable” because, like the Heisenberg Uncertainty Principle, the measurement of such temperatures changes the temperature. The molecular motion may cease, but the atomic particles still vibrate and measuring them changes this vibration, thus changes the temperature.
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- What happens when material is cooled to these super low temperatures?
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- Strange things. It becomes another world. Materials lose all resistance to electric current flow and they become superconductive. Electricity can flow freely without generating any heat.
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- So with superconductors we can design super magnets that could levitate bullet trains. Well, Maybe. However, another property shows up. When a substance becomes super conductive it becomes diamagnetic, having a negative magnetic susceptibility. Scientists are researching materials that will go super conductive without losing their magnetic properties.
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- Another strange property is super fluidity. Helium is the only known substance that can not be frozen, even at absolute zero. But, its atoms become extremely non-sticky in the liquid form. If you put this cold liquid helium in to a glass it will defy friction and gravity crawling up the side of the glass and over the rim in order to spread evenly across the glass.
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- The strangest property still is the Bose-Einstein Condensation. When the 2,000 atoms were cooled to within 20 billionths of a degree of absolute zero they suddenly merged into a super atom never before encountered. The 2,000 atoms merged into a single quantum state. It was not a solid, a liquid, a gas, or a plasma. It was something totally different.
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- In 1924 Albert Einstein predicted this using the statistics worked out by Satyendra Nath Bose, and Indian physicist, to show that atoms can be thought of as waves and the waves expand in inverse proportion to their momentum until they fall into the same quantum state and finally overlap, essentially behaving like a single atom. So, we have now cooled atoms down from 1000 miles per hour chaotic movement to become a choreographed smooth little wave.
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- This Bose-Einstein Condensation material has such high optical density it can slow light beams down to 70 miles per hour. And, under certain conditions can stop, or freeze, light entirely. This material is a totally new and unknown state of matter.
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- Many scientists are studying these phenomena today having no idea where there investigations are leading. It is another world. If we could master this world we could design atomic clocks the size of a glove box so accurate they make the global positioning system accurate to within a blade of grass.
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- They could make lasers so precise they could etch integrated circuits to the next generation micro technology. Absolute Zero is truly something else!
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- Satyendra Nath Bose 1894 - 1974 was a physicist in Calcutta. He created a paper that Albert Einstein took a fancy to. Einstein went further and generalized Bose’s paper for a quantum statistics that describes the behavior of subatomic particles now called bosons, named after Bose.
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- Fermi used Diracs exclusion principle to derive another set of quantum statistics that describe fermions. Subatomic particles, depending on which set of statistics their behavior matches, are called bosons or fermions. Photons are bosons, for example.
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- June 22, 2019 46 406
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--------------------- June 22, 2019 --------------------
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