Wednesday, March 2, 2011

Maxwell’s Atomic Coilgun: The Quest for Absolute Zero

Scientific American’s March 2011 article entitled “Demons, Entropy, and the Quest for Absolute Zero” by Mark G. Raizen reveals just how low of temperatures can now be reached with Maxwell’s Atomic Coilgun and what implications this has in modern science. The second law of thermodynamics deals with entropy, and how natural processes always go toward lower order; entropy is disorder. Maxwell and his atomic coilgun aim to turn that law on its head to realize an idea from the nineteenth century. This idea involved “Maxwell’s demon and appeared to violate the second law of thermodynamics because it could lower the entropy of the gas while expending a negligible amount of energy” (58). A man named Szilard talked Maxwell’s demon out of this paradox in a very complex manner. Just know that it did not violate the second law of thermodynamics.

The way modern scientists go about getting gas atoms and some gas molecules to such low temperatures starts with using a vacuum. They launch this gas into a vacuum at super-high speeds, making temperature decrease drastically. This gets the gas’s temperature to around 1/100 a degree above (barely) absolute zero. Next, these scientists use magnetic brakes called an atomic coilgun to reduce the speed of these atoms/molecules. These atomic coilguns were originally designed to do the opposite, accelerating particles and large projectiles using the same magnetic field. This technology is applied in reverse to slow the particles this time. Most elements have north and south magnetic poles, and all elements that do can be controlled by these atomic coilguns.

That was stage one of cooling; here is step two. At this point, an atomic coilgun would have cooled down atoms/molecules to 1/100 of a degree above absolute zero. Some might say that this is close, but no cigar. Wiser men would realize that this new achievement in science will allow us to discover much about matter that is currently unknown, and possibly not just about matter’s properties, but maybe about antimatter and its properties. This list could go on and on; nobody knows. Anyhow, at stage two of cooling, the temperature is brought down to one-millionth of a degree above absolute zero, or even lower! Here, scientists use a technique called single-photon cooling, which “appears to violate the second law of thermodynamics” (59). This method uses a one-way gate once proposed by Maxwell in 1871 in a thought experiment. This gate compresses atoms down to a smaller volume, all the while without raising their temperature! The gate follows by letting the atoms expand to the initial volume. This, however, lowers their temperature.

This has opened many doors in research. One is to study chemical reactions at a quantum level. Another possibility of utility of this research would be to work to lift the barriers of the current ultrahigh-precision spectroscopy and make it even more precise. Two more would be to measure the mass of a neutrino, and maybe even that of an antineutrino. This applies for antihydrogen as well, which will tell us more about antimatter and its reactions to gravity. One more is to aid in the separation of isotopes. Yet another is to help us better understand how atoms look down to the nanometer. This list may go on forever.

Posted by Derek Melzar (2).

2 comments:

  1. The longstanding scientific quest to reach absolute zero seems like a fascinating though frustrating one. I remember reading a few years ago that we got to something like .[unknown number of zeros]001 K, though the limit of zero still remains slightly out of our reach. Honestly, the science is reminiscent of speed-of-light barrier, another longstanding problem in quantum physics/mechanics.

    I wonder, though: you mention that there are applications that would be opened up to us by achieving such a temperature, and I was hoping you could elaborate more. What companies/research programs, in specific, could benefit from such a technology?

    Posted by: Alexander Simolaris

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  2. [RESPONSE] to Alexander Simolaris,

    Alexander,

    I completely agree with you in that the science of reaching absolute zero is quite redolent to that of reaching the speed of light. And who knows if these feats are even achievable? All I know is that many things like these were thought to be as much impossible in the past but were not; look how far we have come. The possibilities of the knowledge we could attain reaching absolute zero amaze me, and the possibilities of what we could achieve upon reaching the speed of light astound me as well. I believe that the knowledge we will need to be able to reach this temperature and this speed, along with what we must accomplish to be able to do so, will be worth attaining in the end. What we can learn from this, and what doors that will open for us, after reaching these new heights, will be at least equal to our input of efforts.

    If you are interested in the implications of this research, you should definitely check out the article. But I will elaborate on one of these for you. This possible achievement of this study could involve harnessing the power of antineutrinos and antihydrogens, for example. After all, part of dark matter could be antimatter. This is significant because dark matter constitutes 23% of the universe, while dark energy represents a whopping 73% of the universe. Understanding dark matter could help us to harness that huge 73% of the universe's power, and for our own benefit. For starters, this could potentially end the world's oil conflicts. Therefore, I am sure the world's oil and gas companies would be very interested in this research's outcomes.

    Posted by Derek Melzar

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