The purpose of this paper is to examine the materials, properties, and theory of superconductivity, a quantum phenomenon that occurs when a material is brought below a critical temperature and will conduct electricity without any resistance, the nearest model in nature to perpetual motion. According to Ecks (1990), Once current is applied to a superconducting material the current will continue in a closed lope without ever losing intensity. (Ecks, 1990) Superconductive materials can greatly vary in mechanics and materials. They are separated into Type 1 and Type 2 superconductors. All superconductors display the unique ability to repel magnetic fields, known as the Meissner effect.
According to Shachtman (2000), Superconductivity was discovered when a physicist, Heike Kamerlingh Onnes, when he developed the process to produce liquid helium and began testing the electrical properties of material at temperatures nearing absolute zero. Absolute zero is the coldest temperature that is theoretically attainable and is the basis of the Kelvin scale. Onnes first observed the phenomenon in mercury. A sample of mercury was cooled by liquid helium, and at the exact moment the temperature of the mercury reached 4.19K the resistance abruptly disappeared. (Shachtman, 2000)
According to Nave (2000), In Type I superconductors the phenomenon of zero resistance at low temperatures occurs in materials that are have some degree of conductivity under normal conditions. The properties of Type I superconductors were modeled successfully by the efforts of John Bardeen, Leon Cooper, and Robert Schrieffer in what is commonly called the BCS theory after the efforts of John Bardeen, Leon Cooper, and Robert Schrieffer in its understanding. (Nave, 2000)
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...ak Ridge National Laboratory.
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In his piece on climate change, Richard Lindzen addresses his stance on the heated debate of global warming. He claims that there is, in fact, no ongoing catastrophic temperature increase. Lindzen, a Professor of Meteorology at the Massachusetts Institute of Technology and a recipient of the Jule Charney award from the American Meteorological Society (Richard Lindzen), believes that the earth goes through natural phases of warming and cooling. In this piece, he examines why he believes people have a false conception of Earth’s climate shifts.
In his essay, “Global Warming is Eroding Glacial Ice,” Revkin is arguing that global warming is constantly changing the ...
Bose-Einstein condensate is a state of matter of a dilute gas of bosons cooled to a temperature very close to absolute zero. The creation of Bose-Einstein condensates is the basis for super fluidity and super conductivity and allowed for the creation of a new type of matter.
The amazing transformation the study of physics underwent in the two decades following the turn of the 20th century is a well-known story. Physicists, on the verge of declaring the physical world “understood”, discovered that existing theories failed to describe the behavior of the atom. In a very short time, a more fundamental theory of the ...
“There has always been extreme [weather]. There is extreme weather forever. In 1977… "Time" and "Newsweek" both had on their covers, the coming ice age because of the world cooling so fast. That was 40 years ago. All of a sudden we go from the globe cooling too fast to it warming too quickly”
The molar specific heats of most solids at room temperature and above are nearly constant, in agreement with the Law of Dulong and Petit. At lower temperatures the specific heats drop as quantum processes become significant. The Einstein-Debye model of specific heat describes the low temperature behavior.
Superconductivity, a similar phenomenon, was discovered in 1911 by Dutch physicist Heike Kamerlingh Onnes. When he cooled some mercury down to liquid helium temperatures, it began to conduct electricity with no resistance at all. People began experimenting with other metals, and found that many tranisition metals exhibit this characteristic of 0 resistance if cooled sufficiently. Superconductors are analagous to superfluids in that the charges within them move somewhat like a superfluid - with no resistance through sections of extremely small cross-sectional area. Physicists soon discovered that oxides of copper and other compounds could reach even higher superconducting temperatures. Currently, the highest temperature at wich a material can be superconductive is 138K, and is held by the compound Hg0.8Tl0.2Ba2Ca2Cu3O8.33.
Quantum thermodynamic scientists are aiming to explore the behavior outside the lines of conventional thermodynamics. This exploration could be used for functional cases, which include “improving lab-based refrigeration techniques, creating batteries with enhanced capabilities and refining technology of quantum computing.” (Merali P.1). However, this field is still in an early state of exploration. Experiments, including the one that is being performed at Oxford University, are just beginning to test these predictions. “A flurry of attempts has been made to calculate how thermodynamics and the quantum theory might combine” (Merali P. 1). However, quantum physicist Peter Hänggi stated that “there is far too much theory and not enough experiment” (Merali P.1) in this field of study, which is why its credibility is undermined. Nevertheless, people are starting to put more effort into understanding quantum thermodynamics in order to make
19. Novoselov, Kostya S., et al. "Electric field effect in atomically thin carbon films." science 306.5696 (2004): 666-669.
Thelen, Herbert and Withall, John (1949). “Three frames of reference: The description of climate” Human Relations 2(2): 159 -76
American Institute of Physics. Vol. 1051 Issue 1 (2008). Academic Search Premier.> 224. http://login.ezproxy1.lib.asu.edu/login?url=http://search.ebscohost.com.ezproxy1.lib.asu.edu/login.aspx?direct=true&db=aph&AN=34874307&site=ehost-live.
2) Fundamentals of Physics Extended: Fifth Edition. David Hanley, Robert Resnick, Jearl Walker. Published by John Wiley & Sons, Inc, New York, Chichester, Brisbane, Toronto, Singapore. 1997.
These materials conduct by a process known as hole conduction. Within such a material there are locations, called holes, that would normally be occupied by an electron but are actually empty. A missing negative charge is equivalent to a positive charge. When an electron moves in one direction to fill a hole, it leaves another hole behind it. The hole migrates in the direction opposite to that of the electron. In terms of the coordinate axes in Fig. T10.1b, the electrostatic field E for the positive-q case is in the −z-direction; its z-component Ez is negative. The magnetic field is in the +y-direction, and we write it as By . The magnetic force (in the +zdirection) is qvd By. The current density Jx is in the +x-direction. In the steady state, when the forces qEz and qvdBy are equal in magnitude and opposite in direction, This confirms that when q is positive, Ez is negative. The current density Jx is Eliminating vd between these equations, we find (T10.1) Note that this result (as well as the entire derivation) is valid for both positive and negative q. When q is negative, Ez is positive, and conversely. We can measure Jx , By , and Ez, so we can compute the product nq. In both metals and semiconductors, q is equal in magnitude to the electron charge, so
Athanasiou, Tom, and Baer, Paul. Dead Heat: global justice and global warming. New York: Seven Stories Press, 2012.
Lithium's coefficient of thermal expansion is twice that of aluminium and almost four times that of iron.[6] It has the highest specific heat capacity of any solid element. Lithium is superconductive below 400 μK at standard pressure[7] and at higher temperatures (more than 9 K) at very high pressures (>20 GPa)[8] At temperatures below 70 K, lithium, like sodium, underg...