Difference between revisions of "E=mc²"
m (remove tag for moving, not that has been moved) |
DavidEdwards (Talk | contribs) (sp, see also) |
||
Line 97: | Line 97: | ||
The mass of a neutrino is about 0.44x10<sup>-36</sup>kilograms. (Normally all of these things are measured in more convenient units such as Giga-electron-Volts, but that makes implicit use of E=mc<sup>2</sup>. If we don't accept that, we have to do the calculations under classical physics, using SI (meter/kilogram/second) units.) The neutrinos were accelerated to an energy of about 17GeV, or .27x10<sup>-8</sup>Joules. Using the classical formula <math>\mathrm{E} = \frac{1}{2}mv^2</math>, we get v=110x10<sup>12</sup>meters per second. This is about 370,000 times the speed of light. | The mass of a neutrino is about 0.44x10<sup>-36</sup>kilograms. (Normally all of these things are measured in more convenient units such as Giga-electron-Volts, but that makes implicit use of E=mc<sup>2</sup>. If we don't accept that, we have to do the calculations under classical physics, using SI (meter/kilogram/second) units.) The neutrinos were accelerated to an energy of about 17GeV, or .27x10<sup>-8</sup>Joules. Using the classical formula <math>\mathrm{E} = \frac{1}{2}mv^2</math>, we get v=110x10<sup>12</sup>meters per second. This is about 370,000 times the speed of light. | ||
− | Several scientists have gone on record stating that the neutrinos, which have mass, travel at precisely the speed of light. This | + | Several scientists have gone on record stating that the neutrinos, which have mass, travel at precisely the speed of light. This disproves the [[Theory of Relativity]] and the claim that '''E=mc<sup>2</sup>'''. |
+ | |||
+ | ==See also== | ||
+ | [[Counterexamples to Relativity]] | ||
+ | |||
== References == | == References == |
Revision as of 00:35, 27 March 2012
E=mc^{2} is a meaningless, almost nonsensical, statement in physics that purports to relate all matter to light. In fact, no theory has successfully unified the laws governing mass (i.e., gravity) with the laws governing light (i.e., electromagnetism). Simply put, E=mc^{2} is liberal claptrap.^{[Citation Needed]}
Biblical Scientific Foreknowledge predicts that a unified theory of all the laws of physics is impossible, because light and matter were created at different times, in different ways, as described in the Book of Genesis.
Mass is a measure of an object's inertia, and is directly related to the forces of gravity.^{[Citation Needed]} In contrast, the intrinsic energy of an object (such as an atom) is a function of electrostatic charge and other non-inertial forces, having nothing to do with gravity. Declaring the object's energy to be a function of inertia rather than electrostatics is an absurd and impossible attempt to unify the forces of nature, contrary to Biblical Scientific Foreknowledge.
For more than a century, the claim that E=mc^{2} has never yielded anything of value. Often it seems to be used as a redefinition of "energy" for pseudo-scientific purposes, as by the lamestream media. The equation has been used as a possible explanation for process involved in nuclear power generation and nuclear weapons, and in the study of antimatter.^{[1]}
The Theory of Relativity has never been able to derive E=mc^{2}, and a physicist observed in a peer-reviewed paper published in 2011 that "Leaving aside that it continues to be affirmed experimentally, a rigorous proof of the mass-energy equivalence is probably beyond the purview of the special theory."^{[2]}
One aspect of the formula is that radiation has a mass equivalence, which was correctly derived by Henri Poincare in 1904:^{[3]}
“ | The equality of the mass equivalent of radiation to the mass lost by a radiating body is derivable from Poincaré’s momentum of radiation (1900) and his principle of relativity (1904). | ” |
—Herbert Ives, 1952 |
Contents
Description for the layman
Ten top physicists were asked to describe in laymen's terms E=mc^{2}:^{[4]}
“ | Things that seem incredibly different can really be manifestations of the same underlying phenomena. | ” |
—Nima Arkani-Hamed, Theoretical Physicist, Harvard University |
“ | You can get access to parts of nature you have never been able to get access to before. | ” |
—Lene Hau, Experimental Physicist, Harvard University |
“ | It certainly is not an equation that reveals all its subtlety in the few symbols that it takes to write down. | ” |
—Brian Greene Theoretical Physicist Columbia University |
History of E=mc^{2}
The liberal Public Broadcasting Service explained the history of E=mc^{2} for its NOVA series as follows:^{[5]}
“ | Over time, physicists became used to multiplying an object's mass by the square of its velocity (mv^{2}) to come up with a useful indicator of its energy. If the velocity of a ball or rock was 100 mph, then they knew that the energy it carried would be proportional to its mass times 100 squared. If the velocity is raised as high as it could go, to 670 million mph, it's almost as if the ultimate energy an object will contain should be revealed when you look at its mass times c squared, or its mc^{2}. | ” |
Experimental verification
The first experimental verification for the equation was performed 1932 by a team of an English and an Irish physicist, John Cockcroft and Ernest Walton, as a byproduct of "their pioneer work on the transmutation of atomic nuclei by artificially accelerated atomic particles"^{[6]} for which they were honored with the Nobel Prize in physics in 1951. The idea of the mass defect - and its calculation using E=mc² can be found on page 169-170 of his Nobel lecture.^{[7]}
They bombarded Lithium atoms with protons having a kinetic energy less than 1 MeV. The result were two (slightly less heavy) α-particles, for which the kinetic energy was measured as 17.3 MeV
The mass of the particles on the left hand side is 8.0263 amus, the mass on the right hand side only 8.0077 amu.^{[8]} The difference between this masses is .00186 amu, which results in the following back-of-an-envelope calculation:
Accurate measurements and detailed calculations allowed for verifying the theoretical values with an accuracy of ±0.5%. This was the first time a nucleus was artificially split, and thereby the first transmutation of elements using accelerated particles:
Some claim that the best empirical verification of E=mc^{2} was done in 2005 by Simon Rainville et al., as published in Nature (which is not a leading physics journal).^{[9]} The authors state in their article in Nature magazine that "Einstein's relationship is separately confirmed in two tests, which yield a combined result of 1−Δmc²/E=(−1.4±4.4)×10^{−7}, indicating that it holds to a level of at least 0.00004%. To our knowledge, this is the most precise direct test of the famous equation yet described."
An Isolated Example -- Nuclear Fission of Uranium
For most types of physical interactions, the masses of the initial reactants and of the final products match so closely that it is essentially impossible to measure any difference. But for nuclear reactions, the difference is measurable. That difference is related to the energy absorbed or released, described by the equation E=mc². (The equation applies to all interactions; the fact that nuclear interactions are the only ones for which the mass difference is measurable has led people to believe, wrongly, that E=mc² applies only to nuclear interactions.)
The Theory of Relativity played no role in this work, but later tried to retrofit the theory to the data in order to explain the explain the observed mass changes. Here is the most famous example of the mass change.
Nuclear fission, which is the basis for nuclear energy, was discovered in experiments by Otto Hahn and Fritz Strassman, and analyzed by Lise Meitner, in 1938.
The decay path of Uranium that figured in the Hahn-Strassmann experiment may have been this:
- ^{235}U → ^{140}Xe + ^{91}Sr + 4n
(The Xenon decayed within about a minute to ^{140}Ba. There are a large number of fission paths and fission products, but they were searching for the chemical signature of Barium.)
The masses of the particles are:
Substance | ^{235}U | ^{140}Xe | ^{91}Sr | 4 neutrons |
---|---|---|---|---|
Number of protons | 92 | 54 | 38 | 0 |
Number of neutrons | 235 | 140 | 91 | 4 |
Number of electrons | 92 | 54 | 38 | 0 |
Mass | 235.04393 | 139.92164 | 90.910203 | 4.03466 |
The mass of the Uranium atom is 235.04393, and the sum of the masses of the products is 234.866503. The difference is .177427 amu, or, using the E=mc² equation, 165 million electron volts. (The generally accepted value for the total energy released by Uranium fission, including secondary decays, is about 200 million electron volts.)
The insight that the conversion from Uranium to Barium was caused by complete fission of the atom was made by Lise Meitner in December, 1938. She had the approximate "mass defect" quantities memorized, and so she worked out in her head, using the E=mc² equation, that there would be this enormous release of energy. This release was observed shortly thereafter, and the result is nuclear power and nuclear weapons.
A Counterexample: Speed of Extremely Energetic Neutrinos
Here is another example of the use of this formula in physics calculations. Recently there has been quite a controversy over whether neutrinos were observed traveling at a speed faster than light. Relativity doesn't allow that, and, since neutrinos have nonzero (but incredibly tiny) mass, they aren't even supposed to travel at the speed of light. This very issue came up on the Talk:Main_Page#Neutrinos. The speeds under discussion were calculated by the use of E=mc^{2}.
The mass of a neutrino is about 0.44x10^{-36}kilograms. (Normally all of these things are measured in more convenient units such as Giga-electron-Volts, but that makes implicit use of E=mc^{2}. If we don't accept that, we have to do the calculations under classical physics, using SI (meter/kilogram/second) units.) The neutrinos were accelerated to an energy of about 17GeV, or .27x10^{-8}Joules. Using the classical formula , we get v=110x10^{12}meters per second. This is about 370,000 times the speed of light.
Several scientists have gone on record stating that the neutrinos, which have mass, travel at precisely the speed of light. This disproves the Theory of Relativity and the claim that E=mc^{2}.
See also
References
- ↑ Tyson, Peter. "The Legacy of E=mc^{2}." October 11, 2005. PBS NOVA. http://www.pbs.org/wgbh/nova/physics/legacy-of-e-equals-mc2.html
- ↑ http://adsabs.harvard.edu/abs/2011AmJPh..79..591H
- ↑ http://www.opticsinfobase.org/josa/abstract.cfm?uri=josa-42-8-540
- ↑ http://www.pbs.org/wgbh/nova/einstein/experts.html
- ↑ http://www.pbs.org/wgbh/nova/physics/ancestors-einstein.html
- ↑ Nobel Prize Organization
- ↑ http://www.nobelprize.org/nobel_prizes/physics/laureates/1951/cockcroft-lecture.pdf
- ↑ Gerard Piel The age of science: what scientists learned in the 20th century, Basic Books, 2001, p. 144-145
- ↑ Nature 438, 1096-1097 (22 December 2005) doi:10.1038/4381096a; Published online 21 December 2005