Physics posts
- April 26, 2013
- 09:17 AM
- 130 views
Visualization of the Gödel universe
by Perikis Livas in Tracing Knowledge
The standard model of modern cosmology, which is based on the Friedmann–Lemaître–Robertson–Walker metric, allows the definition of an absolute time. However, there exist (cosmological) models consistent with the theory of general relativity for which such a definition cannot be given since they offer the possibility for time travel.... Read more »
Buser, M., Kajari, E., & Schleich, W. (2013) Visualization of the Gödel universe. New Journal of Physics, 15(1), 13063. DOI: 10.1088/1367-2630/15/1/013063
- April 26, 2013
- 05:27 AM
- 92 views
Tartaglia-Pascal triangle and quantum mechanics
by Marco Frasca in The Gauge Connection
The paper I wrote with Alfonso Farina and Matteo Sedehi about the link between the Tartaglia-Pascal triangle and quantum mechanics is now online (see here). This paper contains as a statement my theorem that provides a connection between the square root of a Wiener process and the Schrödinger equation that arose a lot of interest [...]... Read more »
Farina, A., Frasca, M., & Sedehi, M. (2013) Solving Schrödinger equation via Tartaglia/Pascal triangle: a possible link between stochastic processing and quantum mechanics. Signal, Image and Video Processing. DOI: 10.1007/s11760-013-0473-y
Marco Frasca. (2012) Quantum mechanics is the square root of a stochastic process. arXiv. arXiv: 1201.5091v2
Farina, A., Giompapa, S., Graziano, A., Liburdi, A., Ravanelli, M., & Zirilli, F. (2011) Tartaglia-Pascal’s triangle: a historical perspective with applications. Signal, Image and Video Processing, 7(1), 173-188. DOI: 10.1007/s11760-011-0228-6
- April 26, 2013
- 01:32 AM
- 105 views
Confirmation of Einstein’s general theory of relativity in extreme conditions
by Usman Paracha in SayPeople
Main points:
Astronomers have found that the gravitational waves are produced even in the spacetime when the two stars, in the extreme conditions, move around each other. This is the proof of the Einstein's gravity theory in the one of the most extreme conditions yet studied.
Journal:
Science
Study Further:
Einstein's general theory of relativity:
Gravity is the cause of the curvature of spacetime created by the presence of mass and energy, according to the Einstein&#........ Read more »
Antoniadis, J., Freire, P., Wex, N., Tauris, T., Lynch, R., van Kerkwijk, M., Kramer, M., Bassa, C., Dhillon, V., Driebe, T.... (2013) A Massive Pulsar in a Compact Relativistic Binary. Science, 340(6131), 1233232-1233232. DOI: 10.1126/science.1233232
- April 25, 2013
- 04:30 PM
- 83 views
how to shield yourself in a vacuum, sci-fi style
by Greg Fish in weird things
In a fair bit of science fiction, we see advanced alien species use some sort of shielding to walk around other planets or survive being ejected into space. Something around them flickers and a protective invisible bubble is raised, protecting them from a horrible death by dehydration as all the fluid in their bodies effectively boils away. As it turns out, that’s actually possible. [...]... Read more »
Takaku, Y., Suzuki, H., Ohta, I., Ishii, D., Muranaka, Y., Shimomura, M., & Hariyama, T. (2013) A thin polymer membrane, nano-suit, enhancing survival across the continuum between air and high vacuum. Proceedings of the National Academy of Sciences. DOI: 10.1073/pnas.1221341110
- April 24, 2013
- 03:42 PM
- 87 views
Mechanism Behind LED Efficiency Loss at High Currents Identified
by dailyfusion in The Daily Fusion
Scientists from the University of California, Santa Barbara together with colleagues from the École Polytechnique in France, have conclusively identified Auger recombination to be the mechanism that causes light emitting diodes (LEDs) to be less efficient at high drive currents.... Read more »
Justin Iveland, Lucio Martinelli, Jacques Peretti, James S. Speck, & Claude Weisbuch. (2013) Direct Measurement of Auger Electrons Emitted from a Semiconductor Light-Emitting Diode under Electrical Injection: Identification of the Dominant Mechanism for Efficiency Droop. Physical Review Letters. arXiv: 1304.5469v1
- April 24, 2013
- 01:47 PM
- 86 views
Icy experiment catches record-energy neutrinos
by Perikis Livas in Tracing Knowledge
The IceCube experiment has made what could be an important step toward using neutrinos to find the source of ultra-high-energy cosmic rays.... Read more »
Kathryn Jepsen. (2013) Icy experiment catches record-energy neutrinos. Symmetry Magazine. info:/
- April 24, 2013
- 05:49 AM
- 92 views
Seeing Stars
by Perikis Livas in Tracing Knowledge
“WE’LL BE ABLE to see the beginning of the universe as we know it today,” says Charles Alcock, director of the Harvard-Smithsonian Center for Astrophysics (CfA) and professor of astronomy—imaging the radiation signatures from ancient galaxies billions of light years from his hilltop office on Garden Street, near the Radcliffe Quad. Addressing that same frontier, Abraham (Avi) Loeb, Baird professor of science and chair of the astronomy department, characterizes the researc........ Read more »
John S. Rosenberg. (2013) Seeing Stars. Harvard Magazine. info:/
- April 23, 2013
- 05:56 PM
- 2 views
H-Rays and a Giant Atom Primer
by Hamilton Carter in Copasetic Flow
Posts will be a bit terse and scattered for the next few days. Today I was looking into Hirsch's answer to the question "How'd you get all that excess charge got up onto the surface of that superconductor anyways Hoss?", (appropriate nod to Ray Stevens and Shriners everywhere here). Super, super, super attentive readers might remember that the upcoming h-rays experiment[7] will be looking for Bremsstrahlung radiation produced by this theoretical excess surface charge densit........ Read more »
Hirsch J.E. (2001) Consequences of charge imbalance in superconductors within the theory of hole superconductivity. Physics Letters A, 281(1), 44-47. DOI: 10.1016/S0375-9601(01)00101-3
Hirsch J.E. (2003) Superconductors as giant atoms predicted by the theory of hole superconductivity. Physics Letters A, 309(5-6), 457-464. DOI: 10.1016/S0375-9601(03)00204-4
Hirsch J. (2003) Charge expulsion and electric field in superconductors. Physical Review B, 68(18). DOI: 10.1103/PhysRevB.68.184502
Hirsch J. (2005) Why holes are not like electrons. II. The role of the electron-ion interaction. Physical Review B, 71(10). DOI: 10.1103/PhysRevB.71.104522
Dayo A., Alnasrallah W., & Krim J. (1998) Superconductivity-Dependent Sliding Friction. Physical Review Letters, 80(8), 1690-1693. DOI: 10.1103/PhysRevLett.80.1690
- April 22, 2013
- 12:49 PM
- 2 views
LENR and Electron Effective Mass
by Hamilton Carter in Copasetic Flow
Quantum mechanics makes some rather astonishing predictions about how particles behave. One of the most astonishing to me is that an electron's wave function can interact with a periodic potential, (say from the lattice sites of a crystal), and an applied force,(from a constant electric field for example), to make it behave as though its mass is vastly different, (sometimes even negative), compared to its rest mass in free space. Semiconductor physicists make use of this property all........ Read more »
Davisson C., & Germer L. (1927) Diffraction of Electrons by a Crystal of Nickel. Physical Review, 30(6), 705-740. DOI: 10.1103/PhysRev.30.705
- April 22, 2013
- 12:43 PM
- 75 views
Using Black Holes to Measure the Universe’s Rate of Expansion
by Jason Carr in Wired Cosmos
A few years ago, researchers revealed that the universe is expanding at a much faster rate than originally believed — a discovery that earned a Nobel Prize in 2011. But measuring the rate of this acceleration over large distances is still challenging and problematic, says Prof. Hagai Netzer of Tel Aviv University’s School of Physics and Astronomy. Now, Prof. … Read More →... Read more »
Wang, J., Du, P., Valls-Gabaud, D., Hu, C., & Netzer, H. (2013) Super-Eddington Accreting Massive Black Holes as Long-Lived Cosmological Standards. Physical Review Letters, 110(8). DOI: 10.1103/PhysRevLett.110.081301
- April 22, 2013
- 08:04 AM
- 95 views
Cellphone Microbattery That Can Jump-Start a Car Developed
by dailyfusion in The Daily Fusion
New microbatteries developed at the University of Illinois at Urbana-Champaign are only a few millimeters in size, yet they are powerful enough to jump-start a dead car battery.... Read more »
Pikul, J., Gang Zhang, H., Cho, J., Braun, P., & King, W. (2013) High-power lithium ion microbatteries from interdigitated three-dimensional bicontinuous nanoporous electrodes. Nature Communications, 1732. DOI: 10.1038/ncomms2747
- April 21, 2013
- 10:18 PM
- 126 views
Gravity doesn’t actually exist; A new theory
by Usman Paracha in SayPeople
Main point:
According to the new theory, Gravity is not the fundamental force or fundamental interaction but it is actually the result of the laws of thermodynamics, which tells us about the behavior of heat and gases.
Journal:
Journal of High Energy Physics
Study Further:
The New York Times reported on July 12, 2010 that Professor Erik Verlinde, 48, a respected string theorist and professor of physics at the University of Amsterdam, said in the paper, submitted on January 6th, ........ Read more »
Verlinde, E. (2011) On the origin of gravity and the laws of Newton. Journal of High Energy Physics, 2011(4). DOI: 10.1007/JHEP04(2011)029
- April 21, 2013
- 08:00 AM
- 33 views
Interdisciplinitis: Do entropic forces cause adaptive behavior?
by Artem Kaznatcheev in Evolutionary Games Group
Physicists are notorious for infecting other disciplines. Sometimes this can be extremely rewarding, but most of the time it is silly. I’ve already featured an example where one of the founders of algorithmic information theory completely missed the point of Darwinism; researchers working in statistical mechanics and information theory seem particularly susceptible to interdisciplinitis. The [...]... Read more »
Wissner-Gross, A.D., & Freer, C.E. (2013) Causal Entropic Forces. Phys. Rev. Lett., 110(16), 168702. info:/10.1103/PhysRevLett.110.168702
- April 21, 2013
- 07:03 AM
- 2 views
LENR and Muon Catalyzed Fusion
by Hamilton Carter in Copasetic Flow
Reading about low energy nuclear reactions, (LENR), I came across several theoretical references to protons capturing heavy electrons and then participating in nuclear reactions as a result. The heavy electron, because it sits in a much tighter orbit around a proton, serves to shield the proton's positive charge from other unsuspecting nuclei until the proton has crept in close enough to fuse with them via the strong force. In modern day LENR parlance, it is speculated that these sufficien........ Read more »
FRANK F. C. (1947) Hypothetical Alternative Energy Sources for the ‘Second Meson’ Events. Nature, 160(4068), 525-527. DOI: 10.1038/160525a0
LATTES C. M. G., OCCHIALINI G. P. S., & POWELL C. F. (1947) Observations on the Tracks of Slow Mesons in Photographic Emulsions. Nature, 160(4066), 453-456. DOI: 10.1038/160453a0
Jackson J. (1957) Catalysis of Nuclear Reactions between Hydrogen Isotopes by μ- Mesons. Physical Review, 106(2), 330-339. DOI: 10.1103/PhysRev.106.330
Wheeler John. (1949) Some Consequences of the Electromagnetic Interaction between μ--Mesons and Nuclei. Reviews of Modern Physics, 21(1), 133-143. DOI: 10.1103/RevModPhys.21.133
Alvarez L., Bradner H., Crawford F., Crawford J., Falk-Vairant P., Good M., Gow J., Rosenfeld A., Solmitz F., & Stevenson M. (1957) Catalysis of Nuclear Reactions by μ Mesons. Physical Review, 105(3), 1127-1128. DOI: 10.1103/PhysRev.105.1127
- April 19, 2013
- 04:03 PM
- 107 views
Alice and Bob communicate without transferring a single photon
by Perikis Livas in Tracing Knowledge
If physical particles did not carry information between sender and receiver then what did?... Read more »
Edwin Cartlidge. (2013) Alice and Bob communicate without transferring a single photon. Physicsworld.com. info:/
- April 16, 2013
- 04:07 PM
- 91 views
Green Algae Could Produce Hydrogen Efficiently
by dailyfusion in The Daily Fusion
While the possibility to produce hydrogen in biohydrogen reactors exists for some time now, most studies are skeptical about its commercial prospects. New research results from Uppsala University, however, suggest that efficient production of hydrogen with green algae may become possible in the future. ... Read more »
Volgusheva, A., Styring, S., & Mamedov, F. (2013) Increased photosystem II stability promotes H2 production in sulfur-deprived Chlamydomonas reinhardtii. Proceedings of the National Academy of Sciences. DOI: 10.1073/pnas.1220645110
- April 16, 2013
- 12:19 PM
- 73 views
Front Row at the Dawn of Time
by Perikis Livas in Tracing Knowledge
As long as humans have been human, we have been fascinated by cosmic questions. How did the universe begin? Where did we come from? Are we alone? Attempting to answer these questions may not produce a better toaster or a faster airplane, but it is nothing short of remarkable that modern science is revealing facets of our universe that are changing our perspectives on such foundational cosmic questions.... Read more »
LAWRENCE M. KRAUSS. (2013) Front Row at the Dawn of Time. The International Herald Tribune. info:/
- April 16, 2013
- 07:03 AM
- 99 views
Some Lithium-Ion Batteries Actually Do Have Memory Effect, Study Finds
by dailyfusion in The Daily Fusion
Scientists at the Paul Scherrer Institute PSI, together with colleagues from the Toyota Research Laboratories in Japan have recently found that a certain widely used type of Li-ion batteries has a memory effect. ... Read more »
Sasaki, T., Ukyo, Y., & Novák, P. (2013) Memory effect in a lithium-ion battery. Nature Materials. DOI: 10.1038/nmat3623
- April 16, 2013
- 05:24 AM
- 70 views
Underground experiment sees possible hints of dark matter
by Perikis Livas in Tracing Knowledge
The Cryogenic Dark Matter Search experiment adds new intrigue to the hunt for dark matter.
Physicists operating an experiment located half a mile underground in Minnesota reported this weekend that they have found possible hints of dark-matter particles.... Read more »
Kathryn Jepsen. (2013) Underground experiment sees possible hints of dark matter. Symmetry Magazine. info:/
- April 15, 2013
- 01:49 PM
- 68 views
New Material for Rapid Energy Storage and Release Developed
by dailyfusion in The Daily Fusion
A new material developed by a group of UCLA scientists could potentially solve the charging time problem of electric vehicles. Researchers at the UCLA Henry Samueli School of Engineering and Applied Science have synthesized a new material that may bridge the divide between supercapacitors and conventional batteries, being simultaneously able to store and deliver energy efficiently.... Read more »
Augustyn, V., Come, J., Lowe, M., Kim, J., Taberna, P., Tolbert, S., Abruña, H., Simon, P., & Dunn, B. (2013) High-rate electrochemical energy storage through Li intercalation pseudocapacitance. Nature Materials. DOI: 10.1038/nmat3601
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