Swing bowling — when a delivery curves sideways in mid-air — has long been regarded as one of the game’s dark arts, not only deceiving hapless batsmen but also puzzling cricket-loving scientists. Researchers from Britain’s Sheffield Hallam University and the University of Auckland in New Zealand reviewed scientific literature on the subject and conducted their… [Read more…]
May 24, 2012
E. S. Benilov, C. P. Cummins, W. T. Lee Stout beers show the counter-intuitive phenomena of sinking bubbles while the beer is settling. Previous research suggests that this phenomena is due the small size of the bubbles in these beers and the presence of a circulatory current, directed downwards near the side of the wall… [Read more…]
May 3, 2012
Incompatibility with special relativity and momentum conservation Masud Mansuripur The Lorentz law of force is the fifth pillar of classical electrodynamics, the other four being Maxwell’s macroscopic equations. The Lorentz law is the universal expression of the force exerted by electromagnetic fields on a volume containing a distribution of electrical charges and currents. If electric… [Read more…]
April 10, 2012
At a time when we are about to shed light on the fundamental question of the creation of mass after the Big Bang, we are also close to solving another basic mass-related problem. The kilogram is the only base unit of the International System of Units (SI) whose official definition is still based on a… [Read more…]
April 1, 2012
Haye Hinrichsen The human sense of hearing perceives a combination of sounds ‘in tune’ if the corresponding harmonic spectra are correlated, meaning that the neuronal excitation pattern in the inner ear exhibits some kind of order. Based on this observation it is suggested that musical instruments such as pianos can be tuned by minimizing the… [Read more…]
March 29, 2012
By Kate Kelland (Reuters) – Usain Bolt, already the world’s fastest man, could lop another 0.18 seconds off his 100 meter sprint world record even without running any faster. It’s just a question of getting a few conditions right – and doing the maths. Luckily for the top Jamaican sprinter, John Barrow, a professor of… [Read more…]
February 13, 2012
Video: Equations that rule the world Read more: newscientist.com
January 7, 2012
Nope. ….. Read more: motls.blogspot.com
December 31, 2011
Leonardo Hsua, Jong-Ping Hsua Abstract: The natural unit system, in which the value of fundamental constants such as c and h-bar are set equal to one and all quantities are expressed in terms of a single unit, is usually introduced as a calculational convenience. However, we demonstrate that this system of natural units has aphysical… [Read more…]
December 19, 2011
Chemists have solved the 150 year-old mystery of what gives the lead-acid battery, found under the bonnet of most cars, its unique ability to deliver a surge of current. Lead-acid batteries are able to deliver the very large currents needed to start a car engine because of the exceptionally high electrical conductivity of the battery… [Read more…]
December 17, 2011
…. according to physicsworld.com 1st place: Shifting the morals of quantum measurement 2nd place: Measuring the wavefunction 3rd place: Cloaking in space and time 4th place: Measuring the universe using black holes 5th place: Turning darkness into light 6th place: Taking the temperature of the early universe 7th place: Catching the flavour of a neutrino… [Read more…]
December 12, 2011
Teach your teacher: the collapse of the Tacoma Narrows bridge WASN’T resonance. And I defer all arguments to the elocution of Profs. Billah and Scanlon:http://www.ketchum.org/billah/Billah-Scanlan.pdf Vortex shedding video: http://youtu.be/JI0M1gVNhbw?t=2m12s Tacoma Bridge video: http://www.youtube.com/watch?v=3mclp9QmCGs http://youtu.be/6ai2QFxStxo
November 27, 2011
Liang-Cheng Tu and Jun Luo Abstract Coulomb’s Law is a fundamental principle describing the electric force between isolated charges, and represents the first quantitative law achieved in electromagnetism. The degree of confidence with which the law is experimentally known to hold was investigated after the law was put forth by Coulomb in 1785. The electrodynamics… [Read more…]
October 30, 2011
Correspondence between geometrical and differential definitions of the sine and cosine functions and connection with kinematics Horia I. Petrache In classical physics, the familiar sine and cosine functions appear in two forms: (1) geometrical, in the treatment of vectors such as forces and velocities, and (2) differential, as solutions of oscillation and wave equations. These two forms… [Read more…]
October 25, 2011
After decades of worry, toil and argument, metrologists have officially begun the process of tying the definitions of four basic units to nature’s fundamental constants. The General Conference on Weights and Measures (CGPM) in Paris, France, has unanimously agreed on a proposal that would lead to reform of the mole, kilogram, kelvin and ampere, according to the international system… [Read more…]
October 25, 2011
A CME hit Earth’s magnetic field on Oct. 24 at 1800 UT, sparking a strong (Kp=7) geomagnetic storm. Auroras were sighted in the United States as far south as Arkansas and California Video 1: The SOlar Heliospheric Observatory (SOHO) captured this “coronograph” – so-called because the images block the sun, and only show the sun’s… [Read more…]
October 24, 2011
The present issue of the series <Modern Problems in Mathematical Physics> represents the Proceedings of the Students Training Contest Olympiad in Mathematical and Theoretical Physics and includes the statements and the solutions of the problems offered to the participants. The contest Olympiad was held on May 21st-24th, 2010 by Scientific Research Laboratory of Mathematical Physics… [Read more…]
October 21, 2011
High-speed video photography reveals how flowers exploit the kinetic energy of raindrops to disperse seeds The plant world has evolved numerous ingenious ways to distribute seeds. But one of the least known and least celebrated is raindrop dispersal. Just a couple of dozen plants are known to exploit the kinetic energy of rain drops to… [Read more…]
October 18, 2011
Even falling and skulking cats obey the laws of physics, research shows Cats may skulk, and cats may fall – but no matter what they do, cats must obey the laws of physics. Scientists have tried repeatedly to figure out how they manage to do it. At the extreme, physicists analysed what happens to a dropped… [Read more…]
October 13, 2011
Sunil Mukhi This article provides some historical background and then reviews developments in string theory over the last twenty-five years or so. Both perturbative and non-perturbative approaches to string theory are surveyed and their impact on how we view quantum gravity is analysed…. Read more: http://arxiv.org
October 13, 2011
Alejandro Jenkins Physicists are very familiar with forced and parametric resonance, but usually not with self-oscillation, a property of certain linear systems that gives rise to a great variety of vibrations, both useful and destructive. In a self-oscillator, the driving force is controlled by the oscillation itself so that it acts in phase with the… [Read more…]
October 11, 2011
An important aspect of Brownian motion predicted decades ago has been observed for the first time by researchers in Europe. The team has measured how micrometre-sized spheres interact with a surrounding fluid and have shown that the spheres “remember” their previous motion. Their experimental technique, the researchers claim, could be used as a biophysical sensor.… [Read more…]
October 11, 2011
Physicists have predicted that under the influence of sufficiently high electric fields, liquid droplets of certain materials will undergo solidification, forming crystallites at temperature and pressure conditions that correspond to liquid droplets at field-free conditions. This electric-field-induced phase transformation is termed electrocrystallization The study, performed by scientists at the Georgia Institute of Technology, appears online… [Read more…]
October 4, 2011
(update) The Nobel Prize in Physics 2011 has been awarded to Saul Perlmutter, Brian P Schmidt and Adam G Riess for discovering the accelerating expansion of the universe ………………………………………………………. Three scientists shared the 2011 Nobel Prize for physics for the stunning discovery that the expansion of the universe is speeding up, meaning it may one… [Read more…]
September 21, 2011
… in Physics Alain Aspect CNRS Distinguished Scientist and Head of the Atom Optics Group, Laboratoire Charles Fabry, Institut d’Optique, Palaiseau France WHY: with John F. Clauser and Anton Zeilinger, for their tests of Bell’s inequalities and research on quantum entanglement John F. Clauser Research Physicist, J.F. Clauser & Associates, Walnut Creek, CA USA WHY: with Alain Aspect and Anton Zeilinger, for their… [Read more…]
September 17, 2011
The kilogram is currently defined by a lump of metal in Paris – but now researchers in the UK, France and Sweden have confirmed a key assumption of a new method of defining the standard based on fundamental constants. Specifically, they have shown that the quantum Hall resistances measured in a semiconductor and in graphene… [Read more…]
September 13, 2011
This blog entry is somewhat analogous to the text about Ten new things modern physics has learned about time. Matter is made of atoms. This is the proposition that Richard Feynman would have chosen as the single most important insight of the scientific research. The atomic theory, confirming guesses of some ancient Greek philosophers, explains why… [Read more…]
physicsworld newscientist.com NASA dailygalaxy technologyreview science2.0
May 30, 2012
0