Falling cat problem
A falling cat modeled as two independently rotating parts turns around while maintaining zero net angular momentum The falling cat problem consists of explaining the underlying physics behind the common observation of the cat righting reflex: how a free-falling cat can turn itself right-side-up as it falls, no matter which way up it was initially, without violating the law of conservation of angular momentum. Although somewhat amusing, and trivial to pose, the solution of the problem is not as straightforward as its statement would suggest. The apparent contradiction with the law of conservation of angular momentum is resolved because the cat is not a rigid body, but instead is permitted to change its shape during the fall.
free web hosting provider
Can you imagine free web hosting service that has 99.9% uptime? Too good to be true? No more! 000webhost.com has made the revolution, forget the stereotype that free hosting is unreliable.. Here is the proof: uptime stats of 20 servers. We beat your paid hosting provider!
Popper's experiment
Popper's experiment is an experiment proposed by the philosopher Karl Popper. As early as 1934 he was suspicious of, and was proposing experiments to test, the Copenhagen interpretation, a popular subjectivist interpretation of quantum mechanics.[1][2] Popper's experiment is a realization of an argument similar in spirit to the thought experiment of Einstein, Podolsky and Rosen (the EPR paradox) although not as well known. There are various interpretations of quantum mechanics that do not agree with each other. Despite their differences, they are experimentally nearly indistinguishable from each other. The most widely known interpretation of quantum mechanics is the Copenhagen interpretation put forward by Niels Bohr.
Dirac Theory
Next: Smaller EffectsUp: Everything You Always Wanted Previous: Kinetic Energy Correction The theory of Paul Dirac represents an attempt to unify the theories of quantum mechanics and special relativity. That is, one seeks a formulation of quantum mechanics which is Lorentz invariant, and hence consistent with special relativity.
Cat physics – and we are not making this up
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 cat. That's a cat in free-fall, a cat hurtling earthwards with nothing but kitty cunning to keep it from crashing. In 1969, TR Kane and MP Scher of Stanford University, in California, published a monograph called A Dynamical Explanation of the Falling Cat Phenomenon.
Blue Ball Machine
About Blue Ball Machine is a series of YTMND sites illustrating user-generated models of the Rube Goldberg machine, an over-engineered structure designed to perform a very simple task in a very complex fashion, often involving chain reactions. Origin In 2005, the Something Awful forums hosted a contest in which a blue ball machine was to be created. While no specific instructions were provided for creating the instances, hundreds of SomethingAwful forum goons posted small GIF animations in which blue balls ran through a small portion of a virtual Rube Goldberg machine.
Bell test experiments
Bell test experiments or Bell's inequality experiments are designed to demonstrate the real world existence of certain theoretical consequences of the phenomenon of entanglement in quantum mechanics which could not possibly occur according to a classical picture of the world, characterised by the notion of local realism. Under local realism, correlations between outcomes of different measurements performed on separated physical systems have to satisfy certain constraints, called Bell inequalities. John Bell derived the first inequality of this kind in his paper "On the Einstein-Podolsky-Rosen Paradox".[1] Bell's Theorem states that the predictions of quantum mechanics cannot be reproduced by any local hidden variable theory. The term "Bell inequality" can mean any one of a number of inequalities satisfied by local hidden variables theories; in practice, in present day experiments, most often the CHSH; earlier the CH74 inequality. Conduct of optical Bell test experiments[edit] Pan et al.'
Fermat's Last Theorem
The 1670 edition of Diophantus' Arithmetica includes Fermat's commentary, particularly his "Last Theorem" (Observatio Domini Petri de Fermat). In number theory, Fermat's Last Theorem (sometimes called Fermat's conjecture, especially in older texts) states that no three positive integers a, b, and c can satisfy the equation an + bn = cn for any integer value of n greater than two. This theorem was first conjectured by Pierre de Fermat in 1637 in the margin of a copy of Arithmetica where he claimed he had a proof that was too large to fit in the margin. The first successful proof was released in 1994 by Andrew Wiles, and formally published in 1995, after 358 years of effort by mathematicians. The unsolved problem stimulated the development of algebraic number theory in the 19th century and the proof of the modularity theorem in the 20th century. Overview[edit]
If my Pussy smells like Tuna, why doesn't my Cat eat me out?
It's a legitimate question, don't you think? I recently tickled my kitty in front of my cat to answer this question; a question every girl who has ever been mistaken for a fish and chip shop by a blind man has pondered, but has been afraid to ask. Initially I felt guilty about my little experiment, but curiosity won hands down—or possibly fingers in—and I was quickly so horny I didn't really give a bugger. At first my cat was none the wiser as I slyly slid out of my slightly damp knickers beneath the sheets and reached up for my vibrator. At first I was reluctant to turn it on as Lulu was literally six inches from my waist, so why draw attention to what I was doing if I didn't have to, right?
GSoC Proposal: "General RDF export/import in Semantic MediaWiki"
Identity Name: Samuel Lampa Email: samuel.lampa[at]gmail.com Project title: General RDF export/import functionality for Semantic MediaWiki Contact/working info
Elitzur–Vaidman bomb tester
Bomb-testing problem diagram. A - photon emitter, B - bomb to be tested, C,D - photon detectors. Mirrors in the lower left and upper right corners are half-silvered.
Dyson sphere
Dyson sphere is a hypothetical megastructure that completely encompasses a star and hence captures most or all of its power output. It was first described by Freeman Dyson. Dyson speculated that such structures would be the logical consequence of the long-term survival and escalating energy needs of a technological civilization, and proposed that searching for evidence of the existence of such structures might lead to the detection of advanced intelligent extraterrestrial life. Different types of Dyson spheres correlate with information on the Kardashev scale. Since then, other variant designs involving building an artificial structure or series of structures to encompass a star have been proposed in exploratory engineering or described in science fiction under the name "Dyson sphere".
RDF export
Based on the user's semantic annotations of articles, Semantic MediaWiki generates machine-readable documents in OWL/RDF format, that can be accessed via Special:ExportRDF. Moreover, there is a maintenance script for automatically generating complete exports of all semantic data. This article explains how annotations are formally interpreted in the OWL ontology language, and how a suitable RDF serialisation is generated.
