In a "Rainbow" Universe Time May Have No Beginning What if the universe had no beginning, and time stretched back infinitely without a big bang to start things off? That's one possible consequence of an idea called "rainbow gravity," so-named because it posits that gravity's effects on spacetime are felt differently by different wavelengths of light, aka different colors in the rainbow. Rainbow gravity was first proposed 10 years ago as a possible step toward repairing the rifts between the theories of general relativity (covering the very big) and quantum mechanics (concerning the realm of the very small). According to Einstein's general relativity, massive objects warp spacetime so that anything traveling through it, including light, takes a curving path. The effects would usually be tiny, so that we wouldn't notice the difference in most observations of stars, galaxies and other cosmic phenomena. Whereas it is too soon to know if these scenarios might describe the truth, they are intriguing. Yet the concept has its critics.
Dark energy and dark matter The Theory of Everything | Joe Arrigo PERSPECTIVE The above equation was written by Dr. Michio Kaku, theoretical physicist, who graduated first in his physics class at Harvard, and, when he was in high school built a 2.3 million electron volt atom-smasher in his parents garage. It is an equation for String Field Theory—a theory that may unite The Theory of Relativity with Quantum Theory, into a unified theory called The Theory of Everything. Theoretical physicists are those scientists who work in that twilight zone cutting edge realm between reality and science fiction. For thirty years Einstein sought a unified theory of physics that would integrate all the forces of nature into a single beautiful tapestry. String Theory says that at the subatomic level, there are vibrating strings—that particles like protons, electrons and quarks are nothing but musical notes on a tiny vibrating string, that all the stupendous activities in the universe are born from a sub-atomic loop of energy deep within all matter. © Joe Arrigo
How world works. Bohr and beyond: a century of quantum physics › Opinion (ABC Science) In Depth › Analysis and Opinion Our understanding of the quantum world began with Niels Bohr's discovery of the quantum atom in 1913. Bohr would be astounded by where his theory has since led, says Professor David Jamieson. Bohr's discovery of the quantum nature of the atom, published when he was a young man of 28, was an important pioneering contribution to the earliest days of quantum physics. This field emerged to explain the common sense-defying behaviour of atoms, molecules and light at the smallest scales, forming the foundations on which we have built one of the greatest and most successful theories of all time — quantum mechanics. What is quite remarkable to modern eyes was that Bohr had very little to go on. The true nature of the atom as an incredibly tiny nucleus surrounded by a cloud of orbiting electrons had only been discovered a few years earlier, in the separate work of physicists Thomson and Rutherford. ^ to top Bohr's quantum atom: nature is digital From theory to evidence
Dark Matter: The Larger Invisible Universe | Joe Arrigo PERSPECTIVE Normal matter—you, me, oatmeal, mountains, oceans, moons, planets, galaxies—make up about twenty-percent of the universe; the other eighty-percent is dark matter—star-stuff we cannot see or detect…yet. Why are scientists so certain this enigmatic matter exists? Because the evidence permeates the universe, first observed by Fritz Zwicky, when he measured the motions of galaxies and calculated that there wasn’t enough visible matter to affect galaxies to extent they were being pulled around.WWWFirst, there isn’t enough gravitational force within galaxies to bind and hold them in their current formation; then there is an invisible element that keeps them rotating faster than scientists would expect, clusters of galaxies bend and distort light more than they should, and supercomputer simulations exhibit that clouds of ordinary matter in the early universe did not have enough gravity to create the tight formations of galaxies we now see.
Higgs boson: Call to rename particle to acknowledge other scientists 22 April 2013Last updated at 13:00 ET By Pallab Ghosh Science correspondent, BBC News "Fathers" of the Higgs, L-R: Francois Englert, Peter Higgs, Carl Hagen and Gerald Guralnik One of the scientists who helped develop the theory of the Higgs boson says the particle should be renamed. Carl Hagen believes the name should acknowledge the work of others - not just UK physicist Peter Higgs. The long-running debate has been rekindled following speculation that this year's Nobel Prize for Physics will be awarded for the Higgs theory. The detection of a particle thought to be the Higgs was announced at the Large Hadron Collider in July last year. American Prof Hagen told BBC News: "I have always thought that the name was not a proper one. Continue reading the main story “Start Quote Peter Higgs was treated as something of a rock star and the rest of us were barely recognised. End QuoteProf Carl HagenRochester University, New York Peter Higgs is open to a name change to "H Boson" Nobel Prize
The Search For The History Of The Universe's Light Emission The light emitted from all objects in the Universe during its entire history - stars, galaxies, quasars etc. forms a diffuse sea of photons that permeates intergalactic space, referred to as "diffuse extragalactic background light" (EBL). Scientists have long tried to measure this fossil record of the luminous activity in the Universe in their quest to decipher the history and evolution of the Cosmos, but its direct determination from the diffuse glow of the night sky is very difficult and uncertain. Very high energy (VHE) gamma-rays, some 100,000,000,000 times more energetic than normal light, offer an alternative way to probe this background light, and UK researchers from Durham University in collaboration with international partners used the High Energy Stereoscopic System (HESS) gamma-ray telescopes in the Khomas Highlands of Namibia to observe several quasars (the most luminous VHE gamma-ray sources known) with this goal in mind. Source: PPARC
Fluid Experiments Support Deterministic “Pilot-Wave” Quantum Theory For nearly a century, “reality” has been a murky concept. The laws of quantum physics seem to suggest that particles spend much of their time in a ghostly state, lacking even basic properties such as a definite location and instead existing everywhere and nowhere at once. Only when a particle is measured does it suddenly materialize, appearing to pick its position as if by a roll of the dice. This idea that nature is inherently probabilistic — that particles have no hard properties, only likelihoods, until they are observed — is directly implied by the standard equations of quantum mechanics. But now a set of surprising experiments with fluids has revived old skepticism about that worldview. The bizarre results are fueling interest in an almost forgotten version of quantum mechanics, one that never gave up the idea of a single, concrete reality. The experiments involve an oil droplet that bounces along the surface of a liquid. Magical Measurements Bottom: Akira Tonomura/Creative Commons
Uncertainty reigns over Heisenberg's measurement analogy A row has broken out among physicists over an analogy used by Werner Heisenberg in 1927 to make sense of his famous uncertainty principle. The analogy was largely forgotten as quantum theory became more sophisticated but has enjoyed a revival over the past decade. While several recent experiments suggest that the analogy is flawed, a team of physicists in the UK, Finland and Germany is now arguing that these experiments are not faithful to Heisenberg's original formulation. Heisenberg's uncertainty principle states that we cannot measure certain pairs of variables for a quantum object – position and momentum, say – both with arbitrary accuracy. When Heisenberg proposed the principle in 1927, he offered a simple physical picture to help it make intuitive sense. Not necessarily wrong Then in 1988 Masanao Ozawa at Nagoya University in Japan argued that Heisenberg's original relationship between error and disturbance does not represent a fundamental limit of uncertainty. Truer to Heisenberg?
Planck constant Plaque at the Humboldt University of Berlin: "Max Planck, discoverer of the elementary quantum of action h, taught in this building from 1889 to 1928." In 1905 the value (E), the energy of a charged atomic oscillator, was theoretically associated with the energy of the electromagnetic wave itself, representing the minimum amount of energy required to form an electromagnetic field (a "quantum"). Further investigation of quanta revealed behaviour associated with an independent unit ("particle") as opposed to an electromagnetic wave and was eventually given the term photon. Since the frequency , wavelength λ, and speed of light c are related by λν = c, the Planck relation for a photon can also be expressed as The above equation leads to another relationship involving the Planck constant. In applications where frequency is expressed in terms of radians per second ("angular frequency") instead of cycles per second, it is often useful to absorb a factor of 2π into the Planck constant.
Quantum spacetime In mathematical physics, the concept of quantum spacetime is a generalization of the usual concept of spacetime in which some variables that ordinarily commute are assumed not to commute and form a different Lie algebra. The choice of that algebra still varies from theory to theory. As a result of this change some variables that are usually continuous may become discrete. Often only such discrete variables are called "quantized"; usage varies. Physical reasons have been given to believe that physical spacetime is a quantum spacetime. are already noncommutative, obey the Heisenberg uncertainty principle, and are continuous. Again, physical spacetime is expected to be quantum because physical coordinates are already slightly noncommutative. Both arguments are based on pure gravity and quantum theory, and they limit the measurement of time by the only time constant in pure quantum gravity, the Planck time. The Lie algebra should be semisimple (Yang, I. Bicrossproduct model spacetime[edit]
Quantum entanglement Quantum entanglement is a physical phenomenon that occurs when pairs or groups of particles are generated or interact in ways such that the quantum state of each particle cannot be described independently – instead, a quantum state may be given for the system as a whole. Such phenomena were the subject of a 1935 paper by Albert Einstein, Boris Podolsky and Nathan Rosen,[1] describing what came to be known as the EPR paradox, and several papers by Erwin Schrödinger shortly thereafter.[2][3] Einstein and others considered such behavior to be impossible, as it violated the local realist view of causality (Einstein referred to it as "spooky action at a distance"),[4] and argued that the accepted formulation of quantum mechanics must therefore be incomplete. History[edit] However, they did not coin the word entanglement, nor did they generalize the special properties of the state they considered. Concept[edit] Meaning of entanglement[edit] Apparent paradox[edit] The hidden variables theory[edit]
Efimov state The Efimov effect is an effect in the quantum mechanics of Few-body systems predicted by the Russian theoretical physicist V. N. Efimov[1][2] in 1970. Efimov’s effect refers to a scenario in which three identical bosons interact, with the prediction of an infinite series of excited three-body energy levels when a two-body state is exactly at the dissociation threshold. The unusual Efimov state has an infinite number of similar states. In 2005, for the first time the research group of Rudolf Grimm and Hanns-Christoph Nägerl from the Institute for Experimental Physics (University of Innsbruck, Austria) experimentally confirmed such a state in an ultracold gas of caesium atoms. The interest in the "universal phenomena" of cold atomic gases is still growing, especially because of the long awaited experimental results.[8][9] The discipline of universality in cold atomic gases nearby the Efimov states are sometimes commonly referred to as "Efimov physics". References[edit] Jump up ^ В.И.