Margaret Wertheim – The limits of physics Theoretical physics is beset by a paradox that remains as mysterious today as it was a century ago: at the subatomic level things are simultaneously particles and waves. Like the duck-rabbit illusion first described in 1899 by the Polish-born American psychologist Joseph Jastrow, subatomic reality appears to us as two different categories of being. But there is another paradox in play. Physics itself is riven by the competing frameworks of quantum theory and general relativity, whose differing descriptions of our world eerily mirror the wave-particle tension. When it comes to the very big and the extremely small, physical reality appears to be not one thing, but two. Physicists are deeply aware of the schizophrenic nature of their science and long to find a synthesis, or unification. In string cosmology, the totality of existing universes exceeds the number of particles in our universe by more than 400 orders of magnitude Stop for a moment and take a look around you.
Introduction to quantum mechanics Many aspects of quantum mechanics are counterintuitive and can seem paradoxical, because they describe behavior quite different from that seen at larger length scales. In the words of quantum physicist Richard Feynman, quantum mechanics deals with "nature as She is – absurd". For example, the uncertainty principle of quantum mechanics means that the more closely one pins down one measurement (such as the position of a particle), the less accurate another measurement pertaining to the same particle (such as its momentum) must become. The first quantum theory: Max Planck and black-body radiation Hot metalwork. Thermal radiation is electromagnetic radiation emitted from the surface of an object due to the object's internal energy. Heating it further causes the colour to change from red to yellow, white, and blue, as it emits light at increasingly shorter wavelengths (higher frequencies). Predictions of the amount of thermal radiation of different frequencies emitted by a body.
The Everett Interpretation This FAQ shows how quantum paradoxes are resolved by the "many-worlds" interpretation or metatheory of quantum mechanics. This FAQ does not seek to that the many-worlds interpretation is the "correct" quantum metatheory, merely to correct some of the common errors and misinformation on the subject floating around. As a physics undergraduate I was struck by the misconceptions of my tutors about many-worlds, despite that it seemed to resolve all the paradoxes of quantum theory . The objections raised to many-worlds were either patently misguided or beyond my ability to assess at the time , which made me suspect (confirmed during my graduate QFT studies) that the more sophisticated rebuttals were also invalid. I have attempted, in the answers, to translate the precise mathematics of quantum theory into woolly and ambiguous English - I would appreciate any corrections. See "Does the EPR experiment prohibit locality?" eg "In quantum field theory the wavefunction becomes an operator".
New Theory Suggests Universe Could Ctrl-Alt-Delete Itself Life Get short URL It's certainly a grim thought to get your head around, but beyond mere scientific scaremongering, the theory does encourage serious debate among experts. This relates to the Higgs Field theory, also referred to as Higgs Boson, which is thought to permeate the entire universe. "Based on what we know about the Higgs Boson today, we cannot accurately tell whether our vacuum is stable (permanent) or metastable (temporary, albeit long-lived). Described as "the ultimate ecological catastrophe: if it were to occur, in layman's terms it would basically mean we could be here one second and then completely wiped out the next — and we wouldn't even see it coming. Could this theory relate to the demise of the dinosaurs? But the good news, and there is good news… the theory is very much just a theory. Much like the theory of robots and artificial intelligence turning sentinel, or the Simulation Hypothesis that we are all living in some kind of complex computer matrix.
So you think YOU'RE confused about quantum mechanics? An invitation-only conference held back in 2011 on the topic "Quantum Physics and the Nature of Reality" (QPNR) saw top physicists, mathematicians, and philosophers of science specializing in the meaning and interpretation of quantum mechanics wrangling over an array of fundamental issues. An interesting aspect of the gathering was that when informally polled on the main issues and open problems in the foundations of quantum mechanics, the results showed that the scientific community still has no clear consensus concerning the basic nature of quantum physics. Quantum mechanics (QM), together with its extensions into quantum electrodynamics and quantum field theory, is our most successful scientific theory, with many results agreeing to better than a part in a billion with experiment. However, at its roots QM is ghost-like – when you try to pin down just what it means, it tends to slip between the fingers. Introduction to QM Now knock the balls together. The quantum measurement problem
Physics for the 21st Century Course Overview Welcome to Physics for the 21st Century: an on-line course that explores the frontiers of physics. The 11 units, accompanied by videos, interactive simulations, and a comprehensive Facilitator's Guide, work together to present an overview of key areas of rapidly-advancing knowledge in the field, arranged from the sub-atomic scale to the cosmological. About This Course | Using This Site
Northern Light Show Visits South Nature put on one of her most spectacular shows last night when the "aurora^ borealis-northern lights . Reproduced with permission of the copyright owner. Further reproduction or distribution is prohibited without permission. Quantum mysteries John Gribbin For seventy years, physicists have worried about what quantum mechanics means. They can use quantum physics, to be sure; witness the successful designs of lasers and computer microchips, and the understanding of molecules that makes genetic engineering possible. In fact, few physicists worry about such things. The archetypal example of the quantum mysteries is the "experiment with two holes", where the measured position of a single electron that passes through two holes in a screen can only be explained in terms of the wave function travelling through both holes at once and interfering with itself. Imagine that we have a source which will emit a single quantum particle in a random direction (ordinary radioactive nuclei do exactly this, so there is nothing special about the source). So far, simple enough. But a giant leap in what might be called quantum philosophy has recently been taken by the American physicist John Cramer. It works like this.
Hawking at Harvard Black holes have long been painted as eternal prisons, regions of space so dense that nothing — not even light — can escape them. But the truth, Stephen Hawking told a packed Sanders Theatre this afternoon, is that the holes aren’t as black as you might think. In a session that was the hottest ticket on campus in some time, the renowned Cambridge theoretical physicist and cosmologist spoke to more than 1,000 faculty, students, and staff at Sanders, with dozens more watching at simulcast sites in the Science Center and at Jefferson Lab. Hawking’s lecture focused on his research into black holes and the information paradox, which suggests that physical information is permanently lost in such holes, a controversial notion that violates the scientific tenet that information about a system from one time can be used to understand its state at any other time. “It is said that fact is sometimes stranger than fiction, and nowhere is that more true than in the case of black holes,” Hawking said.
Why Physicists Are Saying Consciousness Is A State Of Matter, Like a Solid, A Liquid Or A Gas — The Physics arXiv Blog There’s a quiet revolution underway in theoretical physics. For as long as the discipline has existed, physicists have been reluctant to discuss consciousness, considering it a topic for quacks and charlatans. Indeed, the mere mention of the ‘c’ word could ruin careers. That’s finally beginning to change thanks to a fundamentally new way of thinking about consciousness that is spreading like wildfire through the theoretical physics community. Today, Max Tegmark, a theoretical physicist at the Massachusetts Institute of Technology in Cambridge, sets out the fundamental problems that this new way of thinking raises. Tegmark’s approach is to think of consciousness as a state of matter, like a solid, a liquid or a gas. He goes on to show how the particular properties of consciousness might arise from the physical laws that govern our universe. In 2008, Tononi proposed that a system demonstrating consciousness must have two specific traits. Tegmark does not have an answer.
Parallel Universes: Theories & Evidence Is our universe unique? From science fiction to science fact, there is a concept that suggests that there could be other universes besides our own, where all the choices you made in this life played out in alternate realities. The concept is known as a "parallel universe," and is a facet of the astronomical theory of the multiverse. The idea is pervasive in comic books, video games, television and movies. Franchises ranging from "Buffy the Vampire Slayer" to "Star Trek" to "Doctor Who" to "Digemon" use the idea to extend plotlines. There actually is quite a bit of evidence out there for a multiverse. Arguing for a multiverse Around 13.7 billion years ago, simply speaking, everything we know of in the cosmos was an infinitesimal singularity. One big question with this theory is: are we the only universe out there? There are at least five theories why a multiverse is possible, as a 2012 Space.com article explained: 1. 2. 3. 4. 5. Arguing against a parallel universe