Neil writes, > Do we pass through space or does space pass through us?
Fascinating question Neil. If we are indeed a hologram, then space is passing through us, one might think. I wonder if we are projections from an event horizon? Anyway, you might like these ideas from a couple more recent papers .. The Reality of Quantum Weirdness IN Akira Kurosawa’s film Rashomon, a samurai has been murdered, but it’s not clear why or by whom. Various characters tell their versions, but the accounts contradict one another: Which story is true? The film makes one consider a deeper question: Is there a true story, or is belief in one reality an illusion? This very question, in scientific focus, has long been the subject of debate in quantum physics. Is there a fixed reality, apart from our various observations of it? Or is reality a kaleidoscope of infinite possibilities? This month, a paper in the journal Nature Physics presents experimental research that supports the latter scenario — that there is a “Rashomon effect” not just in our descriptions of nature, but in nature itself. http://arxiv.org/abs/1412.6213 Over the past hundred years, numerous experiments on elementary particles have upended the classical paradigm of a causal, deterministic universe. Consider, for example, the so-called double-slit experiment. We shoot elementary particles — say, electrons — at a screen that can register their impact. But in front of the screen, we place a partial obstruction: a wall with two thin parallel vertical slits. We look at the patterns of electrons on the screen. What do we see? If electrons are like little pellets (classical physics), then each of them would go through one slit or the other, and we would see a pattern of two distinct stripes of light on the screen, one stripe behind each slit. But in fact we observe an interference pattern, as if two waves are colliding, creating ripples. Astonishingly, this happens even if we shoot the electrons one by one, so each electron acts like a wave interfering with itself, as if it is simultaneously passing through both slits at once. So an electron is a wave, not a particle? Not so fast. For if we place devices at the slits that “tag” the electrons according to which slit they go through, there is no interference pattern. Instead, we see two stripes on the screen, as if the electrons, suddenly aware of being observed, decide to act like little pellets. To test their commitment to being particles, we can tag them as they pass through the slits — but then, erase the tags before they hit the screen. Then, the electrons go back to their wavelike behavior, and the interference pattern miraculously reappears. There is no end to the practical jokes we can pull on the poor electron! But, like a well-trained actor, it plays the role it’s been called to perform. It’s like it decides to prove the famous Bishop Berkeley maxim “to be is to be perceived.” Is nature really this weird? Or, is this apparent weirdness just a reflection of our imperfect knowledge of nature? The answer depends on how you interpret the equations of quantum mechanics, the mathematical theory that has been developed to describe the interactions of elementary particles. The success of this theory is unparalleled: Its "spooky" predictions have been observed and verified with stunning precision. It has also brought remarkable technological advances. It's a powerful tool. But is it also a picture of reality? Does the wave function directly correspond to an objective, observer-independent physical reality, or does it simply represent an observer’s partial knowledge of it? If the wave function is merely knowledge-based, then you can explain odd quantum phenomena by saying that things appear to us this way only because our knowledge of reality is insufficient. But the new paper in Nature Physics gives strong indications that this is not the case. If there is a reality at all, the paper demonstrates, then the wave function is in fact reality-based. What this research implies is that there is one true story, but it has many truths, seemingly in contradiction, just like in Rashomon and in the Vedas: “As is the atom, so is the universe; as is the human mind, so is the cosmic mind." However, in addition to this, very recent additional scientific news brings us a theoretical reason for quantum behaviour. This new theory is quite easy to understand. Basically, these Aussie scientists theorize that there are many universes, and the electron as one particle is in our universe, while the electron as a wave is in closely adjoining universes. For years a major question has been whether a single photon is a particle or a wave. As we know, they act like both. So now, well respected researchers propose that we live in one universe, within a multiverse, so that a single quantum particle is here, and its waves are within other universes. Quote: "In a newly published study, physicists propose that parallel universes exist and that they interact and influence one another with subtle forces. Griffith University academics are challenging the foundations of quantum science with a radical new theory based on the existence of, and interactions between, parallel universes. A paper published in the prestigious journal Physical Review X, (see below) Professor Howard Wiseman and Dr Michael Hall from Griffith’s Center for Quantum Dynamics, proposes that parallel universes really exist, and that they interact. Nearby worlds influence one another by a very subtle force of repulsion. They show that such an interaction could explain everything that is bizarre about quantum mechanics. Quantum theory is needed to explain how the universe works at the microscopic scale, and is believed to apply to all matter. But quantum theory is difficult to fathom, and exhibits weird phenomena. As the eminent theoretical physicist Richard Feynman once noted: “I think I can safely say that nobody understands quantum mechanics.” However, the “Many-Interacting Worlds” approach developed at Griffith University provides a new and daring perspective on this baffling field. Professor Wiseman and his colleagues propose that: * The universe we experience is just one of a gigantic number of worlds. Some are almost identical to ours while most are very different; * All of these worlds are equally real, exist continuously through time, and possess precisely defined properties; * All quantum phenomena arise from a universal force of repulsion between ‘nearby’ (i.e. similar) worlds which tends to make them more and more dissimilar. Original Research Publication: Michael J.W. Hall, et al., “Quantum Phenomena Modeled by Interactions between Many Classical Worlds,” Phys. Rev. X 4, 041013, 23 October 2014; http://dx.doi.org/10.1103/PhysRevX.4.041013 Cheers, Stephen > From: nphar...@optusnet.com.au > To: ozteach...@googlegroups.com; l...@anu.edu.au > Subject: NPH RE: [Oz-teachers] Dark Matter and the Dinosaurs > Date: Sun, 1 Mar 2015 22:14:42 +1100 > > A thought provoking article. There is one part of the abstract (.....could > also lead to heating in the core of the planet through capture and subsequent > annihilation of DM particles.) that brought to mind a question that I put to > students: Do we pass through space or does space pass through us? > > cheers > > > -----Original Message----- > From: ozteach...@googlegroups.com [mailto:ozteach...@googlegroups.com] On > Behalf Of Stephen Loosley > Sent: Sunday, 1 March 2015 3:51 PM > To: ozteach...@googlegroups.com; l...@anu.edu.au > Subject: [Oz-teachers] Dark Matter and the Dinosaurs > > An astonishing new scientific paper suggests that dark matter could have > triggered not just the extinction of the dinosaurs, but also all the other > mass extinctions on our planet too. > > Publishing in the Monthly Notices of the Royal Astronomical Society, Michael > Rampino, a geoscientist at New York University in the US, explains that mass > extinctions occur roughly ever 26 million to 30 million years on Earth - > around the same time our Solar System passes through the disc of the Milky > Way. > > This cycle in the range of 26–30 million years has been widely reported > regarding mass extinctions. But also, terrestrial impact cratering (comet > impacts) have been found to exhibit a similar cycle of 31 ± 5 million years. > Thirdly, there is also a similar 30 million year periodicity observed in > terrestrial geologic (eg volcanic, earthquake etc) activity, and, which may > also be involved in the above-mentioned extinctions. > > Finally, the Sun's vertical oscillations through the plane of our galaxy's > disc have also been estimated to take from 30 to 42 million years between > each earth Galactic plane crossing. > > That is, as the Sun follows the swirling motion of the Galaxy's arms in > circling around the galactic centre, the Sun also moves up and down, > periodically crossing the plane that cuts the Galaxy into a top and a bottom > half. This new research suggests that as the Sun oscillates up and down, it > crosses a denser layer of dark matter causing a gravitational push and pull > that disturbs comets in the Oort cloud. Hence, a thin disk of dark matter at > the centre of the Galaxy could be causing the comet storms on earth with a > periodicity of about 35 million years. > > Thus, finally, these four observations taken together suggest that these > cycles of geological and biological evolution on Earth may be partly > controlled by dark matter and the rhythms of Galactic dynamics. > > > Here's the Scientific Abstract for this new research: > > "Disc dark matter in the Galaxy and potential cycles of extraterrestrial > impacts, mass extinctions and geological events" > > http://mnras.oxfordjournals.org/content/448/2/1816 > > By Michael R. Rampino > > Author Affiliations > 1 Department of Biology, New York University, New York, NY 10003, USA > 2 Department of Environmental Studies, New York University, New York, NY > 10003, USA > 3 NASA, Goddard Institute for Space Studies, 2880 Broadway, New York, NY > 10025, USA > > Author E-mail: m...@nyu.edu > > Accepted 2014 December 30. > Received 2014 December 29. > First published online February 18, 2015. > > Abstract > > A cycle in the range of 26–30 Myr has been reported in mass extinctions, and > terrestrial impact cratering may exhibit a similar cycle of 31 ± 5 Myr. These > cycles have been attributed to the Sun's vertical oscillations through the > Galactic disc, estimated to take from 30 to 42 Myr between Galactic plane > crossings. Near the Galactic mid-plane, the Solar system's Oort Cloud comets > could be perturbed by Galactic tidal forces, and possibly a thin dark matter > (DM) disc, which might produce periodic comet showers and extinctions on the > Earth. Passage of the Earth through especially dense clumps of DM, composed > of Weakly Interacting Massive Particles (WIMPs) in the Galactic plane, could > also lead to heating in the core of the planet through capture and subsequent > annihilation of DM particles. This new source of periodic heating in the > Earth's interior might explain a similar 30 Myr periodicity observed in > terrestrial geologic activity, which may also be involved in extinctions. > These results suggest that cycles of geological and biological evolution on > the Earth may be partly controlled by the rhythms of Galactic dynamics. > > > See also: > http://www.nature.com/news/did-dark-matter-kill-the-dinosaurs-1.14839 > http://www.sciencealert.com/new-hypothesis-suggests-dark-matter-wiped-out-the-dinosaurs > > Cheers, > Stephen > > -- > You received this message because you are subscribed to the Google Groups > "OzTeachers" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to ozteachers+unsubscr...@googlegroups.com. > To post to this group, send an email to ozteach...@googlegroups.com. > Visit this group at http://groups.google.com/group/ozteachers. > For more options, visit https://groups.google.com/d/optout. > > -- > You received this message because you are subscribed to the Google Groups > "OzTeachers" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to ozteachers+unsubscr...@googlegroups.com. > To post to this group, send an email to ozteach...@googlegroups.com. > Visit this group at http://groups.google.com/group/ozteachers. > For more options, visit https://groups.google.com/d/optout. _______________________________________________ Link mailing list Link@mailman.anu.edu.au http://mailman.anu.edu.au/mailman/listinfo/link
