Creating a Tau Neutrino Beam (link) |
See Also:
Creating a Tau Neutrino Beam (link) |
Layout of the CNGS beam line. |
The OPERA neutrino experiment [1] at the underground Gran Sasso Laboratory (LNGS) was designed to perform the first detection of neutrino oscillations in direct appearance mode in the νμ→ντ channel, the signature being the identification of the τ− lepton created by its charged current (CC) interaction [2]. See: Measurement of the neutrino velocity with the OPERA detector in the CNGS beam-
Computer reconstruction of the tau candidate event detected in the OPERA experiment. The light blue track is the one likely induced by the decay of a tau lepton produced by a tau-neutrino. See: The OPERA experiment |
Main Components of CNGS |
A 400 GeV/c proton beam is extracted from the SPS in 10.5 microsecond short pulses of 2.4x1013 protons per pulse. The proton beam is transported through the transfer line TT41 to the CNGS target T40. The target consists of a series of graphite rods, which are cooled by a recirculated helium flow. Secondary pions and kaons of positive charge produced in the target are focused into a parallel beam by a system of two pulsed magnetic lenses, called horn and reflector. A 1 km long evacuated decay pipe allows the pions and kaons to decay into their daughter particles - of interest here is mainly the decay into muon-neutrinos and muons. The remaining hadrons (protons, pions, kaons) are absorbed in an iron beam dump with a graphite core. The muons are monitored in two sets of detectors downstream of the dump. Further downstream, the muons are absorbed in the rock while the neutrinos continue their travel towards Gran Sasso.microsecond short pulses of 2.4x1013 protons perFor me it has been an interesting journey in trying to understand the full context of a event in space sending information through out the cosmos in ways that are not limited to the matter configurations that would affect signals of those events.
In astrophysics, the most widely discussed mechanism of particle acceleration is the first-order Fermi process operating at collisionless shocks. It is based on the idea that particles undergo stochastic elastic scatterings both upstream and downstream of the shock front. This causes particles to wander across the shock repeatedly. On each crossing, they receive an energy boost as a result of the relative motion of the upstream and downstream plasmas. At non-relativistic shocks, scattering causes particles to diffuse in space, and the mechanism, termed "diffusive shock acceleration," is widely thought to be responsible for the acceleration of cosmic rays in supernova remnants. At relativistic shocks, the transport process is not spatial diffusion, but the first-order Fermi mechanism operates nevertheless (for reviews, see Kirk & Duffy 1999; Hillas 2005). In fact, the first ab initio demonstrations of this process using particle-in-cell (PIC) simulations have recently been presented for the relativistic case (Spitkovsky 2008b; Martins et al. 2009; Sironi & Spitkovsky 2009).Several factors, such as the lifetime of the shock front or its spatial extent, can limit the energy to which particles can be accelerated in this process. However, even in the absence of these, acceleration will ultimately cease when the radiative energy losses that are inevitably associated with the scattering process overwhelm the energy gains obtained upon crossing the shock. Exactly when this happens depends on the details of the scattering process. See: RADIATIVE SIGNATURES OF RELATIVISTIC SHOCKS
Soliton
In mathematics and physics, a soliton is a self-reinforcing solitary wave (a wave packet or pulse) that maintains its shape while it travels at constant speed. Solitons are caused by a cancellation of nonlinear and dispersive effects in the medium. (The term "dispersive effects" refers to a property of certain systems where the speed of the waves varies according to frequency.) Solitons arise as the solutions of a widespread class of weakly nonlinear dispersive partial differential equations describing physical systems. The soliton phenomenon was first described by John Scott Russell (1808–1882) who observed a solitary wave in the Union Canal in Scotland. He reproduced the phenomenon in a wave tank and named it the "Wave of Translation".
For more than a decade, scientists have seen evidence that the three known types of neutrinos can morph into each other. Experiments have found that muon neutrinos disappear, with some of the best measurements provided by the MINOS experiment. Scientists think that a large fraction of these muon neutrinos transform into tau neutrinos, which so far have been very hard to detect, and they suspect that a tiny fraction transform into electron neutrinos. See: Fermilab experiment weighs in on neutrino mystery
Measurement of the neutrino velocity with the OPERA detectorin the CNGS beam |
Gran Sasso |
deconstruction: soudan mural |
Fermilab experiment weighs in on neutrino mystery
Scientists of the MINOS experiment at the Department of Energy’s Fermi National Accelerator Laboratory announced today (June 24) the results from a search for a rare phenomenon, the transformation of muon neutrinos into electron neutrinos. The result is consistent with and significantly constrains a measurement reported 10 days ago by the Japanese T2K experiment, which announced an indication of this type of transformation.
The results of these two experiments could have implications for our understanding of the role that neutrinos may have played in the evolution of the universe. If muon neutrinos transform into electron neutrinos, neutrinos could be the reason that the big bang produced more matter than antimatter, leading to the universe as it exists today.
The Main Injector Neutrino Oscillation Search (MINOS) at Fermilab recorded a total of 62 electron neutrino-like events. If muon neutrinos do not transform into electron neutrinos, then MINOS should have seen only 49 events. The experiment should have seen 71 events if neutrinos transform as often as suggested by recent results from the Tokai-to-Kamioka (T2K) experiment in Japan. The two experiments use different methods and analysis techniques to look for this rare transformation.
To measure the transformation of muon neutrinos into other neutrinos, the MINOS experiment sends a muon neutrino beam 450 miles (735 kilometers) through the earth from the Main Injector accelerator at Fermilab to a 5,000-ton neutrino detector, located half a mile underground in the Soudan Underground Laboratory in northern Minnesota. The experiment uses two almost identical detectors: the detector at Fermilab is used to check the purity of the muon neutrino beam, and the detector at Soudan looks for electron and muon neutrinos. The neutrinos’ trip from Fermilab to Soudan takes about one four hundredths of a second, giving the neutrinos enough time to change their identities.
For more than a decade, scientists have seen evidence that the three known types of neutrinos can morph into each other. Experiments have found that muon neutrinos disappear, with some of the best measurements provided by the MINOS experiment. Scientists think that a large fraction of these muon neutrinos transform into tau neutrinos, which so far have been very hard to detect, and they suspect that a tiny fraction transform into electron neutrinos.
The observation of electron neutrino-like events in the detector in Soudan allows MINOS scientists to extract information about a quantity called sin2 2θ13 (pronounced sine squared two theta one three). If muon neutrinos don’t transform into electron neutrinos, this quantity is zero. The range allowed by the latest MINOS measurement overlaps with but is narrower than the T2K range. MINOS constrains this quantity to a range between 0 and 0.12, improving on results it obtained with smaller data sets in 2009 and 2010. The T2K range for sin2 2θ13 is between 0.03 and 0.28.
“MINOS is expected to be more sensitive to the transformation with the amount of data that both experiments have,” said Fermilab physicist Robert Plunkett, co-spokesperson for the MINOS experiment. “It seems that nature has chosen a value for sin2 2θ13 that likely is in the lower part of the T2K allowed range. More work and more data are really needed to confirm both these measurements.”
The MINOS measurement is the latest step in a worldwide effort to learn more about neutrinos. MINOS will continue to collect data until February 2012. The T2K experiment was interrupted in March when the severe earth quake in Japan damaged the muon neutrino source for T2K. Scientists expect to resume operations of the experiment at the end of the year. Three nuclear-reactor based neutrino experiments, which use different techniques to measure sin2 2θ13, are in the process of starting up.
“Science usually proceeds in small steps rather than sudden, big discoveries, and this certainly has been true for neutrino research,” said Jenny Thomas from University College London, co-spokesperson for the MINOS experiment. “If the transformation from muon neutrinos to electron neutrinos occurs at a large enough rate, future experiments should find out whether nature has given us two light neutrinos and one heavy neutrino, or vice versa. This is really the next big thing in neutrino physics.”
The MINOS experiment involves more than 140 scientists, engineers, technical specialists and students from 30 institutions, including universities and national laboratories, in five countries: Brazil, Greece, Poland, the United Kingdom and the United States. Funding comes from: the Department of Energy Office of Science and the National Science Foundation in the U.S., the Science and Technology Facilities Council in the U.K; the University of Minnesota in the U.S.; the University of Athens in Greece; and Brazil's Foundation for Research Support of the State of São Paulo (FAPESP) and National Council of Scientific and Technological Development (CNPq).
Fermilab is a national laboratory supported by the Office of Science of the U.S. Department of Energy, operated under contract by Fermi Research Alliance, LLC.
For more information about MINOS and related experiments, visit the Fermilab neutrino website: http://www.fnal.gov/pub/science/experiments/intensity/
Thinking outside the box See: A physicist inthe cancer lab
Ackerman became interested in physics in middle school, reading popular science books about quantum mechanics and string theory. As an undergraduate at the Massachusetts Institute of Technology, she traveled to CERN, the European particle physics laboratory near Geneva, to work on one of the detectors at the Large Hadron Collider, the most powerful particle collider in the world. Then she spent a summer at SLAC working on BaBar, an experiment investigating the universe’s puzzling shortage of antimatter, before starting her graduate studies there in 2007.
An analysis of four Fermi-detected gamma-ray bursts (GRBs) is given that sets upper limits on the energy dependence of the speed and dispersion of light across the universe. The analysis focuses on photons recorded above 1 GeV for Fermi detected GRB 080916C, GRB 090510A, GRB090902B, and GRB 090926A. Upper limits on time scales for statistically significant bunching of photon arrival times were found and cataloged. In particular, the most stringent limit was found for GRB 090510A at redshift z & 0.897 for which t < 0.00136 sec, a limit driven by three separate photon bunchings. These photons occurred among the first seven super-GeV photons recorded for GRB 090510A and contain one pair with an energy difference of E & 23.5 GeV. The next most limiting burst was GRB 090902B at a redshift of z & 1.822 for which t < 0.161, a limit driven by several groups of photons, one pair of which had an energy difference E & 1.56 GeV. Resulting limits on the differential speed of light and Lorentz invariance were found for all of these GRBs independently. The strongest limit was for GRB 090510A with c/c < 6.09 x 10−21. Given generic dispersion relations across the universe where the time delay is proportional to the photon energy to the first or second power, the most stringent limits on the dispersion strengths were k1 < 1.38 x 10−5 sec Gpc−1 GeV−1 and k2 < 3.04 x 10−7 sec Gpc−1 GeV−2 respectively. Such upper limits result in upper bounds on dispersive effects created, for example, by dark energy, dark matter or the spacetime foam of quantum gravity. Relating these dispersion constraints to loop quantum gravity
energy scales specifically results in limits of M1c2 > 7.43 x 1021 GeV and M2c2 > 7.13 x 1011 GeV respectively. See: Limiting properties of light and the universe with high energy photons from Fermi-detected Gamma Ray Bursts
The point here is that Energetic disposition of flight time and Fermi Calorimetry result point toward GRB emission and directly determination of GRB emission allocates potential of underlying structure W and the electron-neutrino fields?
Fig. 3: An electron, as it travels, may become a more complex combination of disturbances in two or more fields. It occasionally is a mixture of disturbances in the photon and electron fields; more rarely it is a disturbance in the W and the electron-neutrino fields. See: Another Speed Bump for Superluminal Neutrinos Posted on October 11, 2011 at, "Of Particular Significance" ***
What I find interesting is that Tamburini and Laveder do not stop at discussing the theoretical interpretation of the alleged superluminal motion, but put their hypothesis to the test by comparing known measurements of neutrino velocity on a graph, where the imaginary mass is computed from the momentum of neutrinos and the distance traveled in a dense medium. The data show a very linear behaviour, which may constitute an explanation of the Opera effect: See: Tamburini: Neutrinos Are Majorana Particles, Relativity Is OK
See Also:
Bee:And for all I know you need a charge for Cherenkov radiation and neutrinos don't have one.
But these details almost don’t matter, because Cohen and Glashow then put another chunk of powerful evidence on the table. They point out that neutrinos have been observed, at two other experiments, SuperKamiokande and IceCube, 100 to 1000 times more energetic than the neutrinos in OPERA’s beam. These neutrinos come out of the earth having traveled many hundreds or thousands of kilometers across interior of the planet. The fact that these neutrinos did not lose most of their energy while traveling all that distance implies that they, too, did not undergo CG emission. In short, they must have traveled very close to, and conservatively no more than about fifteen parts per billion faster than, the speed of light in empty space. (The limit from IceCube data may be as good as ten parts per trillion!)See: Is the OPERA Speedy Neutrino Experiment Self-Contradictory?
Before I comment on the result, let me give you a little background on the whole thing. Opera is a very innovative concept in neutrino detection. Its aim is to detect tau neutrino appearance in a beam of muon neutrinos. A Six-Sigma Signal Of Superluminal Neutrinos From Opera!
The OPERA result is based on the observation of over 15000 neutrino events measured at Gran Sasso, and appears to indicate that the neutrinos travel at a velocity 20 parts per million above the speed of light, nature’s cosmic speed limit. Given the potential far-reaching consequences of such a result, independent measurements are needed before the effect can either be refuted or firmly established. This is why the OPERA collaboration has decided to open the result to broader scrutiny. The collaboration’s result is available on the preprint server arxiv.orghttp://arxiv.org/abs/1109.4897.
In order to perform this study, the OPERA Collaboration teamed up with experts in metrology from CERN and other institutions to perform a series of high precision measurements of the distance between the source and the detector, and of the neutrinos’ time of flight. The distance between the origin of the neutrino beam and OPERA was measured with an uncertainty of 20 cm over the 730 km travel path. The neutrinos’ time of flight was determined with an accuracy of less than 10 nanoseconds by using sophisticated instruments including advanced GPS systems and atomic clocks. The time response of all elements of the CNGS beam line and of the OPERA detector has also been measured with great precision.
By classifying the neutrino interactions according to the type of neutrino involved (electron-neutrino or muon-neutrino) and counting their relative numbers as a function of the distance from their creation point, we conclude that the muon-neutrinos are "oscillating." See: STATEMENT: EVIDENCE FOR MASSIVE NEUTRINOS FOUND by Dave Casper
We present an analysis of atmospheric neutrino data from a 33.0 kiloton-year (535-day)exposure of the Super-Kamiokande detector. The data exhibit a zenith angle dependent de ficit of muon neutrinos which is inconsistent with expectations based on calculations of the atmospheric neutrino flux. Experimental biases and uncertainties in the prediction of neutrino fluxes and cross sections are unable to explain our observation. . Evidence for oscillation of atmospheric neutrinos
Measurements by GPS confirm that the neutrinos identified by the Super-Kamiokande detector were indeed produced on the east coast of Japan. The physicists therefore estimate that the results obtained point to a 99.3% probability that electron neutrino appearance was detected.Neutrino Oscillations Caught in the Act
The NOνA Experiment (Fermilab E929) will construct a detector optimized for electron neutrino detection in the existing NuMI neutrino beam. The primary goal of the experiment is to search for evidence of muon to electron neutrino oscillations. This oscillation, if it occurs, holds the key to many of the unanswered questions in neutrino oscillation physics. In addition to providing a measurement of the last unknown mixing angle, θ13, this oscillation channel opens the possibility of seeing matter/anti-matter asymmetries in neutrinos and determination of the ordering of the neutrino mass states.See:The NOνA Experiment at Fermilab (E929)
Image from a neutrino detection experiment. (Credit: Image courtesy of Southern Methodist University)Hunting Oscillation of Muon to Electron: Neutrino Data to Flow in 2010; NOvA Scientists Tune Design |
What's new @CERN ? a new video programme launched on webcast.cern.ch , every first Monday of the Month. For the first one, the themes are the results of the LHC experiments about Higgs boson, standard model and supersymmetry, and also neutrinos of OPERA experiment faster than the speed of light.
STANDARD MODEL OF PARTICLE PHYSICS:
http://www.youtube.com/user/Best0fScience#g/c/4A8C50311C9F7369
1) First Second Of The Universe:
http://www.youtube.com/watch?v=4HXPYO5YFG0
2) Force And Matter:
http://www.youtube.com/watch?v=p5QXZ0__8VU
3) Quarks:
http://www.youtube.com/watch?v=PxQwkdu9WbE
4) Gluons:
http://www.youtube.com/watch?v=ZYPem05vpS4
5) Electrons, Protons And Neutrons:
http://www.youtube.com/watch?v=Vi91qyjuknM
6) Photons, Gravitons & Weak Bosons:
http://www.youtube.com/watch?v=JHVC6F8SOFc
7) Neutrinos:
http://www.youtube.com/watch?v=m7QAaH0oFNg
8) The Higgs Boson / The Higgs Mechanism:
http://www.youtube.com/watch?v=1_HrQVhgbeo
The Cassiopeia Project is an effort to make high quality science videos available to everyone. If you can visualize it, then understanding is not far behind.
• http://www.cassiopeiaproject.com
We know already why the neutrinos could go faster and what new experiments this suggests, why it does not imply time travel or violates causality, and why it is somewhat expected for neutrinos. Now let us focus on what kind of superluminal velocity is indicated.See:A Million Times The Speed Of Light
Measurement of the neutrino velocity with the OPERA detectorin the CNGS beam |
The OPERA neutrino experiment at the underground Gran Sasso Laboratory has measured the velocity of neutrinos from the CERN CNGS beam over a baseline of about 730 km with much higher accuracy than previous studies conducted with accelerator neutrinos. The measurement is based on highstatistics data taken by OPERA in the years 2009, 2010 and 2011. Dedicated upgrades of the CNGS timing system and of the OPERA detector, as well as a high precision geodesy campaign for the measurement of the neutrino baseline, allowed reaching comparable systematic and statistical accuracies.
An early arrival time of CNGS muon neutrinos with respect to the one computed assuming the speed of light in vacuum of (60.7 ± 6.9 (stat.) ± 7.4 (sys.)) ns was measured. This anomaly corresponds to a relative difference of the muon neutrino velocity with respect to the speed of light (v-c)/c = (2.48 ± 0.28 (stat.) ± 0.30 (sys.)) ×10-5. See:Measurement of the neutrino velocity with the OPERA detectorin the CNGS beam
The OPERA Detector |
The notion of a perfect fluid arises in many fields of physics. The term can be applied to any system that is in local equilibrium and has negligible shear viscosity η. In everyday life, viscosity is a familiar property associated with the tendency of a substance to resist flow. From a microscopic perspective, it is a diagnostic of the strength of the interactions between a fluid’s constituents. The shear viscosity measures how disturbances in the system are transmitted to the rest of the system through interactions. If those interactions are strong, neighboring parts of the fluid more readily transmit the disturbances through the system (see figure 1). Thus low shear viscosities indicate significant interaction strength. The ideal gas represents the opposite extreme—it is a system with no interactions and infinite shear viscosity.
Perfect fluids are easy to describe, but few substances on Earth actually behave like them. Although often cited as a low-viscosity liquid, water in fact has a substantial viscosity, as evidenced by its tendency to form eddies and whorls when faced with an obstacle, rather than to flow smoothly as in ideal hydrodynamics. Even the famous helium-3, which can flow out of a container via capillary forces, does not count as a perfect fluid. What black holes teach about strongly coupled particles
At the recent seminar, the LHC’s dedicated heavy-ion experiment, ALICE, confirmed that QGP behaves like an ideal liquid, a phenomenon earlier observed at the US Brookhaven Laboratory’s RHIC facility. This question was indeed one of the main points of this first phase of data analysis, which also included the analysis of secondary particles produced in the lead-lead collisions. ALICE's results already rule out many of the existing theoretical models describing the physics of heavy-ions.See: 2010 ion run: completed!
Our work is about comparing the data we collect in the STAR detector with modern calculations, so that we can write down equations on paper that exactly describe how the quark-gluon plasma behaves," says Jerome Lauret from Brookhaven National Laboratory. "One of the most important assumptions we've made is that, for very intense collisions, the quark-gluon plasma behaves according to hydrodynamic calculations in which the matter is like a liquid that flows with no viscosity whatsoever."
Proving that under certain conditions the quark-gluon plasma behaves according to such calculations is an exciting discovery for physicists, as it brings them a little closer to understanding how matter behaves at very small scales. But the challenge remains to determine the properties of the plasma under other conditions.
"We want to measure when the quark-gluon plasma behaves like a perfect fluid with zero viscosity, and when it doesn't," says Lauret. "When it doesn't match our calculations, what parameters do we have to change? If we can put everything together, we might have a model that reproduces everything we see in our detector." See:Probing the Perfect Liquid with the STAR Grid
In the above contour plot we see that L4 and L5 correspond to hilltops and L1, L2 and L3 correspond to saddles (i.e. points where the potential is curving up in one direction and down in the other). This suggests that satellites placed at the Lagrange points will have a tendency to wander off (try sitting a marble on top of a watermelon or on top of a real saddle and you get the idea). A detailed analysis (PDF link) confirms our expectations for L1, L2 and L3, but not for L4 and L5. When a satellite parked at L4 or L5 starts to roll off the hill it picks up speed. At this point the Coriolis force comes into play - the same force that causes hurricanes to spin up on the earth - and sends the satellite into a stable orbit around the Lagrange point.Seeing space in a different light helps one to adjust perspective abut the universe and the possibilities of travel. There is indeed a abstractness to such ideas that when one sees the universe in a geometrical way, it helped to push my perspective about tunnels in space. How sound may be used to image WMAP. The three body problem application toward identification of those L positions.
Warp Drives", "Hyperspace Drives", or any other term for Faster-than-light travel is at the level of speculation, with some facets edging into the realm of science. We are at the point where we know what we do know and know what we don’t, but do not know for sure if faster than light travel is possible.
The bad news is that the bulk of scientific knowledge that we have accumulated to date concludes that faster than light travel is impossible. This is an artifact of Einstein’s Special Theory of Relativity. Yes, there are some other perspectives; tachyons, wormholes, inflationary universe, spacetime warping, quantum paradoxes...ideas that are in credible scientific literature, but it is still too soon to know if such ideas are viable.
One of the issues that is evoked by any faster-than-light transport is time paradoxes: causality violations and implications of time travel. As if the faster than light issue wasn’t tough enough, it is possible to construct elaborate scenarios where faster-than-light travel results in time travel. Time travel is considered far more impossible than light travel.
A theme that has come to the fore in advanced planning for long-range space exploration is the concept that empty space itself (the quantum vacuum, or spacetime metric) might be engineered so as to provide energy/thrust for future space vehicles. Although far-reaching, such a proposal is solidly grounded in modern physical theory, and therefore the possibility that matter/vacuum interactions might be engineered for space-flight applications is not a priori ruled out [1]. As examples, the current development of theoretical physics addresses such topics as warp drives, traversable wormholes and time machines that provide for such vacuum engineering possibilities [2-6]. We provide here from a broad perspective the physics and correlates/
consequences of the engineering of the spacetime metric.
One of the issues that is evoked by any faster-than-light transport is time paradoxes: causality violations and implications of time travel. As if the faster than light issue wasn’t tough enough, it is possible to construct elaborate scenarios where faster-than-light travel results in time travel. Time travel is considered far more impossible than light travel.
Dr. Maldacena and Dr. Polchinski each gave brief lectures related to their work. Both included broad overviews of string theory basics, with Dr. Polchinski noting the importance of "thought experiments" to help physicists make advances in the field. He said that physicists are excited about future experiments using particle accelerators such as the Large Hadron Collider at CERN, where some of these "thought experiments" could be validated.
Dr. Maldacena, who was born in Buenos Aires, also spoke about ICTP's important influence on physics in Argentina, noting that many of his professors had spent time at the Centre. Dr. Maldacena himself has participated in ICTP training programmes and was a director of the Spring School on String Theory for four years.
The Dirac Medal is given in honour of P.A.M. Dirac, one of the greatest physicists of the 20th century and a staunch friend of ICTP, to scientists who have made significant contributions to physics. Recipients are announced annually on Dirac's birthday, 8 August. The Medallists also receive a prize of US $5,000.Noted physicists awarded Dirac Medal
Juan Martín Maldacena, Institute for Advanced Study, Princeton
Joseph Polchinski, Kavli Institute for Theoretical Physics, University of California at Santa Barbara
and
Cumrun Vafa, Harvard University
Professors Maldacena, Polchinski and Vafa are being honored for their fundamental contributions to superstring theory. Their studies range from early work on orbifold compactifications, physics and mathematics of mirror symmetry, D-branes and black hole physics, as well as gauge theory-gravity correspondence. Their contributions in uncovering the strong-weak dualities between seemingly different string theories have enabled us to learn about regimes of quantum field theory which are not accessible to perturbative analysis. These profound achievements have helped us to address outstanding questions like confinement of quarks and QCD mass spectrum from a new perspective and have found applications in practical calculations in the fluid dynamics of quark gluon plasma.
The dualities have also led string theorists to conjecture that the five different superstring theories in ten space-time dimensions are manifestations of one underlying theory, yet undiscovered, which has been named the M-theory.See:Dirac Medalists 2008
Another deep quantum mystery for which physicists have no answer has to do with "tunneling" -- the bizarre ability of particles to sometimes penetrate impenetrable barriers. This effect is not only well demonstrated; it is the basis of tunnel diodes and similar devices vital to modern electronic systems.
Tunneling is based on the fact that quantum theory is statistical in nature and deals with probabilities rather than specific predictions; there is no way to know in advance when a single radioactive atom will decay, for example.
The probabilistic nature of quantum events means that if a stream of particles encounters an obstacle, most of the particles will be stopped in their tracks but a few, conveyed by probability alone, will magically appear on the other side of the barrier. The process is called "tunneling," although the word in itself explains nothing.
Chiao's group at Berkeley, Dr. Aephraim M. Steinberg at the University of Toronto and others are investigating the strange properties of tunneling, which was one of the subjects explored last month by scientists attending the Nobel Symposium on quantum physics in Sweden.
"We find," Chiao said, "that a barrier placed in the path of a tunnelling particle does not slow it down. In fact, we detect particles on the other side of the barrier that have made the trip in less time than it would take the particle to traverse an equal distance without a barrier -- in other words, the tunnelling speed apparently greatly exceeds the speed of light. Moreover, if you increase the thickness of the barrier the tunnelling speed increases, as high as you please.
"This is another great mystery of quantum mechanics."Signal Travels Farther and Faster Than Light By MALCOLM W. BROWNE
You and I know it as a time machine. Physicists, on the other hand, call it a "closed timelike curve." Below, feast on the concepts and conjectures, the dialects and definitions that physicists rely on when musing about the possibility of time travel. If this list only whets your appetite for more, we recommend you have a gander at the book from which we excerpted this glossary: Black Holes and Time Warps: Einstein's Outrageous Legacy, by Kip S. Thorne (Norton, 1994).
Mathematics, rightly viewed, possesses not only truth, but supreme beautya beauty cold and austere, like that of sculpture, without appeal to any part of our weaker nature, without the gorgeous trappings of painting or music, yet sublimely pure, and capable of a stern perfection such as only the greatest art can show. The true spirit of delight, the exaltation, the sense of being more than Man, which is the touchstone of the highest excellence, is to be found in mathematics as surely as in poetry.--BERTRAND RUSSELL, Study of Mathematics
In the 1920's about the only entertainment that came to the rural community of Leakey, Texas was the traveling tent shows. This form of family entertainment would come to the canyon about once a year to the delight of all. Everyone looked forward to the horse drawn wagons that brought the much anticipated entertainment to town. In later years the horses were replaced by the Model T Fords but this form of transportation did not deter the excitement.See:"Leakey's Last Picture Show" by Linda Kirkpatrick
What is in mind is a sort of Chautauqua...that's the only name I can think of for it...like the traveling tent-show Chautauquas that used to move across America, this America, the one that we are now in, an old-time series of popular talks intended to edify and entertain, improve the mind and bring culture and enlightenment to the ears and thoughts of the hearer. The Chautauquas were pushed aside by faster-paced radio, movies and TV, and it seems to me the change was not entirely an improvement. Perhaps because of these changes the stream of national consciousness moves faster now, and is broader, but it seems to run less deep. The old channels cannot contain it and in its search for new ones there seems to be growing havoc and destruction along its banks. In this Chautauqua I would like not to cut any new channels of consciousness but simply dig deeper into old ones that have become silted in with the debris of thoughts grown stale and platitudes too often repeated.Zen and the Art of Motorcycle Maintenance Part 1 Chapter 1.(Bold added by me for emphasis)
The conclusion of the whole matter is just this,—that until a man knows the truth, and the manner of adapting the truth to the natures of other men, he cannot be a good orator; also, that the living is better than the written word, and that the principles of justice and truth when delivered by word of mouth are the legitimate offspring of a man’s own bosom, and their lawful descendants take up their abode in others. Such an orator as he is who is possessed of them, you and I would fain become. And to all composers in the world, poets, orators, legislators, we hereby announce that if their compositions are based upon these principles, then they are not only poets, orators, legislators, but philosophers.Plato, The Dialogues of Plato, vol. 1 [387 AD] PHAEDRUS.