“In cosmology there’s this quantum effect,” Ralf Schützhold tells PhysOrg.com. “In the universe, there is a ground state, where it is empty. But if the universe starts to expand or contract, the vacuum is distorted, no longer empty. Particles are created.” This document is subject to copyright. Apart from any fair dealing for the purpose of private study or research, no part may be reproduced without the written permission. The content is provided for information purposes only. Strange warping geometry helps to push scientific boundaries Citation: Analog of cosmological particle creation (2007, December 3) retrieved 18 August 2019 from https://phys.org/news/2007-12-analog-cosmological-particle-creation.html Explore further The quantum effects described by Schützhold, a theorist at the Institute for Theoretical Physics at the Dresden University of Technology, in Germany, are small right now. “This effect right now is probably very tiny,” he says. “But during the formation of the universe, quantum effects probably played a big role.”Schützhold and his colleagues, Michael Uhlmann at the Institute in Dresden, and experimental scientists Lutz Petersen, Hector Schmitz, Axel Friedenauer and Tobias Schätz at the Max Planck Institute for Quantum Optics in Garching, Germany, hope to model quantum particle creation using an analog of phonons in an ion trap. Their work is discussed in an article titled “Analogue of Cosmological Particle Creation in an Ion Trap,” and published in Physical Review Letters.“In this analog, we expect to see the same effect of quantum particle creation that happened in the universe. But instead of electrons and photons, as are present in the universe, we use phonons in an ion trap,” Schützhold explains. He points out that through such an analog, it would be possible to “see cosmological effects and do experiments.”“One of the basic indications we propose to use,” Schützhold says, “is pairs. Particles created by these quantum effects always come in pairs. In the ion trap, it would be the same thing. If there is a quantum effect, the phonons would come in pairs. If we find that we have two particles instead of one, there is a strong indication of quantum effects.” Such detection in the ion trap would help rule out effects leading to particle creation due to such classical physics effects as heating.Schützhold points out that understanding the quantum effects that lead to particle creation would not directly point to how the universe was formed. “This is a way to help understand possible quantum effects in the early universe, but it is not a direct test of cosmological particle creation.” He pauses before continuing. “In the long run, this could help us understand issues of theory better.”One of the attractive qualities of the ion trap analog proposed by the scientists in Germany is that it is possible to see results using current technology. According to Schützhold, Schätz, head of the experimental group in Garching, says that they have already done a preliminary experiment where they cooled the ions close to the ground state and achieved optical pumping at 99 percent accuracy. “It’s not fully ready, yet,” he concedes, “but it should be ready maybe by the end of this year or the beginning of next year.”This experiment, Schützhold explains, is a way to probe the quantum effects behind particle creation and work toward understanding fundamental questions of quantum physics. “This quantum effect was just calculated in theory,” he says. “Of course now we want to see it in an experiment…It hasn’t been seen practically yet.”And while the technology to directly measure quantum effects in particle creation may be years down the road, Schützhold and his colleagues may have found a way to understand these effects now by using an experimental analog that might possibly model the same effects.Copyright 2007 PhysOrg.com. All rights reserved. This material may not be published, broadcast, rewritten or redistributed in whole or part without the express written permission of PhysOrg.com.
Explore further This document is subject to copyright. Apart from any fair dealing for the purpose of private study or research, no part may be reproduced without the written permission. The content is provided for information purposes only. (PhysOrg.com) — When we think of taste, we don’t normally think about how something’s molecular makeup influences our tongues. A group of scientists at the University of Cincinnati and Moscow State University tested the molecular structure of different vodka brands, and began working out some parameters that might indicate which type of vodka is more “smooth”, depending on its chemical properties. Image source: free-extras.com Bourbon versus vodka: Bourbon hurts more the next day, performance is the same More information: Manisha Lalloo, “Vodka’s molecular cocktail,” RSC (May 27, 2010). Available online: www.rsc.org/chemistryworld/New … 010/May/27051001.asp © 2010 PhysOrg.com Citation: Could the Taste of Vodka be Related to Molecular Makeup? (2010, May 28) retrieved 18 August 2019 from https://phys.org/news/2010-05-vodka-molecular-makeup.html It seems a little strange to consider this, since vodka is, for the most part, just a mixture of water and ethanol. But, upon analyzing five different brands of vodka, the researchers discovered that there slight differences in molecular structure. RSC offers this on the vodka study:”We observed measurable differences among the brands,” says [Dan] Schaefer. Analysis of the Raman and IR spectra indicated all the solutions contained four components – pure water, pure ethanol, and two hydrates. However the concentration of one of these hydrates, E·5.3H2O, varied between vodkas. “It looks like this can be used as a measure of the physical properties of vodka,” says Schaefer. The taste, suggests the researchers, could be influenced by the way the water molecules create a cage around the hydrate in question. If there are higher amounts of the hydrate, then there are fewer free water molecules, and that could influence the taste of vodka. Of course, reports RSC, not everyone is impressed with the vodka result:Dirk Lachenmeier, head of the alcohol laboratory at the Chemical and Veterinary Investigation Laboratory in Karlsruhe, Germany, thinks the team’s conclusions are conjectural. “There is no basis to push that this might be the holy grail of vodka taste differentiation,” he says. …And, although thought of as a “pure” spirit, Lachenmeier says vodka manufacturers are allowed to slightly influence the taste with different additives such as citric acids.The effort to quantify items that seem purely subjective, like taste, are likely to continue. Schaefer wants to do additional studies to use a parameter to correlate the molecular structure seen in vodka brand preference amongst consumers.
© 2010 PhysOrg.com More information: Vibrational Signaling in the Agonistic Interactions of Red-Eyed Treefrogs, Current Biology, Volume 20, Issue 11, 1012-1017, 20 May 2010 doi:10.1016/j.cub.2010.03.069 This document is subject to copyright. Apart from any fair dealing for the purpose of private study or research, no part may be reproduced without the written permission. The content is provided for information purposes only. Explore further I am treefrog, feel me shake (w/ Video) (PhysOrg.com) — A study of the Central American red-eyed tree frog has found that the males shake the branches they’re perched on to produce strong vibrations to mark out their territory for mating. Citation: Red-eyed tree frogs use vibrations as a means of communication (2010, June 22) retrieved 18 August 2019 from https://phys.org/news/2010-06-red-eyed-tree-frogs-vibrations.html Red-eyed tree frog of Central and South America. Image: Graham P. Oxtoby, via Wikipedia. Researchers from the Adelaide Zoo and Flinders University, Adelaide, led by Dr. Greg Johnston, were studying the role of bright colors in the behavior of frogs in their breeding rituals, when they discovered that the Panamanian rainforest frogs shake the branches they are posing on as part of the ritual, especially if another male is in the vicinity. Johnston said they struck a pose that displayed all their colors and then did what looked to him like “little tantrums,” which produced strong vibrations that traveled through the plants.The researchers chose red-eyed tree frogs (Agalychnis callidryas) to study because they are brilliantly colored with gold and blue stripes on their sides, purple flashes on their thighs, bright orange feet, and green backs, and their eyes are bright red. They used infrared cameras to study the frogs mating at night, and also used a miniature seismograph to confirm the vibrations were really made by the frogs and not by the wind or other natural effects.The team introduced competing males and observed them. They found the two males shook their branches until one of them gave up, or until they fought to decide the victor. Shaking branches was the most frequent display of aggression, and the behavior and vibrational characteristics varied with the size of the male and the degree of conflict.It was clear to the researchers the frogs were using their vibrations to mark out their territory for mating, with the vibrations traveling around 1.5 meters through the tree branches and male frogs spacing themselves around the rainforest pond accordingly.In another experiment the researchers used a robot frog to produce vibrations when male frogs were in the vicinity. Johnston said the male frogs reacted to the robot in the same way as they would with a real male frog.The research adds to the knowledge of how vibrations can be used as another mode of communication among animals. Scientists have known for a long time that animals are sensitive to vibrations but little is known about using them as a communication method. Another study in April’s edition of Nature described how certain caterpillars used vibrations as a form of communication.The results of the research are reported in the June issue of the journal Current Biology.
© 2011 PhysOrg.com Their idea is based on research that has shown that traffic jams occur when (quite obviously) cars are pouring faster into an area of road than the speed at which they are leaving; this results to some extent, the researchers say because of differences in drivers. They say that there are two kinds of drivers on the road. The first are “optimistic” who believe that driving more aggressively will get them to their destination faster. They tend to be the ones to move closer to the vehicle in front of them than is generally deemed safe. The second group, comprised of “defensive” drivers tend to fear the actions of other drivers and as a result tend to put more space between their vehicle and the one they are following. Not surprisingly, the researchers suggest that it’s the optimistic drivers who contribute more to traffic jams because they are the ones that cause the bunching.To build their algorithm, the team used these bits of information. To put an end to a traffic jam, they reason, all that’s needed is for cars that are headed for the jam to slow down and for those that are leaving the jam to speed up. The problem is, people on their own don’t follow these rules. Thus, they suggest that each car be fitted with controls that can force a car to slow down or speed up when deemed necessary, and with wireless technology so that all the cars in the area can “talk” to each other. In such a system, all of the cars on the road could be made to be of the defensive type as well, thus alleviating the original cause of so many jams.In such a real world system, all of the cars and trucks on the road would broadcast their location and speed to all other vehicles in the area. When an onboard control system for an individual vehicle notes that the cars ahead seem to be slowing down for no apparent reason, it would slow the vehicle right away, preventing things ahead from getting worse. If every car heading into the jam did the same, the problem would be reduced. At the same time, those cars on the other side of the jam would be sped up automatically so as to relieve the pressure of the jam. Such a system would not require a central computer controlling everything; each car would react as it should based on the same algorithm in its own individual controller.Realistically, it does appear that such a system would work. The only problem of course would be getting all of the cars on the road fitted with such controls, especially the part where they driver wouldn’t be allowed to override them as is the case with virtually all other automated controls currently being implemented in vehicles. Explore further Citation: Korean researchers combine algorithm with wireless communication to reduce traffic jams (2011, September 19) retrieved 18 August 2019 from https://phys.org/news/2011-09-korean-combine-algorithm-wireless-traffic.html (PhysOrg.com) — Hyun Keun Lee and Beom Jun Kim, researchers at the University of Seoul, have developed an idea on how to reduce traffic jams or in some cases prevent them all together. In their paper, published in Physica A: Statistical Mechanics and its Applications, they suggest outfitting every vehicle on the road with wireless communications, some on-board controls, and the implementation of a simple algorithm. More information: Dissolution of traffic jam via additional local interactions, Physica A: Statistical Mechanics and its Applications, Volume 390, Issues 23-24, 1 November 2011, Pages 4555-4561. Preprint available: arxiv.org/abs/1109.2191 AbstractWe use a cellular automata approach to numerically investigate traffic flow patterns on a single lane. The free-flow phase (F), the synchronized phase (S), and the jam phase (J) are observed and the transitions among them are studied as the vehicular density ρ is slowly varied. If ρ is decreased from well inside the J phase, the flux Φ follows the lower branch of the hysteresis loop, implying that the adiabatic decrease of ρ is not an efficient way to put the system back into S or F phases. We propose a simple way to help the system to escape out of J phase, which is based on the local information of the velocities of downstream vehicles.via Arxiv Blog If all drivers were polite, they would get where they’re going faster This document is subject to copyright. Apart from any fair dealing for the purpose of private study or research, no part may be reproduced without the written permission. The content is provided for information purposes only.
Pulses of electrons (green, coming from the left) impinge on a micro-structured antenna which is powered by laser-generated terahertz radiation (red). The interaction compresses the duration of the electron pulses to a few femtoseconds. Credit: Christian Hackenberger Attosecond physics: Film in 4-D with ultrashort electron pulses More information: C. Kealhofer et al. All-optical control and metrology of electron pulses, Science (2016). DOI: 10.1126/science.aae0003AbstractShort electron pulses are central to time-resolved atomic-scale diffraction and electron microscopy, streak cameras, and free-electron lasers. We demonstrate phase-space control and characterization of 5-picometer electron pulses using few-cycle terahertz radiation, extending concepts of microwave electron pulse compression and streaking to terahertz frequencies. Optical-field control of electron pulses provides synchronism to laser pulses and offers a temporal resolution that is ultimately limited by the rise-time of the optical fields applied. We used few-cycle waveforms carried at 0.3 terahertz to compress electron pulses by a factor of 12 with a timing stability of <4 femtoseconds (root mean square) and measure them by means of field-induced beam deflection (streaking). Scaling the concept toward multiterahertz control fields holds promise for approaching the electronic time scale in time-resolved electron diffraction and microscopy.Press release Journal information: Science (Phys.org)—A small team of researchers with Ludwig-Maximilians-Universität München and the Max-Planck-Institute of Quantum Optics, both in Germany has successfully demonstrated a means for shaping electron beams in time through interactions with terahertz electromagnetic fields. In their paper published in the journal Science, the team describes their technique and why they believe it may lead the way to ultrafast microscopy and diffraction techniques. In a Perspectives piece in the same journal issue, Claus Ropers with the University of Göttingen, describes the benefits of developing faster electron microscopy, outlines the technique used by the researchers with this new effort and offers some insight into where the science is headed. Explore further This document is subject to copyright. Apart from any fair dealing for the purpose of private study or research, no part may be reproduced without the written permission. The content is provided for information purposes only. Citation: Researchers demonstrate way to shape electron beams in time through interaction with terahertz electromagnetic fields (2016, April 22) retrieved 18 August 2019 from https://phys.org/news/2016-04-electron-interaction-terahertz-electromagnetic-fields.html © 2016 Phys.org There is no doubt that electron microscopy techniques have led to incredible advances in the understanding of matter at the molecular and atomic scale. But such devices could be made even better, Ropers explains, by making them run faster, or ultrafast, i.e. with pulses measured in femtoseconds. This is because there is motion at the atomic scale—using short bursts of electrons to capture the mechanics of such motion would open up a whole new world of discovery. To that end, researchers have developed devices with that goal in mind.To produce short bursts of electrons in traditional devices, a metal surface is illuminated by a laser, causing electrons to be emitted into a vacuum—unfortunately they do not all travel at the same speed, which means they spread apart as they move towards a target—coulomb forces cause even more stretching, which results in problems in time resolution in microscopy devices. To get around this, researchers have tried multiple approaches that rely are various types of devices that manipulate the electron stream. In this new effort, the researchers used optics and terahertz radiation instead.The idea is to cause faster moving electrons to slow down a little bit and slower moving electrons to speed up a little bit, resulting in all of the electrons in a group traveling at the same speed towards a destination. This is achieved with the new technique by having terahertz fields act on the electrons in a microstructure—its bow-tie shape enhances the field in the desired way via tilting. In testing their device, the researchers found that they could measure pulse durations of just 75 fs, a ten times reduction in value over those that were not modified.
Kolkata: A missionary school situated on AJC Bose Road near Moulali witnessed protests from guardians, over a sudden fee hike on Thursday morning. The agitating guardians also resorted to a roadblock and were also involved in scuffle with the police, who tried to push back the agitators. According to the agitating parents, Lady of Providence Girls’ School has suddenly raised the tuition fees by Rs 200- 300 a month, keeping them completely in the dark. Also Read – Heavy rain hits traffic, flightsThe guardians had resorted to an agitation on Tuesday, following which the school authorities had consented to sit for a meeting on Wednesday. However, even after the meeting, the school stuck to their stand of increasing fees.The guardians alleged that the school has been raising fees in leaps and bounds since January and it has now gone up to a hike of nearly Rs 200 -300 a month. The police managed to pacify the agitators. However, they threatened to continue their agitation on Friday, unless the school authorities roll back the fee hike.
Kolkata: An elderly couple was allegedly assaulted by two miscreants when the couple tried to prevent the duo from stealing things at thier residence at Tegharia under Baguiati police station area.According to police sources, two miscreants had somehow managed to enter the house situated in Nandankanan area on Saturday night when they had already gone for sleep.The sexagenarian Alok Ranjan Chakraborty woke up by the noise and he immediately lit the lights of the room. On seeing the two unknown men in their room, he raised alarm and tried to challenge them. Also Read – Speeding Jaguar crashes into Merc, 2 B’deshi bystanders killedThe two miscreants by the fear of getting caught assaulted the elderly man and as his wife Ratna rushed to his rescue, she was also pushed by one of the miscreants. The woman fell down on the ground and sustained injuries on her waist. The miscreants, however, managed to escape.Neighbours came in to their rescue and took the injured couple to a nearby hospital. “Though there was no external injury marks but both of them have sustained serious internal injuries,” a source in the hospital said.The police have taken up the probe on the basis of a written complaint lodged by the couple’s daughter Moumita Chakraborty at Baguiati police station on Sunday afternoon.”The motive behind the case seems to be a previous grudge. We are in the process of identifying the culprits and hope to arrest them soon,” said a senior official of Bidhannagar City Police.
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Kolkata: Despite relentless efforts by the Kolkata Traffic Police, congestion could not be avoided at any of the roads which were used for diversion following the collapse of a portion of Majerhat Bridge on Tuesday.From September 5, police have arranged several diversions for vehicular movement. But as the roads are much narrower than Diamond Harbour Road, the traffic system has got messed up.Following the situation prevailing in the last two days, Kolkata Traffic Police has issued a new set of vehicular movement notifications for commuters on Friday. Additional forces have also been deployed throughout the city. Also Read – Rain batters Kolkata, cripples normal lifeDuring last two days it has been seen that Alipore Road, Bardhaman Road and other linked roads are getting choked with excessive vehicular load. Condition of other diversion roads were almost the same. The stretches which usually take 15-20 minutes to cover are now taking almost one and half hours.Office-goers and students were found suffering greatly, due to the traffic snarls that spread up to Rashbehari Avenue, Tollygunj Circular Road and S P Mukherjee Road Crossing in South Kolkata. Also due to the restriction on the movement of goods vehicles, Vidyasagar Setu also got choked for Kolkata bound traffic. Also Read – Speeding Jaguar crashes into Mercedes car in Kolkata, 2 pedestrians killedObserving the vehicular movement frequency in the last two days, Additional Commissioner of Police (I) Vineet Goyal, who is in charge of traffic management, has issued a new set of route diversions on Friday.According to the plan, all the vehicles coming from Behala have been requested to avail Diamond Harbour Road or Circular Garden Reach Road, following Taratala Road and Hyde Road for Esplanade bound movement.It has also been mentioned that some of the roads in the port area are damaged and concerned agencies have been asked to do the necessary repair work as soon as possible. Following the repair work, the travel time on the roads is expected to improve. During peak hours, all vehicles coming from Budge Budge have been requested to avail Taratala Road, Garden Reach Flyover and Remount Road ramp to reach Mominpur.Several roads has been made one-way for better traffic management. N R Avenue will be used for the East bound vehicular movement from the Mint to New Alipore, while Sahapore Road will cater to the Taratala bound vehicles. According to Goyal, as most vehicles are availing N R Avenue-Durgapur Bridge-Tollygunge to reach Rashbehari, Gariahat and Park Street- Esplanade area, the travel time is increasing.”We found that Taratala Road, West of Brace Bridge, Garden Reach Flyover and Remount Road are relatively less busy. Thus, the travel time is also shorter than the other roads. We strongly advise the people to use these roads to reach North and Central Kolkata,” said Goyal.