Cosmologists expose flaws in anthropic reasoning

first_imgThis graph shows that the probability of observing a value of lambda equal to or greater than the measured value (dashed vertical line) is very small. The three lines represent the anthropically predicted probability density distribution as a function of R, the ratio of the cosmological constant in another part of the multiverse to that in our Universe in Starkman and Trotta’s MANO scheme. T controls the cosmic time when intelligent life emerges, with T=1 representing our Universe. Credit: American Physical Society. “The significance of our work is to offer a concrete example of how anthropic methods of reasoning can be used to reach conclusions contradictory to those usually arrived at,” Starkman told PhysOrg.com. “This suggests to us that anthropic explanations of fundamental questions should be treated very cautiously.”According to the Anthropic Principle, the fact that we are here to observe the universe explains why the laws of nature are what they are. Some scientists point to a great deal of coincidences to support this idea: the perfect strength and relation of the four forces; the many components producing carbon-based life; and the energy density of the universe driving its expansion (aka “lambda”). Add all this up, proponents argue, and it’s pretty unlikely that you should be here today. Not to mention that the Anthropic Principle seems to fit nicely with many popular theories, such as string theory and the multiverse.Prior to Starkman and Trotta, people have taken issue with anthropic reasoning, although most of these arguments have been qualitative (with exception of a few very recent studies). For instance, explaining that things are what they are because of the way things are, doesn’t seem to get us anywhere. In addition, anthropic reasoning narcisstically ignores the possibility of non-carbon-based life. And why must the universe have been created to support life—why not see it as humans adapting to the universe, since natural selection decides which types of life are the best survivors? “The less we rely on anthropic reasoning, the better,” is Starkman’s opinion. “But on the other hand, in using anthropic reasoning, we might, with great caution, agree on what makes life absolutely impossible. However, we should be entirely skeptical of arguments about what life makes more probable.”In their study, Starkman and Trotta attempt to use anthropic reasoning to explain the value of the cosmological constant, which controls the universe’s expansion rate. What is the probability that an observer makes a measurement of this value in a given universe? they ask. First, one must find the number of observers in that universe (automatically eliminating those universes incompatible with intelligent life). Then one must figure out how many measurements each onecould make. Citation: Cosmologists expose flaws in anthropic reasoning (2006, November 28) retrieved 18 August 2019 from https://phys.org/news/2006-11-cosmologists-expose-flaws-anthropic.html 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.center_img Many scientists never liked it anyway, and now Glenn Starkman from Oxford/Case Western and Roberto Trotta from Oxford show that too many details—and too many unknowns—mean that anthropic reasoning gives inconsistent values of the cosmological constant, some that are far from current estimates. In their recent paper, “Why Anthropic Reasoning Cannot Predict Lambda” (Physical Review Letters), Starkman and Trotta find that different ways of defining the probability of observers in different universes leads to vastly different predictions of the cosmological constant. The question of the paper, then, is how to determine the number of observers in a universe and the number of measurements they could make—a number that cannot be measured directly, but which one must try to deduce despite the large number of unknown contributing factors. There are so many factors (e.g. number density of galaxies, baryons in halos, holographic arguments), in fact, that Starkman and Trotta argue that one’s prediction of the cosmological constant with anthropic reasoning depends “enormously” on the different ways of weighting all the factors. Because no single weighting scheme provides a fundamental advantage over any others, they argue, this lack of definition disqualifies anthropic reasoning. To demonstrate, Starkman and Trotta introduce a new weighting factor called the “maximum number of allowed observations” (MANO) in a universe. “This maximum number is the product of two factors—the number of observers and the maximum number of observations that each observer can make,” the scientists write in their study.Starkman and Trotta limit the number of observations per observer by calculating the maximum number of thermodynamic processes a living thing could perform in a lifetime under ideal conditions. Based on this energy-consuming picture, the scientists then limit the number of observers so that each can utilize all the energy in its surroundings without having to share (called the “rare observer limit”). They explain that if the number of observers increased, the energy per observer would decrease due to competition, waste, warfare, and thus wasted energy. Of course, the real outcome of overpopulation is unpredictable—but, the paper argues, this inability to predict the results of higher observer density further compromises the abilities of anthropic reasoning. Finally, the result which this anthropic reasoning gives: Starkman and Trotta measure that the probability of the anthropically predicted lambda being greater than or equal to the currently observed value (about 0.7) is one in 100,000. This result differs dramatically from the anthropic predictions proposed by Steven Weinberg, in predictions from 1989 (in his seminal paper on anthropic reasoning), to the present. Weinberg predicted a result larger than (though more similar to) current observations. Still other approaches have predicted much larger values.Starkman and Trotta explain that at least two assumptions of anthropic reasoning contribute to its flawed results. At its most basic level, anthropic reasoning uses the concept of probability to place limits on lambda. Perhaps, though, probability cannot apply to the entire universe, as the universe is not a lab where repeatable experiments are performed. Secondly, as the scientists write, anthropic reasoning depends heavily “on poorly understood microphysical processes involved in the evolution of life, especially of conscious beings interested in making observations of the fundamental constants.” Even expert biologists can hardly be sure of the various intelligence levels of animals on this planet. As a far-fetched illustration, we can’t eliminate the possibility that ants (or more aptly, aliens) will one day make their own measurements of the cosmological constant, can we?However, just because scientists have not found a weighting factor that would give an accurate prediction of lambda, might not rule out the possibility that a “correct” weighting factor could, in principle, exist. Starkman and Trotta have their doubts, though, not only on this possibility, but also on how valuable knowing the factor would be.“I think that, if such a possibility exists, then it has to be explored from the point of view of probability theory as logic, i.e. starting from fundamental reasoning principles and working our way upward toward a physical prediction,” said Trotta. “As our work demonstrates, attacking the problem from the other end will only give us answers that depend completely on the assumptions we put into our calculations. As such, those answers would probably have little relation with the physical reality and origin of our Universe.”“If there is a correct weighting factor (and I doubt that there is) I think we’re unlikely to be able to know what it is for such a very long time that we’d be better off trying to actually explain the universe we see,” said Starkman, “rather than arguing that it is the way it is so that we could be here to observe it.”Citation: Starkman, Glenn D., and Trotta, Roberto. “Why Anthropic Reasoning Cannot Predict Lambda.” Physical Review Letters 97, 201301 (2006).By Lisa Zyga, Copyright 2006 PhysOrg.comReprinted figure with permission from Starkman, Glenn D., and Roberto, Trotta. Physical Review Letters 97, 201301 (2006). Copyright 2006 by the American Physical Society. Readers may view, browse, and/or download material for temporary copying purposes only, provided these uses are for noncommercial personal purposes. Except as provided by law, this material may not be further reproduced, distributed, transmitted, modified, adapted, performed, displayed, published, or sold in whole or part, without prior written permission from the publisher.last_img read more

Rutgers team has ring prototype for touch authentication

first_imgThe prototype ring and its usage for transmitting short messages from the ring to a touchpad. Image credit: Tam Vu Touchscreens are already designed to detect voltage changes from fingers touching and moving across the screen. They pick up those spikes, and software on the phone would read them as password-like data. Full details of their proposed approach can be seen in their research paper, “Distinguishing Users with Capacitive Touch Communication,” by Tam Vu, Akash Baid, Simon Gao, Marco Gruteser, Richard Howard, Janne Lindqvist, Predrag Spasojevic, and Jeffrey Walling. “We explore a novel form of wireless communication in which a touch panel acts as a receiver and a small ring-like device worn by the user serves as the transmitter.”Project leader Marco Gruteser said the team hopes to commercialize the device in two years. Their homework ahead includes coming up with a miniaturized version of the device, as the one they have now is too “clunky.” Also, the ring can transmit only a few bits of data per second quickly and accurately. “Our experiments show that this is feasible even with an off-the-shelf touchscreen system, albeit at very low bitrates,” the authors wrote. The equivalent of a pin code takes around two seconds for the ring to transmit, but Gruteser said that could be speeded up by modifying touchscreen firmware in phones. “We believe that significantly higher data rates could be achieved by designing receiver capabilities into touch screens,” the authors wrote.When the device is ready for prime time, their ring approach can be counted among the numerous attempts researchers are now making to provide easy but reliable authentication for mobile users. In expanding on that approach, as one computer scientist has suggested, research could lead to a time where numerous electronic devices are developed that “know” their users via touch and can adapt to preferences and offer personalized information.As the authors point out, examples of “who you are” today include iris recognition, face recognition and voice recognition, all of which are being prototyped and tested on mobile devices. With the advent of well known spoofing mechanisms, though, there is more work ahead. The authors point out that even novel approaches such as air gesture based authentication which uses accelerometer sensors of a mobile device are easily visible to an adversary and can be socially awkward.A finger-swipe is something people are already doing, said Gruteser. The appeal of the approach is that so many devices use swiping already, whereas few commercial devices have retina-readers or finger-scanners. WINLAB (Wireless Information Network Laboratory) at Rutgers, described as a cooperative industry-university research center, focuses on new ideas for the mobile Internet. Explore further © 2012 Phys.org 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. More information: www.winlab.rutgers.edu/~grutes … /papers/tammob12.pdfvia Technology Review ShakeID tracks touch action in multi-user display (Phys.org)—What about using the same mobile device touchscreens used every day for direct authentication? What if your touch alone identifies you by code from the ring on your finger? A team from the WINLAB at Rutgers University has turned the what-ifs into a device that makes use of capacitive touchscreens on phones and tablets to confirm the user’s identity. The device can provide an additional layer of protection alongside passwords. The device can send a few bits of data representing a password from a special battery powered ring (with flash memory) on the finger. The data is sent as tiny voltage bursts through the wearer’s skin for phone-screen capture. Citation: Rutgers team has ring prototype for touch authentication (2012, August 31) retrieved 18 August 2019 from https://phys.org/news/2012-08-rutgers-team-prototype-authentication.htmllast_img read more

Interruptible 3D printing method wins Gehry prize w Video

first_img Robot arm at MIT will weave its own web (w/ Video) The prize is given to those who can demonstrate exceptional thesis projects. The couple won for their method of 3-D printing that allows the user to make changes to the design in progress.In 3-D printing an object is created by laying down successive layers of material that can render finished objects.3-D Printers make objects in three dimensions, layer by layer, which may be only microns thick. The model that is destined for replication has usually been fully resolved. The Phantom Geometry method allows the user, in contrast, to print outside the specifications of a given 3-D mode. Fundamentally the Phantom Geometry method is designed to create a physical model of streaming information. Using advanced robotic arms, the von Hasseln team proceeded to manipulate the model as it was being printed. According to their idea, as a printed product emerges, the designer can make alternations to the design in-progress, and in so doing change the downstream architecture of the printed product.Their system has a UV light projector, a special photo-sensitive resin, and controlled robotic arms from SCI-Arc’s Robot House. One robotic arm supports a projector at a stable height, while a second holds a vat of resin. 
The second arm moves the vat into the projector’s light beam of light. The designer tells the computer where and when to expose that vat to the projector’s rays. The designer is free to interrupt the process and change the model while it is being printed. As a result, one can work with a fabrication system that relies on real-time feed-back and feed-forward mechanisms, they said, and is therefore “interruptible and corruptible at any time.”As they explain in their own words, “The system uses UV light from a modified DLP projector to continuously and selectively cure photo initiated resin within a shallow vat system we developed for the project. The cured part is simultaneously and continually pulled away from the vat, allowing un-cured resin to flood in beneath it to be subsequently cured. The result is the material reification of streaming data that emerges along the motion path of the Staubli robot maneuvering the vat/projector apparatus.”SCI-Arc is an independent architecture school. The school’s Robot House is a cross between studio and shop, academy and industry, utilized as a research space for experimentation. Students have access to a multi-robot platform that includes six Stäubli robots, each with a full sphere of motion, operating in one flexible configuration, or in what the school calls a multi-robot work cell. 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 © 2012 Phys.org (Phys.org)—A husband and wife architecture team have managed to turn 3-D printing into something that is less rigidly planned and more on the fly and have won a prestigious award as a result. Liz and Kyle von Hasseln are winners of the inaugural Gehry Prize from the Southern California Institute of Architecture (Sci-Arc) in Los Angeles. The prize is named after architect Frank Gehry, who is known around the world for his architectural wonders including the Guggenheim in Bilbao, Spain; the Walt Disney Concert Hall in downtown Los Angeles; and the Dancing House in Prague. Citation: Interruptible 3-D printing method wins Gehry prize (w/ Video) (2012, October 22) retrieved 18 August 2019 from https://phys.org/news/2012-10-d-method-gehry-prize.htmllast_img read more

Going Punjabi

first_imgFrom Phulkari to Lassi to Makki di Roti and Sarson da Saag, the vibrancy of the land of the five rivers will be on full display as Delhi celebrates the culture and spirit of Punjab in a three-day Punjabi Mela organized by Delhi government’s Punjabi Academy.The cultural carnival will be unveiled at the Indira Gandhi National Centre for Arts on 12 April and will put on display every aspect of Punjabi life – from its rich food to its colorful dances to various forms of its arts – to give a glimpse of the rich cultural heritage of the people of the land. Also Read – ‘Playing Jojo was emotionally exhausting’The event also intends to exhibit and promote the dying ethnic traditions of Punjab through a setting of the traditional ‘mela’ of a Punjabi village where all cultural traditions meet and grow.All Punjabi instruments like the fast-slipping-into-oblivion ‘charkha’ or the spinning wheel, the art of knitting, popularly known as ‘Phulkari’, the making of ‘lassi’ and the playing of old musical instruments like ‘Been’, ‘Algoza’ and ‘Rabab’ will create an aura of  a typical Punjabi Mela. Dotting the IGNCA grounds will be stalls in the traditional Punjabi bazaar pattern selling Punjabi Juttis, Phulkaris, Naale-Prandey and other goods. Also Read – Leslie doing new comedy special with NetflixFor those who love the Punjabi cuisine there would also be the traditional Punjabi food including. Men from the order of the ‘Nihang Singhs’ will perform their popular martial art Gatka.  ‘Punjab’s vibrant culture, its rich cuisine and soulful music, has always attracted people. It is full of love and life. Through this festival we not only want to highlight the culture of the state but also promote the dying traditions of the great land,’ said Rawail Singh, Secretary, Punjabi Academy.While the day will showcase the working arts, the evening will be take viewers to a nostalgic journey through the Punjabi culture with live performances by top singers and dancers. Performers of international fame are expected to participate in the three-day extravaganza where exquisite fusion of Bhangra-Giddha and modern dances would also be presented.last_img read more

Extend full support to AAP Rajnath

first_imgHome Minister Rajnath Singh on Monday, asked the Delhi Police to extend full support to the Arvind Kejriwal-led government, as he reiterated Prime Minister Narendra Modi’s view that the states should be given every assistance, rising above party lines in keeping with the spirit of “cooperative federalism”.“I would like to maintain that a new party has got the mandate and a new government has been formed in Delhi. I expect you to extend full cooperation to this newly-formed government so that it can pave way for the city’s development,” Singh said at the 68th Raising Day parade of the Delhi Police on Monday. Also Read – Company director arrested for swindling Rs 345 crore“And I would also like to assure the new government that Delhi Police will extend full support in maintaining law and order in the city and will not let any anti-social elements disrupt the development work,” he said.He appreciated the force’s efforts for ensuring safety of women in the national Capital, saying that not just the people of Delhi, but even the Prime Minister gets worried whenever there is a crime against any woman. He added that the Centre has asked all state governments to constitute Investigative Units on crimes against women. Also Read – Man who cheated 20 women on matrimonial websites arrestedMeanwhile, speaking about the recent attacks on churches, Singh said that the Delhi Police Commissioner and other officials have taken strong action to prevent the repeat of such incidents. Different communities live here and small things become news, which affects the image of the Delhi Police.Moving on, Singh further said that the people from the North-eastern regions should not feel alienated in the national Capital. “I would like to say that if anybody practises discrimination against them, strict action would be taken,” he said. He also advised the Police to give protection to the lesser privileged and said that the force “should be sensitive to the right to livelihood of street vendors, rickshaw-pullers and traders and strive to win their blessings”. Stressing on the need for adopting modern technologies, Singh said that the new procedure for issuing the Police Clearance Certificate was a step in that direction. He said that the Delhi Police should take the lead to realise the Prime Minister’s dream of ‘SMART Police’ (S-Sensitive and Strict; M-Modern with Mobility; A-Alert and Accountable; R- Reliable and Responsive; T-Trained and Techno-savvy). He also lauded the Himmat app, launched a few weeks ago, terming it an “effective application to provide security to women” in the national Capital.He also mentioned the probe into the 1984 riot cases by the SIT, assuring that justice would surely be bestowed upon the victims and their families.Notably, the Delhi Police Commissioner BS Bassi had invited Chief Minister Arvind Kejriwal and his Cabinet for the event, but nobody from the newly sworn-in AAP government attended the function. However, both the Home Minister and Bassi asked media persons not to “read too much” into the issue. “It is a matter of privilege. I am sure, he (Kejriwal) will attend tomorrow’s (Tuesday) ‘At Home’ function,” said Bassi.last_img read more

CAG raps Arunachal for failing to implement midday meal scheme

first_imgThe Comptroller and Auditor General of India (CAG) has criticised the Arunachal Pradesh education department for its failure in successful implementation of the Mid-Day Meal (MDM) scheme in the state.The Centre had launched the scheme in August 1995 to boost universalisation of primary education by increasing enrolment, retention and attendance and simultaneously improving nutritional status of primary schoolchildren.The CAG report, which was tabled in the state Assembly on Tuesday by Chief Minister Nabam Tuki, attributed inadequate financial management, short-lifting of food grain, delay in release of funds, inadequate infrastructural facilities and lack of monitoring as the reasons for failure of the scheme.The CAG highlighted that no household surveys were conducted to identify the total number of children enrolled at the primary stage and no attempts were made to encourage high-level of enrolment through publicity.The report stated that in 2010-11, against the Centre’s allocation of 6,687.66 MT of grains for primary and upper primary levels, the department lifted only 5,928.37 MT and during 2013-14, against an allocation of 6,625.01 MT, only 6,598.95 MT was lifted leading to short-lifting of 785.35 MT of food grain.last_img read more

Wishes galore for SRK on 50th birthday

first_imgCalling him a wonderful man and a great inspiration, celebrities like Salman Khan, Hema Malini and Karan Johar wished health and happiness to Shah Rukh Khan on his milestone 50th birthday.Many celebrities shared interesting anecdotes about working with Shah Rukh, while others took to social media to talk about how the actor inspired them to give their best in life.Salman, who has worked with SRK in films like Karan Arjun and Kuch Kuch Hota Hai, said, “I wish him the best in life, I wish him good health, family and success and most amazing life. I would want whole family to be healthy.” Filmmaker Karan Johar wished the actor and credited him for turning him into a director with Kuch Kuch Hota Hai.last_img read more