Daily Archives: January 13, 2022

Quantum gravity has fascinated scientists for over a century. The term refers to any theory that seeks to describe gravity in the regimes in which quantum effects cannot be disregarded. Scientists have proposed string theory, loop quantum gravity, and many other theories, but none has achieved universal recognition or been confirmed by the evidence. In that sense, when we speak about quantum gravity, we are speaking not about any single theory, but about one of the great unsolved scientific problems. According to ScitechDaily, a new theory has emerged to compete with these research programs, and it is one that many people will instinctively understand: the universe is pixelated.

ScitechDaily suggests that as digital images become more pixelated the closer you zoom into them, the universe may have a similar structure. Rana Adhikari is one of many scientists who believe that the universe is not perfectly smooth, but is made up of infinitesimally small, discrete units. These spacetime pixels are so small that if they were enlarged to the size of grains of sand, then atoms would become as large as galaxies.

If scientists can find evidence of pixelation, it will be a predictor of quantum gravity. Quantum gravity is important because it unifies two types of physics: the physics of Newton and Einstein, with the physics of Niels Bohr, Erwin Schrdinger, Werner Heisenberg, Max Born and others. It is about bringing together the physics of mass structures, such as the solar system, which are governed by general relativity, with the physics of the very small, which is governed by quantum physics.For many scientists, there has always been a feeling of unease at the fact that there is no unifying principle that brings these two together. If gravity can be quantized, then that great problem is solved and this uneasy state of affairs comes to an end.

Although many people get the impression that these two parts of physics cannot be reconciled, this is in fact not true. There is ample evidence that quantum mechanics exists on this planet, and that alone is evidence of consistency. The problem for many scientists comes when questions around black holes arise, and when they are asked to explain the two in terms o a unified framework in very short distance scales.

This problem has proved so challenging that many scientists do not believe that it can be solved in the next generation. This has not prevented scientists from looking for ways to find evidence of quantum gravity, around black holes, or the early universe, or by using the famed LIGO gravitational wave interferometer.

Yet, there still has not been any evidence of quantum gravity, The absence of evidence is not the evidence of absence. We know from first principles that quantum gravity exists. Indeed, this is also a philosophical problem about the nature of science. Although the Science for Dummies version of what science is about, highlights the importance of evidence, often, there are technological or financial, or other barriers to finding evidence. For example, until LIGO detected gravitational waves in 2016, there was no evidence of them, even though Einsteins work told us that there should be such evidence. A century passed without anything to prove Einstein right.

A new project funded by the Heising-Simon Foundation, and headed by Kathryn Zurek, is attempting to find the evidence that science has been sorely awaiting. Tasked with finding evidence of quantum gravity, the Quantum gRavity and Its Observational Signatures (QuRIOS) is composed of a medley of complimentary talents. There are string theorists, who understand the formal tools of the subject, but typically have no experimental expertise, and particle theorists and model builders, who have a great understanding of experimental design, but little understanding of quantum gravitys formal tools.

Zurek is aware that mainstream science does not believe that you can look for observable features of quantum gravity. This has not dissuaded her or her team. She believes that unless we can link quantum gravity with the world we live in, we will not be able to make any meaningful advances. Observational signatures bring theorists together and allow for more concrete progress to be made.

Zurek and Adhikari will work together in order to design an experiment, the Gravity from Quantum, Entanglement of Space-Time (GQuEST), using tabletop instruments, which, it is hoped, will detect, not so much discrete spacetime pixels, but the connections between them that lead to observable signatures.

The process, akin to tuning an old television set, could bring us closer to observable signatures. The team understands that there are no guarantees. At this stage, what they have is an idea, and it could turn out to be a very bad idea, but the point of science is to experiment, even at the risk of falsifying theories, in the quest for robust theories of how our world works. Truth itself is provisional, in the scientific world. Scientists exist in a perpetual state of experimentation.

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Quantum Gravity And The Search For A Unified Physics - Science 2.0

PROVIDENCE, R.I. [Brown University] Scientists understand quite well how temperature affects electrical conductance in most everyday metals like copper or silver. But in recent years, researchers have turned their attention to a class of materials that do not seem to follow the traditional electrical rules. Understanding these so-called strange metals could provide fundamental insights into the quantum world, and potentially help scientists understand strange phenomena like high-temperature superconductivity.

Now, a research team co-led by a Brown University physicist has added a new discovery to the strange metal mix. In research published in the journal Nature, the team found strange metal behavior in a material in which electrical charge is carried not by electrons, but by more wave-like entities called Cooper pairs.

While electrons belong to a class of particles called fermions, Cooper pairs act as bosons, which follow very different rules from fermions. This is the first time strange metal behavior has been seen in a bosonic system, and researchers are hopeful that the discovery might be helpful in finding an explanation for how strange metals work something that has eluded scientists for decades.

We have these two fundamentally different types of particles whose behaviors converge around a mystery, said Jim Valles, a professor of physics at Brown and the studys corresponding author. What this says is that any theory to explain strange metal behavior cant be specific to either type of particle. It needs to be more fundamental than that.

Strange metal behavior was first discovered around 30 years ago in a class of materials called cuprates. These copper-oxide materials are most famous for being high-temperature superconductors, meaning they conduct electricity with zero resistance at temperatures far above that of normal superconductors. But even at temperatures above the critical temperature for superconductivity, cuprates act strangely compared to other metals.

As their temperature increases, cuprates resistance increases in a strictly linear fashion. In normal metals, the resistance increases only so far, becoming constant at high temperatures in accord with what's known as Fermi liquid theory. Resistance arises when electrons flowing in a metal bang into the metals vibrating atomic structure, causing them to scatter. Fermi-liquid theory sets a maximum rate at which electron scattering can occur. But strange metals dont follow the Fermi-liquid rules, and no one is sure how they work. What scientists do know is that the temperature-resistance relationship in strange metals appears to be related to two fundamental constants of nature: Boltzmanns constant, which represents the energy produced by random thermal motion, and Plancks constant, which relates to the energy of a photon (a particle of light).

To try to understand whats happening in these strange metals, people have applied mathematical approaches similar to those used to understand black holes, Valles said. So theres some very fundamental physics happening in these materials.

In recent years, Valles and his colleagues have been studying electrical activity in which the charge carriers are not electrons. In 1952, Nobel Laureate Leon Cooper, now a Brown professor emeritus of physics, discovered that in normal superconductors (not the high-temperature kind discovered later), electrons team up to form Cooper pairs, which can glide through an atomic lattice with no resistance. Despite being formed by two electrons, which are fermions, Cooper pairs can act as bosons.

Fermion and boson systems usually behave very differently, Valles said. Unlike individual fermions, bosons are allowed to share the same quantum state, which means they can move collectively like water molecules in the ripples of a wave.

In 2019, Valles and his colleagues showed that Cooper pair bosons can produce metallic behavior, meaning they can conduct electricity with some amount of resistance. That in itself was a surprising finding, the researchers say, because elements of quantum theory suggested that the phenomenon shouldnt be possible. For this latest research, the team wanted to see if bosonic Cooper-pair metals were also strange metals.

The team used a cuprate material called yttrium barium copper oxide patterned with tiny holes that induce the Cooper-pair metallic state. The team cooled the material down to just above its superconducting temperature to observe changes in its conductance. They found, like fermionic strange metals, a Cooper-pair metal conductance that is linear with temperature.

The researchers say this new discovery will give theorists something new to chew on as they try to understand strange metal behavior.

Its been a challenge for theoreticians to come up with an explanation for what we see in strange metals, Valles said. Our work shows that if youre going to model charge transport in strange metals, that model must apply to both fermions and bosons even though these types of particles follow fundamentally different rules.

Ultimately, a theory of strange metals could have massive implications. Strange metal behavior could hold the key to understanding high-temperature superconductivity, which has vast potential for things like lossless power grids and quantum computers. And because strange metal behavior seems to be related to fundamental constants of the universe, understanding their behavior could shed light on basic truths of how the physical world works.

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Newly discovered type of 'strange metal' could lead to deep insights - Brown University

A new study aims to solve Stephen Hawkings black hole information paradox and contrast the black hole fuzzball or wormhole debate. Credit: Shree Luitel | Lantern Reporter

A Dec. 28, 2021, study aims to solve theoretical physicist Stephen Hawkings black hole information paradox and end the black hole fuzzball or wormhole debate.

Researchers at Ohio State have found that string theory, which states that particles at their smallest are made of vibrating strings that can stretch within a black hole, might be the answer to Hawkings paradox.

Samir Mathur, professor of physics at Ohio State and lead author of the study, said this suggests that the information paradox is better explained by what he calls the fuzzball theory along with string theory.

The black hole information paradox arises from Hawkings conclusion that information that enters a black hole can never leave.

Madhur Mehta, a Ph.D. candidate in physics and a researcher on the study, said any information captured within a black hole vanishes at the end of the holes life. However, this theory violates quantum mechanics.

Eventually, as the black hole starts to evaporate, it will collapse and vanish. Hence, the information is lost, Mehta said. However, quantum mechanics says that information is always preserved in the universe, and this gives rise to the information paradox.

Such a paradox threatens not only quantum mechanics, but all of physics.

Mathur said this conclusion poses a significant issue to scientists because quantum mechanics is essential to physics.

If black holes are going to destroy quantum mechanics, then we have lost the basic pillar of physics, Mathur said.

Physicists tried to reconcile Hawkings conclusions with what is called the wormhole theory, which states that gravity forces information to the black holes center until it emerges at another point in space.

Mathur said the study found this to be inconsistent with visible physics. Rather, when using string theory, the researchers found radiation emitted by black holes comes from near the horizon, its edge, rather than the center.

When we did try to make a black hole from string theory, we found that gravity did not end up pulling everything to the center, Mathur said. But these particles get stretched into these strings and fluff up like a big ball of strings that fills up the entirety of the black hole.

Mathur said rather than go through a wormhole, the particles captured by a black hole stretch out in a ball of these strings. This explains why radiation is detected near the black holes edge rather than its center.

Mathur said there have been many possible explanations to the information paradox, but the study heavily supported the fuzzball theory.

People in the string theory community looked for many different solutions to the information paradox, Mathur said. However, in every case, the fuzzball theory just became more and more confirmed.

This finding will not only be used to explain the information paradox, Mehta said, but will help researchers explain other phenomena.

Mehta said this study could resolve the unknown reason for the expansion of the universe at an accelerated rate.

We are trying to use ideas from the fuzzballs and apply it to the cosmological models, and try to understand how fuzzballs could lead to a solution to dark energy, Mehta said.

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Ohio State study finds string theory may be solution to Stephen Hawking's black hole information paradox - OSU - The Lantern

Swami Vivekanandas insemination of Vedantic thoughts may have influenced the development of quantum physics and modern-day cosmology. I hope to prove that to my readers by the end of this blog. While many civilizations and their achievements have influenced science, but few are as dramatic as that of Vedanta. This was the first record of intermingling of a ten thousand old philosophy with modern science. Science does not always progress through reductionism by getting things proved in the laboratory! Einsteins concepts of relativity and bending of light waves were established decades after he enunciated the theory. Tesla dreamt of an alternate current that is probably the number one ingredient that runs present civilization on this planet. He did not work in a laboratory to develop it.

The biggest names in science during Swami Vivekanandas time listened to and respected him, including Lord Kelvin and Tesla. On 1st Feb 1896, Swamiji wrote about his interaction with Nicholas Tesla Mr. Tesla was charmed to hear about the Vedantic Prana, Akasha & the Kalpas, which according to him, are the only theories modern science can entertain. He further stated, what we call matter does not exist at all; it is only a certain state of force It took science another decade to accept the fact that only energy exists. The matter is only a form of energy. Prana (Energy) is the only existence. Vivekananda as explained in his book Raja Yoga clearly states that it is vibration that started in the initial dormant form of energy that led to the creation of our visible universe. Almost seventy years later Carl Sagan the famous astronomer conceded that the whole concept of big bang and periodically expanding and contracting universe came from the Vedantic concept of Kalpas.

Just like a modern-day scientist awakening from deep meditation below an old peepul tree beside a stream near Almora (Uttarakhand, India), he jotted down his vision as to how the universe is created. He wrote, the scheme of the universe of both micro-world and macro-world are built on the same plan. Of course, as we all know that the macroworld of giant stars, planets, galaxies, and black holes is totally different from the microworld of quantum fuzziness, but modern-day physics is working on how these two can be connected. Einstein died having failed to create a Theory of Everything-that will bring together many such discordant realities. The string theory which is yet to be proved answers some of these. This theory hypothesizes the presence of small strings at the end point of creation. All matter is created by vibration of such strings. When confronted with the realities of quantum mechanics, even Einstein protested that the universe behaves in this weird way saying, God does not play dice. In other words, if you are sitting in Alpha Centauri our neighboring triple star system and I need to communicate with you based on Einsteinian concepts since light is the fastest medium it will take four and half year to send you any message! However, we know that an entangled electron can know the position of its entangled pair in the other end of the universe. As Einstein suggested, if it did communicate using light, that would take millions of light years for that communication to reach. But this is instantaneous. Experiment has shown this phenomenon even at a macro level in entangled entities.

The truth is that as Swami Vivekananda factually demonstrated to one of his favorite disciples that the universe is a limitless form of energy vibrating. Therefore, all we see as matter is only vibrations that our brain deciphers as reality: chairs, tables, etc. Today a group of neuroscientists calls that controlled hallucination. Yes, our brain converts the reality that is the timeless foam of vibration into the matter we comprehend in our daily lives. Imagine this was what Swami Ji mentioned almost a century back when modern science was still obsessed with the matter being made of an indivisible unit called atoms where electrons rotated around the nucleus as planets revolve around the sun.

It is indeed astounding that some of the current thoughts in modern physics and cosmology are in consonance to what he said a century back Absolute is manifesting itself as many through the veil of Time, space and causation. Time is entirely a dependent existence; it changes with every change of our mind. ..So with space. it cannot exist separate from anything else. So, with causation. John Archibald Wheeler the American physicist put it is more scientific terms, Nothing exists until observed. Thus, as Vedanta contends reality is created by us the observer.

From Einstein to David Bohm, everyone was influenced by such Vedantic thoughts that we know from their own writing. Thus, while we do not want to trivialize the achievements of great minds in the twentieth century that gave us a proper understanding of the universe, we live in. It is true that using meditation and powerful yogic practices, giants like Buddha and Swami Vivekananda had a peek into the truth of creation way before even science thought in those lines.

The question is, how? Richard Davidson, a professor ofpsychologyandpsychiatryat theUniversity of WisconsinMadison,has studied the brains of hundreds of meditators. People with hundreds of hours of meditation can completely change their brains. Everything is possible, from decreasing aging to growing your brain to keeping you healthy. As Swami Vivekananda himself explains, Yet, just as by the telescope and the microscope we can increase the scope of our vision; similarly, we can by Yoga bring ourselves to the state of the vibration of another plane, and thus enable ourselves to see what is going on there.

Views expressed above are the author's own.

END OF ARTICLE

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Did Vedantic thoughts influence Twentieth Century Physics? A perspective on Swami Vivekananda - The Times of India Blog

January 7, 2022

Professor Cheng Chin has received the 2122 Marian and Stuart Rice Research Award, a Divisional honor that provides $100,000 for intellectually exciting and innovative research ventures that enable new research directions.

Chin joined the University of Chicago in 2005 and has been a full professor in the Department of Physics, the Enrico Fermi Institute, and the James Franck Institute since 2012. He is a pioneer in using ultracold atoms to study the quantum phenomena that underlie the behavior of other particles in the universe.

I am very excited about this generous support from the PSD, and especially from Stuart Rice, he said. The fund will enable a brand new research line into molecular quantum matter, on which my students and I are very excited to begin.

Chin's research team explores molecules and their reactions at the extremely low temperatures of 10 billionth of a degree above absolute zero. Molecules at such temperatures condense into a single quantum state with new forms of matter and reactions yet unknown to the molecular physics community. Their proposed experimental research will pursue the emergence of novel molecular quantum matter and quantum reactions.

The first research goal, Chin said, is to characterize these ultracold molecules and investigate their fundamental properties. They are predicted to form novel phases of chemical matter unlike their higher temperature counterparts.

Another goal is to study the conjectured regime of "quantum super chemistry." Similar to superconductors where electrons form super-current that flows without resistance, these Bose condensed molecules can react and interact without friction and energy cost. Chin proposes to study some of the fundamental chemical processes: composition, decomposition, replacement, and dissociation in the quantum super chemistry regime.

The great hope is that these studies will reveal new guiding principles and exciting prospects to control reaction pathways, he said. Novel applications might include inducing chemical reactions without energy dissipation, as in superconducting current; stimulated production of molecules, as in laser operation; and quantum information processing with molecular qubits.

Chin said the award will be used to upgrade the cold atom and molecule experiment to enhance the capability to manipulate and image molecules. Funds will be used to acquire experimental equipment for the proposed research as well as to attract students in physics and chemistry to perform the experiments.

The proposed research builds on work that has shaped and defined atomic, molecular, and optical physics. In 2011, Chin was recognized as the first physicist to observe the Efimov molecules at the ultracold temperature. More recently, in 2019, he designed an experiment that demonstrated a novel way to simulate physics in curved spacetimes, observing emissions that offer a view into the quantum origin of Unruh radiation. Last year, the discovery that multiple molecules can be brought at once into a single quantum state came from Chin labaccomplishing one of the most important goals in quantum physics.

The Marian and Stuart Rice Research Award was established by the family of Stuart Alan Rice, the Frank P. Hixon Distinguished Service Professor Emeritus in Chemistry and former chairman of the Department of Chemistry and dean of the Physical Sciences (1981-1995). It is awarded annually to promote new directions of research in the physical and mathematical sciences at the University of Chicago.

Awards, Faculty

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Cheng Chin receives '21'22 Marian and Stuart Rice Research Award | News | Physical Sciences Division | The University of Chicago - UChicago News