Category Archives: Quantum Physics

Whats God got to do with it? Given that the majority of physicists are agnostics at best, I have always found it puzzling that my community is so obsessed with Gods mind, whether or not God plays dice, the God particle and seeing Godand now with Michio Kakus The God Equation. Title notwithstanding, this is an excellent book written by a masterful science communicator elaborating on a subject that is his research home turfsuperstring theory. The prolific author of multiple popular science books, Mr. Kaku is a futurist, broadcaster and professor of theoretical physics at the City University of New York. He is also the host of the wildly successful and popular weekly radio program Science Fantastic. If there is anyone who can demystify the esoteric mathematics and physics of string theory, it is he. And in this wonderful little book, that is precisely what he doesexplain in clear and simple terms the conceptual breakthroughs, the blind alleys and the unanswered questionsin the search for a grand unified theory of everything. Most of all, what I like best is that he remains open to the possibility that there may ultimately not be a single unifying theory after all, encoded into a single tidy equation.

The dream to synthesize all known physical forces has been a longstanding challenge; many physicists, including Einstein, have embarked on the pursuit and failed. The four fundamental forces of nature are gravity, electromagnetism, the weak force responsible for radioactive decay of some nuclei, and the strong force binding the atomic nucleus together.

When Newton discovered the laws of gravity, he accomplished the phenomenal task of connecting the celestial and terrestrial with a universal theory of gravitation that accounted both for a falling apple and the orbit of the Earth around the sun. Subsequently, as physicists uncovered additional fundamental forces in natureelectromagnetism, the weak force and the strong forcethey set about combining all of them into ever-grander theories. Mr. Kaku traces each of these pivotal moments of unification, describing the key insights that permitted those breakthroughs and bringing us to the precipice, where we currently stand, stymied. The ultimate challengeto unify gravity and quantum mechanicsis yet to be accomplished. To highlight how momentous unification would be, Mr. Kaku ends the book with a quote from Stephen Hawking: it would be the ultimate triumph of human reasonfor then we would know the mind of Godhence, I suppose, the God equation.

Mr. Kaku argues persuasively that every time physicists have decoded one of the four fundamental forces of the universe, it not only revealed the secrets of nature, but radically revolutionized society too. He connects Newtons laws to the invention of the steam engine and the launch of the Industrial Revolution, while Michael Faradays later discovery of electric and magnetic fields powered the electrical age. Mr. Kaku offers a superb description of how electrical transmission works, connecting the dots from Faradays equations to Edisons and Teslas experiments and then to our illuminated, electrified life today. Eventually we come to the revolution of quantum mechanicsthe description of matter on the smallest scalewhich shook the very core of physics. The subsequent applications that came out of the quantum revolution, the transistor and laser, ushered in a world dependent on electronics.

The God Equation dazzles in its account of the unfinished quest for a grand unified theory. As Mr. Kaku describes, controversies have dogged the unified theory project from the very start. Faraday was the first to propose a unification of gravity and electromagnetism. In 1832 he conducted a set of experiments from Londons Waterloo Bridge and dropped magnets, hoping to find some quantifiable effect of gravity. Alas, the experiment failed, though he remained convinced that the effect existed, perhaps at an undetectable level. In 1947, one of the founders of quantum mechanics, Erwin Schrdinger, famously held a press conference to announce victoryhe claimed to have a unified field theory. He did notembarrassingly, his version could not even explain the nature of electrons and the atom. The other illustrious co-founders of quantum mechanics, Werner Heisenberg and Wolfgang Pauli, followed suit and failed as well. The first real major step came with the discovery of quantum electrodynamics (QED), which provided a quantum theory of electrons and light. Then came the connection to the best current description of the strong nuclear force with the development of quantum chromodynamics (QCD). The standard model of particle physics that consolidates the zoo of subatomic particles emerged from these developments, bringing us to a theory of almost everything. The quest to unify all four fundamental forces in the universe has unfortunately stalled here. I write this on the heels of an announcement by Fermi National Laboratory of a potential discovery, a likely hint for the existence of a possible additional force of naturewhich, if it stands up, reveals the existence of physics beyond the currently accepted standard model.

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The God Equation Review: One String Theory to Rule Them All - The Wall Street Journal

April 9, 2021 Quantum Delta NL, a research programme in which Leiden University participates, has been awarded 615 million euros from the National Growth Fund to help develop the Netherlands into a top player in quantum technology. This has been announced at the presentation of the honoured proposals in The Hague.

Quantum Delta NL is a cooperation of companies and research institutes in which the research has been organised in five hubs at the universities of Delft, Leiden, Amsterdam, Twente and Eindhoven.

The research groupApplied Quantum Algorithms (aQa)at the Leiden institutes for physics and computer science develops quantum algorithms for chemical and material science applications, in cooperation with Google, Shell, Volkswagen and Total.

Great enthusiasm

Research into quantum computing has been going on for twenty years, bringing real world application ever closer, says Carlo Beenakker, professor in Theoretical Physics and Deputy Chair of Quantum Delta NL. I seegreat enthusiasm in my students to apply abstract concepts from quantum physics to the solution of practical problems. This is the revolutionary technology of their generation.

The goal of aQa is to make quantum algorithms practically applicable, pertaining to questions ofsocietal and economical relevance. We cooperate narrowly with our industrial partners to render these large investments as useful as possible, says computer science researcher Vedran Dunjko. Recently, he published in the journal Natureabout artificial intelligence implemented through quantum computers.

Quantum technology

Quantum Delta NLs ambition is to position the Netherlands as a Silicon Valley for quantum technology in Europe during the coming seven years. The programme provides for the further development of the quantum computer and the quantum internet, which will be open for end users in business and societal sectors, including education.

It aims for a flourishing ecosystem where talent is fostered at all levels, and where cooperation happens over institutional borders to develop a new European high-tech industry.

Source: Leiden University

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615 Million Euros Awarded to Quantum Delta NL for Quantum Research in the Netherlands - HPCwire

A bold new book by Chanda Prescod-Weinstein combines her love of physics with a strong analysis of the inequalities rife in science

By Anna Demming

The Disordered Cosmos argues that science needs close scrutiny

SOPA Images/LightRocket via Getty Images

The Disordered Cosmos: A journey into dark matter, spacetime, & dreams deferred

Chanda Prescod-Weinstein

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Bold Type Books

THIS isnt just a popular science book. There is plenty of physics in it from the big bang and relativity to particle physics, it is all there. But attention rapidly shifts to the authors other preoccupation: social injustice, such as inequalities, prejudices and the kind of social grooming and timidity that also hinder us from calling out these vices.

The author of The Disordered Cosmos is Chanda Prescod-Weinstein, assistant professor of physics and astronomy, a core faculty member in womens and gender studies at the University of New Hampshire and a New Scientist columnist. This gives her an excellent position from which she can both engage in rich detail with sciences most fascinating theories and grapple with human and inhuman social failings.

She works patiently to disabuse readers of the delusion that their favourite pop-sci ideas those lofty products of cerebral ingenuity and academic brilliance are immune from the prejudices pervading society.

Prescod-Weinsteins heritage is a mix of Black American, Black Caribbean, Eastern European Jewish and Jewish American histories. She identifies as agender, and has a history of debilitating health conditions. The inequalities she covers in her book are issues she has dealt with at first hand.

Some readers may question whether, say, there are indeed damaging racist undertones in the term dark matter, or in the way colour analogies are used in quantum chromodynamics, a theory sometimes referred to in textbooks as colored physics. But it is hard to dismiss the broader issues Prescod-Weinstein argues: inequalities around race, gender, class, nationality and disability.

Diversity and inclusivity are todays buzzwords, but she quotes Jin Haritaworn and C. Riley Snorton in their appraisal of trans politics theory, and questions whether it is enough for the scientific establishment to aim to be inclusive if what people are included in retains what she calls a strong relationship with totalitarian, racialized structures.

The author disabuses readers that favourite popsci ideas are immune from everyday prejudices

Despite the obvious conflict between her love of physics and her outrage at some of the social and personal injustices she sees in institutions propagating physics, the different focuses of the book arent necessarily competing for airtime. And Prescod-Weinstein often uses physics explanations as a springboard or analogy for the social issues she wants to discuss.

Take the description of non-binary wave-particle duality in the double-slit experiment, which precedes her dissection of attitudes to people identifying as non-binary or otherwise. It should be obvious that when you refuse to respect someones pronouns you are making a statement about whats important and what is not, she writes. To tell students that it is too difficult is an egregious, brazen lie.

Although there are times when discussions of minority politics get quite dense, perhaps more so than the physics, on the whole, the book feels very intimate I sometimes felt like I was reading her diary. This can be a treat, such as when she is musing over some charming quirk of particle physics: I tend to think of bosons as pep squad particles: they are happy to share the same quantum energy state Fermions? Not so much.

At other times, it gets more uncomfortable, as when she lays bare episodes of anguished introspection, self-doubt and emotional fatigue caused by traumatising experiences. It is all recounted to serve a point, but is incredibly personal and confiding.

So no, her book isnt a typical popular science read and she makes some comments that may prove unpopular. Beyond the already ardently persuaded, it will be interesting to see how much a broader readership may be convinced by the arguments she presents.

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The Disordered Cosmos review: An insider take on physics and injustice - New Scientist News

USC Dornsifes Thomas Ward of anthropology covers Vodou, witchcraft and shamanism, while focusing on white magic used for holistic healing. [5minread]

Perched on a shelf in Thomas Wards home office is a set of Vodou dolls.

Curiously, theyre not in the shape of human beings but are little round balls topped with conical hats. Filled with dense soil and wrapped tightly with black and red ribbon, theyre as heavy as paperweights.

Ward, associate professor (teaching) ofanthropologyat USC Dornsife College of Letters, Arts and Sciences, shows the Vodou artifacts to students in his spring semester course Magic, Witchcraft and Healing (ANTH 373).

Theyre beautiful objects, he says of the Vodou dolls, which he brought back from a trip to Haiti in 1983.

They can be used for healing and they can also be used for the dark arts.

But Ward is no Severus Snape from the Harry Potter franchise.

Our class explores the magical components of healing, and while witchcraft can be used for healing or harm, our class focuses only on white magic, rather than black magic, which is believed to cause harm.

That doesnt stop some of his students expressing curiosity about the dark side.

They ask me, Are curses real? Can a witch put a curse on you? Ward says. From the indigenous perspective, absolutely. Most non-Western cultures believe that curses can be used for harm.

But anthropologists and Western scientists would argue that its the power of belief that causes people who know theyve been cursed to have accidents.

It depends on who you are, where you are, what culture youre in, your own belief system, Ward says.

Magic and healing

Wards course explores the cross-cultural aspects of healing in non-Western traditions.

In the anthropological, cross-cultural context, the term magic is used for non-Western methods of healing or other ritual practices. Ward defines magic in the context of this course as unexplained causality.

Something happens and it causes something else to happen and we see the result, but we dont know exactly how it works, he says, noting that the term is used even in quantum physics to explain causal relationships that we dont completely understand.

I put a spell on you

Haitian Voudo dolls are often used for healing, according to anthropologist Thomas Ward. (Photo: Courtesy of Thomas Ward.)

Whats fascinating about witchcraft, Ward says, is just how complex and pervasive the idea is, cross-culturally, from Asia to the Americas and Africa. Why have humans for so many thousands of years and from so many different cultures and locations held these beliefs? Is it possible that theres something more to it that were not seeing?

The course explores a number of different historical and geographical aspects of witchcraft: the Salem Witch Trials in New England; the Azande, an ethnic group in Southern Sudan; Vodou tradition and practices in Haiti and Brooklyn, New York;curanderismo traditional healing of the body, mind or soul by shamans or spiritual healers in the Southwest United States; and the genesis of the Wiccan religion in the United Kingdom and its spread to the U.S.

Students read E.E. Evans-Pritchards ethnographyWitchcraft, Oracles and Magic Among the Azande, which explores how witchcraft is used to explain causality. Evans-Pritchard was one of the first anthropologists to point out the logic of witchcraft beliefs and to argue that witchcraft explains unfortunate circumstance in situations that Western science would simply put down to being in the wrong place at the wrong time.

For instance, if you are sitting on a verandah and one of the columns breaks and the roof falls and hits you on the head, Western scientists might tell you that termites were eating the wood, causing the column to fall. The questions that Western science doesnt answer is why at that particular moment in time did the roof fall and why me?

Western science would just chalk it up to unfortunate circumstance, Ward says. With its mystical aspect, witchcraft fills that gap, providing the causal link and explaining why it happened at that particular place and time and to that particular individual.

Ward says one of the most fascinating aspects of non-Western healing practices is its focus on the holistic aspect. These ideas are starting to gain traction in the U.S. with more emphasis on social relationships, community and spirituality.

In Vodou, for instance, practitioners look not only at physical and mental health, but also spiritual health and a persons relationship to the lwa, or spirits. The role of Vodou practitioners, known as servants of the spirits, is to communicate with the lwa, make them offerings and ask for intercession.

Wards course also explores the Wiccan religion, founded by Gerald Gardner in 1929. Gardner did a popular BBC interview that stirred up a great deal of controversy and interest in modern witchcraft.

The Wiccan movement spread from the U.K. to the U.S., where it experienced its greatest growth in the 1960s and 70s, with the civil rights and womens movements and a greater willingness to experiment and explore non-Western or ancient ways of being and healing.

Wiccas emphasis on nature and the sacred feminine made it, in some ways, the response to, and maybe rebellion against, the patriarchal elements of Christianity, Ward says.

The three big takeaways

The focus of the course, he says, is on expanding our horizons while remaining respectful and humble about other peoples traditions. Ward wants students to think about what healing means from a holistic perspective.

We tend to think of healing in the West as mainly physical, emotional and psychological, whereas in the non-Western context, healing means to restore a balance or a sense of wholeness in an individual and his or her environment, including family, friends, nature, spirits and ancestors. So, healing is much more comprehensive it restores a persons health, happiness and wholeness.

Ward hopes students will take away from the course a greater sense of open-mindedness and curiosity, but also humility. Magic is the word that we use to keep us humble, by saying that things are happening that we dont fully understand. We need to respect other peoples views of causality and the etiology of illness and broaden our perspective about what is possibly causing various illnesses.

Ward says the course also peels back the layers of contemporary celebrations like Halloween that depict witches in a stereotypical and sometimes humorous way.

Theres a huge, very complicated worldwide history of what witches are and what they do, Ward says. There should be respect for these traditions, but also understanding.

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Course explores 'Magic, Witchcraft and Healing' > News > USC Dornsife - USC Dornsife College of Letters, Arts and Sciences

Matter is a lush tapestry, woven from a complex assortment of threads. Diverse subatomic particles weave together to fabricate the universe we inhabit. But a century ago, people believed that matter was so simple that it could be constructed with just two types of subatomic fibers electrons and protons. That vision of matter was a no-nonsense plaid instead of an ornate brocade.

Physicists of the 1920s thought they had a solid grasp on what made up matter. They knew that atoms contained electrons surrounding a positively charged nucleus. And they knew that each nucleus contained a number of protons, positively charged particles identified in 1919. Combinations of those two particles made up all of the matter in the universe, it was thought. That went for everything that ever was or might be, across the vast, unexplored cosmos and at home on Earth.

The scheme was appealingly tidy, but it swept under the rug a variety of hints that all was not well in physics. Two discoveries in one revolutionary year, 1932, forced physicists to peek underneath the carpet. First, the discovery of the neutron unlocked new ways to peer into the hearts of atoms and even split them in two. Then came news of the positron, identical to the electron but with the opposite charge. Its discovery foreshadowed many more surprises to come. Additional particle discoveries ushered in a new framework for the fundamental bits of matter, now known as the standard model.

That annus mirabilis miraculous year also set physicists sights firmly on the workings of atoms hearts, how they decay, transform and react. Discoveries there would send scientists careening toward a most devastating technology: nuclear weapons. The atomic bomb cemented the importance of science and science journalism in the public eye, says nuclear historian Alex Wellerstein of the Stevens Institute of Technology in Hoboken, N.J. The atomic bomb becomes the ultimate proof that indeed this is world-changing stuff.

Physicists of the 1920s embraced a particular type of conservatism. Embedded deep in their psyches was a reluctance to declare the existence of new particles. Researchers stuck to the status quo of matter composed solely of electrons and protons an idea dubbed the two-particle paradigm that held until about 1930. In that time period, says historian of science Helge Kragh of the University of Copenhagen, Im quite sure that not a single mainstream physicist came up with the idea that there might exist more than two particles. The utter simplicity of two particles explaining everything in natures bounty was so appealing to physicists sensibilities that they found the idea difficult to let go of.

The paradigm held back theoretical descriptions of the neutron and the positron. To propose the existence of other particles was widely regarded as reckless and contrary to the spirit of Occams razor, science biographer Graham Farmelo wrote in Contemporary Physics in 2010.

Still, during the early 20th century, physicists were investigating a few puzzles of matter that would, after some hesitation, inevitably lead to new particles. These included unanswered questions about the identities and origins of energetic particles called cosmic rays, and why chemical elements occur in different varieties called isotopes, which have similar chemical properties but varying masses.

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New Zealandborn British physicist Ernest Rutherford stopped just short of positing a fundamentally new particle in 1920. He realized that neutral particles in the nucleus could explain the existence of isotopes. Such particles came to be known as neutrons. But rather than proposing that neutrons were fundamentally new, he thought they were composed of protons combined in close proximity with electrons to make neutral particles. He was correct about the role of the neutron, but wrong about its identity.

Rutherfords idea was convincing, British physicist James Chadwick recounted in a 1969 interview: The only question was how the devil could one get evidence for it. The neutrons lack of electric charge made it a particularly wily target. In between work on other projects, Chadwick began hunting for the particles at the University of Cambridges Cavendish Laboratory, then led by Rutherford.

Chadwick found his evidence in 1932. He reported that mysterious radiation emitted when beryllium was bombarded with the nuclei of helium atoms could be explained by a particle with no charge and with a mass similar to the protons. In other words, a neutron. Chadwick didnt foresee the important role his discovery would play. I am afraid neutrons will not be of any use to anyone, he told the New York Times shortly after his discovery.

Physicists grappled with the neutrons identity over the following years before accepting it as an entirely new particle, rather than the amalgamation that Rutherford had suggested. For one, a proton-electron mash-up conflicted with the young theory of quantum mechanics, which characterizes physics on small scales. The Heisenberg uncertainty principle which states that if the location of an object is well-known, its momentum cannot be suggests that an electron confined within a nucleus would have an unreasonably large energy.

And certain nucleis spins, a quantum mechanical measure of angular momentum, likewise suggested that the neutron was a full-fledged particle, as did improved measurements of the particles mass.

Physicists also resisted the positron, until it became difficult to ignore.

The positrons 1932 detection had been foreshadowed by the work of British theoretical physicist Paul Dirac. But it took some floundering about before physicists realized the meaning of his work. In 1928, Dirac formulated an equation that combined quantum mechanics with Albert Einsteins 1905 special theory of relativity, which describes physics close to the speed of light. Now known simply as the Dirac equation, the expression explained the behavior of electrons in a way that satisfied both theories.

But the equation suggested something odd: the existence of another type of particle, one with the opposite electric charge. At first, Dirac and other physicists clung to the idea that this charged particle might be the proton. But this other particle should have the same mass as the electron, and protons are almost 2,000 times as heavy as electrons. In 1931, Dirac proposed a new particle, with the same mass as the electron but with opposite charge.

Meanwhile, American physicist Carl Anderson of Caltech, independent of Diracs work, was using a device called a cloud chamber to study cosmic rays, energetic particles originating in space. Cosmic rays, discovered in 1912, fascinated scientists, who didnt fully understand what the particles were or how they were produced.

Within Andersons chamber, liquid droplets condensed along the paths of energetic charged particles, a result of the particles ionizing gas molecules as they zipped along. In 1932, the experiments revealed positively charged particles with masses equal to an electrons. Soon, the connection to Diracs theory became clear.

Science News Letter, the predecessor of Science News, had a hand in naming the newfound particle. Editor Watson Davis proposed positron in a telegram to Anderson, who had independently considered the moniker, according to a 1933 Science News Letter article (SN: 2/25/33, p. 115). In a 1966 interview, Anderson recounted considering Davis idea during a game of bridge, and finally going along with it. He later regretted the choice, saying in the interview, I think thats a very poor name.

The discovery of the positron, the antimatter partner of the electron, marked the advent of antimatter research. Antimatters existence still seems baffling today. Every object we can see and touch is made of matter, making antimatter seem downright extraneous. Antimatters lack of relevance to daily life and the terms liberal use in Star Trek means that many nonscientists still envision it as the stuff of science fiction. But even a banana sitting on a counter emits antimatter, periodically spitting out positrons in radioactive decays of the potassium within.

Physicists would go on to discover many other antiparticles all of which are identical to their matter partners except for an opposite electric charge including the antiproton in 1955. The subject still keeps physicists up at night. The Big Bang should have produced equal amounts matter and antimatter, so researchers today are studying how antimatter became rare.

In the 1930s, antimatter was such a leap that Diracs hesitation to propose the positron was understandable. Not only would the positron break the two-particle paradigm, but it would also suggest that electrons had mirror images with no apparent role in making up atoms. When asked, decades later, why he had not predicted the positron after he first formulated his equation, Dirac replied, pure cowardice.

But by the mid-1930s, the two-particle paradigm was out. Physicists understanding had advanced, and their austere vision of matter had to be jettisoned.

Radioactive decay hints that atoms hold stores of energy locked within, ripe for the taking. Although radioactivity was discovered in 1896, that energy long remained an untapped resource. The neutrons discovery in the 1930s would be key to unlocking that energy for better and for worse.

The neutrons discovery opened up scientists understanding of the nucleus, giving them new abilities to split atoms into two or transform them into other elements. Developing that nuclear know-how led to useful technologies, like nuclear power, but also devastating nuclear weapons.

Just a year after the neutron was found, Hungarian-born physicist Leo Szilard envisioned using neutrons to split atoms and create a bomb. [I]t suddenly occurred to me that if we could find an element which is split by neutrons and which would emit two neutrons when it absorbed one neutron, such an element, if assembled in sufficiently large mass, could sustain a nuclear chain reaction, liberate energy on an industrial scale, and construct atomic bombs, he later recalled. It was a fledgling idea, but prescient.

Because neutrons lack electric charge, they can penetrate atoms hearts. In 1934, Italian physicist Enrico Fermi and colleagues started bombarding dozens of different elements with neutrons, producing a variety of new, radioactive isotopes. Each isotope of a particular element contains a different number of neutrons in its nucleus, with the result that some isotopes may be radioactive while others are stable. Fermi had been inspired by another striking discovery of the time. In 1934, French chemists Frdric and Irne Joliot-Curie reported the first artificially created radioactive isotopes, produced by bombarding elements with helium nuclei, called alpha particles. Now, Fermi was doing something similar, but with a more penetrating probe.

There were a few scientific missteps on the way to understanding the results of such experiments. A major goal was to produce brand-new elements, those beyond the last known element on the periodic table at that time: uranium. After blasting uranium with neutrons, Fermi and colleagues reported evidence of success. But that conclusion would turn out to be incorrect.

German chemist Ida Noddack had an inkling that all was not right with Fermis interpretation. She came close to the correct explanation for his experiments in a 1934 paper, writing: When heavy nuclei are bombarded by neutrons, it is conceivable that the nucleus breaks up into several large fragments. But Noddack didnt follow up on the idea. She didnt provide any kind of supporting calculation and nobody took it with much seriousness, says physicist Bruce Cameron Reed of Alma College in Michigan.

In Germany, physicist Lise Meitner and chemist Otto Hahn had also begun bombarding uranium with neutrons. But Meitner, an Austrian of Jewish heritage in increasingly hostile Nazi Germany, was forced to flee in July 1938. She had an hour and a half to pack her suitcases. Hahn and a third member of the team, chemist Fritz Strassmann, continued the work, corresponding from afar with Meitner, who had landed in Sweden. The results of the experiments were puzzling at first, but when Hahn and Strassmann reported to Meitner that barium, a much lighter element than uranium, was a product of the reaction, it became clear what was happening. The nucleus was splitting.

Meitner and her nephew, physicist Otto Frisch, collaborated to explain the phenomenon, a process the pair would call fission. Hahn received the 1944 Nobel Prize in chemistry for the discovery of fission, but Meitner never won a Nobel, in a decision now widely considered unjust. Meitner was nominated for the prize sometimes in physics, other times in chemistry a whopping 48 times, most after the discovery of fission.

Her peers in the physics community recognized that she was part of the discovery, says chemist Ruth Lewin Sime of Sacramento City College in California, who has written extensively about Meitner. That included just about anyone who was anyone.

Word of the discovery soon spread, and on January 26, 1939, renowned Danish physicist Niels Bohr publicly announced at a scientific meeting that fission had been achieved. The potential implications were immediately apparent: Fission could unleash the energy stored in atomic nuclei, potentially resulting in a bomb. A Science News Letter story describing the announcement attempted to dispel any concerns the discovery might raise. The article, titled Atomic energy released, reported that scientists are fearful lest the public become worried about a revolution in civilization as a result of their researches, such as the suggested possibility that the atomic energy may be used as some super-explosive, or as a military weapon (SN: 2/11/39, p. 86). But downplaying the catastrophic implications didnt prevent them from coming to pass.

The question of whether a bomb could be created rested, once again, on neutrons. For fission to ignite an explosion, it would be necessary to set off a chain reaction. That means each fission would release additional neutrons, which could then go on to induce more fissions, and so on. Experiments quickly revealed that enough neutrons were released to make such a chain reaction feasible.

In October 1939, soon after Germany invaded Poland at the start of World War II, an ominous letter from Albert Einstein reached President Franklin Roosevelt. Composed at the urging of Szilard, by then at Columbia University, the letter warned, it is conceivable that extremely powerful bombs of a new type may thus be constructed. American researchers were not alone in their interest in the topic: German scientists, the letter noted, were also on the case.

Roosevelt responded by setting up a committee to investigate. That step would be the first toward the U.S. effort to build an atomic bomb, the Manhattan Project.

On December 2, 1942, Fermi, who by then had immigrated to the United States, and 48 colleagues achieved the first controlled, self-sustaining nuclear chain reaction in an experiment with a pile of uranium and graphite at the University of Chicago. Science News Letter would later call it an event ranking with mans first prehistoric lighting of a fire. While the physicists celebrated their success, the possibility of an atomic bomb was closer than ever. I thought this day would go down as a black day in the history of mankind, Szilard recalled telling Fermi.

The experiment was a key step in the Manhattan Project. And on July 16, 1945, at about 5:30 a.m., scientists led by J. Robert Oppenheimer detonated the first atomic bomb, in the New Mexico desert the Trinity test.

It was a striking sight, as physicist Isidor Isaac Rabi recalled in his 1970 book, Science: The Center of Culture. Suddenly, there was an enormous flash of light, the brightest light I have ever seen or that I think anyone has ever seen. It blasted; it pounced; it bored its way right through you. It was a vision which was seen with more than the eye. It was seen to last forever. You would wish it would stop; although it lasted about two seconds. Finally it was over, diminishing, and we looked toward the place where the bomb had been; there was an enormous ball of fire which grew and grew and it rolled as it grew; it went up into the air, in yellow flashes and into scarlet and green. It looked menacing. It seemed to come toward one. A new thing had just been born; a new control; a new understanding of man, which man had acquired over nature.

Physicist Kenneth Bainbridge put it more succinctly: Now we are all sons of bitches, he said to Oppenheimer in the moments after the test.

The bombs construction was motivated by the fear that Germany would obtain it first. But the Germans werent even close to producing a bomb when they surrendered in May 1945. Instead, the United States bombs would be used on Japan. On August 6, 1945, the United States dropped an atomic bomb on Hiroshima, followed by another on August 9 on Nagasaki. In response, Japan surrendered. More than 100,000 people died as a result of the two attacks, and perhaps as many as 210,000.

I saw a blinding bluish-white flash from the window. I remember having the sensation of floating in the air, survivor Setsuko Thurlow recalled in a speech given upon the awarding of the 2017 Nobel Peace Prize to the International Campaign to Abolish Nuclear Weapons. She was 13 years old when the bomb hit Hiroshima. Thus, with one bomb my beloved city was obliterated. Most of its residents were civilians who were incinerated, vaporized, carbonized.

Humankind entered a new era, with new dangers to the survival of civilization. With nuclear physics, you have something that within 10 years goes from being this arcane academic research area to something that bursts on the world stage and completely changes the relationship between science and society, Reed says.

In 1949, the Soviet Union set off its first nuclear weapon, kicking off the decades-long nuclear rivalry with the United States that would define the Cold War. And then came a bigger, more dangerous weapon: the hydrogen bomb. Whereas atomic bombs are based on nuclear fission, H-bombs harness nuclear fusion, the melding of atomic nuclei, in conjunction with fission, resulting in much larger blasts. The first H-bomb, detonated by the United States in 1952, was 1,000 times as powerful as the bomb dropped on Hiroshima. Within less than a year, the Soviet Union also tested an H-bomb. The H-bomb had been called a weapon of genocide by scientists serving on an advisory committee for the U.S. Atomic Energy Commission, which had previously recommended against developing the technology.

Fears of the devastation that would result from an all-out nuclear war have fed repeated attempts to rein in nuclear weapons stockpiles and tests. Since the signing of the Comprehensive Nuclear Test Ban Treaty in 1996, the United States, Russia and many other countries have maintained a testing moratorium. However, North Korea tested a nuclear weapon as recently as 2017.

Still, the dangers of nuclear weapons were accompanied by a promising new technology: nuclear power.

In 1948, scientists first demonstrated that a nuclear reactor could harness fission to produce electricity. The X-10 Graphite Reactor at Oak Ridge National Laboratory in Tennessee generated steam that powered an engine that lit up a small Christmas lightbulb. In 1951, Experimental Breeder Reactor-I at Idaho National Laboratory near Idaho Falls produced the first usable amount of electricity from a nuclear reactor. The worlds first commercial nuclear power plants began to switch on in the mid- and late 1950s.

But nuclear disasters dampened enthusiasm for the technology, including the 1979 Three Mile Island accident in Pennsylvania and the 1986 Chernobyl disaster in Ukraine, then part of the Soviet Union. In 2011, the disaster at the Fukushima Daiichi power plant in Japan rekindled societys smoldering nuclear anxieties. But today, in an era when the effects of climate change are becoming alarming, nuclear power is appealing because it emits no greenhouse gases directly.

And humankinds mastery over matter is not yet complete. For decades, scientists have been dreaming of another type of nuclear power, based on fusion, the process that powers the sun. Unlike fission, fusion power wouldnt produce long-lived nuclear waste. But progress has been slow. The ITER experiment has been in planning since the 1980s. Once constructed in southern France, ITER aims to, for the first time, produce more energy from fusion than is put in. Whether it is successful may help determine the energy outlook for future centuries.

From todays perspective, the breakneck pace of progress in nuclear and particle physics in less than a century can seem unbelievable. The neutron and positron were both found in laboratories that are small in comparison with todays, and each discovery was attributed to a single physicist, relatively soon after the particles had been proposed. Those discoveries kicked off frantic developments that seemed to roll in one after another.

Now, finding a new element, discovering a new elementary particle or creating a new type of nuclear reactor can take decades, international collaborations of thousands of scientists, and huge, costly experiments.

As physicists uncover the tricks to understanding and controlling nature, it seems, the next level of secrets becomes increasingly difficult to expose.

Continued here:

How matters hidden complexity unleashed the power of nuclear physics - Science News Magazine

Highly accurate measurements are possible utilizing atom interferometers that use the atom's wave character. As such, atom interferometers can be used to measure the Earth's gravitational field or spot gravitational waves.

For the first time, scientists were able to perform atom interferometry onboard a sounding rocket.

"We have established the technological basis for atom interferometry on board of a sounding rocket and demonstrated that such experiments are not only possible on Earth, but also in space," said study author Professor Patrick Windpassinger of the Institute of Physics at Johannes Gutenberg University Mainz (JGU).

Windpassinger leads a group of German researchers in the study, "Ultracold atom interferometry in space," with findings published in Nature Communications.

Leibniz University Hannover collaborated with a group of researchers from different universities and research centers to launch the MAUS-1 mission in January 2017. This was the first rocket mission wherein a Bose-Einstein condensate was generated in space. This state of matter happens when atoms are cooled to minus 273 degrees Celsius or the temperature close to absolute zero.

(Photo: NIST/Wikimedia Commons)Atoms interfering with themselves. After ultracold atoms are maneuvered into superpositions--each one located in two places simultaneously--they are released to allow interference of each atom's two "selves." They are then illuminated with light, which casts a shadow, revealing a characteristic interference pattern, with red representing higher atom density. The variations in density are caused by the alternating constructive and destructive interference between the two "parts" of each atom, magnified by thousands of atoms acting in unison.

ALSO READ: New Physics Discovered by Scientists May Help Explain Mysteries of the Universe

The ultracold ensemble, the researchers said, showed a promising starting pointfor atom interferometry. Temperature is among the determining factors since measurements can be done more precisely and for longer periods at lower temperatures.

In the experiments, rubidium atom gas was broken up using laser light irradiation and then superpositioned. As forces act on the atoms on their different paths, various interference patterns can be made, and these can be used to gauge the forces that are influencing them, such as gravity.

The study first showed the coherence or interference capability of the Bose-Einstein condensate as an essentially needed property of the atomic ensemble. Here, the atoms in the interferometer were only partly superimposed as the light sequence was varied, leading to a spatial intensity modulation generation.

Researchers thus showed the viability of the concept that could lead to groundbreaking experiments focused on the Earth's gravitational field, spotting gravitational waves, and challenging Einstein's equivalence principle, which is considered breakthroughs in physics.

The team plans to study further the feasibility of high-precision atom interferometry to challenge Einstein's theory of equivalence. Two more rocket launches slated for 2022 and 2023 will have the mission use potassium atoms and rubidium atoms to create interference patterns.

With the freefall acceleration of the two types of atoms compared, the challenge on the equivalence principle with a precision that has not been earlier achieved can be done.

The experiment is an example of continuing research work on quantum technologies, including developments in quantum communication, quantum sensors, and quantum computing.

RELATED ARTICLE: Scientists Develop Atomic-Scale Imaging Technique To Measure The Age Of Planetary Samples Accurately

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Scientists Perform First-ever Ultracold Atom Interferometry in Space, Leading to Possible Physics Breakthroughs - Science Times

Helgoland

Carlo Rovelli

Allen Lane, pp. 240, 14.99

Helgoland is a craggy German island in the North Sea. Barely bigger than a few fields, it reaches high above the water on precipitous cliffs and is famous for its sweet air. It has a town and a harbour, and the 1,000-odd inhabitants speak a distinct dialect. In the summer of 1925, the 23-year-old physicist Werner Heisenberg went there to sort out hishay fever and solve the problem of reality.

Helgoland is a slightly misleading title for Carlo Rovellis inspiring, chaotic, delightfully unsatisfactory book of popular quantum physics. It isnt about Heisenbergs months there or his mathematical insights; Helgoland is Rovellis shorthand for Heisenbergs pellucid state of mind. On Helgoland, says Rovelli, Heisenberg almost got the philosophical approach to quantum theory right. Ever since, weve been getting it wrong.

The discovery of a quantum world began with experimental results. Certain things were taking place in German physics labs that should not be. Atoms were misbehaving. When scientists in Gttingen and Berlin crouched in front of the latest clever electronic instruments and peered, Alice-like, into the wonderland of the very small, what they saw shocked them bolt upright. Wonderland was ridiculous. There, logic was (and still is) fundamentally different.

Translated up to our size, the following nonsense was apparently perfectly possible: throw a full tankard across the hall in a Bierstube, let somebody notice (as it passes overhead) that this tankard has, say, a picture of a stag on it, and the beer inside turns green. That simple observation hey, look, theres a stag on the tankard and ping! the contents of the mug changes colour. But if nobody notices the decoration, the beer stays brown. In the quantum world, two defining qualities that have nothing to do with each other (tankard decoration and beer colour) can influence one another just because somebodys looked at them. Its a place for hucksters, not respectable people. Even Einstein, who got his Nobel Prize for figuring out the existence of this strange new world, was appalled: God does not play dice! he said. Dont you tell God what to do, retorted the Danish theoretician Niels Bohr, who was less prudish.

Heisenberg worked for Bohr, and on Helgoland started to make sense of this wayward behaviour of small things. The central point was, he discovered, that everything in quantum land works with exactly the same logic as it does up here except in one particular: the order in which you look at things matters. In the quantum world, if the observer had only kept his mind focused on the beer, and paid no attention to the pretty decoration, it would have stayed brown. Some physicists tried to get round the metaphysical implications of this idea by insisting that there were hidden things secretly linking the subatomic equivalents of beer colour and mug decoration. Others have given up all pretence of common sense and believe ideas much more outlandish than God, such as the existence of multiple worlds in which all possible beer mug decorations and beer colours get to exist somewhere, really and truly, all at once.

Rovelli has a different idea. He says reality doesnt exist. The reason physicists have been led astray by bonkers theories in the 100 years since Helgoland is because they cant bear the thought of not being real.

It was at this point a third of the way through the book that I mimicked Heisenberg and took my first long, befuddled walk. Reality doesnt exist? What on earth does that mean? Rovellis favourite example is a red chair. Red doesnt exist, for sure everyone knows that philosophical chestnut: its just the way our brains make sense of light of a certain wavelength. But Rovelli also insists that nothing else about the chair exists either its weight, its shape except in its relationship to the person looking at it. And you can keep banging away at this type of argument until you get to the level of the atoms forming the chair. Insisting that anything about this red chair needs to exist outside of relationships is metaphysical neediness.

Part of the fun of Rovellis book is that your immediate reaction to his ideas repugnance or delight isnt meaningless. Without mathematics or experiment, by page 81 your thoughts are at the frontier of quantum theory, and its time for your second brain-cudgeling walk. If things exist only by virtue of their interaction with other things, what happens to them between times? Do they vanish? Do instants of time also not exist? Does it even make sense to talk this way? Oh dear, oh dear.

Rovelli devotes a precious chapter to the work of the second-century Buddhist philosopher Nagarjuna, who also insists there is no ultimate layer of real things. Another chapter 15 pages, getting on for a tenth of this short book is as unexpected as green beer: its about a fierce philosophical argument Lenin had in 1909 with Aleksandr Bogdanov, the co-founder of the Bolshevik party.

I have digressed, says Rovelli, once this exuberant and not particularly helpful passage is over, then promptly tips off the other side of his bar stool and quotes Douglas Adams:

The fact that we live at the bottom of a deep gravity well, on the surface of a gas-covered planet going around a nuclear fireball 90 million miles away and think this to be normal is obviously some indication of how skewed our perspective tends to be.

In other words, its our skewed perspective, not the scientific evidence, that makes us want to believe in the reality of red chairs and atoms.

Rovelli is not a kook. Hes a world-famous professor of quantum gravity. His relational interpretation of quantum theory is discussed seriously by leading philosophers and physicists. Hes ebullient about his ideas, not crazed by them. He doesnt do a particularly good job of describing in laymans terms the fundamental oddity of quantum theory hes too easily distracted and too poetical; his metaphors are a little too breathless. But that shouldnt put you off. Do what I did after my third Helgoland walk: read the opening pages of Leonard Susskinds superb popular science book Quantum Mechanics: The Theoretical Minimum. Anybody who can use fractions can understand them. Then set back to work with Helgoland. What follows is joyous excitement.

It feels exactly right that Rovelli teaches at the University of Marseille. In the same spirit as hes written this book, I imagine him strolling along the quai, his sleeves rolled up, hailing the devil-may-care crowd by the boats and then, with a quick glance to either side, slipping into that crazy little bar where the tankards are flying and the beer turns green if you look at it funny.

Originally posted here:

The windswept German island that inspired quantum physics - Spectator.co.uk

Jackson Butler, a junior studying physics in Arts & Sciences at Washington University in St. Louis, received the Barry Goldwater Scholarship, a prestigious award that honors students who conduct research in the natural sciences, mathematics and engineering.

Butler is researching the magnetic material -RuCl3, a layered and insulating system widely thought to host an exotic form of matter called a quantum spin liquid. He ultimately would like to earn a PhD in condensed-matter physics and conduct research in the private sector.

Doing research in the private sector will allow me to not only continue to investigate many different types of physical phenomena but also to begin to apply it to real-world applications, Butler wrote in his application. Condensed matter physics has many potential applications such as quantum computing, super conductivity and many other applications that will greatly impact tomorrows technology.

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Junior wins Goldwater scholarship | The Source | Washington University in St. Louis - Washington University Record

WALTHAM, Mass., April 6, 2021 /PRNewswire/ --Raytheon Technologies (NYSE: RTX) today announced Connect Up, a 10-year, $500 million corporate responsibility initiative to drive transformative, generational impact on critical societal challenges. This focused philanthropy expands upon and elevates the company's legacy of community investment through lifelong learning, veteran and military family support, and localized community engagement.

"The measure of business success must include community growth," said Greg Hayes, Raytheon Technologies' chief executive officer. "The Connect Up program leverages our global reach, the expertise and passion of more than 180,000 employees, a heritage of era-defining engineering and technology ingenuity, with a track record of solving some of society's biggest challenges. Through focused investments, volunteer commitment and strategic partnerships, we will create lasting, multi-generational impact in education opportunity, armed services support and local community relief."

To meet the pressing needs of communities, today and into the future, Connect Up combines philanthropic capital, public/private partnership and employee volunteerism to support underserved communities by:

In addition to philanthropy, employee volunteerism is central to the mission of Connect Up, and the company today launched an enterprise-wide employee volunteer initiative to provide opportunities for employees to connect with and give back to their communities. Raytheon Technologies will challenge the company's 180,000 global employees to unlock the power of connections through 1 million acts of service in 2021, starting with the launch of its first-ever Global Month of Service in April.

For more information on Raytheon Technologies' social impact initiatives and to stay updated on programs and investments, please visit us at RTX.com/social-impact

About Raytheon TechnologiesRaytheon Technologies Corporation is an aerospace and defense company that provides advanced systems and services for commercial, military and government customers worldwide. With four industry-leading businesses Collins Aerospace Systems, Pratt & Whitney, Raytheon Intelligence & Space and Raytheon Missiles & Defense the company delivers solutions that push the boundaries in avionics, cybersecurity, directed energy, electric propulsion, hypersonics, and quantum physics. The company, formed in 2020 through the combination of Raytheon Company and the United Technologies Corporation aerospace businesses, is headquartered in Waltham, Massachusetts.

Media ContactChris JohnsonC: 202.384.2474[emailprotected]

SOURCE Raytheon Technologies

https://www.rtx.com

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Raytheon Technologies Announces $500 Million Social Impact Initiative - PRNewswire

WALTHAM, Mass., April 6, 2021 /PRNewswire/ -- Raytheon Technologies (NYSE: RTX) will issue its first quarter 2021 earnings on Tuesday, April 27, prior to the stock market opening. A conference call will take place at 8:30 a.m. ET.

A presentation corresponding with the conference call will be available on the company's website at http://www.rtx.com for downloading prior to the call. To listen to the earnings call by phone, dial (866) 219-7829 between 8:10 a.m. and 8:30 a.m. ET. Please limit your use of the phone's speaker mode to optimize the audio quality of the call for all participants.

Analysts who wish to ask a question following the prepared remarks should press "1" on their phone during the call. Your name will be placed in queue. To remove yourself from the queue, press "#." If you need assistance, press "*0" to reach the conference operator.

The call will be broadcast live on the Internet at http://www.rtx.com. A recording will be archived on the site and will be available for replay by phone from 11:30 a.m. ET Tuesday, April 27th, to 11:30 a.m. ET Tuesday, May 11th. For a replay, dial (855) 859-2056. At the prompt for a conference ID number, enter 9535368.

About Raytheon Technologies

Raytheon Technologies Corporation is an aerospace and defense company that provides advanced systems and services for commercial, military and government customers worldwide. With four industry-leading businesses Collins Aerospace Systems, Pratt & Whitney, Raytheon Intelligence & Space and Raytheon Missiles & Defense the company delivers solutions that push the boundaries in avionics, cybersecurity, directed energy, electric propulsion, hypersonics, and quantum physics. The company, formed in 2020 through the combination of Raytheon Company and the United Technologies Corporation aerospace businesses, is headquartered in Waltham, Massachusetts.

SOURCE Raytheon Technologies

Originally posted here:

Raytheon Technologies to release first quarter results on April 27, 2021 - CapeNews.net