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Category: Physics

A century of quantum mechanics questions the fundamental nature of reality

A century of quantum mechanics questions the fundamental nature of reality

Tom Siegfried writes: Scientists are like prospectors, excavating the natural world seeking gems of knowledge about physical reality. And in the century just past, scientists have dug deep enough to discover that reality’s foundations do not mirror the world of everyday appearances. At its roots, reality is described by the mysterious set of mathematical rules known as quantum mechanics. Conceived at the turn of the 20th century and then emerging in its full form in the mid-1920s, quantum mechanics is…

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How could the Big Bang arise from nothing?

How could the Big Bang arise from nothing?

The evolution of the cosmos after the Big Bang. NASA By Alastair Wilson, University of Birmingham READER QUESTION: My understanding is that nothing comes from nothing. For something to exist, there must be material or a component available, and for them to be available, there must be something else available. Now my question: Where did the material come from that created the Big Bang, and what happened in the first instance to create that material? Peter, 80, Australia. “The last…

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Physicists prove anyons exist, a third kingdom of quasiparticles that only arise in two dimensions

Physicists prove anyons exist, a third kingdom of quasiparticles that only arise in two dimensions

Discover reports: After decades of exploration in nature’s smallest domains, physicists have finally found evidence that anyons exist. First predicted by theorists in the early 1980s, these particle-like objects only arise in realms confined to two dimensions, and then only under certain circumstances — like at temperatures near absolute zero and in the presence of a strong magnetic field. Physicists are excited about anyons not only because their discovery confirms decades of theoretical work, but also for practical reasons. For…

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What impossible meant to Richard Feynman

What impossible meant to Richard Feynman

Paul J. Steinhardt writes: Impossible! The word resonated throughout the large lecture hall. I had just finished describing a revolutionary concept for a new type of matter that my graduate student, Dov Levine, and I had invented. The Caltech lecture room was packed with scientists from every discipline across campus. The discussion had gone remarkably well. But just as the last of the crowd was filing out, there arose a familiar, booming voice and that word: “Impossible!” I could have…

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Humans didn’t invent mathematics — it’s what the world is made of

Humans didn’t invent mathematics — it’s what the world is made of

Geralt / Pixabay By Sam Baron, Australian Catholic University Many people think that mathematics is a human invention. To this way of thinking, mathematics is like a language: it may describe real things in the world, but it doesn’t “exist” outside the minds of the people who use it. But the Pythagorean school of thought in ancient Greece held a different view. Its proponents believed reality is fundamentally mathematical. More than 2,000 years later, philosophers and physicists are starting to…

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What if the universe had no beginning?

What if the universe had no beginning?

Paul Sutter writes: In the beginning, there was … well, maybe there was no beginning. Perhaps our universe has always existed — and a new theory of quantum gravity reveals how that could work. “Reality has so many things that most people would associate with sci-fi or even fantasy,” said Bruno Bento, a physicist who studies the nature of time at the University of Liverpool in the U.K. In his work, he employed a new theory of quantum gravity, called…

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‘Impossible’ particle discovery adds key piece to the strong force puzzle

‘Impossible’ particle discovery adds key piece to the strong force puzzle

Charlie Wood writes: This spring, at a meeting of Syracuse University’s quark physics group, Ivan Polyakov announced that he had uncovered the fingerprints of a semi-mythical particle. “We said, ‘This is impossible. What mistake are you making?’” recalled Sheldon Stone, the group’s leader. Polyakov went away and double-checked his analysis of data from the Large Hadron Collider beauty (LHCb) experiment, which the Syracuse group is part of. The evidence held. It showed that a particular set of four fundamental particles…

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How synchronous firefly flashes illuminate the physics of complex systems

How synchronous firefly flashes illuminate the physics of complex systems

Orit Peleg writes: In the still of the Tennessee night, my colleagues and I are watching thousands of dim little orbs of light, moving peacefully in the forest around us. We try to guess where the next flash will appear, but the movements seem erratic, even ephemeral. This summer, as we set up our cameras and tents, I feel a crippling sense of dread. I had brought us all up here to the Great Smoky Mountains National Park, an unlikely…

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Eternal change for no energy: A time crystal finally made real

Eternal change for no energy: A time crystal finally made real

Natalie Wolchover writes: In a preprint posted online Thursday night, researchers at Google in collaboration with physicists at Stanford, Princeton and other universities say that they have used Google’s quantum computer to demonstrate a genuine “time crystal.” In addition, a separate research group claimed earlier this month to have created a time crystal in a diamond. A novel phase of matter that physicists have strived to realize for many years, a time crystal is an object whose parts move in…

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Can consciousness be explained by quantum physics?

Can consciousness be explained by quantum physics?

Some scientists believe consciousness is generated by quantum processes, but the theory is yet to be empirically tested. vitstudio/Shutterstock By Cristiane de Morais Smith, Utrecht University One of the most important open questions in science is how our consciousness is established. In the 1990s, long before winning the 2020 Nobel Prize in Physics for his prediction of black holes, physicist Roger Penrose teamed up with anaesthesiologist Stuart Hameroff to propose an ambitious answer. They claimed that the brain’s neuronal system…

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Is the universe open-ended?

Is the universe open-ended?

Caleb Scharf writes: One of my favorite albeit heavily paraphrased quotes from Albert Einstein is his assertion that the most incomprehensible thing about the universe is that it is comprehensible. (What he actually said, in his 1936 work “Physics and Reality,” is more longwinded, and includes a digression into Immanuel Kant and the meaning of “comprehensibility,” but he does write “… the eternal mystery of the world is its comprehensibility.”) In truth, this statement holds back a little. The greater…

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Is reality a game of quantum mirrors? A new theory suggests it might be

Is reality a game of quantum mirrors? A new theory suggests it might be

Jurik Peter / Shutterstock By Peter Evans, The University of Queensland Imagine you sit down and pick up your favourite book. You look at the image on the front cover, run your fingers across the smooth book sleeve, and smell that familiar book smell as you flick through the pages. To you, the book is made up of a range of sensory appearances. But you also expect the book has its own independent existence behind those appearances. So when you…

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The value of the Hubble Constant and the fate of the universe

The value of the Hubble Constant and the fate of the universe

Corey S Powell writes: What determines our fate? To the Stoic Greek philosophers, fate is the external product of divine will, ‘the thread of your destiny’. To transcendentalists such as Henry David Thoreau, it is an inward matter of self-determination, of ‘what a man thinks of himself’. To modern cosmologists, fate is something else entirely: a sweeping, impersonal physical process that can be boiled down into a single, momentous number known as the Hubble Constant. The Hubble Constant can be…

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Is a grand theory of everything finally within reach?

Is a grand theory of everything finally within reach?

James Wells writes: When trying to explain what motivates me as a physicist, the film A Passage to India (1984) comes to mind. Based on the play by Santha Rama Rau, adapted from the novel by E M Forster, it describes the fallout from a rape case in the fictional city of Chandrapore, during the British Raj in India in the 1920s. What keeps the viewer’s attention is the subtlety of the relationships between the characters – particularly the fragile…

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With constructor theory, the physicist, Chiara Marletto, invokes the impossible

With constructor theory, the physicist, Chiara Marletto, invokes the impossible

Amanda Gefter writes: They say that in art, constraints lead to creativity. The same seems to be true of the universe. By placing limits on nature, the laws of physics squeeze out reality’s most fantastical creations. Limit light’s speed, and suddenly space can shrink, time can slow. Limit the ability to divide energy into infinitely small units, and the full weirdness of quantum mechanics blossoms. “Declaring something impossible leads to more things being possible,” writes the physicist Chiara Marletto. “Bizarre…

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