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Category: Physics

Chaos researchers can now predict perilous points of no return

Chaos researchers can now predict perilous points of no return

Ben Brubaker writes: Predicting complex systems like the weather is famously difficult. But at least the weather’s governing equations don’t change from one day to the next. In contrast, certain complex systems can undergo “tipping point” transitions, suddenly changing their behavior dramatically and perhaps irreversibly, with little warning and potentially catastrophic consequences. On long enough timescales, most real-world systems are like this. Consider the Gulf Stream in the North Atlantic, which transports warm equatorial water northward as part of an…

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Dark energy may come from giant cosmic voids

Dark energy may come from giant cosmic voids

Paul Sutter writes: Gigantic deserts of almost complete nothingness that make up most of the universe may be causing the expansion of the universe to speed up, new research suggests. That means these vast tracts of nothingness could explain dark energy, the mysterious force that seems to be flinging the universe apart. Zoom all the way out from the solar system and the Milky Way galaxy, and an interesting pattern emerges: the cosmic web, the largest pattern found in nature….

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How the physics of nothing underlies everything

How the physics of nothing underlies everything

Charlie Wood writes: Millennia ago, Aristotle asserted that nature abhors a vacuum, reasoning that objects would fly through truly empty space at impossible speeds. In 1277, the French bishop Etienne Tempier shot back, declaring that God could do anything, even create a vacuum. Then a mere scientist pulled it off. Otto von Guericke invented a pump to suck the air from within a hollow copper sphere, establishing perhaps the first high-quality vacuum on Earth. In a theatrical demonstration in 1654,…

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Webb telescope reveals unpredicted bounty of bright galaxies in early universe

Webb telescope reveals unpredicted bounty of bright galaxies in early universe

Science reports: The James Webb Space Telescope has only been watching the sky for a few weeks, and it has already delivered a startling finding: tens, hundreds, maybe even 1000 times more bright galaxies in the early universe than astronomers anticipated. “No one was expecting anything like this,” says Michael Boylan-Kolchin of the University of Texas, Austin. “Galaxies are exploding out of the woodwork,” says Rachel Somerville of the Flatiron Institute. Galaxy formation models may now need a revision, as…

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The origins of the universe may be hidden in the voids of space

The origins of the universe may be hidden in the voids of space

Paul M. Sutter writes: Beginning in the 1970s cosmologists started to uncover the structure of the universe writ large. They already knew that galaxies occasionally clump together into clusters, but over even larger distances, spanning 100 million light-years and more, they found superclusters. And in between those superclusters they saw something even more unexpected: vast regions devoid of galaxies, great and immense dark hollows. The first of these cosmic voids that cosmologists discovered was 65 million light-years across. No theoretical…

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The spooky quantum phenomenon you’ve never heard of

The spooky quantum phenomenon you’ve never heard of

Katie McCormick writes: Perhaps the most famously weird feature of quantum mechanics is nonlocality: Measure one particle in an entangled pair whose partner is miles away, and the measurement seems to rip through the intervening space to instantaneously affect its partner. This “spooky action at a distance” (as Albert Einstein called it) has been the main focus of tests of quantum theory. “Nonlocality is spectacular. I mean, it’s like magic,” said Adán Cabello, a physicist at the University of Seville…

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Ten years after the Higgs, physicists face the nightmare of finding nothing else

Ten years after the Higgs, physicists face the nightmare of finding nothing else

Science reports: A decade ago, particle physicists thrilled the world. On 4 July 2012, 6000 researchers working with the world’s biggest atom smasher, the Large Hadron Collider (LHC) at the European particle physics laboratory, CERN, announced they had discovered the Higgs boson, a massive, fleeting particle key to their abstruse explanation of how other fundamental particles get their mass. The discovery fulfilled a 45-year-old prediction, completed a theory called the standard model, and thrust physicists into the spotlight. Then came…

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Physicists rewrite the fundamental law that leads to disorder

Physicists rewrite the fundamental law that leads to disorder

Philip Ball writes: In all of physical law, there’s arguably no principle more sacrosanct than the second law of thermodynamics — the notion that entropy, a measure of disorder, will always stay the same or increase. “If someone points out to you that your pet theory of the universe is in disagreement with Maxwell’s equations — then so much the worse for Maxwell’s equations,” wrote the British astrophysicist Arthur Eddington in his 1928 book The Nature of the Physical World….

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What is time?

What is time?

Annaka Harris writes: “I think the flow of time is not part of the fundamental structure of reality,” theoretical physicist Carlo Rovelli tells me. He is currently working on a theory of quantum gravity in which the variable of time plays no part. And throughout our conversation, I’m trying to get my mind around the idea that even though the universe is made up of “events,” as Carlo explains, a single interval between two events can have different values. There…

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The interdependence of all things

The interdependence of all things

Nicholas Cannariato writes: The nature of time. Black holes. Ancient philosophers. The struggle for democracy. Climate change. Buddhist philosophy. In his new collection of essays and articles, Carlo Rovelli, one of the world’s most renowned physicists, broadens his writing to include questions of politics, justice and how we live now. “I look at myself as much more than a physicist,” he said in an interview at his home in London, Ontario, on a cold, calm day in February. The new…

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The universe could stop expanding ‘remarkably soon’, study suggests

The universe could stop expanding ‘remarkably soon’, study suggests

Live Science reports: After nearly 13.8 billion years of nonstop expansion, the universe could soon grind to a standstill, then slowly start to contract, new research published in the journal Proceedings of the National Academy of Sciences suggests. In the new paper, three scientists attempt to model the nature of dark energy — a mysterious force that seems to be causing the universe to expand ever faster — based on past observations of cosmic expansion. In the team’s model, dark…

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Long-awaited accelerator ready to explore origins of elements

Long-awaited accelerator ready to explore origins of elements

Nature reports: One of nuclear physicists’ top wishes is about to come true. After a decades-long wait, a US$942 million accelerator in Michigan is officially inaugurating on 2 May. Its experiments will chart unexplored regions of the landscape of exotic atomic nuclei and shed light on how stars and supernova explosions create most of the elements in the Universe. “This project has been the realization of a dream of the whole community in nuclear physics,” says Ani Aprahamian, an experimental…

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Looking directly towards the edge of time

Looking directly towards the edge of time

Dr Katie Mack writes: “From a tropical rainforest to the edge of time itself, James Webb begins a voyage back to the birth of the Universe” – so went the launch narration when astronomy’s latest superpowered space explorer, the James Webb Space Telescope (JWST), lifted off from French Guiana on Christmas Day. Like most launch announcements, it employed a bit of poetic license to add to the drama. But now that JWST is settled into its orbit and sending back…

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A universe without mathematics is beyond the scope of our imagination

A universe without mathematics is beyond the scope of our imagination

Mathematics is the language of the universe. (Shutterstock) By Peter Watson, Carleton University Almost 400 years ago, in The Assayer, Galileo wrote: “Philosophy is written in this grand book, the universe … [But the book] is written in the language of mathematics.” He was much more than an astronomer, and this can almost be thought of as the first writing on the scientific method. We do not know who first started applying mathematics to scientific study, but it is plausible…

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Time might not exist, according to physicists and philosophers – but that’s okay

Time might not exist, according to physicists and philosophers – but that’s okay

Shutterstock By Sam Baron, Australian Catholic University Does time exist? The answer to this question may seem obvious: of course it does! Just look at a calendar or a clock. But developments in physics suggest the non-existence of time is an open possibility, and one that we should take seriously. How can that be, and what would it mean? It’ll take a little while to explain, but don’t worry: even if time doesn’t exist, our lives will go on as…

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Particle’s surprise mass threatens to upend the Standard Model

Particle’s surprise mass threatens to upend the Standard Model

Nature reports: From its resting place outside Chicago, Illinois, a long-defunct experiment is threatening to throw the field of elementary particles off balance. Physicists have toiled for ten years to squeeze a crucial new measurement out of the experiment’s old data, and the results are now in. The team has found that the W boson — a fundamental particle that carries the weak nuclear force — is significantly heavier than theory predicts. Although the difference between the theoretical prediction and…

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