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Category: Physics

‘QBism’: quantum mechanics is not a description of objective reality – it reveals a world of genuine free will

‘QBism’: quantum mechanics is not a description of objective reality – it reveals a world of genuine free will

In a cubist painting, reality is more than a single perspective can capture. wikipedia, CC BY-SA By Ruediger Schack, Royal Holloway University of London What does quantum mechanics, the most successful theory ever proposed by physics, teach us about reality? The starting point for most philosophers of physics is that quantum mechanics must somehow provide a description of the world as it is independently of us, the users of the theory. This has led to a large number of incompatible…

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Are world happiness rankings culturally biased?

Are world happiness rankings culturally biased?

Emiliana R. Simon-Thomas writes: Every year, the World Happiness Report ranks 146 countries around the globe by their average level of happiness. Scandinavian countries usually top the list, the U.S. falls someplace in the mid-teens, and war-torn and deeply impoverished countries are at the bottom. The happiness scores come from a survey of life satisfaction, which goes something like this: Considering your life as a whole and using the mental image of a ladder, with the best possible life as…

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Shadows in the Big Bang afterglow reveal invisible cosmic structures

Shadows in the Big Bang afterglow reveal invisible cosmic structures

Zack Savitsky writes: Nearly 400,000 years after the Big Bang, the primordial plasma of the infant universe cooled enough for the first atoms to coalesce, making space for the embedded radiation to soar free. That light — the cosmic microwave background (CMB) — continues to stream through the sky in all directions, broadcasting a snapshot of the early universe that’s picked up by dedicated telescopes and even revealed in the static on old cathode-ray televisions. After scientists discovered the CMB…

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The multiverse: Our universe is suspiciously unlikely to exist – unless it is one of many

The multiverse: Our universe is suspiciously unlikely to exist – unless it is one of many

Do universes pop up as bubbles from a multiverse? arda savasciogullari/Shutterstock By Martin Rees, University of Cambridge It’s easy to envisage other universes, governed by slightly different laws of physics, in which no intelligent life, nor indeed any kind of organised complex systems, could arise. Should we therefore be surprised that a universe exists in which we were able to emerge? That’s a question physicists including me have tried to answer for decades. But it is proving difficult. Although we…

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Neutron stars: A form of matter like no other

Neutron stars: A form of matter like no other

Katia Moskvitch writes: On Aug. 6, 1967, Jocelyn Bell was looking at the squiggles drawn by a red pen on moving rolls of chart paper—the data from a radio telescope she was using to do her Ph.D. research on distant galaxies. She noticed one squiggle that looked odd. It was a “a bit of scruff,” she tells me from her office at Oxford University, where she’s now a visiting professor of astrophysics. The “scruff” was a series of sharp pulses…

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Using physics to describe how tiny biological components give rise to living organisms

Using physics to describe how tiny biological components give rise to living organisms

Charlie Wood writes: In a sunny lab at the Massachusetts Institute of Technology, two starfish fought over their prey. Overlapping arms pinned a hunk of thawing cocktail shrimp against the side of the tank. Thousands of suction cups rippled furiously against the glass as each echinoderm struggled to inch the prize toward its own maw. The physicist Nikta Fakhri looked on with a grin. Not many physicists keep ocean life in their labs, but Fakhri has learned to care for…

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The remarkable emptiness of existence

The remarkable emptiness of existence

Paul M Sutter writes: In 1654 a German scientist and politician named Otto von Guericke was supposed to be busy being the mayor of Magdeburg. But instead he was putting on a demonstration for lords of the Holy Roman Empire. With his newfangled invention, a vacuum pump, he sucked the air out of a copper sphere constructed of two hemispheres. He then had two teams of horses, 15 in each, attempt to pull the hemispheres apart. To the astonishment of…

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Asymmetry detected in the distribution of galaxies

Asymmetry detected in the distribution of galaxies

Katie McCormick writes: Physicists believe they have detected a striking asymmetry in the arrangements of galaxies in the sky. If confirmed, the finding would point to features of the unknown fundamental laws that operated during the Big Bang. “If this result is real, someone’s going to get a Nobel Prize,” said Marc Kamionkowski, a physicist at Johns Hopkins University who was not involved in the analysis. As if playing a cosmic game of Connect the Dots, the researchers drew lines between…

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Why doesn’t physics help us understand the flow of time?

Why doesn’t physics help us understand the flow of time?

Gene Tracy writes: I have a memory, a vivid one, of watching my elderly grandfather wave goodbye to me from the steps of a hospital. This is almost certainly the memory of a dream. In my parent’s photo album of the time, we have snapshots of the extended family – aunts, uncles, and cousins who had all travelled to our upstate New York farm to celebrate my grandparents’ 50th wedding anniversary. I am in some of the photos along with…

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Why this universe is more likely than any other

Why this universe is more likely than any other

Charlie Wood writes: Cosmologists have spent decades striving to understand why our universe is so stunningly vanilla. Not only is it smooth and flat as far as we can see, but it’s also expanding at an ever-so-slowly increasing pace, when naïve calculations suggest that — coming out of the Big Bang — space should have become crumpled up by gravity and blasted apart by repulsive dark energy. To explain the cosmos’s flatness, physicists have added a dramatic opening chapter to…

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We tested Einstein’s theory of gravity on the scale of the universe – here’s what we found

We tested Einstein’s theory of gravity on the scale of the universe – here’s what we found

Thousands of galaxies seen by the James Webb Space Telescope. Nasa By Kazuya Koyama, University of Portsmouth and Levon Pogosian, Simon Fraser University Everything in the universe has gravity – and feels it too. Yet this most common of all fundamental forces is also the one that presents the biggest challenges to physicists. Albert Einstein’s theory of general relativity has been remarkably successful in describing the gravity of stars and planets, but it doesn’t seem to apply perfectly on all…

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How I learned to stop worrying and love uncertainty

How I learned to stop worrying and love uncertainty

Paul M Sutter writes: Like most physicists, I spent much of my career ignoring the majority of quantum mechanics. I was taught the theory in graduate school and applied the mechanics here and there when an interesting problem required it … and that’s about it. Despite its fearsome reputation, the mathematics of quantum theory is actually rather straightforward. Once you get used to the ins and outs, it’s simpler to solve a wide variety of problems in quantum mechanics than…

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Scientists working in a subterranean lab in China discover secrets of first stars

Scientists working in a subterranean lab in China discover secrets of first stars

Motherboard reports: Scientists have opened an unprecedented window into the universe’s very first stars by conducting nuclear fusion experiments in a subterranean laboratory located 1.5 miles under China’s Jinping Mountains, reports a new study. The results resolve a longstanding mystery about one of the oldest stars ever discovered, while also shedding new light on the murky reactions that powered the ancestors of all modern stars. One of the biggest quests in astronomy is to directly observe the first stars that…

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Study suggests spins of ‘brain water’ could mean our minds use quantum computation

Study suggests spins of ‘brain water’ could mean our minds use quantum computation

Science Alert reports: In the ongoing work to realize the full potential of quantum computing, scientists could perhaps try peering into our own brains to see what’s possible: A new study suggests that the brain actually has a lot in common with a quantum computer. The findings could teach us a lot about the functions of neurons as well as the fundamentals of quantum mechanics. The research might explain, for example, why our brains are still able to outperform supercomputers…

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Inside the proton, the ‘most complicated thing you could possibly imagine’

Inside the proton, the ‘most complicated thing you could possibly imagine’

Charlie Wood writes: More than a century after Ernest Rutherford discovered the positively charged particle at the heart of every atom, physicists are still struggling to fully understand the proton. High school physics teachers describe them as featureless balls with one unit each of positive electric charge — the perfect foils for the negatively charged electrons that buzz around them. College students learn that the ball is actually a bundle of three elementary particles called quarks. But decades of research…

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Physicists rewrite a quantum rule that clashes with our universe

Physicists rewrite a quantum rule that clashes with our universe

Charlie Wood writes: A jarring divide cleaves modern physics. On one side lies quantum theory, which portrays subatomic particles as probabilistic waves. On the other lies general relativity, Einstein’s theory that space and time can bend, causing gravity. For 90 years, physicists have sought a reconciliation, a more fundamental description of reality that encompasses both quantum mechanics and gravity. But the quest has run up against thorny paradoxes. Hints are mounting that at least part of the problem lies with…

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