Physics

From philosopher Emily Thomas at The Conversation: Is there space between the stars? The relationist Leibniz argued that space is the spatial relations between things. Australia is “south of” Singapore. The tree is “three meters left of” the bush. Sean Spicer is “behind” the bush. That means space would not exist independently of the things it connects. For Leibniz, if nothing existed, there couldn’t be any spatial relations. If our universe were destroyed, space would not exist. In contrast, the absolutist Clarke argued that space is a sort of substance that is everywhere. Space is a giant container, containing all the things in the universe: stars, planets, us. Space allows us to make sense of how things move from one Read More ›

From Shannon Palus at New Scientist: THERE is a hole in the sun. Right in the middle, a mass the size of 1500 Earths has simply disappeared. Much of what we know about the sun’s behaviour says it should be there – but when we interpret the data encoded in sunlight, that chunk of stuff is nowhere to be seen. That has shaken up our understanding of how the sun works, and physicists are struggling to figure out what fills that hole. It could be a thing, like dark matter. It could be a concept, with elements such as carbon and nitrogen simply behaving in a way we didn’t expect under crushing pressure. Or perhaps we’re looking at the sun Read More ›

From Cathay O’Connell at at Cosmos: Like me, physicists around the world are in the midst of an important search that has so far proven fruitless. Their quarry is nothing less than most of the matter in the universe, so-called “dark matter”. So far their most sensitive detectors have found – to be pithy – nada. Despite the lack of results, scientists aren’t giving up. “The frequency with which articles show up in the popular press saying ‘maybe dark matter isn’t real’ massively exceeds the frequency with which physicists or astronomers find any reason to re-examine that question,” says Katie Mack, a theoretical astrophysicist at the University of Melbourne. In many respects, the quest for dark matter has only just Read More ›

From Sabine Hossenfelder at her blog Backreaction: I’ve had many interesting reactions to my recent post about inflation, this idea that the early universe expanded exponentially and thereby flattened and smoothed itself. The maybe most interesting response to my pointing out that inflation doesn’t solve the problems it was invented to solve is a flabbergasted: “But everyone else says it does.” … I’m not sure why that is so. Those who I personally speak with pretty quickly agree that what I say is correct. The math isn’t all that difficult and the situation pretty clar. The puzzle is, why then do so many of them tell a story that is nonsense? And why do they keep teaching it to students, Read More ›

Jeremy England. From John Ellis at PJ Media: In his new novel Origin, Brown includes a character named Jeremy England who is a physics professor. This fictional character based on the real-life Jeremy England has “identified the underlying physical principle driving the origin and evolution of life.” Furthermore, according to the book, Professor England has disproven all other theories of creation, including the Biblical account recorded in Genesis. The real Jeremy England scoffs at Dan Brown’s fictional creation that hijacks England’s actual research. England takes umbrage at Brown’s use of his name and research to suggest that the Book of Genesis has been refuted. England points out that his namesake in Dan Brown’s book offers no real science to interact Read More ›

Recently, we reported on the question of whether the missing dark matter of the universe has finally been found, and we cautioned, Keep the file open but remember: We did find the Higgs boson (and Peter Higgs got the Nobel). But gravitational waves and dark energy are questionable despite the Nobels awarded. More. Our physics commentator Rob Sheldon offers some perspective: The New Scientist was kind enough to link to the arXiv server, so I could read the actual paper. Because the journalese is not making the slightest bit of sense. The two main conundrums of dark matter are: a) It allows galaxies to spin faster than they otherwise would, yet not enough gas is found in the galaxies to Read More ›

According to a report from Leah Crane at New Scientist: The missing links between galaxies have finally been found. This is the first detection of the roughly half of the normal matter in our universe – protons, neutrons and electrons – unaccounted for by previous observations of stars, galaxies and other bright objects in space. Two separate teams found the missing matter – made of particles called baryons rather than dark matter – linking galaxies together through filaments of hot, diffuse gas. Two separate teams found the missing matter – made of particles called baryons rather than dark matter – linking galaxies together through filaments of hot, diffuse gas. … Because the gas is so tenuous and not quite hot Read More ›

Here. Paper. See also: Carlo Rovelli: Theories of everything ill-conceived but we can learn to understand quantum mechanics

From Megan Gannon at LiveScience: BERLIN—As expected by many, the 2017 Nobel Prize for physics went to three scientists who helped detect gravitational waves, ripples in space-time predicted by Einstein. “This year’s prize is about a discovery that shook the world,” said physicist Thors Hans Hansson, announcing the winners from Stockholm. … On Sept. 14, 2015, LIGO’s two extremely sensitive instruments in Washington state and Louisiana simultaneously observed a faint gravitational-wave signal. The ripples in space-time came from a pair of two massive black holes that spiraled into each other 1.3 billion years ago. More. Our physics color commentator Rob Sheldon is, however, left with more questions than answers: The Nobel was awarded because the waves were finally seen–after 10 Read More ›

Uniting quantum mechanics and gravity at last. From Anil Ananthaswamy at New Scientist One approach towards reconciling gravity with quantum mechanics has been to show that gravity at its most fundamental comes in indivisible parcels called quanta, much like the electromagnetic force comes in quanta called photons. But this road to a theory of quantum gravity has so far proved impassable. Now Antoine Tilloy at the Max Planck Institute of Quantum Optics in Garching, Germany, has attempted to get at gravity by tweaking standard quantum mechanics. Odd that no one has thought of this before, given all the strenuous mental effort that has gone into the topic… But now, Nonetheless, his model makes predictions that can be tested. For example, Read More ›

Physicalism is a variant of naturalism: “Physicalism is the thesis that everything is physical, or as contemporary philosophers sometimes put it, that everything supervenes on the physical. ” (Stanford Plato) Naturalism: “… reality is exhausted by nature, containing nothing “supernatural”, and that the scientific method should be used to investigate all areas of reality, including the ‘human spirit’” (Stanford Plato) Philosopher of physics Dr. Bruce Gordon (Houston Baptist University) talks about the tension between Quantum physics and physicalism: Note: Gordon was one of the editors of The Nature of Nature See also: Consciousness as a state of matter Hat tip: Philip Cunningham

From Abigail Beall at New Scientist: We thought electrons and their two mysterious siblings were fundamental particles. Now there are hints that we need to go smaller still to understand matter But the truly inexplicable thing about the electron is that it has two heavier siblings. The universe would tick along fine without these particles, which never hang around long anyway. So why do they exist? And why are there three siblings, not four or 104? More. There may be, we are told, “a hidden world buzzing beneath the surface of the electron – one that would force us to rethink all the fundamental building blocks of matter.” Interesting questions: Why do so many things come in threes? Stability? Also, Read More ›

From ScienceDaily: A long-standing question in astrophysics is whether the universe’s very first black holes came into existence less than a second after the Big Bang or whether they formed only millions of years later during the deaths of the earliest stars. Alexander Kusenko, a UCLA professor of physics, and Eric Cotner, a UCLA graduate student, developed a compellingly simple new theory suggesting that black holes could have formed very shortly after the Big Bang, long before stars began to shine. Astronomers have previously suggested that these so-called primordial black holes could account for all or some of the universe’s mysterious dark matter and that they might have seeded the formation of supermassive black holes that exist at the centers Read More ›

From Mary-Jane Rubenstein at Nautilus: What if God is the creatively emergent order of nature itself? In this case, the difference between pantheism and atheism might be emotional. Einstein, a professed pantheist, wrote that he experienced a “cosmic religious feeling,” a persistent awe at the “sublimity and marvelous order” of the universe. He was not alone. For the German theologian Friedrich Schleiermacher, religion was a feeling of the whole universe at work in each part of it. Or perhaps the difference between pantheism and atheism is ethical. As neo-pagans, ecofeminists, radical environmentalists, new animists, and even some biologists have suggested, the Western opposition between God and world seems to have endorsed our exploitation of nature. So if God is the Read More ›

Isn’t “making sense” a human construct? From Kenneth Francis at New English Review: About seven years ago, during a talk on Hawking at a university, I raised my hand and criticised comments he made in his then latest book, The Grand Design, which he co-wrote with Star Trek screenwriter Leonard Mlodinow. My question was, “why did Hawking write such a nonsensical idea that the universe created itself because of gravity?” (In order for the universe to create itself it would have to have existed before it exists, and gravity is part of the universe). I also asked why did Hawking write “philosophy is dead” at the beginning of his book (a self-refuting statement, as it’s philosophical), while constantly philosophising throughout Read More ›