Showing posts with label physics. Show all posts
Showing posts with label physics. Show all posts

Sunday, March 10, 2024

Controversial new theory of gravity rules out need for dark matter

"We show that it can explain the expansion of the universe and galactic rotation curves without the need for dark matter or dark energy," Oppenheim said on X. "We do urge caution, however, since there is other indirect evidence for dark matter, so further calculations and comparison with data are needed. But if it holds, it would appear that 95% of the energy in the universe is due to the erratic nature of spacetime, signalling either a fundamental breakdown in predictability of physics, or we are immersed in an environment which does not obey the laws of classical or quantum theory." 

Not everyone is convinced, including the well-known theorists Prof Carlo Rovelli and Prof Geoff Penington, who have signed a 5,000:1 odds bet with Oppenheim against his theory being proven correct. 

"I think it's good that physicists explore a wide variety of approaches to very difficult problems like combining quantum mechanics with gravity," said Penington…

Sunday, January 29, 2023

Does God Exist? 4 New Arguments (@PragerU response)

Science tells us that the universe came into being via The Big Bang. But how do you get from energy and matter to a self-aware human being? Frank Pastore thinks that takes three additional Big Bangs that science can't explain and poses the ultimate question that every thinking person must face.
Interview: 

Wednesday, October 5, 2022

Three scientists share physics Nobel prize for quantum mechanics work

Quantum entanglement, in a nutshell, means that the properties of one particle can be deduced by examining the properties of a second particle – even if they are separated by a distance. An easy way to imagine this is to think about being given one of two balls – one of which is white and the other is black. If you receive a white ball, you know the ball that remains is black. Importantly, however, the properties of each particle are not fixed until they are examined – in the ball scenario this would mean that both balls are grey until looked at, where upon one turns white and the other black. 
 This lies at the heart of the "spookiness" – the two particles, or balls, appear to be connected, without the need for any signal to be sent between them…


Monday, January 10, 2022

How could the Big Bang arise from nothing?

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?

Sunday, August 22, 2021

How we know that Einstein's General Relativity can't be quite right

Einstein's theory of General Relativity tells us that gravity is caused by the curvature of space and time. It is a remarkable theory that has been confirmed by countless observations, such as gravitational lensing, light deflection on the sun, redshift in the gravitational potential, black holes and their shadows, and gravitational waves. However, we already know that General Relativity cannot be quite right because it does not fit together with another well-confirmed theory that is quantum mechanics. To resolve this tension, physicists think that we need a theory of quantum gravity. In this video I explain the three key reasons why physicists think that we need a theory of quantum gravity.

Monday, April 19, 2021

New warp drive research dashes faster than light travel dreams – but reveals stranger possibilities

In 1994, physicist Miguel Alcubierre proposed a radical technology that would allow faster than light travel: the warp drive, a hypothetical way to skirt around the universe's ultimate speed limit by bending the fabric of reality...


Sunday, April 11, 2021

Michio Kaku — The God Equation: The Quest for a Theory of Everything (The Michael Shermer Show podcast 170)

Synthesizing relativity and quantum theory would be the crowning achievement of science, a profound merging of all the forces of nature into one beautiful, magnificent equation to unlock the deepest mysteries in science. In this episode, Michael Shermer speaks with professor of theoretical physics Michio Kaku about: the Big Bang, black holes, worm holes, the multiverse, time travel, dark energy and dark matter, gravity, string theory, ETIs, meaning, and God.
Interview: 

Monday, February 15, 2021

5 Misconceptions about Climate Change | Science Matters EP12

Lawrence discusses 5 misconceptions about climate change and physics that sometimes lead to popular confusions about climate change.
https://youtu.be/RRDl0ETzjRc

Thursday, February 4, 2021

Frank Wilczek on the Present and Future of Fundamental Physics (Sean Carroll's Mindscape podcast 130)

What is the world made of? How does it behave? These questions, aimed at the most basic level of reality, are the subject of fundamental physics. What counts as fundamental is somewhat contestable, but it includes our best understanding of matter and energy, space and time, and dynamical laws, as well as complex emergent structures and the sweep of the cosmos. Few people are better positioned to talk about fundamental physics than Frank Wilczek, a Nobel Laureate who has made significant contributions to our understanding of the strong interactions, dark matter, black holes, and condensed matter, as well as proposing the existence of time crystals. We talk about what we currently know about fundamental physics, but also the directions in which it is heading, for better and for worse.

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Frank Wilczek received his Ph.D. in physics from Princeton University. He is currently the Herman Feshbach professor of physics at the MIT; Founding Director of the T. D. Lee Institute and Chief Scientist at Wilczek Quantum Center, Shanghai Jiao Tong University; Distinguished Professor at Arizona State University; and Professor at Stockholm University. Among his numerous awards are the MacArthur Fellowship, the Nobel Prize in Physics (2004, for asymptotic freedom), membership in the National Academy of Sciences and the American Academy of Arts and Sciences. He is the author of numerous books, most recently Fundamentals: Ten Keys to Reality.
Interview: 

Sunday, January 3, 2021

Holiday Message 2020 | The Screwy Universe (Sean Carrol's Mindscape podcast: Science, Society, Philosophy, Culture, Arts, and Ideas, 127)

Welcome to the third annual Mindscape Holiday Message! Just a chance for me to be a little more chatty and informal than usual, although as it turned out this isn’t all that different from a conventional solo episode. With the difference that what I’m talking about — a phenomenon called “cosmic birefringence” — has played a big part in my personal scientific career, so I get to be a bit autobiographical. 

Every photon has a direction of polarization, which generally remains fixed as the photon travels through space. Birefringence is an effect by which the polarization rotates rather than staying fixed. It can happen in materials, but generally not in outer space. But there are exotic physics ideas that could cause such a rotation, including the dynamical dark energy candidate known as quintessence. People have put limits on such cosmic birefringence for a while now, but recently there was a claim that there might be a nonzero amount of birefringence visible in the polarization of the cosmic microwave background! Still very tentative, but if this hint turns into real evidence, it would big extremely big news for our understanding of physics and cosmology, possibly helping us pinpoint the nature of dark energy.
Interview: 

Wednesday, December 30, 2020

New Views of Quantum Jumps Challenge Core Tenets of Physics - Scientific American

One of the most basic processes in all of nature—a subatomic particle's transition between discrete energy states—is surprisingly complex and sometimes predictable, recent work shows.....








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