From “i” for “inspiral” to “g” for “gamma-ray burst”.
Category: cosmology – Page 240
I promise you: this post is going to tell a scientifically coherent story that involves all five topics listed in the title. Not one can be omitted.
My story starts with a Zoom talk that the one and only Lenny Susskind delivered for the Simons Institute for Theory of Computing back in May. There followed a panel discussion involving Lenny, Edward Witten, Geoffrey Penington, Umesh Vazirani, and your humble shtetlmaster.
Lenny’s talk led up to a gedankenexperiment involving an observer, Alice, who bravely jumps into a specially-prepared black hole, in order to see the answer to a certain computational problem in her final seconds before being ripped to shreds near the singularity. Drawing on earlier work by Bouland, Fefferman, and Vazirani, Lenny speculated that the computational problem could be exponentially hard even for a (standard) quantum computer. Despite this, Lenny repeatedly insisted—indeed, he asked me again to stress here—that he was not claiming to violate the Quantum Extended Church-Turing Thesis (QECTT), the statement th at all of nature can be efficiently simulated by a standard quantum computer. Instead, he was simply investigating how the QECTT needs to be formulated in order to be a true statement.
Ever since the start of the hot Big Bang, time ticks forward as the Universe expands. But could time ever run backwards, instead?
What would happen if you fell into a black hole? Join James Beacham, particle physicist at the Large Hadron Collider at CERN, as he explores what happens when the fabric of reality – physical or societal – gets twisted beyond recognition.
Watch the Q&A with James here: https://youtu.be/Q37oEB4bNSI
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James Beacham searches for answers to the biggest open questions of physics using the largest experiment ever, the Large Hadron Collider at CERN. He hunts for dark matter, gravitons, quantum black holes, and dark photons as a member of the ATLAS collaboration, one of the teams that discovered the Higgs boson in 2012.
In addition to his research, he is a frequent keynote speaker about science, innovation, the future of technology, and art at events and venues around the world, including the American Museum of Natural History, the Royal Institution, SXSW, and the BBC, as well as private events for companies and corporations, including KPMG, Bain, Dept Agency, and many others.
This talk was recorded at the Royal Institution on 28 October 2021.
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Why is there something rather than nothing? And what does ‘nothing’ really mean? More than a philosophical musing, understanding nothing may be the key to unlocking deep mysteries of the universe, from dark energy to why particles have mass. Journalist John Hockenberry hosts Nobel laureate Frank Wilczek, esteemed cosmologist John Barrow, and leading physicists Paul Davies and George Ellis as they explore physics, philosophy and the nothing they share.
This program is part of the Big Ideas Series, made possible with support from the John Templeton Foundation.
The World Science Festival gathers great minds in science and the arts to produce live and digital content that allows a broad general audience to engage with scientific discoveries. Our mission is to cultivate a general public informed by science, inspired by its wonder, convinced of its value, and prepared to engage with its implications for the future.
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Original Program Date: June 12, 2009
MODERATOR: John Hockenberry.
PARTICIPANTS: George Ellis, Frank Wilczek, John Barrow, Paul Davies.
Introduction 00:00
What is dark matter? Does it even exist, or do we just need an adjustment to our theory of gravity?
What is dark matter? It has never been observed, yet scientists estimate that it makes up 85% of the matter in the universe. The short answer is that no one knows what dark matter is. More than a century ago, Lord Kelvin offered it as an explanation for the velocity of stars in our own galaxy. Decades later, Swedish astronomer Knut Lundmark noted that the universe must contain much more matter than we can observe. Scientists since the 1960s and ’70s have been trying to figure out what this mysterious substance is, using ever-more complicated technology. However, a growing number of physicists suspect that the answer may be that there is no such thing as dark matter at all.
Scientists can observe far-away matter in a number of ways. Equipment such as the famous Hubble telescope measures visible light while other technology, such as radio telescopes, measures non-visible phenomena. Scientists often spend years gathering data and then proceed to analyze it to make the most sense of what they are seeing.
Berkeley Lab Researchers Record Successful Startup of LUX-ZEPLIN Dark Matter Detector at Sanford Underground Research Facility
An innovative and uniquely sensitive dark matter detector – the LUX-ZEPLIN (LZ) experiment – has passed a check-out phase of startup operations and delivered first results. LZ is located deep below the Black Hills of South Dakota in the Sanford Underground Research Facility (SURF) and is led by the DOE’s Lawrence Berkeley National Laboratory (Berkeley Lab).
The take-home message from this successful startup: “We’re ready and everything’s looking good,” said Berkeley Lab senior physicist and past LZ spokesperson Kevin Lesko. “It’s a complex detector with many parts to it and they are all functioning well within expectations,” he said.
Would you like a warning before the world ends?
Well, it’s now possible. Extraluminal is an Internet of Things (IoT) device that will notify you an hour before the Earth is about to be destroyed by a supernova.
A supernova refers to “the cataclysmic explosion of a massive star at the end of its life. It can emit more energy in a few seconds than our sun will radiate in its lifetime of billions of years.”
It was once thought that gravity and quantum mechanics were inconsistent with one another. Instead, we are discovering that they are so closely connected that one can almost say they are the same thing. Professor Susskind will explain how this view came into being over the last two decades, and illustrate how a number of gravitational phenomena have their roots in the ordinary principles of quantum mechanics.
Leonard Susskind is an American physicist, who is a professor of theoretical physics at Stanford University, and founding director of the Stanford Institute for Theoretical Physics. His research interests include string theory, quantum field theory, quantum statistical mechanics, and quantum cosmology.
