adactio / tags / cosmology

Tagged with “cosmology” (8)

  1. Free Thinking Festival: Time, Space and Science

    Carlos Frenk, Eugenia Cheng, Jim Al-Khalili and Louisa Preston debate time and space.

    Carlos Frenk, Eugenia Cheng, Jim Al-Khalili and Louisa Preston debate time and space with presenter Rana Mitter and an audience at Radio 3’s Free Thinking Festival at Sage Gateshead.

    We can measure time passing but what actually is it? What do scientists mean when they suggest that time is an illusion. Can time exist in a black hole? Is everyone’s experience of time subjective? What is the connection between time and space? How does maths help us understand the universe?

    Professor Carlos Frenk is founding Director of the Institute for Computational Cosmology at Durham University and the winner of the Gold Medal of the Royal Astronomical Society in 2014.

    Dr Eugenia Cheng is Scientist in Residence at the School of the Art Institute of Chicago and an Honorary Fellow of the University of Sheffield. She is trilingual, a concert-level classical pianist and the author of Beyond Infinity: An Expedition To The Outer Limits Of The Mathematical Universe.

    Jim Al-Khalili is Professor of Physics at the University of Surrey and presenter of BBC Radio 4’s The Life Scientific and TV documentaries. His books include Paradox: the Nine Greatest Enigmas in Science, Black Holes, Wormholes and Time Machines and Quantum: a Guide for the Perplexed.

    Dr Louisa Preston is a UK Space Agency Aurora Research Fellow. An astrobiologist, planetary geologist and author, she is based at Birkbeck, University of London. Her first book is Goldilocks and the Water Bears: the Search for Life in the Universe.

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  2. Priyamvada Natarajan: Solving Dark Matter and Dark Energy - The Long Now

    The darkness of dark matter and dark energy

    All that we know of the universe we get from observing photons, Natarajan pointed out.

    But dark matter, which makes up 90 percent of the total mass in the universe, is called dark because it neither emits nor reflects photons—and because of our ignorance of what it is!

    It is conjectured to be made up of still-unidentified exotic collisionless particles which might weigh about six times more than an electron.

    Though some challenge whether dark matter even exists, Natarajan is persuaded that it does because of her research on “the heaviest objects in the universe“—galaxy clusters of more than 1,000 galaxies.

    First of all, the rotation of stars within galaxies does not look Keplerian—the outermost stars move far too quickly as discovered in the 1970s.

    Their rapid rate of motion only makes sense if there is a vast “halo” of dark matter enclosing each galaxy.

    And galaxy clusters have so much mass (90 percent of it dark) that their gravitation bends light, “lenses” it.

    A galaxy perfectly aligned on the far side of a galaxy cluster appears to us—via the Hubble Space Telescope—as a set of multiple arc-shaped (distorted) galaxy images.

    Studying the precise geometry of those images can reveal some of the nature of dark matter, such as that it appears to be “clumpy.”

    When the next-generation of space telescopes - the James Webb Space Telescope that comes online in 2018 and the WFIRST a few years afterward, much more will be learned.

    There are also instruments on Earth trying to detect dark-matter particles directly, so far without success.

    As for dark energy—the accelerating expansion of the universe—its shocking discovery came from two independent teams in 1998-99.

    Dark energy is now understood to constitute 72 percent of the entire contents of the universe.

    (Of the remainder, dark matter is 23 percent, and atoms—the part that we know—makes up just 4.6 percent.)

    But when the universe was just 380,000 years old (13.7 billion years ago), there was no dark energy.

    But now “the universe is expanding at a pretty fast clip.”

    Natarajan hopes to use galaxy-cluster lensing as a tool “to trace the geometry of space-time which encodes dark energy.”

    These days, she said, data is coming in from the universe faster than theory can keep up with it.

    ”We are in a golden age of cosmology.”

    —Stewart Brand

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  3. Brian Greene | The Hidden Reality: Parallel Universes and the Deep Laws of the Cosmos

    Co-presented by The Philadelphia Science Festival Introduced by Dennis Wint, president and chief executive officer of The Franklin Institute Recognized for his groundbreaking discoveries in superstring theory, Brian Greene hosted the Public Broadcasting Service’s NOVA series based on his book, The Elegant Universe. A professor of mathematics and physics at Columbia University, he is also the author of The Fabric of the Cosmos and Icarus at the Edge of Time. He is well-known for making complex scientific principles accessible to general audiences. According to a reviewer for Publishers Weekly, the strength of his books lies ”in Greene’s unparalleled ability to translate higher mathematics and its findings into everyday language and images, through adept use of metaphor and analogy, and crisp, witty prose." In The Hidden Reality: Parallel Universes and the Deep Laws of the Cosmos, Greene shows how a range of different multiverse proposals emerges from theories developed to explain observations of both subatomic particles and the dark depths of space, featuring doppelgängers, strings, branes, quantum probabilities, holographs, and simulated worlds. Brian Greene will be interviewed by Dr. Steve Snyder, vice president of programs and exhibitions at The Franklin Institute. (recorded 4/28/2011)

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  4. Why Not to Fear Black Holes with Astronomer Ian Morison

    Black Holes seem to have bad press that is largely undeserved. This lecture with professor Ian Morison explains what Black Holes are, and how we can discover them even through they can’t be seen.

    This program was recorded in collaboration with Gresham College, on October 27, 2010.

    Gresham Professor of Astronomy Ian Morison made his first telescope at the age of 12 with lenses given to him by his optician. Having studied Physics, Maths and Astronomy at Oxford, he became a radio astronomer at the Jodrell Bank Observatory and teaches Astronomy and Cosmology at the University of Manchester.

    Over 25 years he has also taught Observational Astronomy to many hundreds of adult students in the North West of England. An active amateur optical astronomer, he is a council member and past president of the Society for Popular Astronomy in the United Kingdom.

    At Jodrell Bank he was a designer of the 217 KM MERLIN array and has coordinated the Project Phoenix SETI Observations using the Lovell Radio Telescope. He contributes astronomy articles and reviews for New Scientist and Astronomy Now, and produces a monthly sky guide on the Observatory’s website.

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  5. Paul Davies | The Eerie Silence: Renewing Our Search for Alien Intelligence

    The acclaimed British-born theoretical physicist, cosmologist, and astrobiologist Paul Davies is the director of the Beyond Center for Fundamental Concepts in Science and co-director of the Cosmology Initiative, both at Arizona State University. He is also a member of the Search for Extraterrestrial Intelligence’s (SETI) post-detection committee. Among his numerous scientific distinctions, Davies is a recipient of the prestigious Templeton Prize for his work on science and religion. His writings include the bestsellers The Mind of God, About Time, How to Build a Time Machine, The Fifth Miracle, and The Goldilocks Enigma. In his provocative new book, Davies challenges existing ideas of what form an alien intelligence might take, how it might try to communicate with us, and how we should respond if we ever do make contact. Free Library Festival (recorded 4/17/2010)

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