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Tagged with “matter” (12)

  1. 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

    http://longnow.org/seminars/02016/apr/11/solving-dark-matter-and-dark-energy/

    —Huffduffed by adactio

  2. Kelli Anderson: Design Observer

    Artist and designer, Kelli Anderson, is a New Orleans native, who now lives and works in Brooklyn, New York. Kelli draws, photographs, cuts, prints, codes, and designs a variety of things for herself and others. From interactive paper to layered, experimental websites, everything is done in her studio, which houses a 1919 letterpress! Anderson was the digital collections photographer at the American Museum of Natural History, but stepped down to pursue her own artistic work. She is the recipient of the Ars Electronica Prix Award of Distinction. Kelli also teaches art history at Pratt, where she attended graduate school.

    http://designobserver.com/feature/kelli-anderson/38953/

    —Huffduffed by adactio

  3. Astronomycast 145: Interstellar Travel

    In science fiction it’s easy to hop into your spaceship and blast off for other stars. But the true distances between stars, and the limits of relativity make interstellar travel almost impossible with our current technology. What would it really take to travel from star to star, exploring the galaxy?

    http://www.astronomycast.com/space-flight/ep-145-interstellar-travel/

    —Huffduffed by adactio

  4. Lighting Up The Investigative Path With Polonium-210 : NPR

    Conspiracy theories continue over the death of Palestinian leader Yasser Arafat, and polonium is suspected as the weapon of the alleged assassin. Whatever happened to Arafat, there is a case from 2006 that shows just how destructive the radioactive element can be. It all started with a sip of green tea.

    http://www.npr.org/2013/11/10/244202566/lighting-up-the-investigative-path-with-polonium-210

    —Huffduffed by adactio

  5. Jason Kottke: Observer Media: Design Observer

    Jason Kottke is a blogger and developer living in NYC. As editor of kottke.org for the last 14+ years, he’s scoured nearly every corner of the web for juicy links and things for people to read. Jason is also hard at work on Stellar, a web app for tracking and discovering your favorite things online.

    http://observermedia.designobserver.com/audio/jason-kottke/37617/

    —Huffduffed by adactio

  6. Why We Need Architecture

    A year ago, with a giant economic stimulus package in the works, many Americans envisioned a rebuilt nation. Infrastructure. Bridges. Green cities.

    It hasn’t exactly happened. But the design of all that surrounds us — all that’s built, old and new — is a daily message to us about who we are and what we aspire to.

    Pulitzer Prize-winning critic Paul Goldberger wants to remind us of why architecture matters, in shaping lives and cultures. From ancient Rome to the next wave of American — or Asian — building.

    This hour, On Point: Paul Goldberger, on the power of the built world around us.

    http://www.onpointradio.org/2009/11/why-we-need-architecture

    —Huffduffed by adactio

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