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Science Friday: Anti-gravity-like Magic ... Srsly | Neil deGrasse Tyson: "We've Stopped Dreaming" | NASA Derived R&D Technology

Submitted by Tjadendevries on Fri, 08/12/2011 - 2:43pm

Just to be clear, it's not anti-gravitational, it just seems that way

Why does the magnet fall so slowly? It's a combination of Faraday's and Lenz's Laws. The falling magnet isn't attracted to copper (non ferrous metal), but the movement through, or over, or near the copper (aluminum works also) induces a current which causes a change in the magnetic flux that reacts with the magnetic field of the the magnet itself. More

    The magnet induces currents in the copper pipe as it falls because, at any point in the pipe, there is a change in magnetic flux. By Faraday's Law this induces and emf, and hence a current that, by Lenz's Law, opposes the motion. So as the magnet falls vertically, the change in flux below the falling magnet produces a repulsive force, i.e., an upward force (opposite to gravity), and the change in flux above the falling magnet produces an attractive force, i.e., an upward force also (opposite to gravity). The magnitude of these upward forces depends on the speed of the magnet, the faster the magnet falls the greater the upward force. When the upward force equals the weight of the magnet, the latter will reach its terminal velocity (since there will be no net force acting on it). With a plastic pipe, an emf is generated, but since plastic is an insulator, there will be no currents and so there will be no upward forces.

Must Listen: Neil deGrasse Tyson’s inspirational rant on NASA cutbacks

    Astronomer Neil deGrasse Tyson was on Bill Maher last Friday, and he said everything that needs to be said about plans to slash NASA's budget, including doing away with the James Webb Space Telescope. His phenomenal, astounding rant is one of the greatest pieces of truth-telling you'll hear today:

      First of all, let's clarify what the NASA budget is. Do you realize that the $850 billion dollar bailout, that sum of money is greater than the entire 50-year running budget of NASA?

      And so when someone says, "We don't have enough money for this space probe," I'm asking, no, it's not that you don't have enough money, it's that the distribution of money that you're spending is warped in some way that you are removing the only thing that gives people something to dream about tomorrow.

      You remember the 60s and 70s. You didn't have to go more than a week before there's an article in Life magazine, "The Home of Tomorrow," "The City of Tomorrow," "Transportation of Tomorrow". All of that ended in the 1970s. After we stopped going to the Moon, it all ended. We stopped dreaming.

    And so I worry that the decision that Congress makes doesn't factor in the consequences of those decisions on tomorrow. Tomorrow's gone. They're playing for the quarterly report, they're playing for the next election cycle, and that is mortgaging the actual future of this nation, and the rest of the world is going to pass us by.

http://io9.com/5829707/must-listen-neil-degrasse-tysons-inspirational-rant-on-nasa-cutbacks

50 Consumer Technologies Developed by NASA in the Last 50 Years
    Every year NASA publishes a new edition of their Spinoff magazine, a periodical that outlines NASA-based technologies that have disseminated into everyday devices, improving our lives beyond giving us some nifty new desktop wallpapers. This year marks the 50th anniversary of Spinoff, and to celebrate, NASA has created a "best of" list (that we pasted after the jump). From the aerodynamic principles applied to tractor trailers to advanced imaging techniques that allow 360-degree Real Estate photo tours, NASA demonstrates that their technological breakthroughs are about more than just sticking an American flag on the moon.

      Health and Medicine

      Robotics Offer Newfound Surgical Capabilities

      In-Line Filtration Improves Hygiene and Reduces Expense

      LED Device Illuminates New Path to Healing

      Polymer Coats Leads on Implantable Medical Device

      Lockable Knee Brace Speeds Rehabilitation

      Robotic Joints Support Horses and Humans

      Photorefraction Screens Millions for Vision Disorders

      Periodontal Probe Improves Exams, Alleviates Pain

      Magnetic Separator Enhances Treatment Possibilities

      Transportation

      Lithium Battery Power Delivers Electric Vehicles to Market

      Advanced Control System Increases Helicopter Safety

      Aerodynamics Research Revolutionizes Truck Design

      [...]

http://gizmodo.com/5061120/50-consumer-technologies-developed-by-nasa-in-the-last-50-years