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Deformable Liquid Mirrors For Adaptive Optics

Posted by timothy on from the mirror-mirror-on-the-magnet dept.

eldavojohn writes "Want to make a great concave mirror for your telescope? Put a drop of mercury in a bowl and spin the bowl. The mercury will spread out to a concave reflective surface smoother than anything we can make with plain old glass right now. The key problem in this situation is that the bowl will always have to point straight up. MIT's Technology Review is analyzing a team's success in combating problems with bringing liquid mirrors into the practical applications of astronomy. To fight the gravity requirement, the team used a ferromagnetic liquid coated with a metal-like film and very strong magnetic fields to distort the surface of that liquid as they needed. But this introduces new non-linear problems of control when trying to sync up several of these mirrors similar to how traditional glass telescopes use multiple hexagonal mirrors mounted on actuators. The team has fought past so many of these problems plaguing liquid mirrors that they produced a proof of concept liquid mirror just five centimeters across with 91 actuators cycling at one kilohertz and the ability to linearize the response of the liquid. And with that, liquid mirrors take a giant leap closer to practicality."

8 of 196 comments (clear)

  1. Re:All mirrors liquid by Anonymous Coward · · Score: 1, Funny

    Queue the debate:

    First!

    Okay, I'm in line for a debate. Now what?

  2. bowl? by RapmasterT · · Score: 1, Funny

    Put a drop of mercury in a bowl and spin the bowl. The mercury will spread out to a concave reflective surface smoother than anything we can make with plain old glass right now..

    so our bowl making technology exceeds our bowl shaped mirror technology? seems like we could just hire the bowl makers and fire the current crop of mirror makers, problem solved.

    1. Re:bowl? by goodmanj · · Score: 5, Funny

      The perfect shape comes from the spinning liquid: the bowl doesn't have to have any particular shape. You can even use a flat-bottomed bowl, you just need more mercury.

      "Flat-bottomed bowls, you make the liquid scope go 'round..." -- Freddie Mercury

  3. Re:All mirrors liquid by Jeng · · Score: 3, Funny

    Okay, I'm in line for a debate. Now what?

    Now tell him he is wrong, and why he is wrong.

    --
    Don't know something? Look it up. Still don't know? Then ask.
  4. Re:dumb question... by Grishnakh · · Score: 4, Funny

    I've got a better idea. Just keep using spinning liquid mercury, but put it in an artificial gravity field so that you can point it in any direction with "down" still being at the base of the mirror. This only needs some small advances in the field of physics.

  5. Re:Oil lense by SnarfQuest · · Score: 3, Funny

    I know where you can get a lot of oil, but it might be a bit salty...

    --
    Who would win this election: Andrew Weiner vs Andrew Weiner's weiner.
  6. Some Typoes by RevWaldo · · Score: 2, Funny

    MIT's Technology Review is 'nalyzin a team's success in combating problems with a-bringin' liquid mirrors into the practical applications of astronomy.

    FTFY

    .

    --
    Prisencolinensinainciusol. Ol Rait!
  7. Re:dumb question... by tlhIngan · · Score: 4, Funny

    I've got a better idea. Just keep using spinning liquid mercury, but put it in an artificial gravity field so that you can point it in any direction with "down" still being at the base of the mirror. This only needs some small advances in the field of physics.

    What advance in physics is needed? Gravity works by the attraction of objects to each other, so all you need is a really, really, really massive object at the base of mirror. Such objects could easily range from a planet to a small black hole.

    Problem solved.