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Thread: What if: Laser Umbrella

  1. #1
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    Default What if: Laser Umbrella

    I don't know how many of you are familiar with XKCD or Randall Munroe's what if, but this is an interesting little piece I thought would interest our readership:

    http://what-if.xkcd.com/119/

  2. #2
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    Worth the read for: https://www.youtube.com/watch?v=bRbHDtPbHe0 alone!

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    Quote Originally Posted by hitekvoop View Post
    That is an amazing video. And YouTube follows it up with: Model wears painted-on pants in public, Epic fail collection #87658972, and some guy drilling a hole in an iphone 6.

    Please save me from this insane internet society...

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    Please save me from this insane internet society...
    Let me help out there

    http://what-if.xkcd.com/13/
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    Quote Originally Posted by loopee View Post
    Let me help out there

    http://what-if.xkcd.com/13/
    My favorite section of this mini-paper:

    "A 1-watt laser is an extremely dangerous thing. It’s not just powerful enough to blind you—it’s capable of burning skin and setting things on fire. Obviously, they’re not legal for consumer purchase in the US.

    Just kidding! You can pick one up for $300!"
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  6. #6
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    Quote Originally Posted by hitekvoop View Post
    holy crap that was awesome!

    Quote Originally Posted by dkumpula View Post
    My favorite section of this mini-paper:

    "A 1-watt laser is an extremely dangerous thing. It’s not just powerful enough to blind you—it’s capable of burning skin and setting things on fire. Obviously, they’re not legal for consumer purchase in the US.

    Just kidding! You can pick one up for $300!"
    yes I loled at that also, scary

  7. #7
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    So does this mean i could set up a laser array to dissipate the rain
    when im doin gardening ?
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  8. #8
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    I wonder what the effects of painting the moon with lasers would look like through a narrow band interference filter centered on the laser wavelength?

  9. #9
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    mixedgas is offline Creaky Old Award Winning Bastard Technologist
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    The moon is 7-13% reflective in the Vis depending on which paper you cite. Its total solar irradiance is ~1300 watts per meter. Only a small fraction of that is visible light. But you still have to greatly exceed the solar irradiance. The best A number 1 ranging laser illuminates a 4-7 KM spot with a 3.5 METER telescope!

    So where are you going to get ~9.9x10^6 watts of CW green and a mirror coating that can take it over a 3.5 meter mirror? At CW?

    Some light reading:

    http://what-if.xkcd.com/13/

    http://www.iers.org/SharedDocs/Publi...cationFile&v=1

    Steve
    Last edited by mixedgas; 12-16-2014 at 13:23.
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  10. #10
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    Quote Originally Posted by mixedgas View Post
    So where are you going to get ~1x10^6 watts of CW green and a mirror coating that can take it over a 3.5 meter mirror? At CW?
    I think there is a DJ out in california that can get you that kind of power

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