Added: 1 year ago
From: khanacademy
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  • Fun fact: If you stir a liquid the surface will form into a near perfect parabola. So if you spin some mercury what you get is a parabolic mirror. This spinning mercury can be used as the main reflector on a Newtonian telescope.

    It has been proposed that one of these telescope be built on the moon where there is no atmosphere to contend with. It will only ever point up but will scan the night sky with the rotation and orbit of the moon.

  • if real images formed by concave mirrors are located on front of the mirror, why do we see the image on the mirror itself, as if it were located behind the mirror?

  • what is centre of curvature of mirror

  • @TheDevilvivek if you imagine the mirror as a full circle, it is the centre of that circle ( - ) the - would be the centre of curvature, but all you usually see is - )

  • parabolic mi.. mirr... mirrors xD

  • @SweSmiile :D cute

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  • Sal, I don't know what software you are using, but often times shift and alt shift allow you to form a straight line (vertical and horizontal, respectively).  I love your videos. :D

  • @Melthornal No such function in SmoothDraw 3, which is what he was using last I heard. Seems like a massive oversight to me. It's designed for actual art drawing, but seriously, do they think no artist will ever have a use for a straight line?

  • @hooloovoo1st Actually no artists will ever use a straight line. It spoils drawings.

  • @dalcde Leaving aside for the moment that there are entire fields of art that use exclusively or mainly straight lines, there's no reason they can't be used as a temporary guide.

  • @Melthornal oh! cool! i didt know it too! ))) thx you man!! I will use this in my presentation )))))

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