Watch A Glass Of Water Make These Arrows Change Direction

    Refraction is just the best.

    Here’s a quick optical illusion you can create to impress your friends.

    Draw an arrow or two on a piece of paper and place it behind an empty glass.

    Then pour in some water...

    And watch the magic unfold.

    The illusion is caused by refraction, with the arrows appearing to change direction.

    Physics Central explains: “When the arrow is moved to a particular distance behind the glass, it looks like it reversed itself."

    Light travels through the air, through the glass, through the water, through the back of the glass, and then back through the air, before reaching the arrow.

    BuzzFeed tried the experiment and can confirm it does indeed work.


    Check out a video of the illusion.

    View this video on YouTube