Welcome back readers to Science! For Parties. In this edition, we put a new twist on an old trick. You all remember our previous post Backwards When Wet where we showed you how to change the direction of an arrow using only a glass of water. Well consider this post a spiritual sequel to that one, but in today’s entry, we are going to use that same principle of light refraction we learned before to make a piece of licorice disappear.
Just like last time, you’ll need a clear glass, but for this trick instead of water we’ll be using cooking oil. Fill the glass about halfway up with oil then insert a piece of licorice (or a straw o straw-like object). As you turn the glass you’ll note that the portion of licorice that is submerged in the oil becomes visually distorted. It can seem wider or skinnier depending on how you turn the glass and, from some angles, you can even cause the licorice to disappear from view entirely.
We’ve covered the reason for this already in the Backwards When Wet post but I’ll give you a little refresher here. The effect is accomplished via light refraction. Refraction is the change in direction a wave goes through when it passes through a different medium. In this case, the oil bends the light entering the glass to an even greater extent than water would and thus creates an even more profound effect than the one we previously achieved.
See what did I tell you, a new twist on an old trick. Who doesn’t love a sequel? Especially one that involves Science! Until next time!