Magic Particle Flow

Based on the Chladni patterns

Ali Shtarbanov (MIT Media Lab)

Imagine you enter The Magic Room, and all you see in it is a table, on top of which there are only three items: a square flat plate raised on top of a platform, a circular disk of similar area to the side, and a saltshaker. Behind the table there is a wall with four very strange images. The first image is labeled "1146", the last "112" and the two in the middle have no labels. You also see salt particles all over the table but no salt on the plate. Nothing seems to be making sense.

But you know that this is room is themed Magic, so you realize that there could be something magical about the salt. You decide to sprinkle salt on top of the plate.

All of the sudden, you see something very incredible happening. The salt just magically rearranges itself into very specific locations on the plate. You cannot believe your eyes! Everyone in the room with you is mindblown. But your physicist friend is doubtful that there must be a natural cause to the phenomenon.

A few moments later, the first image on the wall lights up and you see that the pattern on the image matches the one into which the salt has arranged itself.

All of the sudden, a control panel appers underneath the table, and the screen on it reads 1146Hz. You recall that the title of the leftmost image is also 1146, and you you realize that these images on the wall correspond to different excitation frequencies. You realize that in order to unlock the remaining three images, you have to simply have to make the salt rearrange itself in the patterns shown in those images - by chaning the frequency. But the second and the third images have no numerical information associated with them. You seek help from you friends and while one of you is adjusting the frequencies, another one is watching the behavior of the salt.

After a few trials you find the fruency that produces the next pattern shown, and bam - the second images lights up.

After a few more seconds, you crack the third frequency. Everyone in the room is mesmerized and puzzled by how awesome science is!

But when it comes to the last one, there seems to be a problem. The image label tells you "112", but when you set the frequency to 112Hz, you don't get that pattern or any pattern at all. After consulting with your friends, you realize that there is circular symmetry in the image, and a rectangular plate is not going to give you those circles. Fortunately, one member of your group notices that there is a circular plate on the table. You swap the two plates.

You sprinkle some salt onto the circular plate, set the frequency to "112", and you see the salt forming the three rings. Finally, you unlock the last image.