Chladni Figures

By Anupum Pant

If you take a surface, membrane with a layer of loose particles or certain liquids on it, you’ll see that these particles get arranged in beautiful patterns if the membrane is made to vibrate with varying frequencies.

This phenomenon has been known for a long time now, probably since the time when early human tribes used to put grains of sand on drums made of taut animal skin. Since then Leonardo Da Vinci and Galileo Galilei have been known to have observed this phenomenon by hitting or scraping a surface covered with visible particles and .

Later, with information gleaned from Galileo’s and Leonardo’s notes, in the year 1680, Robert Hooke, English scientist from the Oxford University, devised a simple equipment which demonstrated this effect much clearly. He made a glass plate covered with flour to vibrate with the help of a violin bow. And observed beautiful patterns.

Much later, Ernst Chladni explained these figures using mathematics, spread it all across Europe and made a lasting impression on The French Academy of Sciences. These patterns thus came to be known as Chladni figures.

Brusspup, a YouTube channel known for it’s amazing videos demonstrates these Chladni figures on video.

Today, this study, which makes sound and vibration visible to the naked eye, is called Cymatics.

Shepard Tone – An Incredible Auditory Illusion

By Anupum Pant

Here’s the thing. Go to and take that little test they have on their homepage. That is what you need to do first. Stop reading further if you haven’t done it yet.

Assuming you did what I asked you to do…
If you did well in the test (with a few silly mistakes which can be ignored), you’ll probably understand better what I’m talking about in the following article. Otherwise, you might miss the point.

Nevertheless, there is still a chance that you’d understand even if you are tone deaf. I’m not sure because I’m certain not tone deaf and it’s impossible for me to understand the subjective experiences of tone deaf people (I can boast that the first time I took it, I got a perfect score in that test). Anyway, that test is a fun thing to do. You’ll at least learn something about yourself.

The endless stairs and the endless tone

Everyone knows the endless stairs (in the picture below). Now, you’d think why is the author talking about a visual illusion just after he told us to take an auditory test. That is because the popular visual illusion helps you to relate better to a relatively lesser known auditory illusion.

endless stairs illusion

If you start going up on the endless stairs, you always keep moving up. Even after you come back to the same place, you still keep going up. An impossibility. But it’s something that fools your eyes. The same thing happens if you start going down the stairs.

A similar thing can happen with tones. Listen to the following (continuous?) note sweep.

It sounds like a tone that is continuously going down, endlessly. Only, it isn’t. It’s actually a much smaller looped sound that starts from a high point and then goes down. These little loops have been placed one after the other. If you do not carefully listen to it, you’ll never find the exact point at which one loop ends and the next loop starts. You’ll always interpret it as a continuously going down sound. Just like the continuously going down stairs. This is called the Shepard tone.

This works for discreet notes also. Listen to this endless mario stairs video to get an idea how it works for individual notes (not sweeps).


Notes are not simple frequencies. A single note is usually composed of several other frequencies. To not overwhelm us with data, the brain puts all these frequencies together and we hear a single sound (note).

Also, our brains like continuity. So, it cherry picks the frequencies from the loop’s notes that makes us hear a continuous sweep. This is the reason we hear no individual loops. Bah! I’m not very good at explaining this. So, here goes the Vsauce video which explains it better. Note that the arrows in the video are the frequencies I was talking about…

Sad Story of The Lonely Whale – 52 Hertz

By Anupum Pant

Background Story

In the year 1989, a navy technician Joseph George, discovered something mysterious. While looking for enemy submarines in the sea by detecting sound signals, Joseph noticed that there was a mysterious lone sound which stood out in the acoustic signal. From his years of experience as an acoustic analyst, Joseph knew that this sound wasn’t coming from a submarine. As predicted, no enemy ships or submarines were found on further examination.

The sound was a deep pulsing wave and was incredibly loud. It seemed as if it were coming from a machine. But he was certain that this wasn’t a mechanical machine which was making the sound. There was something biological about it. So Joseph decided to call an experienced marine biologist to find out what was making that sound. The researcher confirmed that it was a whale! But not a normal whale…

Did you know?
Whale vomit can make you rich.
and Whale fat is a very healthy thing to eat.

The Twist

If this was really a whale, it still confused the marine biologist because first, the sound was coming from an awkward path. Since whales travel together in a regular migratory path, this wasn’t coming from any of those paths. Also, it was a lone sound.

Secondly, the frequency of sound that was detected was measured to be 52 hertz, and no species of whales were known to make that kind of sound. Usually whales create a sound with a frequency that lies between 15 to 20 hertz. This was definitely not any known species of whale. Or even if it was among any of the known species, it was calling out the wrong note. A note, probably no other whale could hear.

So, for obvious reasons, even when the loud bass was heard for several times, no response by other whales was detected. This was awkward because whales usually respond to the members of their groups. They talk. It was concluded that this whale was travelling alone. No one knew why.

Studies and Theories

In the 13 years of study that ensued, the whale (or whatever it was) was never seen, nor was a response to its song was noted. Scientists started calling it the 52 hertz whale. They could never figure out why the whale sang in a different voice or even an answer to why it was alone, travelling on a completely different path.

Scientists have tried to explain this, but there has never been a solid answer that explains the lonely nature of the creature. To explain the loneliness, some say that the 52 hertz’s voice can’t be heard by other whales, others say that it can’t hear the other whales. Some say that the other whales are scared to respond or go near an unusual voice. Other theories say that the whale must be a hybrid of two different species of whales and that is the reason it sounds so different. What is the real deal, no one knows.

Stories Documentaries and Poems

The 52-hertz whale started having a huge fan following in the late 2000s. A 90 minute documentary was made. However, I couldn’t find it anywhere. Poems were written. Blogs and statuses were written and people sounded touched & concerned. They wanted to extend help to the lonely whale in some way.

lonely whale response

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