Jellyfish Stings and The “Pee on it” Myth

By Anupum Pant

I haven’t been ever stung by a jelly fish, but from how Destin says it in the video, and other people I’ve seen getting bitten, tells me that it is something no one would want to experience in their life. If you did not know, the sting is awfully painful.

A jelly fish uses venom, not poison. They are two different things. Which means that a jellyfish stings you and uses extremely tiny hypodermic needle like things to inject toxins in your body.

But doesn’t jellyfish seem like a bunch of jelly floating around with no visible prickly parts? how does something so soft actually go about inserting something sharp into your skin?

Turns out, on the surface of those long tentacles these fish have, there are microscopic organelles called nematocysts which it uses to sting you. Even a tiny brush with those tentacles can trigger them. The more interesting part is that these tiny needles act very fast, and like I said, they are also very tiny. So, to see them you need a really high frame-rate camera attached to a microscope.

That is exactly what Destin does in the video below. It’s fascinating to see those tiny stingers do their work so fast under a microscope. Not many get a chance to see something like this.

Just FYI. In case you ever end up getting bitten by a jellyfish, please don’t ask your friend to pee on it. There’s a word going around that this helps, but in reality it doesn’t. In fact it can make it worse. Instead try washing it off with sea water. And then use a credit card to scratch the sting to remove any nematocysts stuck in your skin.

Don’t believe me? Please watch this…

Galileo’s Paradox

By Anupum Pant

Here’s an image of a contraption. It is basically a long stick hinged at one end and is free to move about the other. At the end of it rests a ball. Near the ball there’s also a cup fastened to the stick. The big stick is lifted up high and is temporarily supported by a small stick.

galileo paradox

Now, what do you think would happen when the temporary support is removed? Normally, it would be very intuitive to think that the cup and the ball would fall at the same speed. In other words, nothing fascinating would happen. Both would fall and the ball would roll away…no?

However, something very unexpected happens when the support is removed. Something that, in a jiffy demonstrates some very important concepts of physics like centre of mass, torque and acceleration.

The big wooden stick (with the fastened cup) falls and it falls faster than the ball. Actually it falls and also rotates. As a result of the swing, the cup comes under the ball just before ball reaches it and the ball ends up inside it.

Under the influence of the same gravitational force, irrespective of the mass, the cup and the ball must have fallen at the same rate, as predicted by Galileo? What really happens? The video explains…

Double Pendulum and Why We Can Never Predict Weather

By Anupum Pant

A single weight, if suspended from the ceiling, forms a pendulum – A simple device whose position at any point in the future can be predicted fairly easily if the initial conditions are known.

Now, if another pendulum is attached to the bottom of this first pendulum, preferably using a rod (not a string), and is then given a good amount of initial energy, things move from a simple single pendulum to a very complicated two pendulum system.

The system turns so chaotic that it is impossible to make two of such exactly same systems, forget keeping them synchronised. Even if every mass and ever little distance is carefully calculated and two such systems are constructed, it would be impossible to drop them from the same height and see them move in the exactly same manner.

That is because even if they are really dropped from the same position, they’d in reality have a very tiny difference in some parameter, which would eventually become so huge that the two systems would soon go out of sync. Initially they might really seem like they are moving in a synchronized motion, but that doesn’t stay for too long.

This is also the reason why we’ll never be able to predict the weather perfectly. Nikola explains…