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…

Helium Balloon in a Car

By Anupum Pant


Whenever I choose to write about Helium, there’s something I almost never forget to mention – Helium is precious (Click to know why). So, if you’ve read that, you’ll know that you shouldn’t use it in party balloons, nor should you use it to make your voice sound funny. These are the most silliest things you could do with a borderline non-renewable resource. However, if someone uses it in party balloons to make science look cool to 5-year-old, it’s beautiful.

The Experiment

Destin, a super-cool dad, from the YouTube channel Smarter every day, did exactly that. This is what he did:

Pendulum in a car: First, he tied a pendulum to the roof of his car. Then he accelerated the car. As everyone must have guessed, the pendulum moved back as the car accelerated. It’s natural for our brains to assume that everything would move back in an accelerating vehicle.

Helium Balloon in a car: Next, he tied a balloon filled with Helium to the base of the car. Then, right when he was about to accelerate his car, he asked his 5 year olds sitting in the back seat – “Where do you think the balloon would go if I accelerate?”

Answer the question before proceeding, and reason it if you can. (Even if you don’t know it, it’s easier to guess it right now because of the build up I gave in the previous paragraphs)

The Answer

Unless you already have dealt with this “anomaly”, it’s pretty tough to guess that the balloon would actually move forward as the car accelerates. Yes, it moves forward! Something moving forward in an accelerating car sounds counter intuitive. I knew it because someone had asked me it in a physics puzzle sometime back. Just for the record, I had answered it wrong then. There’s no way I could have guessed, or reasoned it accurately the first time. Did you?

The balloon seems to be defying the laws of physics. But a helium balloon moving forward as the car accelerates can be completely explained by physics. It’s just our brain fooling us again.

Simple Analogy

Here’s how Destin explains it with a simple analogy – using a glass jar filled incompletely with water (so there’s an air bubble inside). Assume that the glass jar is like the car. The water in it, is like the air in the car. And the Helium balloon is like the air bubble in the jar – Since an air bubble is lighter than water, it is safe to assume that because even Helium is lighter than the air.

Now when the jar accelerates forward, the water in the jar moves back – so does the air in the car. As a result, the air in the jar moves forward – just like the Helium balloon does.

Here, watch the video if that sounds too confusing…

Most of you probably know this. But I’m sure that many don’t. Moreover I found the video really cute – A super cool dad explaining science to his little kids in a car. Plus they ask you to go to their audible link that would get you a free audio book. At the same time, it would help a cool dad fund his children’s education. My heart melted. If nothing, the video will at least make you smile.