## Helium Balloon in a Car

### Background

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)

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.

## Make Your Voice Sound Like a Cowboy (Girls Also)

###### By Anupum Pant

Everyone who watches The Big Bang Theory on TV must have had a hearty laugh when Sheldon’s voice went funny in the 9th episode of season 3 (video).
In the video, when Sheldon starts talking on an NPR show about magnetic monopoles , Kripke uses a Helium tank to fill Sheldon’s room with Helium. As a result, his [Sheldon’s] voice shifts pitch and starts sounding really funny.

In this article we’ll see, what is it in Helium that makes our voices go funny. And we’ll also see another interesting gas that makes your voice sound like a cowboy. But first, some things about Helium:

### Helium Warning

1. Do not use Helium to play. It is kind of a non-renewable resource. At the same time, it is used in laboratories for physics experiments. When you play with it and release it into the atmosphere, Helium is lost forever. I wrote an article on this couple of days back. [Understanding the impending Helium crisis]

2. Although Helium is a non-toxic gas and no it doesn’t kill brain cells, it can still kill you. Pranks like the one Kripke uses, which could potentially fill up the whole room with Helium could have lethal consequences. Too much Helium and you’ll not be breathing [enough] Oxygen. Even if you don’t care about the first point, you should think about inhaling more than 3 Helium filled balloons (or any other gas) during parties – it could kill you by asphyxiation (specifically, Hypoxia).

Talking about death, these speakers can also kill you – Plasma Speakers.

### Why does Helium make voices go Daffy duck?

Helium is the second lightest element (gas) after Hydrogen. It is six times lighter than air. And if you’ve read this article on how sound works, you probably know that sound travels with different speeds through different mediums.
The speed of sound is about 3 times faster in helium, than in air. When you take in Helium, it increases the speed of sound that comes out of your mouth. It does nothing to your vocal chords. Faster sound and same wavelength results in a higher frequency sound.

Contrary to what is popularly believed, Helium doesn’t technically alters the pitch of your voice. [Read more]

### Sulphur Hexafluoride

Helium voices are quite popular. On the other hand, sulphur Hexafluoride voices aren’t very commonly known.
Completely opposite to Helium, this is 6 times heavier than air. So, inhaling it makes your voice go really deep. The mechanism is just opposite to that of Helium. It makes sound move slower. Again, technically, it doesn’t change the pitch of your voice. Watch the video below:

### Where can you find this gas?

Sulfur hexafluoride is used for eye surgery and ultrasound in hospitals. Also, it is widely used in the industry for various things. So, you could go to someone, who supplies gasses like these (Oxygen, Argon etc.) to hospitals and industries. Then you could request them to let you collect it in a small balloon (they won’t let you).
So, you could simply study science, work in laboratories and have such fun activities everyday (in moderation).

Side Note: Inhaling another non-toxic noble gas, Xenon, also does something similar. It is heavier than air so it makes your voice deep. At the same time, xenon will make your pockets extremely light.