A Few Amusing Physics Phenomena

By Anupum Pant

Veritasium has always amused us with very interesting physics phenomena over the years. And now, as always, the channel has asked its users to send their answers to these 5 interesting physics mystery.  Here have a look at them…

Do leave a reply on his channel if you think you know why these happen.

For all of the 5 things, I do have my own theories but I’d rather wait till the next week when Derek will release the solution video. I do not want to publish my haphazard theories, which might be wrong.

However, I’m quite sure about one thing. Why does cereal get attracted by a magnet?

That is mostly because it has iron in it. By iron I mean real iron in its pure form. In fact, you can even extract iron from cereal. The best part is that it is not even difficult. All you need is cereal, a neodymium magnet, water, a bowl and a resealable bag.

It’s So Easy To Make A Speaker At Home!

By Anupum Pant

While doing a random experiment with the ordinary motor, a youtuber Andy Elliott who runs the channel mist8k (known for his awesome videos) mistakenly touched the 3.5 mm jack of a speaker cable to the motor’s wires.

This resulted in something very interesting. The sound being transmitted through the cable started coming from the motor. And consequently, he invented the very basic speaker. Then he made a video of him explaining how to make a speaker at home using just a copper wire, magnet, tape, jacks and a disposable plastic cup.

I first saw this on Gizmodo and I thought it deserved a mention in the engineering section of this blog. I can’t wait to try it myself and probably improve the “very basic speaker” to make a nice iPod dock in the future…

Here is what he does –

  • Uncoils a copper wire from a component of an old PC, turns it into a small circular coil of the size of the circular magnet and then tapes it to the back of a disposable plastic cup.
  • Then, makes a larger coil by winding it around a bottle cap and tapes it on top of the smaller coil.
  • Connects one end of the larger coil to the tip of the 3.5 mm jack and the other end of the coil to the base of the jack. The other end of this wire having the 3.5 mm jack is also a 3.5 mm jack, which goes into the computer’s (or any player’s) speaker plug.
  • Places a strong neodymium magnet on top of the coils and plays the music. That’s it!

The computer turns the sound signal into an electric current. This current flows into the jack and then into the coil. Thus, the coil produces a magnetic field of its own. This varying magnetic field coupled with the static magnetic field of the neodymium magnet makes the coil move. Which in turn moves the back of the cup (as it’s taped on it) and makes the air vibrate. As a result, sound is created.

Here’s the video where he teaches how to do it…

Revolutionary – A Simple Yet Much Stronger Artificial Muscle

By Anupum Pant

Background

Some things are just too simple to be noticed by most adults, rather a child would notice it better. Scientists are the ones who manage to hone their ability to  look at things like a child would see it – Children of course are the best scientists. That is what makes scientists different from most other people. And that is what helps them make elegant discoveries, like the one we are seeing here today.

Now, this may seem like a useless thing to some, but in reality the simple fishing line muscle is a huge step towards creating affordable personal robots, exoskeletons and a host of other earth changing devices. I can’t stop thinking how massive this simple thing could end up being.

The Discovery

A team of researchers at the University of Texas at Dallas, did exactly that. In a simple nylon fishing line, these researchers saw something that everyone till date has failed to notice. They noticed that, by twisting a nylon line into a coil (and heat treating), they could turn it into an artificial muscle. Later it was learnt that a simple artificial muscle made in this manner is about 100 times stronger than a human muscle and can go through millions of cycles without failing.

It’s actually so simple to do that you could make an artificial muscle in your own home. In fact, it works with a variety of other kinds of materials too, but better stick to the tested fishing line for now.

All you need to do is to hold one end of a long fishing line and start twisting the other end (a hand mixer could come in handy here). At some point the line reaches a point where it can’t twist any more, and then it starts getting coiled into a telephone wire kind of a spring. Now it can be heated in an oven (carefully, without melting) and cooled to lock it in this coil shape. There, you’ve got your own artificial muscle.

Working

Unlike what you think it would do when heated, the coil actually contracts and can lift a good amount of weight. An array of such artificial muscle fibres could lift a much heavier weight. as shown in the video below.

At first I found it confusing. It was hard for me to understand, what physics goes inside that makes the coil contract as a whole when it is heated. From the words of a wise scienitist, I found that it works like a chinese finger trap (and then I had to look what this piece of origami was). Whatever the coil does is absolutely elegant. It’s almost impossible for me to explain in words how it works. You might have to watch the video below…

The catch is that the nylon muscles made in this manner are very inefficient, but that can be worked upon.