The Science of Sound: Part IV (Conclusion)

In today's final installment of our Science of Sound series, we will specifically explore how sound travels. Have you ever heard someone mention how sound carries more over water? We'll find out why.

Remember, sound waves have to travel in order to be heard. They travel through one of three different ways:

-Through an object (solids)

-Through water (liquids)

-Through air (gas)

Look at the following photo:

Objects that are solid are made up of particles that are very densely packed together. In a liquid, the molecules are more spaced out, and even more so for a gas (or the air).

How close together these particles are directly affect how fast the sound can travel. The closer the particles are to one another, the quicker they "touch" or transmit the message to the next particle. The further they have to travel to bump the next particle, the longer it takes to travel.

Looking at the above photo, which medium do you think carries sound the fastest?

If you said solid, you're correct! If you put your head on a metal railing and someone strikes it with a metal rod, you'd immediately hear the noise, and much louder than is probably even safe for your ears. Sound travels the quickest through solid objects, since the particles are so tightly packed together.

Looking at liquids, they travel the next fastest, and gases the slowest. You can see how spaced out gas particles are, which is why the sound travels slower. Have you ever heard someone tell you to lower your voice over water, or just that sound travels better over water? Compared to where we usually carry out sound (in the air, which is a gas) that's true!

How fast the sound travel through different mediums? Check this out:

If you're more of a visual person (like I am), the following video from the folks at Designmate Pvt. Ltd created a video that helps you see this particle interaction more. I recommend starting at 2:22 in, but feel free to start at the beginning if you want.

Pretty neat stuff. Let's get into something even more interesting. Have you ever seen the MythBusters episode where a singer breaks a glass using just their voice? Check it out:

Speaking of MythBusters, they also did a very short segment where they played with a Rubin's tube. Have you ever wanted to see sound represented by FIRE? Of course you do!

We've covered a lot in the past 4 blog posts. If you missed any of them, just scroll down! With school starting this week for us, I'm going to move to posting every other week instead of every week.

I hope you've enjoyed this 4 part series; this has always been one of my favorite units to cover. Next week, we're going to look at music therapy. Did you know that the parts of the brain that recognize music can't be touched by Alzheimer's? Stayed tuned!

Until next week,

-DMM