Friday, March 8, 2013

Do You Hear What I Hear?

At today's lab shift at the museum I did some basic demonstrations regarding sound waves. I love learning about such things, so during the small breaks between groups I did some research to enhance the demonstrations. It was a lot of fun striking tuning forks and then dipping the tip in a shallow container of water! (It would spray water everywhere :-D)
The tuning forks looked just like these

One thing I talked about is that sound waves need a medium to travel through, such as air or atmosphere, so in the vacuum of space we wouldn't be able to discern sounds. However, I recalled that there have been recordings made of the sounds the sun makes. So how does the sun generate sound? Well, there are a few processes that make the sounds, one of which is pressure waves created by convection. (If you want to geek out, here are some additional links: http://www.guardian.co.uk/science/2003/jul/24/research.sciencehttp://www.smartplanet.com/blog/thinking-tech/if-we-could-hear-the-sun-what-would-it-sound-like/5401http://www.cora.nwra.com/~werne/eos/text/solar_waves_main.html)
The sun makes a pulsating,  "om" sound. It's meditating!
I even found and played some recordings made of the sun's sound. Here's one that we listened to: http://youtu.be/9URQW_hZ-vo. And some additional recordings: http://youtu.be/GWCJkG31h0chttp://youtu.be/Z2eQPOo95l0

As I was thinking about sound waves and trying to remember back to physics class in college, I wondered what are the differences between sound waves and radio waves? (There's always a kid or two who is really smart and will ask a lot of questions, so I did some quick searching to be prepared.) Though I wasn't asked any brainy questions, I was reminded of the speed in which sound travels, roughly 770 mph (it can vary depending on temperature, etc). If by some chance that the sound of my voice could travel across the country to my sister, it would take about 3 hrs 45 mins for the sound waves to reach her. It's a good thing that sound waves can be converted into an electromagnetic waves (such as a radio wave) which travel at the speed of light, making it seem like it is traveling instantaneously. (If I lived on Mars and called my sister on Earth there would be a lag of about 4 minutes.)

The final part of what I discussed about sound waves is their volume, and we reviewed some very loud noises that we should try to avoid being exposed to, or to use ear protection if we encounter them. I found this list of the Top 10 Loudest Noises. I think there are two more sounds to be added on the list: 1. A cat yowling in your ear at the crack of dawn; 2. Snoring.

1 comment:

~Must Love Dogs~ said...

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Anna