They Might Be Giants - Here Comes Science

I am not musically trained but I did find a CD that I would like to comment on. They Might Be Giants (tmbg) is a band that does some creative no conventional music. I have enjoyed their previous albums but this is the first educational one that I have listened to (they have done 3 previous ones).

This is "Here Comes Science". It is a combination of CD and DVD. I have not watched the DVD but the CD is very cleaver. With songs like "I am a Paleontologist", "Roy G. Biv", and "Solid Liquid Gas" they are covering physics, scientific theory, biology, and other branches of science.

The songs are short enough for children and the music is catchy. The lyrics are easy to sing along with. I think that children from 3 to 10 would enjoy this.

As a devout Christian I do need to let you know that there are two songs that each person needs to decide for themselves if it is right for their children. The songs are "Science is Real" and "My Bother the Ape" The first talks about the Big Bang being real and the second refers to the relation between animals in the animal kingdom. I personally did not find it to be offensive and would use them as a teaching opportunity about science and religion. (that I will save for another posting).

I also really appreciated that they did a pair of songs that help stimulate conversation about how science has changed as new things are learned. "Why Does the Sun Shine?" and "Why does the Sun Really Shine?". These songs indicate that we had one theory and fact to support it but as more study reveiled new facts the theory changed.

I would recommend this CD for anyone who wants to share some fun songs about science.

Speed of Sound

Does the speed of sound change with elevation?

Yes it does is the short answer but because I learned from my father that is never the way to answer here are the details.

The basic formula for finding the speed of sound is:

• R (287.05 J/(kg·K) for air) is the gas constant for air
• κ (kappa) is the adiabatic index (1.402 for air)
  
• T is the absolute temperature in kelvins

As can be seen by this the only thing that changes is temperature. As the temperature is lower the speed of sound is slower. This is the primary reason that sound is slower at higher elevations, the air is cooler there.

Just some examples the speed of sound at sea level is about 760 miles per hour and it is about 660 miles for an airplane.

Now what about sound through a solid object?

The stiffness and density of the material will affect the speed. Stiffness will will increase the speed and density will slow it down. This can make the calculations complicated. Here is the basic formula used to calculate the speed through solid materials:

C is a coefficient of stiffness

ρ is the density

There are other variations of this formula to calculate for liquids and gases.

Most of the information for this post was obtained from:

http://en.wikibooks.org/wiki/Acoustics/Sound_Speed

http://www.engineeringtoolbox.com/speed-sound-d_82.html

There is also a great slide show that has some examples and video of sound and speed: http://www.slideshare.net/darrella/speed-of-sound

Please post comments if you want clarification about any information in this posting or have any comments or questions.

Keep exploring your world.