Jump to content

Eigenfrequencies... Huh?


Recommended Posts

So I finally got a day off yesterday and for some odd reason started skimming through my copy of Standard Mathematical Tables and Formulae [Zwillinger]. I'll be the first to admit that I'm no mathematician. I usually don't have the patience (or interest) to sort through all the formalized symbolism so there is a lot of stuff in there I don't understand. But when I ran across this bit of explanation about eigenfrequencies the only thought I could muster was, "uh.... what?"

post-7603-0-98261700-1314027684_thumb.pn

Link to post
Share on other sites

Not sure I'll be able to make that clear, but when you hit a drum, a bell (or any object actually), it emits a sound composed of a series of frequencies which are the eigenfrequencies. Those frequencies depends on many things like the material the object is made of or its shape. (That's why a small bell sounds differently than a large one). Now, there is no unique dependence between shape and frequency: 2 different shapes can produce the same sounds. And I guess that's waht your book tried to say by "you cannot hear the shape of a drum". (although you could hear if it is broken or not by looking at harmonics, but I won't go there).

hope that's help...

  • Like 1
Link to post
Share on other sites

That sounds reasonable. It seems odd the book just made the statement without any explanation, unless that methphor is commonly used when teaching eigenfrequencies?

Link to post
Share on other sites

Having read your post before pylb gave an explanation, the concept made sense but I doubt could have explained it as well as he did. That, and I assumed what I was thinking was too simple ;)

Link to post
Share on other sites

Considering that my math skills are roughly those of a 5th grader, I wanted to know where it came from. This wikipedia entry has the history and some details...

http://en.wikipedia.org/wiki/Hearing_the_shape_of_a_drum

This begs the question, can I smell the color of a fruit?

  • Like 1
Link to post
Share on other sites
This begs the question, can I smell the color of a fruit?

Only as well as you can taste it :D

Extended into the physical/philosophical world, the idea is the same: armed with the knowledge of only the destination, one cannot know the path of the journey. Therefore, the ends may, or may not, justify the means.

Link to post
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

×
×
  • Create New...

Important Information

By using this site, you agree to our Terms of Use.