Buzz Blog

PODCAST:The Physics of Vinyl (and other records)

Wednesday, June 12, 2013
This week on the Physics Central Podcast we're talking about the physics of vinyl records. How do records record sound, and why can't you make a record out of wood or ice or some other material? (A: You CAN! It just might not sound very good!).




One of my favorite bands, the Swedish-based Shout Out Louds, recently released a new album, featuring a song called "Blue Ice." The song is about "fading devotion." As part of their publicity efforts to promote the album, the band sent 10 lucky individuals a kit that allowed them to create a record of the new song out of ice. Here's a video showing how to make an ice record (you need a pre-stamped mold), and a recording of the final product (not great, but still awesome):




In this week's podcast we'll talk about why an ice record sounds so noisy compared to a vinyl record. Even though the sound quality of the ice record isn't great, it demonstrates the fundamental principle behind LP's: any material can serve as a record, as long as it can hold the imprint of a sound wave.

Image of a record groove, captured by Chris Supranowitz, an optics researcher at the University of Rochester.
Various materials will do this better than others. Vinyl not only holds the imprint of the sound wave well, it's also cheap and durable. People in the former Soviet Union made records out of discarded X-ray film (they played well, but didn't last long). Engineer Amanda Ghasshaei (who has a B.S. in physics) made records out of wood, acrylic and paper. Here's David Bowie's Rebel Rebel on wood:


Like the ice record, these records have a lot of accompanying noise. In addition, they're likely to damage the needle on a record player over time. But the process is interesting. Ghasshaei used a laser cutter to carve the grooves into the wood, and she shares instructions on how you can make your own (assuming you have access to the right tools). She's also printed records with a 3D printer; they also don't sound great. But, perhaps this is a starting point to improve these methods of record production. In the same way that book publishers now have print-on-demand options for rare or out-of-print books, perhaps record producers will one day use 3D printers or laser cutters to create single copy LP's.

Listen to this week's podcast (and subscribe via iTunes!) for more about the science of sound and vinyl!

Additional:
You can listen to samples of different sound wave shapes (square, triangle, sawtooth) here.
Posted by Agent Utah