Hedy Lamarr and frequency hopping

hedy lamarrWe’ve been learning about radio frequency transmission in sensors class, and today Ari told us about how actress Hedy Lamarr and composer George Antheil came up with the idea of frequency hopping to avoid jamming of radio-controlled torpedoes during WWII. The best part was their idea to use a roll from a player piano, on both the torpedo and transmitter, to change the transmission frequencies. I had fun looking at their patent here.

From http://hypatiamaze.org/h_lamarr/scigrrl.html:

Hedy knew that “guided” torpedos were much more effective hitting a target, a ship at sea for example. The problem was that radio-controlled torpedos could easily be jammed by the enemy. Neither she nor Antheil were scientists, but one afternoon she realized “we’re talking and changing frequencies” all the time. At that moment, the concept of frequency-hopping was born.

Antheil gave Lamarr most of the credit, but he supplied the player piano technique. Using a modified piano roll in both the torpedo and the transmitter, the changing frequencies would always be in synch. A constantly changing frequency cannot be jammed.

They offered their patented device to the U.S. military then at war with Germany and Japan. Their only goal was to stop the Nazis. Unfortunately or predictably, the military establishment did not take them or their novel invention seriously. Their device was never put to use during World War II.

From http://en.wikipedia.org/wiki/Hedy_Lamarr#Frequency-hopped_spread_spectrum_invention:

Lamarr’s frequency-hopping idea served as the basis for modern spread-spectrum communication technology used in devices ranging from cordless telephones to WiFi Internet connections.

Lamarr was awarded by the EFF in 1997 for her contributions to this invention.

May 4, 2007. academics, media lab, music, sound. No Comments.

What’s the sound of one piano dropping?

piano flyerYesterday was MIT‘s “drop date”, the last day during which you can drop classes. MIT’s drop date tradition is, of course, to drop a piano off of the top of Baker House.

I went to this event, expecting a cacophonous crash full of pops and twangs and vibrating strings, and wood splintering everywhere (“Should I be wearing safety goggles?”). And, to my dismay, the piano had no strings (hence, no crazy resonating sounds), and it really just sort of made a simple wood-breaking sound that seemed too short after what seemed like a very long fall. Still, it *was* loud, and was very silly. So I was happy.

Luis took a video of the occasion. And this guy has some great photos from last year’s event.


April 27, 2007. MIT, music. No Comments.

Spectrograms to hide images in music

Spectrograms are pictures of sound over time. People use them to visualize waveforms, often to try to highlight musical relationships or sounds in speech.

Here’s what someone saying “She sells sea shells” looks like (spectrogram on bottom):

she sells sea shells

You can go the other way, too, by drawing a picture in a spectrogram and playing the sound it represents. Several musicians have used this to hide pictures in their albums. In many cases, you’ll hear some weird noise at the end of a track… and when the waveform is put through a spectrum analyzer, you get the picture back.

There are some fairly ridiculous examples of this…

aphex face
Aphex Twin: Windowlicker
NIN: viral marketing
NIN: My Violent Heart
songs about my cats
Venetian Snares: Songs About My Cats

A good description of finding these hidden pictures can be found here: http://www.bastwood.com/aphex.php
…and, of course, there is a Wikipedia section devoted to it.

April 24, 2007. information visualization, music, sound. 1 Comment.

Last.fm widget

Yay!! Ian finished up the first version of the last.fm widget we started working on when he visited in February. This widget allows you to enter in your friends’ (or un-friends’) last.fm usernames, and track what everyone is listening to… sortable by time, artist, and user. As far as I know, there isn’t another last.fm widget out that lets you track multiple users at once.

Here’s what mine looks like right now:

If you’re using Mac OS X 10.4+, go ahead and download the widget. Feedback is much appreciated!

Note: The widget only reloads songs if at least 15 minutes have passed since it last loaded everyone’s songs. To force a reload, just hold down the OPTION key and click in the bottom-left where it usually says “Loading…”.

(My username is dorq, in case you want to see what I’ve been listening to.)

April 23, 2007. computers/programming, music. 2 Comments.

Flaming Lips and Beck in 2002

Tonight in iTunes, I noticed someone sharing an iTunes library by the name of “Lame Crap”, which of course made me click on it. And I found possibly the biggest Flaming Lips fan I’ve ever seen (in iTunes shared libraries). This person had an album called “Live Bass Concert Hall Austin, 11-12-02” by “Beck/Flaming Lips”, and I was like “WTF, what IS this?!” And in the next 30 seconds I learned that Beck asked the Flaming Lips to tour with him as his backup band/opening act for his “Sea Change” record in 2002. The fact that I had no idea this happened really shows how out-of-touch I’ve gotten with music in the last several years :(

As I should have expected, the internet session quickly deteriorated into an all-out Flaming Lips solo fanfest, only the very highest points of which I’ll include here.

Beck, Flaming Lips heat up Texas — “If you haven’t seen Coyne live in concert, then it’s something you need to put on the short list of to-dos. The man, undeniably a genius, looks something like the coolest professor you have ever had, but acts like a five-year-old on stage.”

Beck and the Flaming Lips on how Beck decided to do the 2002 tour:
Beck’s Plan For Keeping Everyone Awake: The Flaming Lips

wayne coyneThis article is notable for its choice of photo for the band (left), and for backing up Beck’s decision to hire “a psychotic carnival like the Flaming Lips”.

The same year, BUDDYHEAD said of the Flaming Lips’ new album:
“These weirdos are tripping balls so hard, they’re singing about pink robots and karate shit.”

A good NPR interview with a warbly Wayne Coyne talking about covering Queen’s “Bohemian Rhapsody”, and then the whole band performing a Sonic Youth/Led Zeppelin cover, and even a nice, super-slow “Yeah Yeah Yeah Song”:
“The Flaming Lips, a Slow-Growing Phenomenon”

March 31, 2007. music. No Comments.

Sky Blue Sky

wilco albumWilco has a new album coming out on May 15. I was lucky enough to hear it today; I really like it.

My friend John was blogged about in Wired yesterday! I considered creating a “corn” category in his honor. But, you know, I can’t do that!

One more thing: my votes paid off.

March 13, 2007. friends, music. No Comments.

Frida Hyvonen can be very entertaining.

Tonight I went to see a show at the MFA. (The MFA!! I had a little Mrs. Basil E. Frankweiler moment…)

The first band was not good. Not horrible, but not good either. Working strongly against them was the fact that not one of the four performers broke a smile during the set, and I’m pretty sure that the bassist was going to go kill himself immediately following the performance. I need some glee, people. ¡F minus, El Perro del Mar!

Then, Frida Hyvönen took the stage, complete with red shawl, paper Starbucks coffee cup, spiral notebook. Very funny, poetic lyrics, beautiful music, perfect timing. I believe she, at one point, rhymed “Cricket cricket cricket” with “It’s sick it’s sick it’s sick.” One of the most entertaining performances I’ve seen in a long time.
+10 for looking like Daryl Hannah in Blade Runner.

The last band: Under Byen. You get a B-:

+5  someone played a saw
+4  cello spiccato rock-out
+2  having a girl bassist
+12 someone played a xylophone
-80 extensive use of strobe light
B-   *total*


March 3, 2007. Boston/Cambridge, music. No Comments.

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