The Spooktacular Sounds of Halloween

By Cassie Martin
BU News Service

The staples of any good Halloween are candy, cobwebs, skeletons and other scary creatures, and of course the eerie music of the theremin–the world’s strangest and spookiest musical instrument that has produced the signature sounds of this frightful holiday for decades. The instrument itself may as well be a ghost; you can see it, you can hear it, but you can’t touch a theremin.

The device is named after it’s creator, Russian scientist and KGB spy Leon Theremin. 
In 1919, Theremin was working in a lab on a gas density meter when one day he brought his hand close to the meter and heard a high-pitched squeal. As he moved his hand away from the meter, the pitch became lower. Intrigued, he began playing with the machine creating melodies. Based on this discovery, Theremin created a free-standing musical instrument which debuted in the U.S. in 1928. 

The theremin isn’t a gas density meter, but a circuit that uses the heterodyne principle–combining two or more frequencies to create a new frequency–to generate audio signals. The instrument has two metal antennas which sense the position of the performer’s (called a thereminist) hands relative to two oscillators: one that controls pitch and the other that controls frequency. Instead of plucking on strings, the thereminist waves his or her hands through invisible electromagnetic fields to create music.

Although the instrument didn’t catch on as it was difficult to play, it’s creepy out-of-this-world sound was perfect for the Hollywood horror genre and for psychedelic rock of the 1960’s and 70’s. Its music was featured in a range of films from sci-fi thrillers such as The Day the Earth Stood Still (1951) to Alfred Hitchcock’s Spellbound (1945). The legendary rock band Led Zeppelin also sampled the instrument in performances of Whole Lotta Love and No Quarter. 

Sounds of theremin can still be heard today. While it’s a hallmark of the halloween music played in haunted houses, a few dedicated thereminists have made it their profession. And even though you might not follow this niche crowd, if you listen to electronic music then you’re listening to the legacy of Leon Theremin.

But whatever happened to the man behind the machine? Well, after the successful debut of his instrument in the U.S., Theremin abruptly disappeared for 30 years only to re-emerge in 1991, a few years before his death. Some people speculate he was kidnapped by the KGB while others think he fled back behind the Iron Curtain to escape his crushing debt. His life remains a mystery.

Harvard/MIT Scientists Invent Light Sabers…Basically.

By Cassie Martin
BU News Service

Hold on to your seats, Star Wars fans, because what I’m about to tell you is seriously cool. Scientists from Harvard and MIT have created a new form of matter that they are comparing to light sabers.

One of the lead researchers behind this discovery, Harvard Physicist Mikhail Lukin, said in a written statement “The physics of what’s happening in these molecules is similar to what we see in the movies.” Excuse me while my inner nerd jumps up and down with joy.

Toy versions of Luke Skywalker and Darth Vader battle in this recreated scene from Star Wars: Return of the Jedi. Photo courtesy of JD Hancock, Flickr Creative Commons.
Toy versions of Luke Skywalker and Darth Vader battle in this recreated scene from Star Wars: Return of the Jedi. Photo courtesy of JD Hancock, Flickr Creative Commons.

But what is happening, exactly?

Essentially, the researchers created an environment where mass-less photons (light particles) interact so strongly with one another that they act as though they have mass and bind together, forming molecules. But Lukin and his colleagues didn’t use the force to bind the photons together. No, they needed something more substantial.

The researchers pumped a rubidium (highly reactive metal) atom cloud into a vacuum, cooled it to just above absolute-zero, and fired two photons into the cloud using a weak laser. The photons emerged from the cloud stuck together thanks to what’s called the Rydberg blockade — an effect where one photon has to pass off its energy to an atom and move forward before a second photon can excite other nearby atoms. This results in the two photons pushing and pulling each other through the cloud, Lukin explained. “…when they exit the medium they’re much more likely to do so together than as single photons,” he said. The research was published in Nature online September, 25.

No word yet on the creation of real light sabers (one can only hope), but there are potential practical applications for this new discovery including quantum computing and the formation of 3-D structures completely out of light.

Food Physics: Dessert Edition

By Cassie Martin

It’s that time of year again, readers! Every week from September through December, hundreds of people line the halls of Harvard University eagerly waiting to get their hands on one of the hottest tickets in town and a chance to sample some truly delectable creations. If you love food and are even mildly interested in science, then Harvard’s free lecture series, Science + Cooking: From Haute Cuisine to the Science of Soft Matter, is the place to be.

Last night’s lecture featured Bill Yosses, the White House pastry chef and frequent contributor to the series. He kicked-off the night with a Youtube video of two Tesla coils playing House of the Rising Sun. At first I thought it was a techno cover until I saw the bolts of electricity flash across the screen. “Oh, this is gonna be good,” I thought.

Yosses presented the concept of elasticity and how it informs the texture and flavor of desserts to make for an incredible dining experience. The first half of the lecture felt like a high school physics class. We watched cool, old-timey gadgets build up and discharge static electricity; we watched Yosses bend the glowing green ray inside of a cathode ray tube with a magnetic field; we brushed up on surface tension; and we picked up some cool science history facts along the way. 

Did you know that Benjamin Franklin used one of the gadgets–called a Leyden jar–in his infamous kite experiment? Neither did I. Franklin’s portrait is also the only portrait in the White House not of a president or first lady.

White House Pasty Chef Bill Yosses teaches the crowd about electricity and magnetism. He uses these concepts to create intricate desserts. Photo courtesy of Cassie Martin.
White House Pasty Chef Bill Yosses teaches the crowd about electricity and magnetism. He uses these concepts to create intricate desserts. A Leyden jar can also be seen in the foreground. Photo courtesy of Cassie Martin.

After a quick overview of the science, the demonstrations began. Yosses’ demos covered some building blocks of desserts including foam, gel, and sugar–here are the coolest ones:

Peaches are one of my favorite fruits, so when he brought out peach puree to make foam I was excited, hoping I would get to taste it. Foam is a congregation of bubbles held together by surface tension and electrical charge that builds up between between the molecules. Immersion blenders are generally used to beat air into liquids, which releases more flavor molecules, according to Yosses. At one point, he pulled out a metal container brimming with fog. Liquid nitrogen is used by chefs to manipulate surface tension to get the right consistency (without adding unhealthy ingredients such as butter or oil) and preserve the flavor of food. It has a much lower boiling point than water, so it requires less energy to disrupt bonds which means that fewer flavor molecules are lost to heat. 

For one of the gel demos, which demonstrated bond formation and the cross-linking of molecules, he dipped a spoonful of hibiscus sauce into a mixture of water and a gelling agent (I’m unsure of it’s name). The gelling agent bound to the sauce, forming a skin around the outside. “It’s like an egg yolk, still liquid in the middle,” he said. After a few minutes, he scooped out a purple ball and added it to the plate of desserts.

Yosses ended the evening sculpting, but it looked more like glass-blowing. Under a red heat lamp sat a blob of sugar stuck between liquid and solid phases. Chefs commonly refer this as glass–the sugar is malleable, has a shiny quality, and becomes very brittle once it cools. Initial heating to 320 degrees Fahrenheit disrupts the crystalline structure resulting in a soft consistency, but the structure reforms upon cooling. Yosses carefully stretched the ball of sugar, wrapping small strands around a plastic stick. When he removed the wrapped strands of sugar from under the heat lamp, he was left with a hardened sugar coil which was promptly added to the dessert plate.

A plate of sugar and gelatin based desserts made by manipulating their molecular structure. Photo courtesy of Cassie Martin.
A plate of sugar and gelatin based desserts made by manipulating their molecular structure. Photo courtesy of Cassie Martin.

The Take Away:

Molecular gastronomy is giving chefs new tools and re-purposing old ones to make food better–not just by improving how a dessert looks or tastes, but it’s healthfulness too. Manipulating food at the molecular level makes it possible to achieve the same textures and flavors without adding notoriously unhealthy ingredients such as butter, oil, and fat. Yosses hopes his legacy will be known for “including desserts as part of a healthy diet, restoring food as a pleasurable experience, and preserving flavor,” he said.

The Critique:

The lecture was fun and informative. I learned something new and I sampled cocoa beans and fruit gel–can’t get much better than that. The one criticism I have is that there were a few times where I was unsure of how the science applied to his cooking techniques. I wish he would have explained the science alongside his demos instead of separating the two, so I could get a better understanding of what I was watching.

Tuning Jordan Hall

March 29, 2013 -- A piano tuner adjusts the piano at Jordan Hall at the New England Conservatory in preparation for a concert that evening. Photo by Poncie Rutsch.
March 29, 2013 — A piano tuner adjusts the piano at Jordan Hall at the New England Conservatory in preparation for a concert that evening. Photo by Poncie Rutsch.

by Poncie Rutsch
BU News Service

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The faint scent of varnish and dusty carpets greets me when I enter Jordan Hall at the prestigious New England Conservatory on a Friday morning. I carefully lower myself into a chair nestled snugly into a curved row, wondering how the narrow rows can accommodate several hundred people hunting for their seats. The chamber orchestra, comprised of about fifteen students, is rehearsing Honegger’s Symphony Number 2. The deep reds, greens, and golds in the hall reflect the mournful midtones and Honegger’s dark outlook on World War II, when he worked with the French Resistance.

First the violins play an agonizing escape upwards. Short notes ring in the domed ceiling because of their high pitch. The cellos and basses pulse forward as if a cyclone formed within the rounded walls. The storm reaches a feverish whirling, and then comes a release. The rhythm starts to slow as each part plays a countermelody. Finally the violas and cellos pick up the orchestra, humming the melody slowly, as if seeking solace from the cyclone.

Every so often, the players stop to critique one another. A chamber orchestra functions like a large quartet: the group has to communicate through eye contact and cues rather than taking the beat from a conductor’s hand movements. Palma guides the rehearsal, but mostly stands amongst the seats and lets these aspiring professionals take the lead.

The warbled echoes off the hall’s walls are louder than the sound directly from the students’ mouths; from the back row, I can’t understand the students’ garbled voices. I am the only body in the audience this morning, which means the sound ricochets more than usual. Filling the hall with bodies absorbs more direct sound, reducing the sound waves reverberating off the walls.

Jordan Hall appears globe-shaped, with panels arcing high overheard and a thousand chairs arranged in horseshoe-shaped rows. The balcony forms a perfect half circle, with the stage at its diameter. The floor of the hall slopes toward the stage, so that each individual seat has an intimate, unobstructed view. The stage floor is angled at audience, almost like a teacher leaning in to advise her pupils.

March 29, 2013 -- Seats curve around Jordan Hall, making the space feel small and intimate. Photo by Poncie Rutsch
March 29, 2013 — Seats curve around Jordan Hall, making the space feel small and intimate. Photo by Poncie Rutsch

Yet the room doesn’t sound like the inside of a globe; curved walls would focus the sound at one seat and throw every other into chaos. Like a lens in a pair of glasses focuses a blurred image at one point inside the eye, a curved wall can both focus and distort music, depending on the location of one’s ear. At the focal point, the music would sound extra loud and perfectly balanced. But all other points would sound unbalanced because the high notes and low notes would reach the listener at different times and volumes. A closer look reveals that only the back wall of the hall is curved.

A perfectly flat surface reflects sound too quickly, making it sharp and harsh. This is why many halls are covered in panels of different sizes; they reflect the music without making it echo like an empty hallway. A panel will reflect only the pitches with wavelengths that are multiples of the panel’s size. Larger panels reflect deeper sounds, while smaller panels reflect higher pitched sounds. Too many same-sized panels placed adjacently will distort the sound, so the ceiling of the hall looks more like a stack of uneven tiles than a geodesic dome.

Every hall can be tuned, just like the instruments on the stage. Many stages have a canopy that can be lowered to dampen the sound or raised to amplify it. The designers of Jordan Hall covered the curved rear wall in a layer of felt because the audience complained the hall sounded too bright after a 1995 renovation.

The Boston Symphony Orchestra played Jordan Hall’s inaugural concert on October 20th, 1903, but hasn’t frequented the establishment much since then. The large orchestra sound overwhelms the small hall, while the shoebox shaped Symphony Hall makes their sound broad and full. At the time that Jordan Hall was constructed, the New England Conservatory was essentially a finishing school, training young women in piano and voice. Jordan Hall was their recital hall, perfect for soloists and small groups. Many esteemed European soloists would stop in Boston on their way to Carnegie Hall, and would choose Jordan over Symphony Hall for its intimacy and robust solo performance sound.

The chamber orchestra completes its rehearsal, and then a tour group comes in, begging their guide to sing for them. He waffles, unsure whether to accept the compliment and sing or to modestly keep quiet. He finally concedes, straightens his shoulders, and fills the hall with a few swelling tenor lines.

When he finishes and herds his group out of the hall once more, there’s a momentary silence. Then the piano tuner comes in to massage the keys for tonight’s performance, and the hall is filled once more with the chromatics of careful tuning.