Science

TED Weekends listens to outer space

Posted by: Shirin Samimi-Moore

Honor-HargerHonor Harger isn’t your typical artist. Or your typical astronomer. At the TEDSalon London Spring 2011, Harger shared how she brings these two seemingly unrelated disciplines together — the study of sound and the study of space — to record the songs of planets, moons and quasars.  Honor Harger: A history of the universe in soundHonor Harger: A history of the universe in soundHer talk is called “A history of the universe in sound,” and it is simply a must-see.

Today’s TED Weekends on the Huffington Post explores the soundtrack of our universe, featuring essays from Harger and others. Below, find excerpts from three for your reading pleasure.

Honor Harger: Tuning Into the Universe

Images of space are ubiquitous in our lives. We have been surrounded by stunning portrayals of our own solar system and beyond for generations. But in popular culture, we have no sense of what space sounds like. And indeed, most people associate space with silence.

There are, of course, perfectly valid scientific reasons for assuming so. Space is a vacuum. But through radio, we can listen to the Sun’s fizzling solar flares, the roaring waves and spitting fire of Jupiter’s stormy interactions with its moon Io, pulsars’ metronomic beats, or the eerie melodic shimmer of a whistler in the magnetosphere. Read the full essay »

Mario Livio: What Is the Color of the Universe?

Honor Harger’s TED Talk is on radio astronomy, or, in some sense, the “sound” of the universe (even though radio waves are really electromagnetic radiation, just like light). Can we, however, say what the color of the universe is? To answer this question, we must first establish what we actually mean by the “color of the universe.” A reasonable definition would be to add up all the visible radiation emitted by a very large number of galaxies in a huge cosmic volume, and to determine how all of that light might be perceived by the human eye. This is precisely what astronomers Karl Glazebrook and Ivan Baldry attempted to do in 2002. Using a survey of more than 200,000 galaxies (the “2dF Galaxy Redshift Survey”) and reaching to distances of a few billion light-years, they constructed the distribution of the colors (the spectrum) the eye would see if all that light were to be separated into its components by passing it through a prism.

Since our universe is expanding, light from distant galaxies is stretched to longer (redder) wavelengths (a phenomenon known as redshift). The farther away the galaxy, the greater the amount of stretching that occurs. Glazebrook and Baldry removed this effect before combining all the light to form a smoothed-out average color. Read the full essay »

Seth Shostak: Celestial Sound Effects

Remember the tag line for the 1979 sci-fi flick Alien? It was boldly emblazoned on the film’s advertising posters, and helpfully informed the public that “in space, no one can hear you scream.”

Well, of course that’s true; at least if you’re floating around without your protective helmet and its built-in walkie-talkie. But then again if you’re bare-headed in space, the fact that no one can hear the noises you’re making is scarcely your biggest problem.

Nonetheless, there’s a widespread perception that space — which after all, is mostly air-free — is as silent as the shadows. Read the full essay »

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