Archive for the ‘astronomy’ Category

Scientist Brian Greene Transforms Greek Myth Into Physics Folklore


Supermassive Black Hole

An artist’s interpretation of a supermassive black hole. (Credit: Alfred Kamajian/Goddard Space Flight Center)

by Joseph Caputo

With waxen wings, young Icarus took off from the island of Crete and into the sky. Charged by the feeling of flight, he ignored his father’s warnings and soared higher and higher towards the stars. Flapping hard, Icarus soon flew so near to the sun that his wings melted. As he crashed into the water below, he became another tragic figure in Greek mythology.

This story always troubled scientist Brian Greene. “Here is a young boy who goes against what his father says and pays the ultimate penalty,” he told a crowd gathered at the Brattle Theatre in Harvard Square Tuesday night.  For Greene, this moral is completely antithetical to scientific investigation, which is about challenging the established order.

There is a bit of Icarus in Greene as well. The Columbia University professor and well-known string theorist is a maverick in the particle physics community for his desire to bring the mathematics of time and space to mass audiences. He has authored two popular science books, “The Fabric of the Cosmos” and “The Elegant Universe,” which later became a PBS documentary starring Greene. At his Tuesday-night talk, sponsored by Harvard Book Store,  Greene promoted his latest and riskiest work, “Icarus at the Edge of Time,” a graphic-heavy, fictional science story aimed at both adults and children.

Greene’s version of the Icarus tale is a futurist vision that rewards curiosity, one that he calls “much closer to the experience of science.” The reader is introduced to Icarus, a young astronaut born on a spaceship, on route to an alien planet he will never see. The entirety of his life is to be spent traveling and he passes the days learning about space and life on Earth.  Along the journey, his ship passes a nearby black hole, and Icarus is overcome by the desire to go to its edge.  Although his father warns him against it, Icarus eventually feeds his curiosity. The outcome is both tragic and satisfying, an excellent metaphor for scientific investigation.

The book contains a considerable amount of scientific fact about black holes, but the storytelling element drives the reader along. “For so many people, science is the material that sits between the two covers of a textbook,” Greene says. He calls this a shame, “because science is one of the most wonderful adventure stories.” This is a true and fascinating statement, especially since it is is made by a string theorist.  The power of Greek mythology to teach a lesson is much greater than a detail-laden science lesson. In this respect, “Icarus at the Edge of Time,” is an unconventional textbook, one that should be read by physics students from elementary age to graduate school.

Posted by Joseph, under astronomy  |  Date: September 17, 2008

MetroLAB: Eavesdropping on the Dark Ages



Artist’s conception of the Dark Ages Lunar Interferometer, with a simulated sky showing what it will observe. Credit: Naval Research Laboratory

Scientists and engineers selected by NASA are designing a radio telescope destined for the far side of the Moon. The telescope will listen for echos from the “Dark Ages,” the period of time before the formation of the stars. The challenge for the team, made up of representatives from the Naval Research Laboratory and Harvard-Smithsonian Center for Astrophysics, is designing a telescope that can cope with the conditions on the Moon. Eva Zadeh has the story:

Audio clip: Adobe Flash Player (version 6 or above) is required to play this audio clip. You also need to have JavaScript enabled in your browser.

For a transcript of this story, click here.

This is the first episode of MetroLAB with Eva Zadeh: A series of short audio pieces that will drag you inside the labs of the Boston area. You’ll lean about the experiments upon which scientists scratch their heads, and the questions they still need to answer in the fields ranging from neurosciences to particle physics.

Posted by Joseph, under astronomy, audio, MetroLAB  |  Date: April 18, 2008
1 Comment »

News to Watch: Mercury’s Tail



If you’re lucky enough to see a comet whiz through the night sky, you’re likely to notice the trail of rock, dust and ice it leaves behind. But did you know bigger solar bodies, including Jupiter, the Earth’s moon and Mercury, also leave evidence of their movements through space?

To understand how these tails fit into the clockwork of our galaxy, scientists at Boston University’s Center for Space Physics have spent the past decade developing instruments and techniques to observe the planet closest to our sun.

Earlier this month the group published photographs of Mercury’s tail, already known to extend up to 25,000 miles off its surface, going as far as 1.5 million miles. According to the press release, that is 1,500 times the radius of the planet.

The figure above [credit: The Center for Space Physics, Boston University] shows Mercury’s tail captured by a wide-angle telescope. Since Mercury is close to the Sun, sodium atoms that escape the surface are pushed away from the planet by the pressure of light and form the tail. The bottom right corner of the figure is highlighting the regions of Mercury where the sodium comes from, mostly the high latitudes. Dr. Baumgardner, one of the paper’s co-authors, says there are probably other atoms in the tail, but because of their spectral lines they are not as easy to detect.

Because Mercury is never very far from the sun, getting a glimpse of the tail from Earth can be difficult. The 1.5 million mile tail has only been observed a few times since its initial discovery, raising the question of whether it is permanent or a snapshot of many possible lengths.

The answer lies in the mechanism behind what creates the sodium dust. It’s still unknown but competing theories say they are either the result of solar winds, micrometeorites or magnetic fields. Once Messenger, the NASA spacecraft sent to study Mercury, goes into orbit around the planet in 2011, there may be some definitive evidence.

Dr. Baumgardner and his colleagues are part of the International Mercury Watch, a collaboration of scientists in France, Italy, Japan and the United States who coordinate their efforts to cover as much of Mercury as possible. For more information on their work to reveal the mysteries of the night sky, check out Boston University’s Imaging Science Website.

Paper Source:Baumgardner, J., Wilson, J. and M. Mendillo. (2008) Imaging the sources and full extent of the sodium tail of the planet Mercury. Geophysical Research Letters. v. 35 (doi: 10.1029/2007GL032337)

— Photo by The Center for Space Physics, Boston University

Posted by Joseph, under astronomy, news  |  Date: February 7, 2008
No Comments »

Stars Over Boston


On the first Saturday of every month, the Boston Globe publishes “Star Watch” by Alan M. MacRobert, senior editor of Sky & Telescope Magazine. In each column, he colorfully alerts Bostonians to the constellations or cosmological oddities in view over the coming weeks. (Whether or not you can see them over the light or smog is another issue.)In this month’s entry, “Look south to see winter’s brightest constellations,” MacRobert discusses the Dog Star Sirius located in Canis Minor, which along with Canis Major follows the Hunter Orion. Although it makes for a strong visual, unless you’re a serious stargazer, it is difficult to pinpoint key stars like Sriuius or Procyon in a sea of commoners.

For a little help, online star charts for local areas do exist, but not in the quantity one might expect. The one I used to help me pinpoint Orion, pictured above, was provided by Weather Underground. If you’re in the United States, the site generates a star map based on zip code, date and hour. From there you can customize whether to reveal star names, constellations or planets. Although there is an option for more info, wikipedia is probably your best immediate source if you want to learn about Coma Berenices for example.

Each of MacRobert’s columns includes a small history lesson about the sight of the month. After discussing the Dog Star for instance, he tells the story of a Cambridge telescope maker who discovered the Pup, a duller star following Sirius because of gravitational pull. In MacRobert’s November column about Comet Holmes, he includes a bit about previous comets that burst.

If you’re a Boston/Cambridge resident interested in taking stargazing up as a hobby, a good place to start or for advice would be the Harvard-Smithsonian Center for Astrophysics. They hold regular events for the public and are always up to day on interesting sky events. (Don’t forget to check out the lunar eclipse on Feb. 20).

Don’t miss the lunar eclipse above Boston on February 20.

Posted by Joseph, under astronomy  |  Date: February 2, 2008
No Comments »