Wednesday, June 23, 2010

Visitors from Manhattan East School

Today, we had a visit from the Astronomy Club of Manhattan East for the Arts and Academics in East Harlem, NY. A few of the graduate students presented several interactive activities for the club, including a solar-system walk, solar observing, an observatory tour, and a 3D flight through the Universe. In addition, we fielded several questions they had about astronomy, physics, science and college life. They were a great group of kids, and we were happy to have them here!

Thanks to all 15 of our visitors and the 4 volunteers who put this on.


Monday, June 21, 2010

Time Machine: June 18

The free screening of H.G. Wells classic tale “The Time Machine” (1960) drew around 45 viewers this Friday. Following this movie, graduate student Jennifer Weston led a discussion about the film with the audience, and talked about some of the implications of time travel and the ideas behind it.

Some of the topics covered included: Discussing what humans will be like in 800,000 years, with a review of how we’ve changed in the past 800,000 years. We concluded that while the human race could potentially split into two very different species, our time traveler would NOT be able to speak perfect English with them.

How to resolve the apparent paradoxes of time travel. Multiple time lines and predestination were thought to be some possible ways to prevent paradoxes when you attempt to kill your own grandfather. We also introduced the concept of closed time-like curves.

After this, we had an overview of the physics of traveling through time. We reviewed some of the background for Special and General Relativity, light cones, and black holes. Finally, we outlined how one might build a time machine with wormholes and cosmic strings.

Following the movie, telescopes were set up outside on College Walk, manned by a number of students. Passersby were able to see close up views of the beautiful quarter moon, and the planets Mars, Venus, and Saturn, and the stars Arcturus, Mizar and Alcor. Over the course of a bit more than an hour, about 90 people came by to take advantage of the clear night. Thanks to everyone who attended and to those who volunteered!

Saturday, June 5, 2010

From Physics 101 to Pigeons

Around 60 people attended our first event of the summer -- a free screening of The Core. Afterwards graduate student Lia Corrales guided the audience in a discussion around two major topics:

(1) Where does the earth’s electromagnetic field come from?
We reviewed the “Physics 101” of generating magnetic fields. We debunked the idea that simple rotation generates the earth’s magnetic field, and explained how much energy it would take to ‘stop’ or ‘reverse’ the rotation. We reviewed some of the scientific research showing that the earth’s magnetic field can have a complicated interior, can change over time, and occasionally switches polarity.

(2) What effect does the electromagnetic field have on life?
We discussed what solar wind does and does not contain, as referenced in the film. The highlight of the evening was the discussion centered on pigeons! We reviewed the scientific article showing that pigeons could sense magnetic fields. However, we also learned that pigeons used landmarks like roads to navigate. We concluded that a change in the earth’s magnetic field would not be enough to disorient pigeons into a kamikaze death dive, but would be enough to force them to ask for directions on the way home.

Unfortunately, the cloudy sky prevented telescope viewing for the night. Fortunately, the summer series of events got off to a great start, thanks to all the people who attended and our five volunteers!