A blog explaining science and technology through the movies ... or explaining the movies through science and technology, depending on the point of view. English is not my first language, so I apologize for the mistakes you are likely to find in the posts

Saturday, October 28, 2006

Jodie Foster's contacts

Contact (1997) is an unusual extraterrestrial movie for several reasons. First, it doesn't judge the main character, played by Jodie Foster, for being a feisty single woman with no kids. She doesn’t have a romantic affair in the movie either, and what is even worse, she is an atheist. Apart from that, we’re talking about the adaptation of a best-seller from Carl Sagan, one of the most important writers in the popularization of science. Therefore, the subject is dealt in quite serious terms, far away from good men from Mars or bad men from Mars invading Earth movies.

The contact with extraterrestrials about which this Robert Zemeckis movie talks about is inspired by a real event that took place in 1967: a young Irish woman working on her doctorate in Physics noticed a sign on her radiotelescope. It was repeated in very short and extraordinarily regular time laps, a sort of heartbeat coming from somewhere in space. Any possible terrestrial source for that sign, such as radio hams, radiotaxis, etc. was studied until certainty of the fact that it came from out of our planet was reached. The young woman, named Jocelyn Bell, believed for some time that she had got in touch with extraterrestrial civilizations, until she found out another sign, identical to the previous one, which had its origin somewhere else in the galaxy. Were two extraterrestrials civilizations sending the same sign at the same moment in the same direction?

The Carl Sagan book and the Zemeckis film dealt with the attractive possibility of Jocelyn actually getting in touch with intelligent beings from out of the Earth, but prosaic scientific logic stated that they were pulsating stars or pulsars, something unknown until that moment. This discovery meant a Nobel prize, not for Jocelyn but, as it is usual, for her work’s supervisor.

What are these pulsars and how are they created? Stars, like the sun, stay alive because fusion of hydrogen nuclei into helium is constantly taking place inside them. The heat coming from the sun and allowing life on the Earth comes from the energy generated in these reactions. What happens when combustible material runs out and fusion doesn’t take place anymore? Nothing can thwart the star’s gravitational force then, so it collapses and implodes into its centre: this phenomenon is known as a supernova. The gravitational force reduces all the star’s volume into a tiny hiperdense nucleus spinning at great speed. Its huge gravitational field produces a magnetic field causing radiation noticed by Jocelyn: this is a pulsar. If a pulsar’s density gets even higher, then a black hole is created: this is a subject it would be worth discussing in greater detail on another occasion.


At 3:46 pm, Blogger Patrick Roberts said...

Contact reminds me a lot of an earlier sci-fi flick, The Abyss starring Ed Harris... both main characters meet the aliens face to face at the end.


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