Wednesday, December 8, 2010

Foundation Of SETI Research

In year 1959, Philip Morrison and Giuseppe Cocconi were physicists atCornell University. They were both, very interested in gamma rays. "One spring day in 1959," said Morrison, "my ingenious friend Giuseppe Cocconicame into my office and posed an unlikely question: would not gamma rays, he asked, be the very medium of communication between the stars?" Morrisondid agreed suggesting them to consider entire electromagnetic spectrum for possibility.  

Dr. Philip Morrison

The Image above of Dr. Philip Morrison was taken in the month of September, 1959 Morrison and Cocconi published a short article with heading-“Searching for Interstellar Communications”. In this article they admitted that it is impossible to estimate the probability of the existence of any alien civilization on any distant planet orbiting some star. They believed that if the alien race is more technologically advanced in our comparison, then they will surely try to make contact. But the question that was killing them was the way of communication that the alien race would choose.

On long argument Morrison and Cocconi came to the conclusion, that the aliens should use electromagnetic waves like the radio waves and the light waves for communication with us.
After this, they moved to the second critical question which was regarding the frequency at which the aliens should transmit their signals.
Morrison and Cocconi argued that the most rational frequencies for the communication between the stars were between 1 and 10,000 MHz. At these frequencies the interference of planetary atmosphere interferenceis minimum with the electromagnetic signals.
Frequency range of 10,000 MHz was still very wide for conducting any systematic search. As a result Morrison and Cocconi therefore guessed that the aliens would most probably use the frequency of 1420 MHz as this is the emission frequency of the most common element in the universe-Hydrogen.
Thereafter, another great observation was made on the Doppler shift. It was stated that the signal sent from the aliens planet to our planet will necessarily drift from its actual frequency as a result of Doppler shift. Since the planets are not moving at relatively constant speed, therefore, the frequency of transmission will definitely drift over time. Therefore, the search for alien signal begun taking this deviation into account. 

Check These:
IndiaHistory of India

No comments:

Post a Comment

Add This