Saturday, April 25, 2009

Decoding the Heavens: A 2000 year old computer and the century long search to discover its secrets

by Jo Marchant

Deciphering the Antikythera Mechanism

Most people would not have heard of the Antikythera Mechanism - it is a 2000 year old device which was discovered in 1900 in an ancient ship wreck close to the island of Antikythera between Cape Malea and Crete in the Mediterranean. The device was so much damaged and in many fragments of corroded lumps that it could be fully deciphered only recently using the latest microfocus X-ray imaging and computed tomography (CT). We now understand that it was meant to be used as complex scientific calculator (or an analog computer) for calculating astronomical positions.

In a fascinating story written more like a detective novel, Jo Marchant takes us through the discovery of this device from the ship wreck by sponge divers, the early futile attempts in figuring out what the device was, the years it spent in anonymity in the Athens archeological museum, the laborious efforts by some scientists in the last few decades who figured out parts of it, and the final culmination of its near complete understanding by 2008 when better technologies were available.

Written very well, with simple and clear explanations of the basic science involved the author is able to bring out clearly the trials and tribulations involved in scientific research. In addition, the author succeeds in bringing out the excitement of solving a mystery and educating the reader of the gap in our understanding of the progress made by the ancient greek scientists two thousand years ago. The Antikythera Mechanism not only proves that complex geared mechanisms existed (till recently thought be invented in the 18th century) then but also that they were in rather common use because of the detailed instructions provided in the device for enabling its operation by the layman.

I also very much liked the author's attempt to figure out who in the ancient greek world would have devised such a mechanism and how it could have ended in the ship wreck. The logic as well as the detailed research makes the book a pleasure to read.

Friday, April 17, 2009

Solar power from space?

Science fiction to turn into reality!

Originally proposed by science fiction author Issac Asimov in 1941, the concept of a space station capturing solar energy and beaming it back to earth - seems to become a distinct possibility now.

Solaren, a start up based in Southern California plans to deploy a solar array in space, convert the solar energy into radio frequency waves and beam it back into earth. Unlike nuclear or coal fired plant which have a conversion efficiency of about 33 %, the RF conversion is supposed to get an efficiency of 90%. Further solar arrays will have 8 to 10 times the efficiency of terrestrial solar arrays since they can work continuously ( no night time) and there is no cloud cover or atmospheric impurities.

Find all this difficult to believe? Well, California's PG&E has requested approval from the California Public Utilities Commission (PUC) to enter into a power purchase agreement with Solaren Corp. in Southern California. Solaren would deploy a solar array into space to beam an average of 850 gigawatt hours (“GWh”) for the first year of the term, and 1,700 GWh per year over the remaining term, according to a filing to the PUC.

While Solaren would provide 200MW of electricity to PG&E, according to the filing with the PUC, Solaren anticipates generating a total 1,000MW from its satellite. Expected to go live by 2016.

Friday, April 3, 2009

ET - Where are you?

Confessions of an Alien Hunter: A Scientist's Search for Extraterrestrial Intelligence - by Seth Shostak

As a senior astronomer at SETI (Search for Extraterrestrial Intelligence), Seth Shostak is eminently qualified to take us through the last fifty years of our search for alien life in the universe. Interspersed with humor, Seth brings to life the challenges such an effort faces and raises the question of how we would respond on the search being successful. The book is an easy read and provides the layman a frank opinion of the low chances of success our current efforts have, and the inadequacy of our tools. It is a good confession indeed - from one of the experts in the field.

The author then tries to the justify the continued efforts - which however is not very convincing. Even a science enthusiast will wonder whether the money and effort is being put in the right direction in our search for alien life. Other than providing a small chance of knowing whether we are alone or not, the SETI efforts do not seem to provide much benefit.

Considering that our technology development is progressing so fast wouldn't it make sense to wait till we have the right tools? And maybe put more effort in developing better tools and different approaches other than just depending on tracking radio signals? Further, everybody (including the author) seems to agree that any civilization that we might find will have to be many times more advanced than ours. In that case wont it better to let them find you? (the needle in the haystack analogy).

The book clearly explains the fundamentals underlying the current search of ET life, but unfortunately fails to inspire or reach the level of books like Carl Sagan's Cosmos. However for anyone interested in learning more about SETI and understanding the limitations of the technologies that we have now, this book will be useful.