Date: August 29, 2010
Title: The Search for Intelligent Life
Podcaster: Marc West
Links: Mr. Science Show: http://www.mrscienceshow.com
Description: Marc West speaks to Dr Carol Oliver, a science communication researcher working for the Australian Centre for Astrobiology, whose key goals include contributing to the understanding of the origin of life on Earth and to set an Australian life-seeking instrument on the surface of Mars.
Bio: Marc West was a University Medallist in Chemistry at Sydney University, completed a Graduate Diploma in Science Communication at ANU and a Masters of Operations Research and Statistics at UNSW. Having grown up in Sydney, he ventured to Canberra and then London to be editor of Plus Magazine, and now works in Operations Research back in Sydney. Marc has written freelance for a number of magazines and newspapers, including G Magazine, The Canberra Times, The Helix and All Out Cricket Magazine, his article Political Music was published as one of top 50 science blogs of 2008 in The Open Laboratory 2008: The Best Science Writing on Blogs, whilst A sorry saga – the crumbling cookie made the 2009 version. Marc set up the Mr Science Show when on a trip to China, frequently talks on radio with The Diffusion Science Radio Show on 2SER, and co-founded The Beer Drinking Scientists podcast.
Today’s sponsor: This episode of “365 Days of Astronomy” is sponsored by David Rossetter on behalf of the Mid-Hudson Astronomical Association: A goofy group of geeks who love to observe and share the night sky around New York State’s Mid-Hudson region. [And my name is pronounced Ross' e ter' (that should be one of those upside-down e's in the middle).]
The search for intelligent life
Marc West speaks to Carol Oliver
Marc West: Greetings and welcome to the 365 days of astronomy podcast, my name is Marc West and this week we’re talking about the search for extraterrestrial life. I usually podcast as part of the Mr Science Show – www.mrscienceshow.com – and you’ve probably heard me before on the 365 days of astronomy podcast as one of the things I like to tackle on the podcast is astronomy.
Astrobiology is a fascinating and complex field of science. It is the study of the origin, evolution, distribution, and future of life in the universe, and is a relatively new field of science incorporating astronomy, biology, geology, palaeontology, physics, mathematics and other disciplines. It is even more fascinating given that we have never actually discovered life anywhere else in the universe!
Dr Carol Oliver is a science communication researcher working for the Australian Centre for Astrobiology, whose key goals include contributing to the understanding of the origin of life on Earth and to set an Australian life-seeking instrument on the surface of Mars.
I spoke to Carol about astrobiology and the SETI Project – the search for extraterrestrial life. The first question I asked here was “what is SETI all about?”
Carol Oliver: SETI uses the radio spectrum to look for signals from outer space that may hint at intelligence out there in our galaxy – it is limited to our galaxy because of the fact that space is very large – across our galaxy is 100 thousand light years – that’s the time it takes light to travel from one end of the galaxy to the other, which is around about 300 thousand kilometres per second for 100 thousand years, so its very large. And our galaxy is one of maybe another 100 billion galaxies in the Universe. So there’s an awful lot of space out there. It would be unusual if we were the only other life out there in the Universe – but we might be, we just don’t know the answer to that question, and that’s what SETI is about.
MW: Cause looking for intelligent life I guess is different to looking for just ordinary life. The electromagnetic spectrum is infinitely big – where do you look?
CO: Oh well, that’s very easy. It happens there’s a space in the radio spectrum where noise fro the rest of the Universe drops to the minimum level, and its between two molecules – the H line and the OH line. And you put those two together you get water – so its called the water hole. And its assumed we would actually find a message from extraterrestrial intelligence at that point because it would be the same for everyone in the Universe. If you’re going to transmit, you’re going to transmit at the quietest part of the spectrum.
But even then, there are billions of frequencies we could be looking for. Really SETI is a 9 dimensional search. It’s three times in space – up down and across. Time frequency, polarization – there’s two of those – modulation and transmitted power – it truly is looking for a needle in a haystack.
We really can’t rely on a directed message to Earth – which we are at the moment. But if you can imagine that in the last 70 years we have been transmitting television and radio signals – they just leak naturally into space. If we could detect those, then we may be able to detect intelligence elsewhere in the Universe.
MW: Presumably it would be a fairly big media event if we found some ET life – so we haven’t found any yet. But in 1977 they had the WOW signal. What was that about?
CO: Well that was at a telescope no longer in existence, and it was when they used to have ream of paper to deliver what was coming through the collection system. The operator came in one morning and looked at the numbers on these charts and they were way off the scale. They could only be a very narrow band signal from very far away. The operator circled those numbers and wrote “Wow” – hence the name the “Wow Signal”
In spite of many years of searching that part of the spectrum, it has never been found again. So for SETI purposes, we don’t regard it as a SETI signal as we need proof. We need for others to be able to go alone and look at that part of the spectrum and detect this narrow band signal them.
So although SETI has occasionally found a signal repeated twice, its not continuous and there could be other explanations. SETI is a scientific search for ET intelligence in the Universe, so it has a very high bar to then announce that they’ve actually found a signal.
MW: Where on Earth is SETI based? Its based all over the Earth I guess.
CO: Yes! The most strategic and biggest organisation is the SETI Institute in California – they sit just outside the gates of NASA AMES and most of their employees actually work at NASA in aspects of astrobiology, which is looking forward life elsewhere in the Universe, but not necessarily intelligent. They use the largest telescopes on Earth at Arecibo in Puerto Rico and also the Parkes Radio Telescope here in New South Wales. And they’ve also got the Allen Telescope Array. Now that’s in Hat Creek in California. They want 350 small 6-meter dishes there. They’ve currently got 42. Those have cost $50 million to date. But they’re doing SETI in concert with normal radio astronomy so those dishes have a double use, and also in off time the US Air Force uses it for tracking Satellite debris. So they’re hoping to increase that number of dishes, but they are the only dedicated search in the world.
There are other smaller projects in the world. There are none currently in the southern hemisphere, which is a shame because in the southern hemisphere we look right into the heart of the galaxy, which means we have the best real estate in the world. And all the others are in the northern hemisphere – but that’s what we’re stuck with.
MW: And you can participate in SETI at home on the Internet?
CO: You can! And that’s been going since about 1995 and basically it’s collecting all the data that has ever been collected by SETI, by the SERENDIP group at UC Berkeley. Real parcels of data are sent out to your CPU when you’re not using it, and it analysis it and sends it back. If you discovered a signal then you’d be on the paper. To date since 1995 they haven’t found anything – there have been a couple of interesting episodes, but they haven’t found anything. The interesting thing about SETI at home is that that technology has been employed for other things, for example cancer research.
MW: Well that’s all the time we have in today’s episode of the 365 days of astronomy podcast. My name is Marc West and I was speaking to Dr Carol Oliver. If you’d like any more information and a slightly longer version of this podcast, get over to my website at www.mrscienceshow.com. Thanks for tuning in, I’ll hopefully catch you soon on this podcast, and I’m sure the 365 days of astronomy podcast will catch you tomorrow.
End of podcast:
365 Days of Astronomy
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