Erstellt am: 2. 12. 2016 - 21:00 Uhr
Are we alone?
Reality Check Special
The search for extra-terrestrial intelligence, Saturday 03.12.16 at 12 midday and afterwards for 7 days on demand.
Guests include:- Dr. Seth Shostak, Senior Astronomer at the SETI Institute in California. Andrew Norton, Professor of Astrophysics Education at the Open University, Dr James Carney at Lancaster University, Dr Mark Gallaway, at the University of Hertfordshire and Dr Meg Schwamb at the Gemini Observatory’s Northern Operations Center in Hilo, Hawai’i.
Russian astronomers gave the world of SETI (that’s the search for extra-terrestrial intelligence) something to think about earlier this year. Pointing a radio telescope at a distant star, about 900 trillion kilometres from Earth, they heard a rather loud burst of radio waves. Unfortunately, it failed some of the usual tests: the signal came and went, so it was not consistent, and when scientists took a closer look, the noise was gone. So, it could have been anything, rogue signals from a satellite or somebody switching on a nearby microwave. But it got me thinking about the huge global search that’s been going on for a number of years, and I was curious about how the hunt is currently going for an advanced alien civilisation.
Alerts such as the Russian one are analysed by a community of scientists involved in the SETI Programme (the Search for Extraterrestrial Intelligence). So, for a Reality Check Special on the subject, I turned to some astronomers, astrophysicists & psychologists to tell me and us what they think about the search and how they see the future of SETI.
One of those scientists is Dr. Seth Shostak, Senior Astronomer at the SETI Institute in California. I began by asking Dr Shostak about Frank Drake. Frank Drake essentially (scientifically) launched SETI with a mathematical starting point, an equation, to try and help point scientists in the right direction.
Seth: Frank Drake is an American astronomer. In fact, he works down the hallway from where I am speaking to you now. Although he’s in his mid-80s now, so he doesn’t come in every day. But in 1960, he did the first modern SETI experiment. He used a big antenna (well big for the time) in West Virginia, and he pointed it at a few nearby stars in the hopes of eavesdropping on signals from extra-terrestrials. The year after that, there was a small conference because this experiment generated a lot of public interest. He invited very eminent scientists and he wrote down an equation which became known as the Drake Equation. It goes like this:
N = R* • fp • ne • fl • fi • fc • L
It was used to estimate how many societies there were out there within the Milky Way. By the way the Drake Equation is said to be the second most important equation in science after Einstein’s E=mc2.
Steve: Why do you think intelligent life is out there, because if it is out there, and it is intelligent, why haven’t they made themselves known to us?
Seth: Well, one can only speculate on the motivations of aliens, we don’t know too much about them but there is this to be said. They probably don’t know that we are here. Think about it, how could you find homo sapiens if you were a Klingon or something like that, you couldn’t see anything from the distances of the stars, you couldn’t look at downtown New York, but what you could do is pick out our broadcasts, in particular television and FM radio, and most visibly our radar. But in order to do that, you’d have to be closer than 70 light years, because we’ve only been sending that signal into space since the 2nd World War. So, if they are further away than that, they probably don’t know that we are here. I don’t know if they would just visit a random planet that they know … well it has water and it has oxygen in its atmosphere....maybe it has some sort of biology but maybe it’s not very interesting.
Steve: If a radio telescope picks up something and it is pretty obviously from an intelligence source, a prime number signal for example, what is the protocol, what happens?
Seth: Well, there is a protocol and it’s sounds like it is very serious, perhaps even ominous. It was cooked up by an international academy of astronautics committee, something I happened to chair when it was doing this stuff. It was to say: look, if you find a signal the first thing to do is check it out. Make sure it’s not just a local college prank or bug in your software. The second thing it says, is tell everybody. Well, I can assure you that every time we find a signal that looks interesting the media are calling us up immediately. The third thing it says is don’t broadcast any replies without some form of international consultation. But on the basis of false alarms that we have actually had, it would take about a week before we can actually be sure, but on that basis of false alarms, the radio, tv stations, and newspapers are all calling up and it would be a big story irrespective of whether it is true or not.
Steve: If we are sending signals back, what happens if they are hostile or hungry?
Seth: Well, Stephen Hawking has certainly an opinion on this. He says it’s like shouting in the jungle, which is maybe not a good idea if you don’t know what is out there. You can’t argue against that, but maybe 99% of the aliens are friendly and are happy to read poetry and play video games, but maybe the rest are not so nice. And, maybe you would hate to be responsible for the obliteration of the earth because you sent something back, telling them where we are. It’s hard to argue against that except for this: from the 2nd World War we have indeed been broadcasting the news of our presence and sure those signals are pretty hard to find but any society that could come here and ruin your day by destroying the planet or whatever else they have in mind, any society that is at that technical level could easily pick up those signals. So it’s too late, that horse has already left the barn! We’ve already been busy for 70 years telling them that we are here!