Corvus
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Fermi vs. Drake -- Some Thoughts
These thoughts were brought up by an examination of the Fermi Paradox, the Drake Equation and SETI over at Damn Interesting.
The Fermi Paradox has been a fruitful playground for science fiction authors for a long time. It's been the seed idea behind multiple series that I have read (Ian Douglas's "Heritage Trilogy", the "Inhibitorverse" works of Alastair Reynolds), and is one of my favorite scientific mysteries.
The famous Drake Equation makes a valiant attempt to estimate how many other civilizations might be out there in the galaxy. It doesn't attempt to answer Fermi, just provide possible responses to the single question, "How many others are out there?"
The fatal flaw with Drake's equation, and the problem with SETI in general, are that they rely on the universality a method of communication that we have only had for a little over a century: radio. SETI and Drake assume that we'll wind up intercepting "leaked" alien radio signals because those aliens will be using radio. Yes, radio is a wonderful medium, which is why it's awfully popular here on Earth. But just for a moment, consider that it isn't anywhere near the best transmission medium for a technological civilization.
We've only been listening to the skies for alien radio transmissions since approximately 1960 (Drake, again); that means 47 years. In about 115-120 years since the development of radio, we've already begun to explore the edges of more advanced nonradio communication techniques. It's doubtful that we will be using radio very much at all within a few centuries. Why, then, must Drake and SETI fixate on that method of communication?
Here's how the problem forms in my mind. The final variable of the Drake Equation, L, is the time period during which a given civilization will release detectable (here meaning radio) signals into space. Common estimates for L are in the thousands, often five or even ten thousand years. But judging from our own technological advance, I can't believe these estimates are even close. I believe they are far too high. Radio communication is like technological baby-talk. Civilizations reach a certain level of maturity and stop doing it.
What I see happening is a brief period of radio communication followed by total silence as the civilization moves on to other methods. There are short bursts of radio emissions coupled with long periods of silence, and we aren't listening at the right time. In short form, my answer to Fermi and SETI's continued utter failure is that we're listening in the wrong way. We're listening for the brief bursts of baby-talk and not hearing them, because we happen to be in one of those long gaps.
I'm interested in what you all think.
Last edited by Corvus, 12/6/2007, 4:16 pm
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12/6/2007, 4:14 pm
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David Meadows
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Re: Fermi vs. Drake -- Some Thoughts
I'm intrigued by these more advanced communications techniques you say we are exploring. Nothing springs to my mind as a viable replacement for radio.
I think the answer is much more prosaic: we are listening for radio transmissions. What happens if every other civilization is doing the same?
Nobody is talking!
No wonder none of us can hear each other, we're all listening in silence 
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"No matter that you have a PhD and have read all of Henry James twice. If you still persist in writing, 'Good food at it's best', you deserve to be struck by lightning."
-- Lynne Truss
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12/6/2007, 4:23 pm
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Corvus
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Re: Fermi vs. Drake -- Some Thoughts
quote:
David Meadows wrote:
I'm intrigued by these more advanced communications techniques you say we are exploring. Nothing springs to my mind as a viable replacement for radio.
Directed beam transmissions for long-range communication, the very beginnings of quantum communication, and so on. At the beginning, everything looks slow, but technology accelerates at dizzying rates, especially these days.
Not only that, but just because you can't imagine what might replace radio doesn't mean nothing can. Keep in mind that the Next Big Thing might come from a completely different area, and will likely be a composite of many discoveries that haven't been made yet along with things nobody thought to look at. (Go watch James Burke's Connections. It really changes how you look at the advancement of civilizations.)
quote:
David Meadows wrote:
I think the answer is much more prosaic: we are listening for radio transmissions. What happens if every other civilization is doing the same?
Nobody is talking!
No wonder none of us can hear each other, we're all listening in silence
We aren't listening for directed communications. We're listening for ambient radio noise, the same kind we put out -- radio and television transmissions, and so on. It's a horribly anthropocentric and hidebound idea, that since we're doing it now, alien civilizations will do it for thousands of years.
Last edited by Corvus, 12/6/2007, 4:53 pm
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12/6/2007, 4:50 pm
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Reythia
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Re: Fermi vs. Drake -- Some Thoughts
Corvus, what you are saying is possibly true: perhaps in a hundred, or even a thousand, years (not long on the universal timescale), we and other civilizations will come up with a vastly better medium for galactic transmissions. That's certainly possible. As Meadows said, at the current moment, I can't think of anything that would be better -- but, that's "at the current moment". Newton wouldn't have thought of radio, either.
So you're right... but to be, it's something of a moot point. At the moment, we don't have the capability to search for these other communication types. We don't understand them yet. At the moment, the electromagnetic spectrum (including xray, light, and radio, all of which we track regularly) is our best bet for finding someone out there to talk to.
quote:
We aren't listening for directed communications. We're listening for ambient radio noise, the same kind we put out -- radio and television transmissions, and so on. It's a horribly anthropocentric and hidebound idea, that since we're doing it now, alien civilizations will do it for thousands of years.
I don't think this is really the case. I mean, yes, it's entirely possible that there is a radio signal being sent to us right now, but it's so different from what we'd think of as a signal that we're missing it entirely. But I don't think there's much we can do about that, except try and keep an open mind (and most scientists do try!). Also, recall that the whole point of the article you pointed us to was to show that even a strong, coherent radio signal would arrive at Earth as mostly noise. If that's the case, then looking for patterns in the noise (rather than "real" signals) makes sense.
quote:
Meadows wrote:
I think the answer is much more prosaic: we are listening for radio transmissions. What happens if every other civilization is doing the same?
Nobody is talking!
No wonder none of us can hear each other, we're all listening in silence
Haha! I've thought much the same thing, Meadows! Unfortunately, the power requirement to continually output radio waves which would be recognized as "signal" rather than "noise" is immense! Translation: it'd be hard to build and VERY expensive. And, if Corvus is right, it would likely be pointless. That's not to say I don't think it should be done, but it's the reason it hasn't been done already, in my eyes.
Good topic, Corvus!
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12/6/2007, 6:13 pm
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Corvus
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Re: Fermi vs. Drake -- Some Thoughts
I'm certainly not calling for an end to SETI (nobody said I was, I just wanted to clarify for future readers). My main problem is that many people think that because SETI is searching for radio transmissions, radio is this huge thing, when in fact it's not. SETI is a minor sidelight and I honestly don't believe it's going to ever find anything. If it does, I will, of course, do this...:
 
...but I'm not holding my breath.
I do believe the Drake Equation should be changed. Its reliance on radio (for more than one variable, even) isn't in keeping with the development of technology. We need a new Equation, of some kind.
Last edited by Corvus, 12/6/2007, 6:19 pm
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12/6/2007, 6:19 pm
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Reythia
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Re: Fermi vs. Drake -- Some Thoughts
quote:
Corvus wrote:
I do believe the Drake Equation should be changed. Its reliance on radio (for more than one variable, even) isn't in keeping with the development of technology. We need a new Equation, of some kind.
As soon as we come up with a new form of communication, I believe it will be changed. But until then, the probability of us detecting a transmission we can't recieve is 0%. So why bother adding another term to the equation?
Actually, looking at how the website you wrote defined the Drake's Equation variables, the most relevant are:
" Percentage of civilizations which eventually send signals into space (TV, radio, etc.)"
and
"Average number of years that an advanced civilization will send such signals:"
If you include new technologies into the "etc" part of the first one, then for this sort of crude estimate, there's not even a need to change the definition.
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12/6/2007, 7:15 pm
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QS2
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Re: Fermi vs. Drake -- Some Thoughts
Sadly the article is gravely mistaken about signal sensitivity of our large arrays. Also its example of two Arebico dishes is confusing sensitivity for precision. You don't need to be precise to detect a signal, just sensitive.
To get more down to the meat, I believe the upcoming Square Kilometer array will be sensitive enough to detect any civilization emitting Earth like radio levels for up to a range of 20 ly, so that isn't even directional.
Another point is, is that Drake doesn't miss the point of the civilization stopping to emit radio, that is the estimate period for emitting radio waves after all. To incidentally defend the relatively high numbers, we should remember that humanity in principle usually never gives up old methods of communication, it just adds new ones to them. Whereby each will then be used as is useful, of course, maybe at some point something so advanced will be developed that it completely obsoletes it all, but that could be many centuries or more away.
So what this all comes down to is, is that in this century we will be able to listen for Earth type civilizations at last, instead of hoping for ultra powerful emissions from some much more advanced civilization.
PS Typically not mentioned in things like the Drake equation or so, but the even bigger issue with the Fermi Paradox is, that even with a mere slow 10% of light speed rocket engine, which even us puny humans can pretty much already hope to engineer. It becomes possible to colonize the entire galaxy within a few million years, so where is everyone? They should be already here, never mind looking elsewhere.
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12/7/2007, 12:41 am
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