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Why We're Looking For ET All Wrong
StartsWithABang writes: When you consider that there are definitely millions of planets in the habitable zones of their stars within our Milky Way galaxy alone, the possibility that there's intelligent life on at least one of them, right now, is tantalizing. But we're in our technological infancy, relatively speaking, having only been broadcasting electromagnetic signatures visible by an alien civilization for around 80 years. Unsurprisingly, we're looking for exactly the types of signals we're capable of sending, but what if that's totally wrongheaded? Based on how technology is evolving and what the Universe is capable of, perhaps we should be looking not at electromagnetic radiation, but neutrino or gravitational wave signals from the distant Universe to search for alien civilizations.
At the very least we should be looking for spread spectrum modulation methods. Amplitude and Frequency modulation are so last century. On the other hand, a good spread spectrum signal looks like band limited white noise, so we need better methods to detect it.
--- Often in error; never in doubt!
The methods we have been using so far have always been based on our own technology level and therefore an assumption that other civilisations will be using the same methods.
One such assumption was sensing infra-red emissions, though the problem there is that a civilisation sufficiently advance may be using technology that has low emissions, due to optimisations. Though, at the same time we need to take note of different technology levels that different civilisations may be using for themselves and those they may be employing for their mutual search of 'extra terrestial' life. What I mean by this, is that they may be employing optimised radio technology, such as lasers and high encryption methods (which may be hard to distinguish from background noise, for us) for communication, but still using wide beam/wide spectrum, unencrypted radio in their search?
Jumpstart the tartan drive.
For most advanced civilizations, this may turn out to be pretty short. Between the discovery of radio and the development of efficient (below the noise floor) methods of modulation, this era may last a few hundred years. So if we are looking for inadvertent radiation, the probability of seeing it must be reduced by this factor.
The latency problem: Any sufficiently advance civilization will certainly understand the latency problems involved with communications at the speed of light. They might set up a beacon to advertise "Here we are" with no expectation of receiving an answer. But then again, probably not. They might run into the same problems we do with such 'science'. Funds will be better spent elsewhere, so why bother with the gigawatt beacon?
One possibility: A sufficiently advanced civilization might develop the technology to generate wormholes. Not big enough to physically traverse (due to the energy requirements). But large enough through which to inject photons. And if they can pop them open in the vicinity of candidate solar systems, they could find us in a reasonable (compared to light speed communications) time. So, they've found us. The next step would be to pop open some wormholes where we could actually 'grab' one, observe it for an intelligent optical signal and return one of our own. That would be a useful, two way, low latency link.
We don't have to understand the physics of how one goes about generating such tiny wormholes. Or aiming them at remote points in our universe. All we have to do is figure out how to detect one, confine it and couple it to optical instrumentation.
Have gnu, will travel.
See see Sentient Quotient
At present, human scientists are attempting to communicate outside our species to primates and cetaceans, and in a limited way to a few other vertebrates. This is inordinately difficult, and yet it represents a gap of at most a few SQ points. The farthest we can reach in our "communication" with vegetation is when we plant, water, or fertilize it, but it is evident that messages transmitted across an SQ gap of 10 points or more cannot be very meaningful. What, then, could an SQ +50 Superbeing possibly have to say to us?
And further progress seems likely to continue using broader bands, including shorter wavelengths (up to and including visible light), cleverer encoding techniques, more encryption and lower transmission power. All of which will make it harder and harder to detect from interstellar ranges. I think the most likely scenario is that our civilization will only emit detectable radio waves for a couple of centuries, so if we assume a similar progression for other civilizations, what we're looking for with radio-band scanning is a short-term blip emitted by emerging technological civilizations. So we may as well look for the crudest, most easily detected forms, since looking for more advanced forms is harder and doesn't extend the window by all that much.
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Let's admit it, we don't even know what we're looking for. I mean that in the broadest, most philosophical sense. We say we're looking for E.T. but there's no way we can look for something too dissimilar to ourselves so we end up looking for ourselves as an end result.
As many here have pointed out, the RF era may only last a short while. It would be a pretty heady coincidence if we did receive signals from that era from an exo race just at the time we're spending (wasting?) our time looking for such signals.
Consider the law of inverse squares. It doesn't take very many light-years for a radio signal to become a whisper. People are talking about compressed and distributed radio that is indistinguishable from background noise. I haven't seen many people offering a similar argument for AM and FM - not very far away (about 120 light years from some things I'm reading) and the same thing happens to even very strong broadcasts from Earth.
So unless we're really, really blowing on the dice, here, we don't have much hope of finding something this way. We're talking about the coincidence of not only E.T.'s radio era and our listenership, but also the coincidence that E.T. lives extremely, extremely close to our neighborhood. Two coincidences at once, playing out to our whims? I doubt it.
But think about what we broadcast that doesn't get attenuated so easily. Think about our space probes.
Surely even the most technologically advanced races have to give up trying to receive propagating radio signals beyond a certain distance. But space probes always stay the same size (don't quote me on that, cosmogony and quantum mechanics experts) so even if they aren't going at the speed of light, they stay detectable across time and space.
I'm sure it's far easier to pick up a tiny, tiny little pinprick of metal and electrical energy (valuable things in space) for an advanced race than it is to find random signals amidst the background noise of the universe.
Maybe we should learn to apply a similar technology. Maybe we need to develop "sensor arrays" that can quickly and easily detect artificial satellites drifting through space. For all we know, several have gone through our solar system since the advent of, say, radar, and we don't know it because we're not really looking or don't know how to look properly.
If we're so certain that there are exo races out there that have lived in an advanced state for long enough that by now their intelligent creation of radio signals is reaching us, then it's just as safe to assume that by now their space probes are reaching us as well. Voyager is escaping the sun at 38,500mph. Light travels at roughly 300,000mph. So this dramatic leap in assumption is simply a magnitude of ten.
Considering the milky way is 100,000 years across, I think it's okay to play with a magnitude of ten in terms of light years when asking ourselves how big of a "neighborhood" we live in. It's like saying maybe our neighborhood is the size of our subdivision and not just our cul de sac.
When you take all of this into consideration, it looks actually very silly to spend time looking for radio signals. It makes looking for radio signals seem like a sideshow game that some people just happen to be distracted by.
Meanwhile, our solar system could be bristling with tiny little space probes that we ignore because we haven't learned how to effectively differentiate them from rocks.
Maybe that's because we really actually fear the universe. Our biggest concern about exo objects is space rocks because we're so afraid that a big one is going to slam into our planet.
It reminds me that a lot of people have argued that we should be learning how to mask our signals and to stop sending out calling card broadcasts in the hope of gaining an audience.
"Stratigraphically the origin of agriculture and thermonuclear destruction will appear essentially simultaneous" -- Lee