Zero. Zilch. Nada. That's how many signs of intelligent life astroboffins found in probe of TEN MILLION stars The latest survey searching for signs of alien civilizations radiating from over ten million distant Suns and six known exoplanets in space has thrown up a big fat nothing. “We observed the sky around the constellation of Vela for 17 hours, looking more than 100 times broader and deeper than ever before,” said Chenoa Tremblay …
I'm beginning to think that intelligent life is a temporary phenomenon and self destructs beyond a certain level, either through destruction of the host planet's eco system or through ever advanced weaponry such as an accidentally released bio-weapon or world-wide nuclear war or other more exotic means of total annihilation yet to be discovered.
There are too many vested interests in making money in the short term for businesses and politicians to do much to change things. With some issues like climate change, by the time politicians realise they've fallen off their bike it will be too late to get back on it again. There are many who still deny climate change is happening and some of them are in power (Trump).
Trump publicly denies climate change while spending his own money defending his golf courses from rising sea levels. More republicans think climate change is real than think it is a hoax but they will still vote for someone utterly delusional or a coal mine operator if he also promises to hurt brown people.
Welcome to the stupid ages.
I've just finished reading "Closing Time" by Joseph Heller, he who gave us Catch 22, where the president is referred to by everyone, including himself, as the "the little prick" and who starts the apocalypse by confusing the buttons for ending the world with those of his favourite video game.
IOW: rinse and repeat for every US* president because they're usually dicks.
* insert your country of choice
Kurzgesagt did a pretty good video about this on YouTube. The principle is called the Great Filter.
Link: https://www.youtube.com/watch?v=UjtOGPJ0URM&ab_channel=Kurzgesagt%E2%80%93InaNutshell
The interesting question is that, if such a filter exists that prevents intelligent life progressing past a certain point, have we somehow already passed it? Or is it still there waiting for us to hit it?
It's more likely there are "filters" rather than one filter. And the more technological advanced a society, the more filters will be open to it.
We have always been vulnerable to a meteor strike or a period of supervolcanism. And a flip of the magnetic poles is overdue - who knows what that would be like to live through. Outside long shots are a nearby supernovas or even a GRB pointing at us.
In addition to those ever present threats, we can now start a nuclear war. We're on the verge of being able to engineer a deadly plague or do silly things to our DNA. And it won't be long before we can build an army of killer robots. [Cylon and thanks for all the fish.]
And then, of course, we are re-engineering the earth's environment on a planetary scale - and nobody's found the manual. Our cells are filling up with nano-scale bit of plastic and who knows what other pollutants; what effect might they have on our biology? We can't even arrange our society so we don't have a mental health epidemic.
Who knows how well our civilisation would cope with any these eventualities. And although I optimistic, all it takes is one moment of bad luck. If the Cuban missile crisis had played out slightly differently, there might not be a technologically advanced society for the aliens to detect.
We've had radio for 100 years. How much will it be used 100 years from now? 1000? Even if there isn't something better than radio we haven't discovered yet, we're already getting better at aiming RF where it needs to go rather than radiating it wastefully in all directions like the typical FM/TV station does.
How much off planet signal bleed will the Earth have in 100 years? How much in 1000, if we're still using radio? Would there enough be enough that it could heard from thousands of light years away?
If we'd been looking for aliens 150 years ago, we would have looked for evidence of coal smoke in a planet's atmosphere...
We've had radio for 100 years. How much will it be used 100 years from now?
That's been my thought on it. As it is we're already moving away from the loud, wide-spectrum broadcast, and are moving more towards cable/fiber transmission, as well as satellite transmission which focuses it's energy down to the surface (the feed upward is much more narrow and focused). To an outside observer our communications might seem to be declining. So unless *we're* picking up someone's transmissions for the equivalent 120-150-year timespan, we'll never hear them.
Additionally, the conditions on some other planet might have precluded a broadcast system like ours, and they may have had to rely on narrow-beam communication, maybe even just point-to-point. Which would also mean they wouldn't be listening for OUR signals, because it wouldn't seem likely to them that some other world would use such an unworkable (from their viewpoint) technology.
Why assume that extraterrestrial life emits electromagnetic radiation? We've only done this to any extent since around 1900, which is a mere blink in human history. Next they'll be trying to decode tweets in any signals they find, because obviously all life everywhere evolved to replicate the rise of the urban USA.
Most life in most places probably just mosies around eating, sleeping, fighting and reproducing (and always did). The rest is pure froth, and may not even last much longer here on Earth.
I think there is a school of thought that actually we are already becoming less detectable. Already our radio emissions (at least the non-deliberate ones) are likely reducing in power and/or becoming more directed and hence harder to pick up. (or just moving to optical fibres, etc. and short range radio of various kinds).
My recollection is that our big three "detectables" would be: nuclear EMPs (which peaked a few decades ago); Terrestrial TV broadcasts which are becoming more directed, lower power and more signal efficient (so no big old carrier to easily detect); and early radar systems which are now, again, more efficient, directed, etc.
Our window of easy observability over cosmic distances may have already closed and is a vanishingly short fraction of our existence so far. Taking as a guess that this is also true for other technical civilisations it does suggest that our chances of spotting anything is very small indeed (even if they do exist in vast numbers).
I agree that at the moment, our use of high powered radio transmission is being supplanted by low powered localised alternatives, however, if / when regular commercial spaceflight gets going, then at present the only way for craft moving between bodies in the solar system to communicate will be by radio signals transmitted at a higher power than most localised terrestrial signals are, so the solar system will be more noticeable as a source of EM radiation.
No they wouldn't, because the far narrower beam width means that not only is there a low probability that they would happen to be aimed in our direction, but that if they did happen to hit us, they would remain aimed at us long enough for us to detect an artificial pattern (modulation) before planetary rotation etc. moves their direction away from us.
"
... will be by radio signals transmitted at a higher power than most localised terrestrial signals ...
"
Sure, but they are *highly directional* signals, so the probability that any happen to be aimed at a distant star during the window when someone is listening for them is low. In addition, a higher and higher percentage of radio signals are being modulated by multiplexed digital information, which is a lot harder to recognise as being artificial than analogue information. In fact GPS signals are spread spectrum and below the background noise floor, and so virtually undetectable even on the surface of the Earth unless you know exactly what you are looking for.
It's also likely to be a relatively short period of time that such communication methods are used - already we are seeing experiments in laser communication with space craft, which are both narrower and lower power. And the future may see us using neutrinos or other exotic means to communicate over a distance.
signals to/from spacecraft use microwave beams, as I understand it, a highly directional signal. Transmitters on setellites don't put out kilowatts of power as I understand it. You need about 3 or 4 times the radiated power to amplify it to that level, and that's a LOT of solar panels or fuel cell or nuclear power. One source says that Voyager has a 23 watt transmitter. Another source says that the current total power consumption is 249 watts for the entire spacecraft. Yet another source says that GPS satellite transmit at around 25 watts. In any case, it's not the kilowatts or megawatts you'd need to send an easily detectble signal out in an omnidirectional broadcast. [you make up for the low power by using high gain directional antennas, aka 'beams'].
But if you were _REALLY_ lucky, you might be listening within the cone of such a beam and so you might detect it. Might. And that's the point of SETI and others searching everywhere for many years. Various conditions may not allow us to receive signals for long enough so we just scan what we can. The earth has day/night periods and revolves around the sun, and you can't really listen well during the day on Earth, nor in the general direction of the sun with satellites. So there ya go. "When we can". Maybe do it enough times, you find something. [similar thinking in nuclear physics sometimes]
effective encryption looks like random noise
yes. and in theory if you analyze it and find 'peaks' or repitition in the distribution, it might suggest a weakness in your algorithm.
For an AM or FM receiver, modulation like spread spectrum or QAM look like noise, too. But in theory it would show up as a peak on a spectrum analyzer, if the frequency band were narrow enough. Unfortunately, Earth broadcasts spread across the entire radio spectrum all the way up into the 10's of Ghz without a whole lot of gaps... and would therefore look JUST LIKE NOISE. "no peaks" probably. (or no significant ones).
Receiving a signal requires that it be above the noise threshold, or that you have such a good error correction algorithm that you can base demodulation on "presence of a tone" whether it's noise or not.
The aliens use modulated neutrino beams.
Meanwhile, we're the ants: https://xkcd.com/638/
some kinds of modulation would appear as "pure noise" to an un-initiated listener. Even the kinds of modulation used by cell phones would be COMPLETELY un-decodable 50 years ago, let alone the stuff we use for digital TV (like QAM).
So it may simply be we're not recognizing it. Either that or they found out that we could receive their signals and are doing "radio silence" like a WW2 sub running silent to hide from a destroyer...
And 30 years ago we had no proof of planets outside of our solar system. We do now.
The "Bozo Bit" - it's the bit that gets flipped on when you fail the bozo test, like asking really stupid questions one too many times, wanting to be hand-held through a process where a simple RTFM would get you going, or similar. Customer Service and Tech Support identify YOU as a "Bozo". it's not a good thing. So, in that regard, MAYBE they're sending us a signal that's been modulated in such a way that when our tech evolves sufficiently, we'll be able to demodulate it. Then the 'Bozo Bit' will be cleared, and first contact established. Just a thought.
We assume we are intelligent but it may just be arrogance on our part.
Perhaps really intelligent beings avoid the type of industrialization that we have gone for and are peacefully meditating and being one with the universe.
I can't see hyper intelligent slime moulds doing a lot of metal working for example.
Assuming that aliens are subject to the laws of supply and demand ( ie: they don't have limitless resources ) and that Alien Smith said that "Alien wants are infinite", aliens will also strive for economic growth so that they can eat sufficiently, own more slime to play with, etc.
In the hope that somewhere out there is a Bender selling cheap solar panelling to unsuspecting alien civilisations.
The Galaxy Song song was never so true, "And pray that there's intelligent life somewhere out in space, 'Cause there's bugger all down here on Earth!"
Why do they assume those "aliens" civilizations would necessarily be exactly like 20th century humans' one was?
The "solar panel" thing is utterly stupid, about the same level as looking for "blockchain" (because "intelligent life" is bound to use it!)...
A single century ago there were no solar panels on Earth, and by the end of the 21st century we might have switched to something we don't even imagine yet, much like people in the wood/coal ages didn't expect electricity. So, even if that alien civilization is totally human-like and goes through the exact same technological evolution (very unlikely), why would they be in the "solar panel" phase just now? They could be still using steam engines, or have mastered fusion. Or their planet might have enough geothermic potential and/or a weather so unfriendly solar panels never were a serious option. Or, more likely, they have followed a technology path we don't understand at all.
In short, their message is rather "we didn't found any trace of Golden Arches in the star systems we scanned"... Which is fortunate and means nothing at the same time.
I guess it is important that someone looks and checks the easy things and crosses them off the list - it would be embarrassing to discover in 100 years that aliens emit RF we could have found in 2020.
But it tells us virtually nothing about the likelihood of intelligent life.
The problem with all SETI searches is they are limited by what we can detect. If FTL drives are not science fiction how would we detect them when we have no idea what to look for. Any advanced technology would be the same, we have no idea what it is and definitely no idea how to detect it. Some of the ideas such as look for technosignatures in principle are correct, but what signatures should we be looking for and can we even detect them is an issue. Looking for fluorocarbons sounds good there is the assumption the alien civilization produced them and a local biological process did not. If they were not produced at all by an alien civilization and the local biosphere there is no signature to detect.
It's called the anthropic principle: even though it's all chance. Combine this with rectlinear perspective, which is as ideological as it is aesthetic and humanity must be considered the most advanced life form. We consider our situation special, even though it's just unlikely.
The really, really depressing possibility is that they WERE out there, but got killed off by some cosmic event beyond their control before we had the ability to discover them, and now we'll never even know that their civilization existed.
They looked at 100 Million Stars.
There are 100 Billion stars in our galaxy. There are over a billion galaxies. So, thats, <click> <click> 1E20 stars in the universe (give or take the odd one or two).
So they have looked at a sample size of 0.000000001%
No shit sherlock.
Life is an extremely improbable* arrangement for preserving the improbable. It's not really surprising that they've found nothing.
* We have several quite different chemical systems linked together. Some of these are made out of polymers of amino acids**: systems capable of handling energy by manipulating electrons and protons, chains of specific catalysts to synthesise other molecules including assembling amino acid polymers, structural elements including membranes made from combinations of lipids. The "other molecules" include those which are necessary for the energy handling such as chlorophyll, heam and adenosine and its phosphates and, of course, the amino acids themselves. Then there's the nucleic acid system, DNA or, in some cases, RNA genes, mRNA transcripts of the genes, tRNA to specifically bring the correct amino acid to add to the amino acid polymer and rRNA in the ribosomes. Individual monomers and other molecules may be readily enough found but assembling them together at random into a combination that is capable of bootstrapping itself into what we know today is extremely improbably, even taking into account that some mineral surfaces could have stood in for what proteins do now.
** Not just random chains but chains of specific sequences which lead to folding into specific shapes to provide the other functions.
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We appear to be looking for signs of activities that are very likely to be a fleeting stage in the cycle of an intelligent species. We have probably not emitted radio signals that could be detected at light-years distances for more than the past 100 years (if that), and I doubt will will be doing so for all that much longer (if indeed we still do).
It assumes that all intelligent life will create electromagnetic signals that can span vast distances of space and are identifyable as being artificial. But that is hardly a sensible assumption. You cannot even assume that intelligent life will always modify its environment in a way that is readily detectable even if we had images taken from orbit around their planet.
I remember Steven Tingay from the excellent BBC Horizon's documentary Cosmic Dawn: The Real Moment of Creation. Specifically because I thought that I wouldn't want to argue with him at an astronomy conference, as he looks like a rugby player that could throw you across the room.
The reason for non contact is we are making too many assumptions?
The "Water Hole" isn't as universal as we think it is.
For example, for PO3/HF/H2SO4 based life as might be found on Venus it might be near the atomic resonance for sulphur which is if memory serves in the 5332.49 range.
http://time.kinali.ch/nist/1041.pdf
We don't typically search in this band and even detecting free oxygen in an exoplanet atmosphere is problematic as its host star usually masks out any signature.
Maybe if we search for SO3- it might yield something?
Also useful: one of the resonances for ammonia (NH3) might be worth a try as its been detected in quantity already even in our own Solar System.
Same with ethane and other hydrocarbons you might find in a super-Jupiter.
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