With intelligent life in scant supply on Earth, boffins search for technosignatures of civilizations in the galaxy
- Reference: 1592812327
- News link: https://www.theregister.co.uk/2020/06/22/if_you_want_to_find/
- Source link:
The team, from the Harvard-Smithsonian Center for Astrophysics and the University of Rochester in the US, believe these so-called “technosignatures” are evidence of intelligence in other places than Earth. If advanced life forms exist they'll be using electronics, the thinking goes, and that means emissions that could be detected.
"Technosignatures relate to signatures of advanced alien technologies similar to, or perhaps more sophisticated than what we possess," Avi Loeb, chairman of Harvard University’s Department of Astronomy, [1]said this month. "Such signatures might include industrial pollution of atmospheres, city lights, photovoltaic cells, megastructures, or swarms of satellites."
Loeb told us his team will be awarded a total of $286,926 by NASA over two years to scour space for technosignatures. They will kickstart their search by trying to find signs that civilizations are trying to harvest star light for energy with the use of solar panels.
The researchers pointed to the example of [2]Proxima b , the closest Earth-like planet that may be habitable located some 4.25 light years away. Proxima b is believed to be rocky and is tidally locked to its parent star Proxima. That means that the same side of the planet faces the small yellow star as it orbits, and the other side is permanently shrouded in darkness.
"If a civilization wants to illuminate or warm up the night side, they would place photovoltaic cells on the day side and transfer the electric power gained to the night side," said Adam Frank, a professor of physics and astronomy at the University of Rochester working on the study.
"Our job is to say, 'this wavelength band' is where you would see sunlight reflected off solar panels. This way astronomers observing a distant exoplanet will know where and what to look for if they’re searching for technosignatures."
“Solar panels absorb light up to a certain wavelength and reflect the rest,” Loeb explained to The Register . “This leads to a spectral edge in their reflected light, which is distinguishable from the ‘red spectral edge’ produced by vegetation. By observing the starlight reflected off the surface of a planet, you can tell whether it is coated with solar panels.”
Their search will be narrowed down to exoplanets that are more likely to have environments that can support and sustain life. These candidates orbit their stars at distances that keep its surface temperatures warm enough to hold liquid water, are rocky, and have atmospheres filled with gas.
“The search for extraterrestrial intelligence (SETI) has always faced the challenge of figuring out where to look. Which stars do you point your telescope at and look for signals. Now we know where to look. We have thousands of exoplanets including planets in the habitable zone where life can form. The game has changed," Frank concluded.
Click here to meet your nearest alien neighbour now!
In other related news across the pond, a pair of astrophysicists from the University of Nottingham in the UK reckon there are more than 30 intelligent species of alien living in the Milky Way.
“There should be at least a few dozen active civilizations in our Galaxy under the assumption that it takes 5 billion years for intelligent life to form on other planets, as on Earth,” [3]said Christopher Conselice, who led the study [4]published in The Astrophysical Journal this week. “The idea is looking at evolution, but on a cosmic scale.”
Venerable astroboffin Frank Drake came up with his famous Equation in 1961, guestimating how common intelligent life might be. It's controversial, and has been [5]reviewed since, but math ain't everything.
Well, if there are extraterrestrials that have managed to invent the internet and are now reading El Reg in another planet far away, we welcome our alien overlords. ®
Sponsored: [6]Free Hands-on Training: Anthos Service Mesh
[1] https://www.cfa.harvard.edu/news/2020-12
[2] https://www.theregister.com/2016/08/24/exoplanet_found_right_under_our_noses_may_be_earthlike/
[3] https://www.nottingham.ac.uk/news/research-sheds-new-light-on-intelligent-life-existing-across-the-galaxy
[4] https://iopscience.iop.org/article/10.3847/1538-4357/ab8225
[5] https://www.theregister.com/2018/03/15/drake_equation_gets_an_update_not_good_news_for_alien_hunters/
[6] https://go.theregister.com/tl/1956/-9050/free-hands-on-training-anthos-service-mesh?td=wptl1956
Good luck with that
Intelligent life on a tidally locked planet? Easier to find arguments why it is unlikely. There is only a narrow stripe which could be arable land. The rest is either too hot and bright or too cold and dark. There are no tides. Hard to explain water circulation which does not disappear into either the too hot area or too cold area. Tidally locked makes it unlikely there are plate tectonics. This also means likely there is no or are very weak magnetic field. The solar wind would remove the atmosphere in this case.
Now it would be interesting to see how all of this could be overcome regardless...
Re: Good luck with that
The answer to that would depend on your own interpretation of varying Metaphysical concepts.
Socrates and Newton might have differing opinions.
Alternatively and away from philosophical viewpoints I would personally agree with the proposition that 42 is probably the answer.
Re: Good luck with that
In a probability somewhere, 42 is almost certainly the answer, although it's a million to one chance, nine times out of ten it will/ might happen.
As for intelligent alien life, PV panels are in their infancy here, anything reasonably well advanced or subject to development we haven't thought of yet and the reflective signature will be nothing like that expected from terrestrial PV.
The commonest pollutants that we produce are often similar to normal environmental pollutants such as methane, co2, sulphur dioxide etc and there is no guarantee another civilisation will necessarily develop along the same limes that we have, the thinking seems to be either simplistic or arrogant.
Re: Good luck with that
I'd say simplistic and naieve. There would only be a very short period of time for any society to be in the state that's looking for. Even our own EM emissions are drastically reduced now we have better broadcast technology but even if you rounded things up to 100 years of high powered directionless broadcasts, that's a very small window of time that another culture has to be within reasonable of range of these transmissions and to be looking for them. A 100 year sliding window in a galaxy that is already around 13.5 billion years old? Just not going to happen, or if it does, it's a phenomenal piece of luck. A culture looking for other cultures would have to monitor many thousands of systems for many thousands of years and would still have to be incredibly lucky. Human development within the time frame of vertebrate life on Earth is pretty much a rounding error.
Our search for life should involve better and better telescopes, of varying frequencies, to look for potential signs of life, as in chemically unstable anomolies where non-routine processes are affecting the balance of elements in a planet. The alternative is for some other culture to be deliberately broadcasting signals knowing that they would have to do this for tens of thousands of years and largely to never expect a reply, at all, let alone within any form of lifetime. The stronger these signals the better as the more power the more detectable range and therefore the more potential cultures could be looking.
Re: Good luck with that
I think the idea is probably to look, first, at the plausible planets we can find which tend to be tidally-locked because they need to be in very tight orbits around very dim stars or we don't find them. Then when we get better at finding planets which really are earthlike we'll have the techniques sorted and we can look at them. This is like all the iterations of LIGO and its predecessors which no-one expected to hear anything: its technology & skill development.
Edge case
Life is an edge case in itself, is it me or does it sound like this search is searching for an edge case of an edge case of an edge case?
Re: Edge case
Which pretty much sounds like the Drake equation, a fraction of, then another fraction of, and another fraction of, etc.
Unfortunately too many unknowns, and so assumptions currently, so the Drake equation isn't all that useful really!
Re: Edge case
IMO the Drake equation, whilst a useful list of things to consider, was never really an equation in any useful sense. And in the absence of known values for parameters, you have to take a different approach; e.g.
" The Great Silence - the Controversy Concerning Extraterrestrial Intelligent Life",
G. D. Brin,
Quarterly Journal of the Royal Astronomical Society 24, 283-309 (1983)
(you should be able to find a pdf online if you search)
Reminds me of a song
Especially the last line of the lyrics of [1]this one
[1] https://www.youtube.com/watch?v=buqtdpuZxvk&t=32s
Re: Reminds me of a song
Or pretty much all of [1]this one, flat-out titled 'The Drake Equation' .
[1] https://youtu.be/v2HoyR9EXw4
Evidence?
"... planetary atmospheres spewing pollutants" are "... evidence of intelligence in other places than Earth" ?? The phenomenon is evidence of lack of intelligence here on Earth.
Quite apart from which, why should the technologies of an alien planet be automatically similar to our own?
Re: Evidence?
If we really believe that life will be similar to our on another world then we should be checking for facebook and twitter postings too. But maybe "life" could be like ours but very different, does anyone remember the intelligent alien locusts in the movie "Independence Day"? They had invented UNIX but that didn't make them like us ... or maybe, these days, it did?
Re: Evidence?
We made the mistake of using Unix, SCO vs Mystronix has been going on for over 20 years now and they are still trying to get us to use our regenerative powers to make their money reappear.
Apparently replacing Kill with "WESHALLBEAVENGED" and ECHO with "THISISTHEVOICEOFTHEMYSTERONS" isnt enough
Re: Evidence?
> why should the technologies of an alien planet be automatically similar to our own?
Indeed. We're way too narrow-minded. Looking for solar panels? Why not look for blockchain and IoT too? Do those aliens really need to check all the current buzzwords of human technology?
The environmental conditions of their planet are most likely to be different, meaning those aliens will be quite different from us, and have found completely different solutions to their completely different problems.
And even if this is a low-budget universe, and aliens are just regular humans with strange skin colors, living on a totally USA-like planet, why would they necessarily be exactly in our time frame of solar panels and mindless pollution? In human history it is but a short flash. Those aliens might be already mastering fusion, or they might have enough volcanic activity to be able to use geothermal power generation at large scale (for instance).
In short, those people are searching for humans , not for alien intelligent life ...
Other signs
Given the probable outcome of the only civilisation we know about, I wonder whether it might be more useful to look for the signatures of dead civilisations. Perhaps our civilisation might have been detectible by 1900, and if we assume it will be dead by 2200 at the latest then the chance of finding it alive are tiny.
So, for instance, how detectible and characteristic is the result of a nuclear way, say? It might be quite characteristic as there will be lots of decay products from weapons which might be quite distinct from the stuff dying stars spit out. Of course you need to look for long-lived things and they don't emit much, which is why they're long-lived.
Another approach I wondered about is: how bright are the flashes from nuclear weapons? Are they bright enough that you could see them from far enough to expand the search area for planets far enough to make it worth looking for them? Of course they'd also need to be distinct enough to be able to find them (does the double-flash thing from a nuclear weapon help?).
Re: Other signs
Problem is, nuclear wars don't last long so you will be looking for very short duration flashes.
Every way I look at it, I keep coming back to the relative numbers - long time, long distance, short lived civilizations etc. Even if we have one civilization per star we are looking at a signature of a vary small number of years relative to the life of the stars.
I'd love to see proof of intellligent (well any) life outside of our own particular paradise but I think I will be dead before we find it. We haven't even found it in our own back yard yet.
I really do hope we are not alone - the universe would be a complete failure if we were all/the best it had to offer :-)
And there's me thinking...
..that the technosignature is usually 4/4 at around 140 bpm.