Opinion: Why the $100m alien listening project may be a huge waste of time

Opinion: Why the $100m alien listening project may be a huge waste of time
Credit: Beckie/Flickr, CC BY-SA

The launch of the $100M Breakthrough Initiative project to Search for Extraterrestrial Intelligence (SETI) has been supported by many leading scientists including Stephen Hawking and astronomer royal Martin Rees. But there is no evidence – and few convincing theories – to suggest that intelligent, communicative aliens actually exist. So are listening projects really the best way to search for extraterrestrial life?

The possibility of life outside our own planet has been the subject of debate for centuries, with the essence of the problem crystallised by Italian physicist Enrico Fermi in 1950. His now famous "Fermi paradox" runs simply: if intelligent life exists elsewhere in the Galaxy, then why do we see no evidence for it?

Colonising the galaxy – hard but possible

We now know that planets around other stars are very common. Since the first discovery of a planet orbiting the star 51 Pegasi in 1995, around 2000 exoplanets have now been found. Most of these are close by – within a few hundred light years.

Statistical analysis of the results from the Kepler spacecraft suggest that as many as one-fifth of all sun-like stars has an Earth-like planet in its habitable zone, where conditions are such that liquid water could exist.

So if planets are so plentiful, then what about life? The Drake equation, formulated by Frank Drake in 1961, attempts to answer this question by suggesting there could be many civilisations in the Milky Way that we should be able to communicate with.

However, while many of the terms in the equation are now known fairly well, others are highly uncertain. But let's assume for a moment that such civilisations do exist. If they do, then might we notice them? A straightforward way for an alien civilisation to make itself known is simply to colonise the galaxy. Let's consider how long this might take, assuming technology that is not too far away.

It would be possible now to build probes that could be sent out into space to search for other planets, land on them, and build replicas of the probe that could in turn be sent out to other planets and so on.

At the sort of speeds we can now imagine, such as that achieved by the New Horizons spacecraft (60,000 km/h), it would take a mere 18,000 years to travel a distance of one light-year. Let's assume such a probe were sent to a planet ten light-years away, arriving after 180,000 years. It then builds ten copies of itself, and sends them off to other planets, each a further ten light years-away. In this way it would take only 5,000 probe generations to fill the entire galaxy – an accomplishment that would be achieved in less than a billion years.

But it's not hard to imagine that an advanced civilisation might produce space probes that could travel significantly faster than ours currently do, so colonising the galaxy in just a few hundred million years is not unlikely.

Opinion: Why the $100m alien listening project may be a huge waste of time
Credit: Nick Risinger/wikimedia

But here's the thing: the Milky Way has existed for around ten billion years, and we know that some planets exist around stars that are almost this old. So if intelligent life really is common, the likelihood is that it evolved elsewhere to our stage of intelligence several billion years ago, giving it plenty of time to colonise the galaxy. So where is everybody?

Are we all alone …?

Entire books have been written exploring the various solutions to the Fermi paradox, but they fall into the following general categories.

Rare Earth: It may be that there are no civilisations in the galaxy any more advanced than we are. Perhaps the combination of astronomical, geological, chemical and biological factors needed to allow the emergence of complex, multicellular life is just so unlikely that it's only happened once.

Doomsday: Perhaps life and civilisations emerge often, but it is the nature of "intelligent" life to destroy itself within a few hundred years?. The human race certainly has no shortage of ways of accomplishing this, whether it's via physical, chemical or biological weapons of mass destruction, or as a result of climate change, or even a nanotechnology catastrophe. If life doesn't persist very long on any planet, we shouldn't expect to see much evidence of it around the galaxy.

Extinction: Even if we don't wipe ourselves out, perhaps the universe conspires to eliminate civilisations on a regular basis? It's clear on Earth that there have been at least five mass extinctions. Some of these may have been triggered by the impact of massive asteroids, but other possible extinction causing events might include nearby supernovae or gamma-ray bursts.

…or are the aliens just hiding?

There is another class of possible solutions to the Fermi paradox that boil down to the fact that alien civilisations do exist, but we simply see no evidence of them.

Opinion: Why the $100m alien listening project may be a huge waste of time
Is intelligent life destined to destroy itself? Credit: United States Department of Energy/wikimedia

Distance scales: Perhaps civilisations are spread too thinly throughout the Galaxy to effectively communicate with each other? Civilisations may be separated in space, and also in time, so two civilisations just don't overlap during the time that they're each active.

Technical problems: Maybe we're not looking in the right place, or in the right way? Or maybe we just haven't been looking for long enough? Perhaps we've not recognised a signal that's out there, because the alien civilisation is using technology that we simply cannot comprehend.

Isolationist: Perhaps the aliens are out there, but they're choosing to hide themselves from us? Perhaps everyone is listening, but nobody is transmitting? It may be that other civilisations know we're here, but the Earth is purposely isolated, as if we're some kind of exhibit in a zoo.

Finally, there are of course the more extreme possibilities such as that the Galaxy that we observe to be empty of life is a simulation, constructed by aliens. Or perhaps the aliens are already here among us. Such speculation is great for science fiction, but without evidence, it's not worth pursuing further.

My own hunch is that life is indeed common in the galaxy, but is rare – either because it doesn't evolve very often, or it doesn't last very long once it does. For that reason I think that SETI programmes are probably doomed to fail – although I would love to be proved wrong.

Instead I think the best chance of finding life elsewhere in the galaxy is through spectroscopy of the atmospheres of transiting terrestrial planets. That will be carried out by missions such as such as the European Space Agency's PLATO spacecraft, due for launch in 2024. Such life may just be a green slime that we can scrape off a rock with our finger, but its detection would truly transform our view of the universe, and ourselves.

Explore further

Intelligent life in the universe? Phone home, dammit!

This story is published courtesy of The Conversation (under Creative Commons-Attribution/No derivatives).The Conversation

Citation: Opinion: Why the $100m alien listening project may be a huge waste of time (2015, July 23) retrieved 21 August 2019 from https://phys.org/news/2015-07-opinion-100m-alien-huge.html
This document is subject to copyright. Apart from any fair dealing for the purpose of private study or research, no part may be reproduced without the written permission. The content is provided for information purposes only.

Feedback to editors

User comments

Jul 23, 2015
Its always been realised that the money spent on SETI may not result in anything. If the money is there though why not go both routes - imaging candidate planets and scanning radio signals? The longer and more thoroughly we look, the firmer our conclusions will be either way...

Jul 23, 2015
Spare me. Scientific questions, even when ansered in the negative, are never considered "a huge waste of time" except when policy or politics come into play. Who would today say that searching for exoplanets would be a waste of time?

SETI is complementary to exoplanet characterization, each has its problems and potential rewards. (Sometimes they are the same, such as when looking for light sources on night hemispheres.) And eaxch have their time table, we can do SETI today but _habitable_ exoplanet atmospheres will not be studied in the next couple of years while we wait for the technology to do so.


Jul 23, 2015

Finally, we shouldn't call it "Fermi's paradox" since it isn't his conjecture, except if we want to advance policy or politics. It is the Hart-Tipler Conjecture, originally (and still) promoted by those who opinion against SETI. [ http://www.univer...jecture/ ] I expect a professor of astrophysics to know that. It is a too unconstrained conjecture (unknown frequency of false negatives) to be useful.

@markush: Sorry, I voted you down erroneously in haste. (I blame a rare cold - how do people stand these things anyway?) You say pretty much what I think, and I wouldn't down vote myself now, would I? ;-) But it doesn't seem to be a way to revoke votes on this site.

Jul 23, 2015
"Where is everybody?"

-They've all been replaced by machines. Machines have no reason to communicate with organic lifeforms.

The machine singularity is a common explanation. I'm surprised it's not included in the article.

We are already busy designing machines which are far more competent than we are at many things. Look at the progress in only the last century.

What will be the result of this trend in another century? 10 centuries? 100?

100,000 years is but a blip on the timescale of the universe. No reason to think that organic sentience wouldn't typically replace itself shortly after it emerged, and have absolutely nothing to say to us.

Jul 23, 2015
""Fermi paradox" runs simply: if intelligent life exists elsewhere in the Galaxy, then why do we see no evidence for it?"

It's not a paradox if the premise isn't true. There is plenty of evidence by credible eye witnesses that UFO's are real. Hell, pilots have seen mile long spacecraft out their windows.

Jul 23, 2015
This comment has been removed by a moderator.

Jul 23, 2015
Technological intelligent life is around 35 light years (ish) away in the Pegasus region...

Jul 23, 2015
The machine singularity is a common explanation. I'm surprised it's not included in the article.

It was implicitly implied by the article, i.e. the self-replicating probes.

Given how quickly technology is moving after only a few hundred years of organized science, the article's suggestion that a galaxy would be quickly colonized by an intelligent civilization is on solid ground.

It wouldn't matter if they wanted to communicate with us or not. A civilization harnessing the resources of a galaxy should be obvious due to galactic-level engineering and energy harvesting.

Since our galaxy has not been obviously tampered with, and stars continue to radiate their energy off into space uncollected, it is unlikely a successful civilization has come before us.

Jul 23, 2015
As exciting as it would be to discover other intelligent life, our future is much brighter if it doesn't exist.

Even a civilization a few thousand years ahead of us would render our technology irrelevant and we would exist completely at their mercy.

Also, an advanced civilization would likely have trillions times trillions (or more) individuals, making a few billion human individuals insignificant in the scheme of things.

Jul 23, 2015
More and more of our communications are via the internet and more and more of the internet is encrypted. An ever smaller part of our communications are over long-range radio. That part will sound like noise without the encryption keys, so.aliens will not be able to distinguish our signals from natural ones. On the scale of our species, the time between the discovery of radio and undetectability is short.

So for us, so for aliens. You can detect aliens by their radio signals only at the beginning of their technical period.

In conclusion, form the list of reasons offered by the article, "Technical problems" seems the best answer.

Jul 23, 2015
Should probably look for systems undergoing sudden cataclysmic events.. Those are usually keen on establishing radio communications and sending out sos signals, although unethical :-)

Jul 23, 2015
"An ever smaller part of our communications are over long-range radio."

Yeah, that's been the most ridiculous thing about SETI, assuming we could catch a civilization just in that brief period of time they were using radio waves to communicate, in all those vast billions of years. It's been nothing but a colossal waste of resources, the odds of success on that basis are infinitesimal.

Jul 23, 2015
Of course we're not alone. Unfortunately, the vast distances of space make meeting impossible.

Jul 23, 2015
It would be possible now to build probes that could ... build replicas
Really? "Now"? That is where the article starts smelling bad, obviously it has not been written by a scientist, not even amateur. We can't do this "now", we are not even close to it!
It is a pity to read fake science about this because the subject is really interesting. To start with, the closest device to an auto-replicating machine that we have is a 3D printer. The fact is that it could print most of the pieces and basic circuitry, but not the critical components. We can't print the CPU, precise cameras & lenses, lasers.. not yet. Probably nothing unsolvable, but there huge problems to solve. Once it is solved then yes, print miner robots, ovens for mineral processing, produce electricity (windmills are easy), batteries (flywheels are among the easiest ones), and finally build replicas. Rockets & fuel are not the most complex. But to start with, we need to figure out how to print a 3D printer!

Jul 23, 2015
There are some common assumptions in this article that are simply not reasonable.

Isolationist: This one suffers from the odd man out problem. It tacitly assumes that EVERY other alien race out there - except us - is the same - xenophobic or has a reason not to travel to or communicate with other civilizations. That's one huge conspiracy theory.

Technical problems: I often hear the suggestion that aliens are using 'some other technology'. Here's the thing. You have to take into account the laws of physics. The simplest force carrier you can generate intentionally that works over distance is electromagnetism. Electrons are the simplest stable carrier of it. Every civilisation will have to go through an EM tech phase just to get to any other tech. The radio signals from that should be very easy to spot if civilisations are wide spread and common. And we don't see that.

Jul 23, 2015
It is imperative that we find them before they find us.

Jul 23, 2015
One benefit is that it will keep a couple of radio telescopes out of mothballs, and upgrade their equipment too, so that other science studies should get better results. Even if nothing is found the project will have been more useful than filling out many rejected grant applications.

Jul 23, 2015
Technological intelligent life is around 35 light years (ish) away in the Pegasus region...

I like the (ish.) LoL

Jul 24, 2015
It is imperative that we find them before they find us.

Hint: the more advanced species is pretty much assured to find the less advanced species first.
- If they're more advance they already know we're here by the time we find them.
- If they're less advanced when we find them they're not a problem.

(In any case why would another species be a problem? We certainly won't compete for resources or land or other such rubbish. None of that matters when you have the capability to go interplanetary - much less interstellar)

Jul 24, 2015
It is fun to speculate on intelligent life elsewhere. It is even fun to speculate on life in general elsewhere. But until/unless we find life outside this solar system, we can assign no probability to the emergence of life anywhere but here.

Our search should concentrate on an atmosphere like earth (now) since our atmosphere requires life to create and sustain it.

Jul 25, 2015
Communications on this planet are becoming less diffuse, and more directed, thanks to cable and lasers. Could it not be the case that advanced alien civilizations use very directed communications that are beyond our ability to detect, unless such is directed at us?

Jul 25, 2015
Given the virtually infinite possible environments which we understand as viable for intelligent life development and the infinitesimal probability that such life might evolve there we are left with the (infinity * zero) probability that it has happened and the even smaller probability that we might detect it in a time period relevant to human time scale and even less that we could do anything meaningful with the information, it remains in the realm of scientific curiosity or religion but of no real consequence to our species.

Jul 25, 2015
Until we have reason to think otherwise, the most scientific assumption is that we're a fairly run-of-the-mill form of life, orbiting an unremarkable star upon an unremarkable planet.

Most people seriously over-estimate our ability to detect radio signals – in fact the only signals that we generate that we could detect even as far away as the nearest star, are 1.) high-powered radar (which contains no meaningful information), and 2.) the 3-minute 1974 Arecibo broadcast. And we're not currently scanning radar frequencies.

Frankly I think we'll have a much better shot when we can detect artificial light on the dark sides of orbiting planets, because the radio era is likely to be as brief elsewhere as it's been here – and that defines a very narrow shell of signals radiating from a newly industrialized planet...and more advanced transmissions are going to be more efficient (lower energy and more focused on the receivers).

Jul 27, 2015
I think the entire universe has only become recently habitable.

Yes, the galaxy has existed for 10 billion years, but their was much fewer heavy elements. I think the rate of supernova is important as well.

It took 4 billion years for intelligent life to evolve.
If super nova rates are above a certain threshold, maybe it just became statistically so unlikely for a planet to go 4 billion years without receiving a radiation blast and wiping out complex life on a planet that it just never happened.

I think the silence is a combination of the rarity of the right solar system and planetary environment to create the conditions that drove the evolution on earth to what it is today, and just statistics of the environment in the universe and the galaxy in the past.
I think the universe is only recently really coming alive and that the other civilizations are just rare and young enough that any galactic sized colonization effort is simply to new of a thing for our telescopes to see.

Jul 27, 2015
My guess is that there are a few civilizations out there and they have clear knowledge of us, but they avoid us for a reason: our planet and its surroundings may be possessed by dangerous beings that contaminate any intelligent life they come in contact with to the point of its utter destruction.

These are the green or gray daemons that played for us at times as fairies, ghosts or recently as aliens, while performing scary procedures in order to inculcate us with their demonic character. Their essence is chaos and the destruction of anything orderly and right.

Somehow (or by someone?) humans are shielded to a degree from their maleficient actions so that they can carry on, while at the same time having to do with their enmity, traps and strikes. But other civilizations may not be able to bear them so that the best approach for them is to steer away from our surroundings and leave no sign of their existence.

Or at least that's what I think is plausible.

Jul 27, 2015
Its a waste of time because there is no evidence alien life exists? Hello idiot writer, that's what the project is for, to try to find evidence.

Whiel I agree that we should be looking: Looking by listening for radio signals is pretty much pointless. I can see no scenario where this would/could yield results. All the assumptions about 'broadcasting aliens' seem deeply flawed (not THAT any are broadcasting, but the notion that any are so advanced as to be broadcasting with enough power for us to notice while at the same time being so primitive as to be unaware of how to do directional transmissions. It's much easiert to figure out how antennas work before you get to the 'massive power emitter' stage)

Jul 27, 2015
Thanks yob,
I remember reading about that when that study was first published.
Panspermia is a cool idea, I hope when I'm an old man we have enough data to be able to reflect on these ideas in a more meaningful way.

Aug 02, 2015
Judging from the intelligent life on this planet, most of it wouldn't give a rats arse about using a spoon, let alone a radio.
Why should we expect anything different in the rest of creation?
Here is my guess. Life on other planets has oodles of intelligent life. Just like we do. Question: which animal has the largest brain on this planet? (Please don't regurgitate that self-aggrandising rationalization about brain/bodyweight ratio. Brains have only one function, and it is not to cool the blood).
So which one? Have you guessed yet? The Sperm Whale, you stupid Ape.
Does the Sperm whale try to communicate with the rest of creation?
And do you recognize his superior intelligence?
No to both.

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more