A universe full of dead aliens

Gwynston

Not much new here, but it's a relatively interesting high-level article with a good number of reference links:
We’re Probably Living In A Universe Full Of Dead Aliens

The stand-out take for me is how the Gaia hypothesis might well out-weigh the Goldilocks zone theory:

Planetary habitability is a property more associated with an unusually rapid evolution of biological regulation of surface volatiles than with the luminosity and distance to the host star

jcsoulinger

If an alien race had evolved to a level above us then why would they contact us? No good would come from it, I reckon our only chance of contact is with a race that are equally evolved and are also just sending out radio waves in a stab in the dark kind of way.

hgfj

If an alien race had evolved to a level above us then why would they NOT contact us? They would have nothing to fear from us as they would be technologically superior to us. Also, what if we were the ONLY OTHER intelligent life-form they had come across? Surely curiosity alone would entail some kind of contact. Being more technologically advanced than us wouldn't mean they have nothing to learn from us.

seamus

The problem with discussions that try to draw conclusions from the silence of the universe is that they lack sufficient information to draw those conclusions in the first place.

If I were stand in the middle of the sahara shouting "Hello?" over and over for my entire life, it's pretty likely that I would never see or hear from anyone. So I could conclude that everyone else is gone. On an astronomical scale I can move a centimetre or so in any direction to try and shout from there. I can also whip out a telescope, but I'm not going to be able to detect a human at 500km.

A passing satellite might spot me; but from its point of view I'm one of several billion and therefore not exactly remarkable and worthy of investigation.

When I get to the stage of launching my own satellites, then the US government might send someone out to find out WTF I'm doing.

Avatar MIA

seamus wrote: »

not exactly remarkable and worthy of investigation.

Bit harsh on yourself there, Seamus.

hgfj

“Even if life does emerge on a planet, it rarely evolves quickly enough to regulate greenhouse gases, and thereby keep surface temperatures compatible with liquid water and habitability,”

The above quote is taken from OP link about 5 or 6 paragraphs down. I'd be curious to know how many other planets life has emerged on to justify stating "it rarely evolves quick enough". So far as I know Earth is the only planet where any form of life has evolved that we know of. Do the authors know something the rest of us don't?

jcsoulinger

hgfj wrote: »

If an alien race had evolved to a level above us then why would they NOT contact us? They would have nothing to fear from us as they would be technologically superior to us. Also, what if we were the ONLY OTHER intelligent life-form they had come across? Surely curiosity alone would entail some kind of contact. Being more technologically advanced than us wouldn't mean they have nothing to learn from us.

If we discovered a race of monkeys on a planet in the next solar system over, what would we learn from them? our first concern would be not to do anything that would have any effect on there habitat, it could be we decide the best course of action is to observe them from afar.

qrx

hgfj wrote: »

“Even if life does emerge on a planet, it rarely evolves quickly enough to regulate greenhouse gases, and thereby keep surface temperatures compatible with liquid water and habitability,”

The above quote is taken from OP link about 5 or 6 paragraphs down. I'd be curious to know how many other planets life has emerged on to justify stating "it rarely evolves quick enough". So far as I know Earth is the only planet where any form of life has evolved that we know of. Do the authors know something the rest of us don't?

Theoretical models and computations. Problem is their models are only as good as the data they put in. The question is, do we need more data to get a better and more accurate understanding or is the data good enough already?

qrx

Could very well be that the universe is teeming with life and they just don't know we are here. Maybe they use something other than radio waves? Maybe Jupiter is in the way and blocking their view? We could be the equivalent of an undiscovered amazon tribe.

qrx

Gwynston wrote: »

The stand-out take for me is how the Gaia hypothesis might well out-weigh the Goldilocks zone theory:

Taken from the Wikipedia link within the article:

the Gaia hypothesis continues to attract criticism, and today some scientists consider it to be only weakly supported by, or at odds with, the available evidence

jcsoulinger

qrx wrote: »

Could very well be that the universe is teeming with life and they just don't know we are here. Maybe they use something other than radio waves? Maybe Jupiter is in the way and blocking their view? We could be the equivalent of an undiscovered amazon tribe.

Jupiter in the way? Only if it's constantly eclipsing us.

PirateShampoo

hgfj wrote: »

If an alien race had evolved to a level above us then why would they NOT contact us? They would have nothing to fear from us as they would be technologically superior to us. Also, what if we were the ONLY OTHER intelligent life-form they had come across? Surely curiosity alone would entail some kind of contact. Being more technologically advanced than us wouldn't mean they have nothing to learn from us.

That's assuming they view us as a Intelligent life form and not mearly as Monkeys using a rock to break open a nut.

hgfj

jcsoulinger wrote: »

If we discovered a race of monkeys on a planet in the next solar system over, what would we learn from them? our first concern would be not to do anything that would have any effect on there habitat, it could be we decide the best course of action is to observe them from afar.

I think we'd have a hard time trying to contact a race of monkeys, or any other unintelligent life form for that matter. What would even be the point? They would have nothing to tell us anymore than a monkey on Earth would. So yes , unintelligent life forms could simply be observed from afar but if the life form discovered was intelligent, albeit less technologically advanced, then at least we could communicate with them.

jcsoulinger

hgfj wrote: »

I think we'd have a hard time trying to contact a race of monkeys, or any other unintelligent life form for that matter. What would even be the point? They would have nothing to tell us anymore than a monkey on Earth would. So yes , unintelligent life forms could simply be observed from afar but if the life form discovered was intelligent, albeit less technologically advanced, then at least we could communicate with them.

We are not far above monkeys on the evolutionary path yet we are completely dismissive of them, if this being is even slightly more evolved it will more than lightly see us in the same way.

It may also realise that any contact could have potential risks to our development so why risk it when they have nothing to gain anyway, As I said before there first concern would probably be our preservation.

Gwynston

the Gaia hypothesis continues to attract criticism, and today some scientists consider it to be only weakly supported by, or at odds with, the available evidence

Fair enough, but it's not much worse than the Goldilocks theory IMO.

Just look at Mars and Venus in our own Goldilocks zone (or close, anyway). They're good examples of how many different factors drive a planet's chaotic path away from habitability (as we know it).

And with serious consideration being given to the potential for life on moons around Jupiter and Saturn, we can see that there are other possible mechanisms that lead towards habitability.

Maximus Alexander

jcsoulinger wrote: »

If we discovered a race of monkeys on a planet in the next solar system over, what would we learn from them? our first concern would be not to do anything that would have any effect on there habitat, it could be we decide the best course of action is to observe them from afar.

We'd have to discover and observe them first in order to be able to answer that question...

hgfj

I would say we are tens of thousands of years ahead of monkeys on the evolutionary path. There may not be a huge difference DNA wise but when it comes to intelligence and self-awareness there is little comparison. Our brains have evolved far beyond any other living creature on this planet in terms of intelligence and self-awareness. Yet there is no reason to assume that intelligent aliens are MORE intelligent than us just because they may be more technologically advanced. They may be more knowledgeable and have discovered things that we haven't discovered yet, but then are we more intelligent than our ancestors from just 100 years ago simply because our society is more advanced than back then? I reckon Newton or Galileo would disagree.

jcsoulinger

Tens of thousands of years is nothing in an evolutionary sense.

In my original post I said that if they were on a similar level of evolution then they would try and make contact.

In the article it assumed that had we been discovered by an et race they would make contact, I am only suggesting the reasons why they might choose to not make contact.

Another reason is if they had discovered us they would first observe us, It would not take them long to conclude we as a race are not ready to be contacted.

seamus

"Similar level of evolution" is something of a misnomer. There are no "levels" of evolution, nothing is "more evolved" than anything else.

Evolution doesn't have a set path that it follows where it is trying to achieve peak intelligence. Intelligence is an emergent property of evolution under certain conditions.

My point is that while we see a gulf of a world between ourselves and a chimpanzee, in real terms we are closer to chimps in evolutionary terms than chimps are to Orangutans.

Yet we would tend to place them both into the "monkeys" bucket because they have similar behaviours. Climbing trees and using simple tools - old hat, fairly primitive, a curiosity.

For aliens with the capability to travel between worlds and carry out surveillance, the existence of a species who has developed agriculture, electricity and basic machinery may similarly be quite unremarkable. Such species might be everywhere; old hat, fairly primitive, a curiosity.

Why would they go out of their way to make contact?

Gwynston

seamus wrote: »

Why would they go out of their way to make contact?

For the same reason we humans go out of our way to observe and make contact with gorillas in the remote mountains of Rwanda.

If tomorrow a rover on Mars suddenly detected trace signs of life in ice under rock, do you think we wouldn't immediately invest vast sums to launch new exploratory missions to find out all we could about it?

Just because life on another planet is more primitive than us, it doesn't mean we wouldn't want to investigate....

jcsoulinger

Gwynston wrote: »

For the same reason we humans go out of our way to observe and make contact with gorillas in the remote mountains of Rwanda.

If tomorrow a rover on Mars suddenly detected trace signs of life in ice under rock, do you think we wouldn't immediately invest vast sums to launch new exploratory missions to find out all we could about it?

Just because life on another planet is more primitive than us, it doesn't mean we wouldn't want to investigate....

No one is saying they wouldn't investigate, it's making contact that's the issue

hgfj

Such species might indeed be everywhere. On the other hand they might not. And if not, then if an intelligent species discovered another intelligent species, regardless of their technological capabilities, and if that was the only other alien intelligence they had ever come across, then why not? They may be just as interested in our philosophical outlook on life, the universe and everything as they might be in anything else. They may actually want to get to know us. They may decide they want to help us advance. No doubt they would spend time observing us for a period but eventually if they felt safe enough and were not afraid of us I don't see why they wouldn't want to contact us.

Gwynston

Exactly what I was thinking, hgfj.

Just like Europeans sought to explore new lands and make contact with "more primitive" natives.

Not that that worked out especially well for the natives, mind... :eek:

Maximus Alexander

seamus wrote: »

For aliens with the capability to travel between worlds and carry out surveillance, the existence of a species who has developed agriculture, electricity and basic machinery may similarly be quite unremarkable. Such species might be everywhere; old hat, fairly primitive, a curiosity.

Why would they go out of their way to make contact?

I see two possible reasons straight off the bat. Firstly, the great apes don't appear to simply be further behind us on the technological tree - they appear to be completely incapable of ever developing language and technology like ours; at least without eventually evolving into something else entirely. We can't, for example, take a chimpanzee from birth and teach it to be as clever as a human, whereas we could do that if we snatched some humans from the neolithic period.

The point being that if we suppose that humans are capable of one day travelling between the stars then the gulf between such a species and ours may only be one of knowledge, rather than intelligence. That would be quite a different thing than the gulf between ourselves and the great apes. Yet even so, we (as a species) do find the great apes interesting. We do study them and try to communicate with them and teach them language and tool use, for example. Their lesser intelligence doesn't negate our curiosity.

The second problem is that it seems a massive leap to assume that if a more advanced species exists and is roaming the stars, then creatures at our level of advancement must be common, unremarkable, and old hat. Even if we suppose that the evolution of intelligent species was surprisingly common, perhaps we are one of the few who make it this far without wiping themselves out after the discovery of nuclear weapons, for example. Or perhaps we are on the cusp of some even greater discovery that will almost surely wipe us out as it does most other intelligent species.

We might be incredibly rare and interesting, we might be relatively common yet still interesting due to some small unique trait or development, or we might even be completely alone.

It seems to me just as fallacious to assume that they would not attempt contact, as it is to assume that they would. We simply don't know.

user1842

I really think the issue is "time". The chances that an alien civilisation exists at the same time as us is negligible. Our intelligence exists in an infinitesimal small time period in relation to the age of the universe. Civilisation does not exist forever and probably many civilisations have started and died even before the Earth was created and probably many will start and die after the Earth is consumed by our star.

Aliens may have visited Earth but humans did not exist at the time and may visit in the future when everyone is dead.

The chance that they visit us our we visit them when we both exist at the same time in the age of the universe is tiny.

And by the same time I mean give or take a couple of 10 thousand years.

storker

user1842 wrote: »

Aliens may have visited Earth but humans did not exist at the time and may visit in the future when everyone is dead.

Imagine an alien exploration mission landing on earth long after humans have gone, perhaps even after all life has gone, and all trace of us vanished. They look around, take some samples, do some analysis and conclude, "Nope, nothing here...dead planet..." and off they go, oblivious to the amazing story that had played itself out long before they arrived...

jcsoulinger

We don't know and this probably won't change in our life time.

The Ops article suggests that there isnt a more intelligent life form in the universe than us as they would have made contact already.

Imo it is reasonable to assume that a more intelligent et race would choose not to make contact,

Gwynston

That kind of assumes species don't get much more advanced than us before dying out.

But the romantic argument against that is that if species get to a higher level capable of travelling around the galaxy, they'll also be capable of surviving much longer than a few thousand years. They won't be constrained by the limited resources of their original home.

That's why the length of time a species lasts is a fundamental part of the Drake equation, and is crucial to indicating if we are likely to encounter intelligent aliens during our existence.

Saipanne

Loads of folk assuming to know what advanced aliens would think. I'd take the more humble road, personally, and claim not to know what a more advanced being would think.

jcsoulinger

Saipanne wrote: »

Loads of folk assuming to know what advanced aliens would think. I'd take the more humble road, personally, and claim not to know what a more advanced being would think.

Lol no one here is saying they know what aliens think, we are all just speculating, nothing to do with being humble.

hgfj

Personally, I love the idea of an advanced alien civilisation zipping about the universe at warp speed in and out of wormholes exploring new planets and whatnot, and all the while scratching their heads saying, "Okay, we know this and we know that, we understand this and we understand that but what does it all mean?"

Gwynston

hgfj wrote: »

Personally, I love the idea of an advanced alien civilisation zipping about the universe at warp speed in and out of wormholes exploring new planets and whatnot, and all the while scratching their heads saying, "Okay, we know this and we know that, we understand this and we understand that but what does it all mean?"

Well obviously the answer is 42.
All they need now is to find Earth to work out what the question means! :P
(Before it gets destroyed prematurely...)

Stuxnet

"Earth's broadcasts reach only about 80 light-years into space. If humanity is average, then other civilizations would have reached a similar distance, covering less than a tenth of 1 percent of the Milky Way."

We may have to wait 1500 years lads to hear anything !!

http://www.space.com/33203-aliens-extraterrestrial-life-1500-years-for-contact.html

qrx

Stuxnet wrote: »

"Earth's broadcasts reach only about 80 light-years into space. If humanity is average, then other civilizations would have reached a similar distance, covering less than a tenth of 1 percent of the Milky Way."

We may have to wait 1500 years lads to hear anything !!

http://www.space.com/33203-aliens-extraterrestrial-life-1500-years-for-contact.html

And seeing as the first broadcasts they'll see are the Nazis, chances are they'll want to avoid us.

Gwynston

qrx wrote: »

And seeing as the first broadcasts they'll see are the Nazis, chances are they'll want to avoid us.

To be fair, I don't think the Nazis broadcast much of the bad stuff they were doing. Their early powerful broadcasts were all populist propaganda, so aliens viewing them might actually be impressed by such a well-ordered and well-behaved civilisation...

ThunderCat

I'm not sure contact is necessary on the part of a species far more technologically advanced than us. If they have the means to travel between the stars then they are advanced enough to send microscopic probes undetectable to us to Earth to observe what life is like here.

PMBC

What is the current thinking on the 'Drake Equation' which estimated the chance of more life forms in the Universe - I think it didn't allow for stages of development/evolution i.e. that life forms might be at single cell or other early status?

Gwynston

Yes, the Drake equation does include something for that:
https://en.wikipedia.org/wiki/Drake_equation

L = the length of time for which such civilizations release detectable signals into space

The trouble with the the Drake question though is that the result varies hugely with a small change of any one of the factors.

So what might seem like logical values can produce promising results, but a reasonable small tweek to one parameter up or down to see what variation it causes, ends up with something wildly different and a supposedly unrelated answer. In practice this means the input values can be subconsciously fiddled in order to produce a pre-conceived desired outcome.

It is useful in helping to understand the factors that inevitably affect the possibility of there being other intelligent life out there. But it's no good at giving an accurate answer as most of the inputs are wild guesses!

qrx

Gwynston wrote: »

Yes, the Drake equation does include something for that:
https://en.wikipedia.org/wiki/Drake_equation


The trouble with the the Drake question though is that the result varies hugely with a small change of any one of the factors.

So what might seem like logical values can produce promising results, but a reasonable small tweek to one parameter up or down to see what variation it causes, ends up with something wildly different and a supposedly unrelated answer. In practice this means the input values can be subconsciously fiddled in order to produce a pre-conceived desired outcome.

It is useful in helping to understand the factors that inevitably affect the possibility of there being other intelligent life out there. But it's no good at giving an accurate answer as most of the inputs are wild guesses!

If seti detects your post it'll be another Wow moment.

mickmackey1

What I don't often see discussed is that aliens could be in the same boat as us... even if they are a million years ahead of humans they could be a million years behind other aliens. So they cannot embark on galactic voyages because of the superior technology they might encounter. Which could be a possible solution to the Fermi paradox.

ps200306

I didn't find the paper referenced from the article in the OP all that compelling. First of all, the idea that there is no stable circumstellar habitable zone, and that life must evolve fast enough to make the biosphere self-regulating... how can we possibly have any idea of the likelihood of that? Isn't is just as likely that a planet will push itself out of the CHZ on the way to self-regulation? For instance, imagine a four billion year old Mars with a thick CO2 atmosphere and liquid water. If photosynthesis evolves and floods the atmosphere with oxygen, it probably pushes Mars over the age so that the water freezes, the atmosphere thins and gets lost over time due to lower gravity. The point is Mars was close to the edge to begin with.

Was it inevitable that earth would evolve toward a self-regulating competition between respiration and photosynthesis? The oxygen would initially have been a poisonous waste product. How important, and how common, is the percentage of metallic iron that we have in the planet's crust? It kept the oxygen levels down for a billion years until the surface had literally rusted. How self-regulating was the resulting system anyway? We seem to have had a high-oxygen period during the Carboniferous when a lot of plant life died and was buried in an anoxic environment, giving rise to the buried hydrocarbons that we are unleashing today. Giant insects preserved in amber from the period suggest that oxygen levels were several percent above present day levels. Could we survive today at that level?

The problem is there are so many contingencies and what-ifs with poorly understood answers that it's hard to say anything reliably. The only definite fact is that the universe is not teeming with advanced life anxious to talk to us. It might be dead, or we might be too dumb, who knows. The naive version of the Drake equation certainly seems to have some holes in it, just as we are discovering that exoplanets are as common as muck.

Gwynston

ps200306 wrote: »

Isn't is just as likely that a planet will push itself out of the CHZ on the way to self-regulation?

Well yes, of course. There are way more possible uninhabitable outcomes than habitable ones. It just so happens that we ended up in one that worked out, so we're in the position try to look back time and speculate what happened. Obviously there's no-one on all the dead planets that didn't work out habitable to compare with.

But that's not to say that out of the billions of planets in the galaxy, a few couldn't have followed a self-regulating biosphere kind of model.

ps200306

Gwynston wrote: »

But that's not to say that out of the billions of planets in the galaxy, a few couldn't have followed a self-regulating biosphere kind of model.

The problem with all such speculation is that we need the number to be very low in order to explain the apparent absence of visitations, but perhaps not so low as to make the Earth unique. But whether the number is singular or merely tiny, there is a worrying whiff of fine tuning to whittle the number down from the billions of rocky planets that we now know exist.

Smiles35

According to the SETI people the search for radio hasn't really begun yet. A Russion billionare threw 100mil at them recently.

I'm convinced we will get one or two 'hits' in the next few years.

Gwynston

In the wake of the discovery of a planet around Proxima Centauri, this BBC article discusses at a high level some of the factors other than the Goldilocks Zone which affect habitability:

Where should we look for alien life?

_Tombstone_

​What If We Haven’t Found Aliens Because Humans Came First?

http://motherboard.vice.com/read/what-if-we-havent-found-aliens-because-humans-came-first.

Capt'n Midnight

PMBC wrote: »

What is the current thinking on the 'Drake Equation' which estimated the chance of more life forms in the Universe - I think it didn't allow for stages of development/evolution i.e. that life forms might be at single cell or other early status?

IMHO the Fermi paradox counters it.

And yes the Drake equation had terms for going from life to intelligent life and then to intelligent life that sends signals and for how long that intelligent life would do so.

We have already stopped sending intelligible signals into space. Almost everything is digital, with focused beams and the signal to noise margins are pared right back, and even then most of it is encrypted. Shannon's Law means that ET how has much chance of deciphering our signals as you'd have picking up SaorSat in London.

High power radio is going too, the MW band is practically empty during the day and LW is heading that way.

The big spikes are now 50Hz/60Hz mains and 3GHz radar. The former contains no info and could be explained away as something physical, the latter isn't synchronised and will fade slowly with more GPS and better receivers.

Maximus Alexander

Capt'n Midnight wrote: »

IMHO the Fermi paradox counters it.

And yes the Drake equation had terms for going from life to intelligent life and then to intelligent life that sends signals and for how long that intelligent life would do so.

We have already stopped sending intelligible signals into space. Almost everything is digital, with focused beams and the signal to noise margins are pared right back, and even then most of it is encrypted. Shannon's Law means that ET how has much chance of deciphering our signals as you'd have picking up SaorSat in London.

High power radio is going too, the MW band is practically empty during the day and LW is heading that way.

The big spikes are now 50Hz/60Hz mains and 3GHz radar. The former contains no info and could be explained away as something physical, the latter isn't synchronised and will fade slowly with more GPS and better receivers.

In fairness, you don't need to be able to decipher them in order to identify them as artificial, which is the key thing really. The rest is true though, so it's moot. The encrypted signals won't be going anywhere for ET to detect them.

ps200306

_Tombstone_ wrote: »

​What If We Haven’t Found Aliens Because Humans Came First?

http://motherboard.vice.com/read/what-if-we-havent-found-aliens-because-humans-came-first.

The problem with that, it seems to me, is that if something is astonishingly, unbelievably unlikely -- so unlikely that it hasn't happened in all the hundreds of billions of stars and planets of our galaxy and the countless trillions in others -- then stripping a few zeros out of the 0.0000...001% probability still leaves it very improbable.

Likewise, if something is overwhelmingly likely, so likely that trimming a few nines off the end of 99.999999...% makes no difference, then it is still very likely.

The universe is old enough to have had generations of G type stars like ours. Even trimming off lots of time to allow for the galaxies to be enriched with lots of heavy elements from supernova explosions, there have still been billions of years of evolution of countless suitable stars. M type dwarfs may well last three orders of magnitude longer than our Sun, perhaps even more, but three orders of magnitude doesn't seem all that much when amplifying an exceedingly tiny probability, or attenuating an exceedingly large one.

To my mind that would still either leave the Earth in a quite unique position, forcing us to rethink the Copernican Principle, or it would imply an oddly finely balanced probability of (intelligent) life ... neither very probable nor very improbable in spite of the countless numbers of similar locations in which it could get going. Add to this the observation that some sort of life got going on Earth almost as soon as physically possible, and it suggests even stranger probabilities for intelligence.

PMBC

Would we have eveloved if the dinos had not been wiped out? Was that event not very small statistically?

Maximus Alexander

PMBC wrote: »

Would we have eveloved if the dinos had not been wiped out? Was that event not very small statistically?

It's impossible to know what direction life on Earth would have taken if the dinosaurs weren't wiped out, but mass extinction events like the one that wiped them out have been pretty regular over geological time scales.