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RESOLVING THE FERMI PARADOX

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#1 rekokich

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Posted 10 September 2018 - 11:41 AM

In 1975 astronomer Michael Hart proposed the Fermi Paradox, implying a contradiction between the lack of direct evidence for extraterrestrial intelligence (ETI) and the presumed probability that they exist in substantial numbers. Recently, Oxford researchers Sandberg, Drexler, and Ord applied the Monte Carlo simulation to the Drake equation, and concluded that there is up to 99.6% probability that we are alone in the Milky Way galaxy, and up to 85% probability that no other intelligent life exists in the entire observable universe.

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#2 Araguaia

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Posted 10 September 2018 - 11:54 AM

When I was a student one of the big unknown variables was the number of stars with planets, and the number of those in the habitable zone.  Oddsmakers at the time thought exoplanets would range between rare and almost non-existent, with fewer still in the very narrow habitable zones.

 

Now we know that practically every star has a planetary system, and that almost any planet or moon can be habitable, even in the icy outer reaches of the system.

 

Extrapolation from a single data point is too mind bending for me.


 

#3 Araguaia

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Posted 10 September 2018 - 12:27 PM

Also consistent with the Fermi paradox is that we are too primitive to notice anything and too commonplace to be studied intrusively.


 

#4 rowdy388

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Posted 10 September 2018 - 12:37 PM

I doubt if we could even define intelligent life and I agree with Araguaia that the probability

is that life is everywhere. My idea of intelligence is the ability to solve problems. That would

indeed be a competitive advantage. Too much intelligence could also be a two edged sword

leading to one's eventual destruction as a species. I think the jury is still out on that one.


 

#5 Migwan

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Posted 10 September 2018 - 01:33 PM

Take me to your leader.   But really, not convinced either way.  Regarding the article,  the very notion that they could colonize was as far as I needed to go.   We should not use one unresolved question to argue another.  jd


 

#6 js57usa

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Posted 10 September 2018 - 03:37 PM

If ETI exists, I'll be afraid.

If ETI doesn't exist, I'll be very afraid.


 

#7 RyanSem

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Posted 10 September 2018 - 04:24 PM

I thought that was a well articulated article. Part of the problem I've had with the Fermi paradox is that it assumes a galactic-hopping civilization would want to land on Earth in the first place. Well, if they didn't find our planet habitable to their needs, or the resources they expected to find on our planet wouldn't help them in any foreseeable goal, why would they trudge thousands of light-years in this direction just to say they did? At that point they would have landed on thousands or millions of other planets, if Earth showed no promise they wouldn't have wasted their time. So, the Fermi paradox states "we should have seen them already!" but no, perhaps our planet just wasn't interesting enough to waste time landing on in the first place. 


 

#8 Steve C.

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Posted 10 September 2018 - 04:27 PM

We say intelligent but we're basically using that as shorthand for intelligences that we can communicate with, i.e. human-like enough.

 

We have four types of creatures on Earth that demonstrate intelligence: primates, cetaceans, cephalopods, and certain parrots. If we could effectively communicate with them, I'll believe we're capable of communicating with a hypothetical ET. 

 

There's no purpose to evolution, and there's nothing that says intelligence has to resemble human intelligence. 

 

There could be fearsomely intelligent creatures out there who have zero interest in communicating with others.  There could be others that are violently xenophobic. There could be others that communicate with chemicals on their skin and have no human analog. There could be others that have no mathematics like ours.

 

Endless possibilities. 


 

#9 droe

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Posted 10 September 2018 - 05:05 PM

We assume intelligence is the highest form of creatures in the universe. There may be 1000s of creatures passing by looking at the Earth saying, "no need to stop, they are just a bunch of intelligence creatures down there. They got a long way to go before they become relevant."

 

Also this happy zone of life we live in is only a happy zone for us. The creatures living on Pluto would hate it here with all this heat and liquid water. To them this planet could never support any form of life. Just the mere suggestion of this Earth planet supporting life would be laughable, at most it could only support very primitive biological life no higher then having the simplest form of intelligence that couldn't do anything more then building some minor machines like rockets or computers. (Plutotonian's laughter can be heard)

 

We think like earthlings, time to think beyond that.


Edited by droe, 10 September 2018 - 05:06 PM.

 

#10 nmoushon

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Posted 10 September 2018 - 07:08 PM

Great write up! Loved all the background history on the subject(s). 

My personal opinion, and its an opinion not any scientific fact, is that the odds of INTELLIGENT life in our own galaxy is extremely small.  The odds of everything coming together from the start of a star forming, to a planet forming in the perfect position around a perfect star, to life forming on said perfect planet, to life surviving long enough to form any level of intelligence, then that intelligent life creating technology needed for contact is just too many very specific ducks in a row to have anything but very lows odds of happening. Let alone multiple and multiple of times in one galaxy multiplied by the 200B+ galaxies. I just think logically the cosmological odds are just too small. Then again I see no whales in my glass lol. 

I do disagree that we are the only intelligent life in the universe though. Is just too vast with too many variables to rule out. My, very unscientific guess, is there probably averages 1 intelligent life in every galaxy, maybe more, but the odds just are not in that favor. 

I want to make clear I'm talking about intelligent life not just life in the general definition of the word. 

Again, great write up OP. I appreciated the read.


 

#11 siriusandthepup

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Posted 11 September 2018 - 01:12 AM

We are going to find that life is the rule in the universe, not the exception.

 

This will happen in this solar system first.


 

#12 sg6

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Posted 11 September 2018 - 10:23 AM

-Life developed very early in the history of our planet.

Yes, but that was not early on in the history of the universe. Makes sense that we need stars and so planets that are of similar age. No carbon or other elements in the first stars or universe.

 

-The probability of life increases in proportion to the number of suitable environments.

Pretty obvious really.

 

-Life is highly adaptable to extreme environments and to competition.

Is it? Also if it fighting for existance can it develop further.

 

-Probability of complex organisms increases with the passage of time.

Seems reasonable. Also however destruction of complex life increases with time. Mars perhaps is an example.

 

-Evolutionary pressures favor the emergence of the brain and intelligence.

Cannot see a reason for this assumption. How long were dinosaur's around. Have seen it stated "Intelligence is not a prerequisite for life." At least not great intelligence. Consider the US tar pits from which many bones and skeletons are found. If intelligent after the number of years they existed wouldn't the creatures have avoided them? Put a sign up "Danger Tar Pit".

 

-Some intelligent species can develop technology.

Again yes, but not all, however you need the intelligence first.

 

Problem I have is that everyone argues their side, either for or against. Drake equation is too simplistic, and the people at the meeting/conference were all and only people that wanted to find other life. In effect the conclusion was set before it even started.


 

#13 Araguaia

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Posted 11 September 2018 - 10:44 AM

-Life is highly adaptable to extreme environments and to competition.

Is it? Also if it fighting for existance can it develop further.

 

-Evolutionary pressures favor the emergence of the brain and intelligence.

Cannot see a reason for this assumption. How long were dinosaur's around.

1) Evolution is fastest when selective pressure is highest.

 

2) Dinosaurs were more intelligent than fish.  Fish are more intelligent than marine worms.  The trend towards complexity and intelligence is clear.


 

#14 555aaa

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Posted 11 September 2018 - 02:54 PM

The colonization, or "infection", model, does a pretty good job of colonizing the galaxy on time scales on the order of galactic rotation, which you can also think of as a mixing rate. But it does mean that the time SINCE colonization is on the same order of magnitude, i.e. a few hundred million years. But if you have efficient colonizers, even if they are slow, they will get the job done eventually. At least that's my impression from some low-fidelity modeling. There should be solutions where you can have many civilizations popping up, colonizing, and dying out within the galaxy with non-relativistic travel speeds (still requiring immense amounts of energy, that is another pacing parameter I think). If you've ever played the old Conway's "game of life" (a computer sim game from the 1970s) you know what I mean. So the probability of being contacted NOW is tiny, but the probability of having been contacted (colonized) in the geological past is not tiny.


 

#15 llanitedave

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Posted 12 September 2018 - 12:22 AM

I thought that was a well articulated article. Part of the problem I've had with the Fermi paradox is that it assumes a galactic-hopping civilization would want to land on Earth in the first place. Well, if they didn't find our planet habitable to their needs, or the resources they expected to find on our planet wouldn't help them in any foreseeable goal, why would they trudge thousands of light-years in this direction just to say they did? At that point they would have landed on thousands or millions of other planets, if Earth showed no promise they wouldn't have wasted their time. So, the Fermi paradox states "we should have seen them already!" but no, perhaps our planet just wasn't interesting enough to waste time landing on in the first place. 

This was an extremely well-done article.  I enjoyed reading and musing about the possibilities, and the analysis was well thought out.

 

To build on RyanSem's idea, it's interesting to consider it might not be just the Earth that would be considered inadequate for a space-faring civilization (Including, maybe, future humanity).  As Tsiolkovsky famously said, "Earth is the cradle of mankind, but one cannot remain in the cradle forever."  That is just as true for any other advanced civilization developing on another planet.  When we look at the place to find abundant and easily retrievable resources beyond Earth, we're not really gaining anything if we simply look for another copy of home.  For a technological species with the capability to travel throughout its solar system and beyond, the most practical sources of raw materials and energy are to be found in the small icy bodies of the Oort clouds.  I would suggest that, if we suspect there are such advanced technologies, that's where we should concentrate our search.

 

In the Drake Equation, there's a heck of a lot of distance between Fl, Fi, and Fc.  It would be interesting to insert some "Rare Earth" hypothesizing into the mix.  One way that the Earth is a "Goldilocks Planet", and possibly an unusual feature compared to other Earthlike planets, is that it contains a "just right" volume of water.  Not only do the oceans make up 70% of the Earth's surface water, but much of its upper crust is saturated, and it turns out there is even more water in the mantle.  If Earth had accumulated just a little bit more during its formation, it would now be a water planet with little or no exposed land surface.  In such an environment, life might develop easily, and possibly even evolve substantial intelligence, but it's difficult to imagine them harnessing fire, mastering metallurgy, and developing a space-faring technology.

 

On the other hand, just a little less water, and seas would be small, and maybe ephemeral.  The vast deserts would be hostile to most life, evolutionary histories would be localized and truncated, and it might be much harder to develop the complexity required for advanced behaviors.  These conditions might conspire to make Earth-type life, and the ability to envision crossing the galaxy, a rare commodity indeed.

 

Of course, they might not!

 

We can take comfort in one thing, though.  In a 10" telescope, a solar-brightness star can be visible to a bit more than 3,000 light years.  In a 16" telescope, the visibility is twice that.  So if there is a better than vanishingly small chance of civilizations developing in our galaxy, it's quite possible that we can go out on any given night and sweep our eyes across one!


 

#16 Araguaia

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Posted 12 September 2018 - 05:21 AM

All these colonization models assume that altering planets to suit your biology is as easy or easier than interstellar travel.

 

And yet in our own example, we are close to send the first probes to Alpha Centauri, but have no idea how to stop wrecking our still-functioning biosphere.  But people in the space business throw around idle talk of terraforming Mars.


 

#17 RyanSem

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Posted 12 September 2018 - 07:03 AM

This was an extremely well-done article.  I enjoyed reading and musing about the possibilities, and the analysis was well thought out.

 

To build on RyanSem's idea, it's interesting to consider it might not be just the Earth that would be considered inadequate for a space-faring civilization (Including, maybe, future humanity).  As Tsiolkovsky famously said, "Earth is the cradle of mankind, but one cannot remain in the cradle forever."  That is just as true for any other advanced civilization developing on another planet.  When we look at the place to find abundant and easily retrievable resources beyond Earth, we're not really gaining anything if we simply look for another copy of home.  For a technological species with the capability to travel throughout its solar system and beyond, the most practical sources of raw materials and energy are to be found in the small icy bodies of the Oort clouds.  I would suggest that, if we suspect there are such advanced technologies, that's where we should concentrate our search.

Agreed. We also have to take into consideration the reason for expanding in the first place - likely to bring a better life for whichever civilization is expanding. If other intelligent species are bound by the laws of physics (spoiler, they are) then they're not going to reach a new planet any quicker than we would be able to. This means a necessary multi-generation-long flight just to arrive at the new planet before harvesting some resources to bring back. 

 

Unless there are self-replicating robots doing this work, or the people aboard these ships are enslaved in some way, I can't imagine a species willing to go on a 400 year journey to Earth just for the mediocre amount of rare resources we contain compared to other planets. Estimates I've seen to get to our closest star, Alpha Centuri, is 200 years with an antimatter drive (of course this technology isn't even fathomable right now). This would necessitate having and raising children in space no fewer than 7-8 times in just one direction (assuming a similar reproduction cycle and life span to humans). All these generations later they're supposed to stay on target and bring stuff home? My point is, if true space exploration is an act out of bettering the species' own lives, why would anyone agree to "waste" generations of their future family on traveling to a planet without much promise? 

 

To make matters more difficult, should they come close enough and catch our radio signals, we would be encountering a species who have lived their entire lives in a spaceship (and their great-great-great-great grandparents did too). Would they get spooked and abort the mission? There's no reason to believe they've ever negotiated inter-species relationships before, and any example of it in their civilization's history was just a lesson aboard a spaceship years ago. Unless a galactic fleet was descending on our solar system (requiring that many more families to agree to waste 400 years of family progeny) they'd be ill equipped to do anything except hope we won't blow them to smithereens. At that point maybe it's a matter of "they're more scared of you then you are of them".

 

Now, there are a slew of arguments against what I just said, I just thought it was an interesting exercise in the theoretical.  


 

#18 Araguaia

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Posted 12 September 2018 - 07:55 AM

You can get to Alpha Centauri in 40 years using a laser sail.  The basic technology is well understood and has been tested on a tiny scale.  The only major challenge is to scale it up.

 

OTOH, altering the biosphere of a planet so that its gas mix, climate, etc. become inhabitable for an alien species is something that takes nature tens or hundreds of millions of years (see: the oxygenation of the Earth by cyanobacteria).  And we are very, very far from understanding what it takes, let alone to be able to do it artificially, in a controlled manner, and thousands of times faster. 

 

The generations that would have to be born and die in wait for an interstellar mission are nothing compared to how many would have to pass before you could take your spacesuit off on another planet.  Look at our political systems: they can't plan anything beyond ten years.  That is why no one went to Mars.  You really think a social species can organize and follow through with hugely expensive projects that will yield no benefits at all for several millenia?


 

#19 RyanSem

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Posted 12 September 2018 - 09:14 AM

You can get to Alpha Centauri in 40 years using a laser sail.  The basic technology is well understood and has been tested on a tiny scale.  The only major challenge is to scale it up.

 

OTOH, altering the biosphere of a planet so that its gas mix, climate, etc. become inhabitable for an alien species is something that takes nature tens or hundreds of millions of years (see: the oxygenation of the Earth by cyanobacteria).  And we are very, very far from understanding what it takes, let alone to be able to do it artificially, in a controlled manner, and thousands of times faster. 

 

The generations that would have to be born and die in wait for an interstellar mission are nothing compared to how many would have to pass before you could take your spacesuit off on another planet.  Look at our political systems: they can't plan anything beyond ten years.  That is why no one went to Mars.  You really think a social species can organize and follow through with hugely expensive projects that will yield no benefits at all for several millenia?

Interesting on the solar sail. The rest of your post is definitely accurate about environmental conditions. I always figured they would use planets unsuitable to life for resources though, not secondary habitations, so the waiting period isn't needed if they're just beaming down to collect some loot before moving on. 

 

To your last point, I'm inclined to agree but we're assuming similar personalities of the ETI to those of humans in that case. Maybe they're all really cooperative! wink.gif


 

#20 Araguaia

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Posted 12 September 2018 - 09:43 AM

If all they want is resources they will stick to the smaller gravity wells in the outer reaches of star systems.  More volatiles too, farther from the heat central star.

 

It doesn't matter if they are cooperative.  The problem is the discount rate and risk management.  If all goes well you still get no return on your investment for thousands of years.  If not, you lose everything - and there are a thousand ways the project can go wrong.  Odds are that it will, with the long time available for small deviations to accumulate.   Terrible investment.


 

#21 Procyon

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Posted 12 September 2018 - 10:39 AM

Wow, that was a great read! Makes you feel glad just to be alive somewhere! 

 

Thanks for sharing!


 

#22 ed_turco

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Posted 12 September 2018 - 11:06 AM

Extremely well-written piece.  Above reproach for the most part, but I'm having trouble with the Law of Diminishing returns when it comes to knowledge.  There is an implication here that some knowledge will be totally beyond our reach, or there is a finite amount of knowledge in the Universe.

 

I really cannot believe these premises..


 

#23 llanitedave

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Posted 12 September 2018 - 01:02 PM

Extremely well-written piece.  Above reproach for the most part, but I'm having trouble with the Law of Diminishing returns when it comes to knowledge.  There is an implication here that some knowledge will be totally beyond our reach, or there is a finite amount of knowledge in the Universe.

 

I really cannot believe these premises..

Well, if the universe is finite, then so is the information it contains.  However, we should still have plenty to argue about for billions of years to come.


 

#24 rekokich

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Posted 12 September 2018 - 01:10 PM

Extremely well-written piece.  Above reproach for the most part, but I'm having trouble with the Law of Diminishing returns when it comes to knowledge.  There is an implication here that some knowledge will be totally beyond our reach, or there is a finite amount of knowledge in the Universe.

 

I really cannot believe these premises..

 

Ed,

 

I thought a great deal about the law of diminishing returns when it comes to knowledge. I define knowledge as genuine scientific and technological capability. I exclude digital data collected on our browsing history, social media experiences, and detailed shopping habits.

 

I think it is mathematically not possible for scientific capability to keep expanding at an exponential rate, because at some point it will have to double every second, then every half a second. At some point the cost of an additional increment in terms of money, time, and required infrastructure becomes too high for the expected benefit. In very general terms, we have already witnessed the phenomenon in numerous fields. It took two brothers in a bicycle shop to design the first airplane; only a couple of teenagers in a garage to make the first personal computer; only a few people with a battery, a capacitor, a coil, and a switch to make the first radio... And now it takes trillion dollar international conglomerates to make incremental improvements in the current technology. Computer CPUs seem to be approaching the upper limit of capability due to the physical limits of circuit integration and to quantum effects. We now need to stack them in order to increase capacity. And they have to be designed by artificial intelligence because no living human being has the capacity to understand what is really happening inside of them. Yes, we will develop quantum computers, but think how much more complicated and expensive that process has become.

 

With every step in knowledge and technological progress we come a step closer to some physical constant which can not be violated, or to a physical limit in measurement precision which can not be exceeded.

 

Then, there are social and financial considerations. Again, in simple terms, we are technologicaly capable of making passenger planes which fly at mach 6. We simply can't get our populations to accept constant sonic booms, and can't find a sufficient number of passengers who can afford the exorbitant price.

 

Every field of human endeavor, whether physical, intellectual, social, or economic manifests the law of diminishing returns.

 

I don't think scientific progress will ever stop, but I think it will at some point inevitably slow down to approach some undefined upper limit.

 

Rudy


 

#25 mlanglois

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Posted 13 September 2018 - 02:50 PM

1) Evolution is fastest when selective pressure is highest.

 

2) Dinosaurs were more intelligent than fish.  Fish are more intelligent than marine worms.  The trend towards complexity and intelligence is clear.

1) Not necessarily true and still very much under debate in the scientific community. Evolution is dependent upon mutation and selection. Mutation rates for most populations of most species are generally stable and slow, and it is the rate of mutation that determines the 'speed' of evolution, not the rate of selection. Recent research argues that certain organisms/populations under stress (what you refer to above as high selective pressure) can show increased rates of mutation. However, this trait is certainly not ubiquitous in all stressful situations or in many species, so your blanket statement does not/should not apply to the questions in the paper above.

 

2) Most definitely untrue... Evolution is not teleological. It does not have a goal or destination, certainly not intelligence (however it is defined) nor even complexity. This view is properly known as orthogenesis and the current state of evolutionary biology specifically and completely excludes anything like it.

 

Michael


 


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