Are we alone? Intelligent aliens may be rare, new study suggests

[Admin]

A new interpretation of the famous Drake equation finds little reason to be optimistic about the search for extraterrestrial intelligence.

Are we alone? Intelligent aliens may be rare, new study suggests : Read more

 

[Unclear Engineer]

I don't disagree with what is in the article, but I don't think it does much more than update us to what we currently know.

At this point, I think we are close to finding out if life originates easily on many planets, or not. If it does, then the search for planets with intelligent life that has the potential to communicate with other planets would need to look for planets that have both water and rocky surfaces, etc. because a bunch of creatures confined to an ocean are not going to start transmitting radio signals, and probably don't understand fire.

So, the search for the necessary type of planet would be the next major issue.

Only with that information can we deduce whether the product of the probability that a intelligent and technologically communicative society will arise times its length of time in existence is rare or common, given the opportunity. And, we aren't likely to figure out that last pair of parameters separately unless we are able to find dead civilizations on other planets.

So, the existential question for humans on Earth is whether we can keep finding our way through the problems we create for ourselves, or not.

Even if we do survive as a technological society for the next few billion years, there is still the possibility that it is simply not possible for us (or any other technological society) to "spread across the galaxy" due to the limits imposed by physical reality of distance and speed limits. So, we can't use the apparent fact that no technological society has "spread across the galaxy" as evidence that there are no other technological societies in existence in the galaxy with very long periods of existence ("L" in Drake's Equation).

 

[ChrisA]

THere is an easier way to figure this out. It also agrees with what we observe.

If we assume that Earth is not rare or unique and that there are millions of Earthlike planets in the galaxy then if this were true what should we expect? How can we calculate what we would see. Not "guess" but "calculate"

Lets build a simulated galaxy populated with exact copies of Earth but the key is each copy of Earth is made on a different year over the 4 billion years of Earth's existence. So our simulated galaxy has 4 billion earth-like planets and they all have different ages.

What would we see? Out of the 4 billion Earths
1) about 100 of them would be humans who know how to build radios. So radio technology would be very rare. with one
2) most of them would have only microscopic life
3) A fair fraction would have multi-cellular life
4) one in a million planets would have mammals, like mice and monkeys and such

Earth is the only data point we have but Earth has existed for 4 billion years, we can look at Earth one each of those billion years and get 4,000,000,000 data points

This is actually VERY disappointing from a SETI perspective because it means that even of something like 1 in 25 plants has an exact copy of Earth we can expect only 100 planets with radio and perhaps zero that can transmit a radio signal over interstellar distances.

So, bacteria-like life might be common, multi-cellular life would be rare, intelligent life would be a one-in-a-billion level rare and advanced technological life would be exactly zero (as we are not there yet.)

I think this is the ONLY method of prediction that does not use extrapolation or guessing. It makes an impossibly optimistic assumption and then concludes that we should expect to hear and see nothing even in a galaxy teaming with "life". In other words, this theory predicts what to observe.

If you want a theory that predicts that we will find ETs then you have to introduce guess and extrapolations like
1) High-tech societies do not destroy themselves be war or global warming or advanced AI.
2) As societies age they continue to care about the universe around them. We don't know. Perhaps they only play video games and live in simulations.
3) perhaps the biological people are peacefully replaced by some kind of hybrid AI and therefore required very small amount of resource for trillions of them to live and expansion is possible by simply building a one meter cube server room

We have no idea about 1,2 or 3 and any answer is a guess. But if you assume only what we 100% know, we should expect a silent galaxy that is filled with simple life.

 

[Unclear Engineer]

At this time, I don't think we really have the data to tell us even that we should not be able to detect a signal from another technological species on another inhabited world even within the range of detection that we currently have.

We really don't know what planets are out there around relatively nearby stars. because we need transits or big planets close-in creating wobbles in their host stars. There are certainly more planets that remain undetected by us than the number we have detected so far.

And, we really just have a lot of speculation about what it takes to have indigenous lifeforms, and more importantly, why intelligence develops.

Do we really need a star similar to the Sun, with a guide planet similar to Jupiter, and an Earth-like planet with plate tectonics, a strong magnetic field, a large moon, an amount of water that creates oceans and dry lands, and a series of cataclysmic events that favor the development of intelligence over specialization to fixed environmental parameters?

If all of that set of conditions is necessary, then life at the technology level we have already created could be quite rare in the galaxy. IF so, then the lifetime of such technological civilizations could be quite long, and we might still never detect one.

The place where such speculation seems to go off-the-rails of logical scientific conjecture is when it is supposed that an intelligent species will eventually develop the capability to travel throughout the galaxy if not killed off while doing that development. We have no logical or scientific basis for assuming that we or any other technological society will ever be able to develop even interstellar travel, much less trans-galactic travel. There could be a sizeable population of planets inhabited by disillusioned beings who have realized that they are never going to reach the stars that they can see.

But, they could certainly send signals farther than they, themselves, could ever travel.

 

[Galumph]

A new interpretation of the famous Drake equation finds little reason to be optimistic about the search for extraterrestrial intelligence.

Are we alone? Intelligent aliens may be rare, new study suggests : Read more

Oh, the good ol' Drake Equation--one of the least useful predictive formulae that exist.

This particular analysis has at least some basis in mathematics/physics, in that the conclusion is based on the hypothetical scenario where we detect at least one other intelligent species in the galaxy.

Earth really isn't a data point we can use to form statistics about the likelihood of life arising under the right conditions, because there is a total observer bias. Without knowing how life arises or how likely it is to arise under ideal conditions, all we can say is that life can exist at least once throughout the observable universe and throughout time.

Without at least one other data point (e.g., confirming or ruling out life in ANY other star system)--The Drake Equation can only provide you with an estimate of the upper limit of how many other worlds have intelligent life. Anything in between 1 (representing life on Earth) and that upper limit number is just a wild guess because it's directly dependent on guessing the likelihood that life will arise under the right conditions. I.e., something we don't have usable data to determine as a result of not being able to actually check a single other star system for life.

 

[billslugg]

In essence, the Drake Equation tells us the number of intelligent civilizations is equal to the number of planets there are times the percentage that have intelligent civilizations. It seems circular to me.

 

[Unclear Engineer]

Agree, except that Drake did not intend his equation to be predictive. He introduced it to try to create some structure in the speculation about what it would take for there to be life that we can communicate with elsewhere in the galaxy.

Frankly, unless the planet is within a few dozen light years of Earth, it seems unlikely that we could hold a useful interstellar conversation, just due to signal transit times. So, even finding a more advanced life form on another planet might not be useful to us for learning anything other than that we are not alone.

Or, at least we weren't alone when they last transmitted. If their existence is as precarious as some of the pessimists on Earth say our own is, they might be gone before we get their last message.

 

[Classical Motion]

If we ever find convincing evidence or even strong suspicion, it won’t matter. We will never be able to confirm it. And will always be in contention if it’s really evidence.

Especially if we only find ONE.

 

[Hildy]

A new interpretation of the famous Drake equation finds little reason to be optimistic about the search for extraterrestrial intelligence.

Are we alone? Intelligent aliens may be rare, new study suggests : Read more

We already know, for certain, that we are not alone. Octopuses are certainly intelligent but would be undetectable on another planet. Their short life spans do present a barrier to civilizations but with a longer life an aquatic civilization is not out of the question.

Even if we limit it to civilizations that spew out radio waves, we have seen our own reduce its footprint steadily since clear channel stations have been shut down. If we build colonies on the Moon or Mars, communication will be via laser, not detectable by other civilizations.

Civilizations living in space habitats would be invisible to us.

 

[Unclear Engineer]

And then there is the "theory" that the reason we can't detect 95% of the matter and energy in the universe is that the Klingons have it cloaked.

But, seriously, good point about lasers as communication systems that we would not detect. An advanced civilization might need to actually want to be detected in order for them to emit something that we can readily detect.

 

[Manix]

The problem here is us. Humans have this ego of they're the pinnacle of existance. There could be many millions or even billions of intelligent species out there whom have advenced passe dour primitive radio signals. They could also "mask" or cloak their planet from detection, to hide them from being observed. We might just be starting out, trying to discover other intelligent life forms out there, but it is possible several scenarios exist A: the don't to be detected; either because like Hawkins said they believe it could be dangerous to them; or they have already had that encounter and it didn't turn out well and now out of self preservation are hiding themselves even in plane sight. Or B: they are so far advanced that they simply see us, but we are so primitive they truly don't want to communicate with us. Their technology maybe so advanced we simply cannot detect it with our own primitive equipment as advanced as we think it is. Until we start thinking out of the box, I feel we're going to keep seeing the same results over and over again with no real conclusion.

 

[Questioner]

Traversing & communicating through space-time is problematic.

If techno-advanced life finds a means to bypass space-time it means we will find little evidence of them where we are looking.

Godel already proved the universe can not be a completely closed system.

It's a wild card, but not without some foundation in rational logic.

 

[avenuePad]

Kipping is biased. He claims he agnostic on the issue of intelligence species in the galaxy or universe, but he seems to always brush aside the legitimate criticisms of the Rare Earth Hypothesis and the Fermi Paradox.

To make any kind of conclusion about the possibility of intelligent life on other planets is akin to dipping your spoon into the ocean and declaring that the ocean is lifeless. (Yes, of course there is bacteria for the pedants. Thanks for missing the point. I'm talking to you Fraser Cain.)

The truth is we are out of our depth. We have no idea what is out there and to pretend that we can make claims one way or another at this stage is beyond ridiculous.

 

[ChrisA]

Oh, the good ol' Drake Equation--one of the least useful predictive formulae that exist.

Yes, if Drake were more honest he would have computed the error bounds by estimating the error bars of each parameter and then we'd know the confidence of the result. He certainly knew how to do that kind of calculation. If you do actually do this then no matter what inputs you assume the answer always comes out uselessly as "between nearly zero and 400 billion". The trouble is that you have to multiply all those uncertainties together to get the uncertainty in the result.

That said, at least it gives us a way to think about the problem. I think that was all he wanted. We take his equation mre seriously than he did. I once had a boss who was very smart. I was a young engineer at the time and he told us to put "something" (anything) on paper even if it was wrong because if it is wrong someone will point that out and give a better answer. But no one will comment on a blank paper. I think Drake knew this and just put something out on paper.


BTW is there a way to guess at the parameters and make the Drake Equation equal to exactly 1.0000 without making known-to-be wrong stupid inputs?

 

[Catastrophe]

In essence, the Drake Equation tells us the number of intelligent civilizations is equal to the number of planets there are times the percentage that have intelligent civilizations. It seems circular to me.

Billslugg, whilst I do not completely disagree with your post, have you not omitted (at least) one factor?

How about:

A "Drake Equation" might attempt to suggest that the number of intelligent civilisations (able and wishing to communicate with other intelligent civilisations) is equal to the number of planets (able to support such civilisations on such planets or on successive suitable locations) subject to distance and time constraints imposed by the 'speed of light'?

My guess (and nothing better than a guess is possible) is that distance and time constraints suggest any contact is very unlikely. Not only is distance a severe constraint, as has been well covered, but I suggest that time constraints have been underestimated.

Consider the time for which we have been able to send or receive anything remotely like decode-able communication, let alone visits. I would suggest much less than 100 years (if any at all) out of how many billion years? This assumes that none have taken place and left no trace.

Cat

 

[ChrisA]

Billslugg, whilst I do not completely disagree with your post, have you not omitted (at least) one factor?

How about:



My guess (and nothing better than a guess is possible) is that distance and time constraints suggest any contact is very unlikely. Not only is distance a severe constraint, as has been well covered, but I suggest that time constraints have been underestimated.

Consider the time for which we have been able to send or receive anything remotely like decode-able communication, let alone visits. I would suggest much less than 100 years (if any at all) out of how many billion years? This assumes that none have taken place and left no trace.

Cat

Yes, even if there were an Earth-twin with humans just like us only 100 light years from our planet, we would not know about it because humans just like us can not send signals or travel 100 light years.

The ONLY way we could communicate is if the other civilization was centuries more advanced than we are. But then perhaps these very advanced scientists happen to be anthropologists where fist would like to study this primitive society they discovered. If there were so smart, they would be carful not to "contaminate" the Earth with their culture or technology. It would invalidate the science they wanted to do.

It is the same with sending hamans to mars to try and find life. They would 100% for sure find live but it would be life-from -Earth. The ETs came here and said "Hi I'm from plant Zorcho-9 we want to learn about Earth culture. They would fail as then they could only study post-contact culture.

What would we do if we discovered and Erth-like alien world? We would first build a truly huge telescope, perhaps in interferometer with a one million kilometer effective diameter. We could build one in a few hundred years, much quicker than sending a probe. If we detected city lights on continents we would then send a prob. It would arrive in 20,000 years. Who would want to pay for that. No, we'd build and even bigger telescope and perhaps a huge communications laster.

 

[billslugg]

I happen to believe life is abundant in the universe, even intelligent life. The distances and times are so vast that contact between them is very unlikely.

 

[Catastrophe]

Billslugg, would you agree with the time element I mentioned in #15?

Consider the time for which we have been able to send or receive anything remotely like decode-able communication, let alone visits. I would suggest much less than 100 years (if any at all) out of how many billion years? This assumes that none have taken place and left no trace.

To me, this is probably even more important than distance.

Of course, distance and time are related, but I am thinking more "how long ago" rather than (as well as) travel time. Chance of contact being small, of existence coincidentally.


Cat

 

[billslugg]

The Hundred Year Window where we leak radio signals is a nothing burger. No AM/FM/SW radio station can make it past the orbit of Jupiter before it goes below the noise level. Sun and planets are very radio noisy. Radio does things nothing else can do, such as go through buildings, so radio will never go away. It can't make it out of the Solar System anyway, so who cares?
Our most powerful radars could be heard across the galaxy provided their beams are narrow enough, the power density high enough and knowing where to point. It needs an Arecibo size dish on the far end also knowing where to point. Radar will never go away.

Lasers much more energy dense. Perhaps x-ray and gamma ray lasers will be used for communication between stars someday.

 

[bolide]

"Now Kipping and Lewis have ascribed Haldane's logic to the famous Drake equation."

You mean applied, not ascribed. Let's maintain intelligent life on Earth, first of all.

 

[Dave]

Yes, there is only one form of intelligence in the entire universe. It's you guessed it right, human. We are the center of the universe. We always have been and we always will be. What a load of crap. Here, I'll give you this. We are the most ethnocentric species in existence.

Intelligent lifeforms are observing us. They do not wish to contact us. They do not wish to be discovered. Here's the question that needs to be answered. If your science is the more primitive science; how much can your science help you if an intelligent species observing you wishes to remain hidden?

As an intelligent species we have many attributes. The ability to remain hidden has served mammals since the dawn of our existence and it remains one of our greatest strengths. When we go to other worlds in the future this trait will serve us well. We will want to hide from any socially aggressive and very dangerous species like for example humanity.

 

[Catastrophe]

Dave,

The ability to remain hidden has served mammals since the dawn of our existence and it remains one of our greatest strengths.

How well do you think we have been hiding?

Cat

 

[Questioner]

Maybe external observers don't consider us, perhaps especially collectively, 'intelligent'.

Deterministic logic only applies in deterministic locales.

If one has a reasonably deterministic domain and one fails to deploy rational actions,
I think that would be definitionally unintelligent.

Intelligence may actually be overrated.

More about ego & prestige than productive results.

 

[Dave]

One of the greatest feats in the history of humanity has been the ISS. It has been orbiting our world for decades. If an advanced alien species used a method for observing, similar to our 'transit method' they may mistake the ISS for a small moon. After further study, they should determine exactly what this object is. An alien spacecraft built by an alien race from another world. Humanity makes no attempt to hide its technology. If anything we advertise it.

Drake was a brilliant man and his equation continues to be the foundation of understanding life on other worlds. Using earth as a model we can concentrate on stars systems like our own, to find earth's twin or sister world. In short time, we should find such a world and direct our studies to these exoplanets.

 

[Archibald]

I happen to believe life is abundant in the universe, even intelligent life. The distances and times are so vast that contact between them is very unlikely.

Respectfully, I'd like to assert that we do not intuit very well the size and age of the universe.
Here is a simple calculation:

How much longer will it take for humanity to achieve interstellar travel? Some here assert that we have no reason to believe it will ever happen. However, I feel it would be conservative to say we achieve it within 1000 years. Even if we said 10,000 years it wouldn't affect this calculation noticeably.

Some other relevant numbers:
The earth is about 4.5 billion years old.
There are about 100 billion stars in the Milk Way
The Milky Way is about 100,000 light-years across
Our interstellar ships can accelerate at 0.001 g (conservative, in my view)

Using this simple calculator, we will inhabit the entire galaxy within 102,919 years. This may seem like a long time, but compared to the age of the earth, it is insignificant. 102,919 years is just 0.002% of the age of the earth. If another earth-like planet in the Milky Way got a teeny tiny head start in its formation, then it's intelligent species would already be all over the galaxy. Out of the hundred billion stars in our galaxy, are there really no earth like planets that developed just a fraction of a moment sooner than earth did? That may very well be the case.

Now consider other galaxies. The nearest 200 galaxies (including dwarf galaxies) are within 12 million light years of us. The time it would take to travel to the furthest of these galaxies is still only 0.26% of the age of the earth! It's reasonable to assume at least one intelligent species on one planet in one of those galaxies got a 1% head start on us... So where are they? We see no possible signs of their existence - no mega structures, no signals, no Von-Neuman probes, no traces of the cosmic microwave background interacting with their relativistic spaceships.

This tells me that there is something else going on here. I can't see how it can be chalked up to vast distances and times -- because considering the actual distances and the age of the universe, we are packed like sardines!