Humanoid Aliens?

[Moontanman]

What would aliens look like? Many people seem to think they would be more less human in appearance, "humanoid" is the term often used. But what does that mean and how likely is an alien to be "humanoid"? 

I guess defining humanoid is the best way to start, a head, a torso, two arms, two legs? By that definition a gorilla is humanoid. 

Stephen Jay Gould, is his book "Wonderful Life" Gould suggested that rerunning the "movie" of life would not result in the same organisms we are familiar with, even something as basic as vertebrates might not exist if the tape of life was rerun. 

This would suggest that aliens that resemble us at all would be highly unlikely. However there is the idea of Convergent evolution where vastly different creatures that occupy similar ecological niches often look like each other. Sharks, Ichthyosaurs, and dolphins are often cited as examples. Would this process be likely to produce alien creatures that look like us, ie humanoid?   

Should we expect intelligent aliens to resemble us? If so how closely?  

[Vmedvil]

On 9/26/2023 at 4:38 PM, Moontanman said:

What would aliens look like? Many people seem to think they would be more less human in appearance, "humanoid" is the term often used. But what does that mean and how likely is an alien to be "humanoid"? 

I guess defining humanoid is the best way to start, a head, a torso, two arms, two legs? By that definition a gorilla is humanoid. 

Stephen Jay Gould, is his book "Wonderful Life" Gould suggested that rerunning the "movie" of life would not result in the same organisms we are familiar with, even something as basic as vertebrates might not exist if the tape of life was rerun. 

This would suggest that aliens that resemble us at all would be highly unlikely. However there is the idea of Convergent evolution where vastly different creatures that occupy similar ecological niches often look like each other. Sharks, Ichthyosaurs, and dolphins are often cited as examples. Would this process be likely to produce alien creatures that look like us, ie humanoid?   

Should we expect intelligent aliens to resemble us? If so how closely?  

I don't think that aliens would necessarily be "humanoid" because the vastly different biochemistries and evolutionary processes that happened on their planet. Just because intelligent life on earth has evolved a certain form being the humanoid form does not mean that on another planet's "evolutionary tree" that intelligent life has that form because it most likely did not follow the same natural selection process as Earth's life, if you know what I mean. Meaning that different natural selections, because of different environmental factors, would happen in their Planet's "Tree of Evolution" than Earth's "Tree of Evolution". This is baring that idea that life was seeded by a common source on both planets such as what happened in Star Trek The Next Generation when John Luc Picard finds out a "Super Old Alien Species" seeded life on to many planets and had a program in the seeds to make the "humanoid form" for intelligent life.

 

Edited September 27, 2023 by Vmedvil

[Halc]

On 9/26/2023 at 4:38 PM, Moontanman said:

What would aliens look like? Many people seem to think they would be more less human in appearance, "humanoid" is the term often used. But what does that mean and how likely is an alien to be "humanoid"? 

The vast majority of lifeforms on Earth is non-humanoid, and that's stuff with a common biological origin. Aliens have well under a 1% chance of it, and is more likely to be something that us humans would have a hard time recognizing as life at all.

The aliens in Star Wars and other video fiction are humanoid (and human size) either due to lack of imagination of the writers, or more likely the lack of budget of the costume/special-effects departments.

[Moontanman]

15 hours ago, Halc said:

The vast majority of lifeforms on Earth is non-humanoid, and that's stuff with a common biological origin. Aliens have well under a 1% chance of it, and is more likely to be something that us humans would have a hard time recognizing as life at all.

The aliens in Star Wars and other video fiction are humanoid (and human size) either due to lack of imagination of the writers, or more likely the lack of budget of the costume/special-effects departments.

You don't think the idea of convergent evolution might play a role? 

[OceanBreeze]

14 hours ago, Moontanman said:

You don't think the idea of convergent evolution might play a role? 

How would convergent evolution play a role if the aliens live on a planet that is very different from Earth? How can we use convergent evolutionary theory to make predictions that can apply to aliens that , for example, are not carbon based, breathe hydrogen, do not have DNA, and have a totally different chemistry to ours?

 

[Moontanman]

10 hours ago, OceanBreeze said:

How would convergent evolution play a role if the aliens live on a planet that is very different from Earth? How can we use convergent evolutionary theory to make predictions that can apply to aliens that , for example, are not carbon based, breathe hydrogen, do not have DNA, and have a totally different chemistry to ours?

 

 

 

The OP did not suggest anything but an Earth like planet, even a planet identical to earth couldn't be expected to produce identical creatures but even if vastly different than life on our planet couldn't similar environmental pressure result in life forms with similar shapes? I guess what I am really asking is how much environmental pressure is there to produce a humanoid shape in response to pressures that produce technological advanced beings like us. 

[Vmedvil]

On 10/1/2023 at 12:31 PM, Moontanman said:

The OP did not suggest anything but an Earth like planet, even a planet identical to earth couldn't be expected to produce identical creatures but even if vastly different than life on our planet couldn't similar environmental pressure result in life forms with similar shapes? I guess what I am really asking is how much environmental pressure is there to produce a humanoid shape in response to pressures that produce technological advanced beings like us. 

Well, Moontanman, that is really hard to determine the exact environmental pressure that causes the "humanoid form" as we as humans don't even understand what caused them on our planet as far as I know. If you can tell me that exact environmental conditions in time slices of like days for the last around 400 million years, then there could maybe be a computer program made to compute those evolutionary triggers based on the environmental pressures however I am uncertain if that will be ever possible unless we have reverse time travel and physically measure the environment at those time periods. My answer to that question is... Hell if I know...

Edited October 4, 2023 by Vmedvil

[Moontanman]

5 hours ago, Vmedvil said:

Well, Moontanman, that is really hard to determine the exact environmental pressure that causes the "humanoid form" as we as humans don't even understand what caused them on our planet as far as I know. If you can tell me that exact environmental conditions in time slices of like days for the last around 400 million years, then there could maybe be a computer program made to compute those evolutionary triggers based on the environmental pressures however I am uncertain if that will be ever possible unless we have reverse time travel and physically measure the environment at those time periods. My answer to that question is... Hell if I know...

Standing upright seems to have been a deal breaker for us, freeing up our front limbs to manipulate tools. 

[OceanBreeze]

On 10/1/2023 at 11:31 PM, Moontanman said:

The OP did not suggest anything but an Earth like planet, even a planet identical to earth couldn't be expected to produce identical creatures but even if vastly different than life on our planet couldn't similar environmental pressure result in life forms with similar shapes? I guess what I am really asking is how much environmental pressure is there to produce a humanoid shape in response to pressures that produce technological advanced beings like us. 

Moontanman, maybe your OP did not suggest anything but an Earth-like planet, but it certainly did not rule out other possibilities.

Since you now have clarified that you are only interested in Earth-like planets, in that case then I would certainly include convergent evolution as one of the main driving factors towards development of a humanoid creature.

In fact, I briefly discussed this in another thread recently.

Link to my post in that thread

 

And the text:

Yes, and my guess is we transitioned away from claws to fingernails to facilitate making and using tools.

It may well be that as the human mind slowly evolved to adapt to that new world of tool use and complexity, there was also a complimentary effect on other organs and limbs, including the transition from claws to fingernails.

No doubt, this evolutionary process continues to this day.

Would we ever have developed precision machinery, art work, writing or electronics if we did not trade our claws for fingernails?

Just imagine using a keyboard or a touchscreen with claws!

It may be interesting to guess how the human body will adapt in the future to the latest advances of the human mind.

I  am guessing that our transition from claws to fingernails was a major step forward in convergent evolution.

I also agree with you that standing on our two hind legs was another.

 

 

 

 

[Moontanman]

20 hours ago, OceanBreeze said:

Moontanman, maybe your OP did not suggest anything but an Earth-like planet, but it certainly did not rule out other possibilities.

Since you now have clarified that you are only interested in Earth-like planets, in that case then I would certainly include convergent evolution as one of the main driving factors towards development of a humanoid creature.

In fact, I briefly discussed this in another thread recently.

Link to my post in that thread

 

And the text:

Yes, and my guess is we transitioned away from claws to fingernails to facilitate making and using tools.

It may well be that as the human mind slowly evolved to adapt to that new world of tool use and complexity, there was also a complimentary effect on other organs and limbs, including the transition from claws to fingernails.

No doubt, this evolutionary process continues to this day.

Would we ever have developed precision machinery, art work, writing or electronics if we did not trade our claws for fingernails?

Just imagine using a keyboard or a touchscreen with claws!

It may be interesting to guess how the human body will adapt in the future to the latest advances of the human mind.

I  am guessing that our transition from claws to fingernails was a major step forward in convergent evolution.

I also agree with you that standing on our two hind legs was another.

 

 

 

 

So freeing up the front legs to be hands was a factor? I agree but the idea of being a vertebrate has to figure in and there is no guarantee that vertebrates would evolve on even an earth like planet but I have to ask where is the line between earth like and not earth like planets that have complex life? I am not real sure what Earth like means and why would a non earth like planet be incapable of evolving vertebrates?  

[Vmedvil]

15 hours ago, Moontanman said:

So freeing up the front legs to be hands was a factor? I agree but the idea of being a vertebrate has to figure in and there is no guarantee that vertebrates would evolve on even an earth like planet but I have to ask where is the line between earth like and not earth like planets that have complex life? I am not real sure what Earth like means and why would a non earth like planet be incapable of evolving vertebrates?  

We have spoken about this before, what if the planet had a different biochemistry that was silicon based or methane based or something, wouldn't that be a non-earthlike planet with life? Link = Hypothetical types of biochemistry - Wikipedia

Secondly, I am uncertain if such a biochemistry would allow for things like bones, it could be so radically different from Earth that you would not even understand it as life...

Edited October 6, 2023 by Vmedvil

[OceanBreeze]

18 hours ago, Moontanman said:

So freeing up the front legs to be hands was a factor? I agree but the idea of being a vertebrate has to figure in and there is no guarantee that vertebrates would evolve on even an earth like planet but I have to ask where is the line between earth like and not earth like planets that have complex life? I am not real sure what Earth like means and why would a non earth like planet be incapable of evolving vertebrates?  

If you are asking for a specific delimiting line between Earth-like and non-Earth-like planets I think there is no specific answer to that.

There are probably many millions of ways for a planet to be non Earth-like. So it is impossible to be specific about this.

We can only speak in generalities and let the language be sufficient; Earth-like and non Earth-like should be obvious from the language and not require further explanation, in my opinion.

Since we have both vertebrates and non-vertebrates on our own planet, it is fair to think that there may be planets that have only non-vertebrates, if indeed there are other planets with any life at all.

 

[Moontanman]

10 hours ago, Vmedvil said:

We have spoken about this before, what if the planet had a different biochemistry that was silicon based or methane based or something, wouldn't that be a non-earthlike planet with life? Link = Hypothetical types of biochemistry - Wikipedia

Secondly, I am uncertain if such a biochemistry would allow for things like bones, it could be so radically different from Earth that you would not even understand it as life...

The current thinking this problem is that only carbon will work for life (currently all other possibilities have fatal flaws) other working fluids are still on the table, water and ammonia are at the top of the list but sulfuric acid has some interesting attributes and methane is in the mix and for really extreme environments liquid hydrogen has been suggested. But environmental pressures would still be in play for complex life based in these fluids. 

7 hours ago, OceanBreeze said:

If you are asking for a specific delimiting line between Earth-like and non-Earth-like planets I think there is no specific answer to that.

No I want earth like to be defined in this conversation. 

7 hours ago, OceanBreeze said:

There are probably many millions of ways for a planet to be non Earth-like. So it is impossible to be specific about this.

Yes but would they have life, while extremophiles exist on Earth, Venus while quite Earth like in many ways is off the list for sure while Mars is not particularly Earth like it is still on the list. 

7 hours ago, OceanBreeze said:

We can only speak in generalities and let the language be sufficient; Earth-like and non Earth-like should be obvious from the language and not require further explanation, in my opinion.

I disagree, in astronomy any planet with a similar mass is considered Earth like (see Venus) yet a planet 20,000 miles in diameter with a 10 bar hydrogen atmosphere and oceans and land could harbor complex life but not be Earth like. 

7 hours ago, OceanBreeze said:

Since we have both vertebrates and non-vertebrates on our own planet, it is fair to think that there may be planets that have only non-vertebrates, if indeed there are other planets with any life at all.

 

So you are a skeptic about extraterrestrial life? 

[Vmedvil]

On 10/6/2023 at 1:03 PM, Moontanman said:

The current thinking this problem is that only carbon will work for life (currently all other possibilities have fatal flaws) other working fluids are still on the table, water and ammonia are at the top of the list but sulfuric acid has some interesting attributes and methane is in the mix and for really extreme environments liquid hydrogen has been suggested. But environmental pressures would still be in play for complex life based in these fluids. 

 

I believe that any solvent would work for life, I do not think that carbon based and water as a solvent is the only possibility. I do not think that life would necessarily exist in the goldilocks zone, but then of course mainstream science would disagree with me. Mainstream science has been wrong about a great many things though and sometimes the non-mainstream answers are correct. You may see Silicon Based with Sulfuric acid as a solvent or Methane Based with ammonia as a solvent, the possibilities for life are endless in my opinion especially considering the vastness of the universe, that's if extraterrestrial life exists at all like OceanBreeze has said. Would environmental pressures affect them you ask, well, only if they obey natural selection which they most likely would, however we could find another method on another planet that selects the "Superior Life" in alien ecosystem. Hell, we may even find a form of life that doesn't have DNA or any sort of storage like that on another planet that cannot even mutate, how would natural selection happen in life that doesn't mutate due to genetic changes? Once again, the possibilities are endless in a universe that has more galaxies than every grain of sand on every beach in the world, that's how vast the universe is... I think we will find life to be just as vast in possibilities as the universe is vast in size.

My evidence you may ask... what the hell is a theoretical silicon based nano factory is that anything like carbon-based life, the answer is no, Link = The Self Replicating Nanofactory - Biology - Science Forums. I tend to think the universe to be vastly more intelligent than Victor Medvil of Earth in its brilliance. We have yet to see the universe's hand yet in this game of poker, I bet it's a royal flush when it comes to this stuff. More evidence you may ask, what the hell is a nanoparticle is that carbon based nanodevices? The answer is once again, No..., Link = Nanoparticle - Wikipedia. Even with our minor human knowledge, we have created essentially the building blocks for non-carbon-based life and non-carbon based virii. Where does the life begin and the nanorobot end? I think that is going to be a major question of the 21st century... I think it is naive to think carbon based and water solvent is the only possibility like mainstream science. We will find life on another planet someday and I bet you a wooden nickel that it isn't carbon based like current mainstream science understanding says!

"Several definitions describe a "molecular machine" as a class of molecules typically described as an assembly of a discrete number of molecular components intended to produce mechanical movements in response to specific stimuli. The expression is often more generally applied to molecules that simply mimic functions that occur at the macroscopic level.^[2] A few prime requirements for a molecule to be considered a "molecular machine" are: the presence of moving parts, the ability to consume energy, and the ability to perform a task.^[3] Molecular machines differ from other stimuli-responsive compounds that can produce motion (such as cis-trans isomers) in their relatively larger amplitude of movement (potentially due to chemical reactions) and the presence of a clear external stimulus to regulate the movements (as compared to random thermal motion).^[2] Piezoelectric, magnetostrictive, and other materials that produce a movement due to external stimuli on a macro-scale are generally not included, since despite the molecular origin of the motion the effects are not useable on the molecular scale.

This definition generally applies to synthetic molecular machines, which have historically gained inspiration from the naturally occurring biological molecular machines (also referred to as "nanomachines"). Biological machines are considered to be nanoscale devices (such as molecular proteins) in a living system that convert various forms of energy to mechanical work in order to drive crucial biological processes such as intracellular transport, muscle contractions, ATP generation and cell division.^[4][5]"

 

For Dramatic Effect

 

Edited October 8, 2023 by Vmedvil

[OceanBreeze]

On 10/7/2023 at 12:03 AM, Moontanman said:

 

No I want earth like to be defined in this conversation. 

You do? Then go ahead and define it!

For example:

The term "Earth-like" can refer to different things depending on the context. Here are some possible meanings of "Earth-like":

    1)Consisting of or resembling soil.

    2) A planet that is very similar to Earth. (very vague)

    4) A planet that can support liquid water and thus hypothetically life. (This may be the best definition for this thread)

   5) A true Earth analog would require a mix of oceans or lakes and areas not covered by water, or land.  (A leading contender)

But MM, this is your thread so I think you have the responsibility to provide the context and the definition so we can all be on the same page.

Quote

Yes but would they have life, while extremophiles exist on Earth, Venus while quite Earth like in many ways is off the list for sure while Mars is not particularly Earth like it is still on the list. 

Your OP asks “how likely is an alien to be "humanoid"?

Now it seems you have changed the question to “would any planet have life”

That is a completely different question.

Quote

I disagree, in astronomy any planet with a similar mass is considered Earth like (see Venus) yet a planet 20,000 miles in diameter with a 10 bar hydrogen atmosphere and oceans and land could harbor complex life but not be Earth like. 

Again, you should provide the definition of Earth-like that you want to be used in this discussion.

Do you want to use definition # 3) A rocky planet that is about 0.5 to 1.5 times the size of Earth? (That is the astronomy definition)

Quote

So you are a skeptic about extraterrestrial life? 

That’s known as a leading question.

What if I asked you “So, you are absolutely sure there is extra-terrestrial life in the Universe?”

You see how the question is trying to force a predetermined answer?

I am less of a skeptic about the possibility of any form of extra-terrestrial life.

However, If we limit the discussion to intelligent extra-terrestrial life, as this thread seemed to be doing, then I must have my doubts in accord with the Fermi paradox: “where is everybody”?

According to new models *** based on the Fermi paradox, and the Drake equation, the existence of intelligent extra-terrestrial life is either very rare or even non-existent.

I will wait for some evidence other than the mathematical guess work of the Drake Equation before I form a strong opinion, one way or another about the existence of intelligent extra-terrestrial life in the observable Universe.

 

Further discussion: Optional Read

The new study that takes a more critical look at the Drake equation finds “many parameters are very uncertain given current knowledge”. In fact, in order to use the equation, it is necessary to make a guess at the value of many parameters, reaching a result that is based on guesswork and bias.

In the new study, Dr Anders Sandberg, Eric Drexler, and Tod Ord (three famed scholars at Oxford University) looked at the equation’s parameters as uncertainty ranges. Instead of focusing on what value they might have, they looked at what the largest and smallest values they could have based on current knowledge. Whereas some values have become well constrained – such as the number of planets in our galaxy based on exoplanet studies and the number that exist within a star’s habitable zone – others remain far more uncertain.

When they combined these uncertainties, rather than the guesswork that often go into the Drake Equation, the team got a distribution as a result. Naturally, this resulted in a broad spread due to the number of uncertainties involved. But as Dr. Sandberg explained, it did provide them with an estimate of the likelihood that humanity (given what we know) is alone in the galaxy:

    “We found that even using the guesstimates in the literature (we took them and randomly combined the parameter estimates) one can have a situation where the mean number of civilizations in the galaxy might be fairly high – say a hundred – and yet the probability that we are alone in the galaxy is 30%! The reason is that there is a very skew distribution of likelihood.”

“If we instead try to review the scientific knowledge, things get even more extreme. This is because the probability of getting life and intelligence on a planet has an *extreme* uncertainty given what we know – we cannot rule out that it happens nearly everywhere there is the right conditions, but we cannot rule out that it is astronomically rare. This leads to an even stronger uncertainty about the number of civilizations, drawing us to conclude that there is a fairly high likelihood that we are alone. However, we *also* conclude that we shouldn’t be too surprised if we find intelligence!”

Link:*** New Model Predicts That We’re Probably the Only Advanced Civilization in the Observable Universe

Bottom line: Nobody knows with certainty if any form of extraterrestrial life exists; we are all skeptics to some degree.

 

[Moontanman]

23 hours ago, OceanBreeze said:

You do? Then go ahead and define it!

When I asked the question I admit it as too vague but as defined by astronomers life doesn't necessarily figure into it. 

23 hours ago, OceanBreeze said:

 

For example:

 

The term "Earth-like" can refer to different things depending on the context. Here are some possible meanings of "Earth-like":

    1)Consisting of or resembling soil.

    2) A planet that is very similar to Earth. (very vague)

    4) A planet that can support liquid water and thus hypothetically life. (This may be the best definition for this thread)

   5) A true Earth analog would require a mix of oceans or lakes and areas not covered by water, or land.  (A leading contender)

 

But MM, this is your thread so I think you have the responsibility to provide the context and the definition so we can all be on the same page.

Again, I admitted the question as asked was too vague, the official definition would include Venus, Mars, and Mercury so I will as well. 

23 hours ago, OceanBreeze said:

 

Your OP asks “how likely is an alien to be "humanoid"?

Yes that is the question which you muddied by suggesting that a planet would have to be identical to Earth for convergent evolution to occur without any reason why. 

23 hours ago, OceanBreeze said:

 

Now it seems you have changed the question to “would any planet have life”

A life bearing planet would not have to be identical to Earth, in fact large rocky worlds with vast high pressure atmospheres of oxygen and nitrogen or even hydrogen could be better for life than the Earth.

https://www.space.com/superhabitable-planets

23 hours ago, OceanBreeze said:

Your OP asks “how likely is an alien to be "humanoid"?

Now it seems you have changed the question to “would any planet have life”

That is a completely different question.

Yes and again I'll apologize for the vagueness of the question but that is not what I am asking. 

I am asking how likely is the humanoid form in intelligent life, you were right the OP did not suggest an Earth like planet, only a planet with intelligent aliens in humanoid shape. 

23 hours ago, OceanBreeze said:

 

Again, you should provide the definition of Earth-like that you want to be used in this discussion.

Personally I think speculations about life based on chemicals other than carbon are highly speculative but other solvents are not quite as speculative but still we only have one data point. 

23 hours ago, OceanBreeze said:

 

Do you want to use definition # 3) A rocky planet that is about 0.5 to 1.5 times the size of Earth? (That is the astronomy definition)

No as I said earlier in this post many worlds can be even better than Earth for life but as Sara Seager  has suggested, Hycean worlds might be capable of life and have a range further away from a star than an this atmosphere rocky planet. 

23 hours ago, OceanBreeze said:

 

That’s known as a leading question.

Yes, I wanted to know what your views on this subject are, in our own solar system there are several bodies, five I can think of off hand, that have a high probability of having life. Thomas Gold in his book "The Deep Hot Biosphere" suggested that life is a natural chemical occurrence on nearly all large planets as they form later becoming extinct as chemical conditions change as the planet grows. 

23 hours ago, OceanBreeze said:

 

What if I asked you “So, you are absolutely sure there is extra-terrestrial life in the Universe?”

I would answer yes absolutely, in fact I would say we have already found it on Mars!

23 hours ago, OceanBreeze said:

 

You see how the question is trying to force a predetermined answer?

No, I was actually asking for your opinion. 

23 hours ago, OceanBreeze said:

 

I am less of a skeptic about the possibility of any form of extra-terrestrial life.

As am I. 

23 hours ago, OceanBreeze said:

 

However, If we limit the discussion to intelligent extra-terrestrial life, as this thread seemed to be doing, then I must have my doubts in accord with the Fermi paradox: “where is everybody”?

Actually that is easily answered but not a part of this conversation. Let it be known that if a civilization exactly the same level of technology as us existed in the Alpha Centaury system none of our most powerful radio telescopes would be able to detect it. Interstellar gas and dust limit our detection capabilities of detecting radio signals leaking from a planet like our to less than two light years due to interference from gas dust and ions in the interstellar medium.  IMHO the requirement a signal having to repeat before it can be considered an intelligent signal is far too stringent. We have received several strong signals from other stars that very closely resembled military radar sweeping over us from hundreds of not thousands of light years away but since they didn't repeat we discount them. We have send intentional signals into space but we never repeat them why would anyone else? 

23 hours ago, OceanBreeze said:

 

According to new models *** based on the Fermi paradox, and the Drake equation, the existence of intelligent extra-terrestrial life is either very rare or even non-existent.

 

I will wait for some evidence other than the mathematical guess work of the Drake Equation before I form a strong opinion, one way or another about the existence of intelligent extra-terrestrial life in the observable Universe.

 

 

Further discussion: Optional Read

 

The new study that takes a more critical look at the Drake equation finds “many parameters are very uncertain given current knowledge”. In fact, in order to use the equation, it is necessary to make a guess at the value of many parameters, reaching a result that is based on guesswork and bias.

 

In the new study, Dr Anders Sandberg, Eric Drexler, and Tod Ord (three famed scholars at Oxford University) looked at the equation’s parameters as uncertainty ranges. Instead of focusing on what value they might have, they looked at what the largest and smallest values they could have based on current knowledge. Whereas some values have become well constrained – such as the number of planets in our galaxy based on exoplanet studies and the number that exist within a star’s habitable zone – others remain far more uncertain.

 

When they combined these uncertainties, rather than the guesswork that often go into the Drake Equation, the team got a distribution as a result. Naturally, this resulted in a broad spread due to the number of uncertainties involved. But as Dr. Sandberg explained, it did provide them with an estimate of the likelihood that humanity (given what we know) is alone in the galaxy:

 

    “We found that even using the guesstimates in the literature (we took them and randomly combined the parameter estimates) one can have a situation where the mean number of civilizations in the galaxy might be fairly high – say a hundred – and yet the probability that we are alone in the galaxy is 30%! The reason is that there is a very skew distribution of likelihood.”

“If we instead try to review the scientific knowledge, things get even more extreme. This is because the probability of getting life and intelligence on a planet has an *extreme* uncertainty given what we know – we cannot rule out that it happens nearly everywhere there is the right conditions, but we cannot rule out that it is astronomically rare. This leads to an even stronger uncertainty about the number of civilizations, drawing us to conclude that there is a fairly high likelihood that we are alone. However, we *also* conclude that we shouldn’t be too surprised if we find intelligence!”

Link:*** New Model Predicts That We’re Probably the Only Advanced Civilization in the Observable Universe

 

Bottom line: Nobody knows with certainty if any form of extraterrestrial life exists; we are all skeptics to some degree.

 

 

 

I honestly did not mean to push your buttons. But the studies you cite are no less speculative than any other concerning the Fermi paradox. I think we should hold all posters to the same stand as we do each other... it would shake up the status quo a bit but it's difficult for only one and a half moderators to do this. 

[Moontanman]

On 10/6/2023 at 1:52 AM, Vmedvil said:

We have spoken about this before, what if the planet had a different biochemistry that was silicon based or methane based or something, wouldn't that be a non-earthlike planet with life? Link = Hypothetical types of biochemistry - Wikipedia

Secondly, I am uncertain if such a biochemistry would allow for things like bones, it could be so radically different from Earth that you would not even understand it as life...

Silicon based or Silicone based? I'm not sure why an animal without bones wouldn't be recognized as life, octopus are certainly intelligent but have no bones.