Thoughts on Abiogenesis

[SelfSim]

Perhaps we should keep it simple and apply a variant of the obscenity test:

I don't know what life is but I'll know it when I see it.

Yes, exactly - I was thinking of that when I posted!

A rather humorous example of that, was what Curiosity imaged way back in 2012 (just after it landed).

Now when I saw that image, I was convinced it was the leftovers of a prawn (or shrimp), from some kind of barbeque, hosted on Mars in the ancient past.
(Turned out to be a chunk of Curiosity's pre-launch plastic protective wrapping).

Anyway, the point here is that that object stuck out like a sore thumb from the backdrop in that image ... and that's how it all starts. (The martian blueberries and the face of Cydonia are two other examples .. list goes on).
I don't see that process changing anytime soon .. it all starts with us noticing what looks different or odd, compared with the landscape or backdrop/context.

 

[Bradskii]

A rather humorous example of that, was what Curiosity imaged way back in 2012 (just after it landed).

Now when I saw that image, I was convinced it was the leftovers of a prawn (or shrimp), from some kind of barbeque, hosted on Mars in the ancient past.
(Turned out to be a chunk of Curiosity's pre-launch plastic protective wrapping).

Anyway, the point here is that that object stuck out like a sore thumb from the backdrop in that image ... and that's how it all starts. (The martian blueberries and the face of Cydonia are two other examples .. list goes on).
I don't see that process changing anytime soon .. it all starts with us noticing what looks different or odd, compared with the landscape or backdrop/context.

That's quite a reasonable approach. But what would you look for to differentiate between a number of objects that look different to tbe environment? What characteristics would it need before you'd think about classing it as alive?

 

[SelfSim]

That's quite a reasonable approach. But what would you look for to differentiate between a number of objects that look different to tbe environment? What characteristics would it need before you'd think about classing it as alive?

Have you ever heard of the empirical principle of 'going wherever the data leads'?

'It is a capital mistake to theorise before one has data' - Sherlock Holmes

 

[Bradskii]

Have you ever heard of the empirical principle of 'going wherever the data leads'?

'It is a capital mistake to theorise before one has data' - Sherlock Holmes

So what data are you going to get that will lead you to a conclusion that what you are looking at is alive?

Edit: I'll rephrase that because you might not know what data you're going to get. But you are examining something to determine if it's alive. So what type of data will suggest to you that it's alive?

Let's face it, something alive is not going to be completely inert. Otherwise it's just inanimate material. What is it going to do that will indicate life.

 

[SelfSim]

What is it going to do that will indicate life.

That's going to depend on how the things around the sample present (or behave).
I mean, like, if its on Titan, where the ambient temp is around -185 degrees C, one might not expect to see much change over short observation times, anywhere .. but there again, who knows what might actually be observed? (Ie: it can't be predicted now, can it)?
(One might see a big tongue lick a camera lens .. but one may also see something blue)

 

[Bradskii]

That's going to depend on how the things around the sample present (or behave).
I mean, like, if its on Titan, where the ambient temp is around -185 degrees C, one might not expect to see much change over short observation times, anywhere .. but there again, who knows what might actually be observed? (Ie: it can't be predicted now, can it)?
(One might see a big tongue lick a camera lens .. but one may also see something blue)

Good grief. I should have been a dentist...

OK, so a tongue licking the lens would do it for you? So...we've covered independent motion as being a sign of life. And it's interacting with it's environment. Another tick. And we can determine that if it's a tongue then it has a digestive system. So we're half way to metabolism. And now we have saliva on the lens so we can check for dna. Might be another one there as well. And a tongue presumes a mouth. Quick, test for respiration.

And the blue thing? Nup. No independent motion. And it's not interacting with the environment. Completely inert. There's no signs of a digestive system. No signs of dna or rna or any other form of material it could use in reproduction. And zero evidence of respiration.

So we have two things that differentiate themselves from the environment. Which one of them do we know is alive? I've made my selection. You keep examining the blue thing over there and get back to me.

 

[SelfSim]

Alas, upon further analysis of the environment sensor data, it was concluded that the tongue was in fact, a quite rare, massive splodge of dusty methane rain which appeared on the camera lens and behaved as something with the consistency of a light mud.

The blue however, was a different matter altogether ..

 

[Bradskii]

Alas, upon further analysis of the environment sensor data, it was concluded that the tongue was in fact, a quite rare, massive splodge of dusty methane rain which appeared on the camera lens and behaved as something with the consistency of a light mud.

So all those characteristics I mentioned were absent. So...not alive. It works both ways.

 

[jacknife]

So all those characteristics I mentioned were absent. So...not alive. It works both ways.

I think thier just trying to say that if were talking about alien lifeforms they could (and perhaps likley be) so alien that you may not be able to recognize it as life. Whose to say an alien organism couldnt have a diffrent process then the metabolism we know. And still be alive?

 

[SelfSim]

I think thier just trying to say that if were talking about alien lifeforms they could (and perhaps likley be) so alien that you may not be able to recognize it as life. Whose to say an alien organism couldnt have a diffrent process then the metabolism we know. And still be alive?

I think that if we were unable to recognise that some sample was so unusual/different from its natural surroundings, then it wouldn't really matter whether it was 'alive', or not too, eh?

When something such as 'alien life' is so totally unconstrained by any real-life data whatsoever, (which it is), then anything is possible .. and so, that's the meaning we currently have when we use that term.
This then implies that each and every case we dream up in our minds, for what 'alien life is', is equally possible (and equally likely/unlikely). Going out there and snooping things out, is the only way we know of getting the data we need, in order to even begin constraining that term, (for the purpose of giving it some tangible (reality based) meaning).

All the hypotheses/logical inferences imaginable, make no difference in the process of gathering data, when the empirical basis behind a term like 'alien life' is completely absent and they always take a back seat, when some new probe on some unexplored planet/body, has just stumbled across something of interest.

“You can have data without information, but you cannot have information without data.” -Daniel Keys Moran

 

[jacknife]

I think that if we were unable to recognise that some sample was so unusual/different from its natural surroundings, then it wouldn't really matter whether it was 'alive', or not too, eh?

When something such as 'alien life' is so totally unconstrained by any real-life data whatsoever, (which it is), then anything is possible .. and so, that's the meaning we currently have when we use that term.
This then implies that each and every case we dream up in our minds, for what 'alien life is', is equally possible (and equally likely/unlikely). Going out there and snooping things out, is the only way we know of getting the data we need, in order to even begin constraining that term, (for the purpose of giving it some tangible (reality based) meaning).

All the hypotheses/logical inferences imaginable, make no difference in the process of gathering data, when the empirical basis behind a term like 'alien life' is completely absent and they always take a back seat, when some new probe on some unexplored planet/body, has just stumbled across something of interest.

“You can have data without information, but you cannot have information without data.” -Daniel Keys Moran

Okay I get it, that makes sense.

 

[Bradskii]

I think thier just trying to say that if were talking about alien lifeforms they could (and perhaps likley be) so alien that you may not be able to recognize it as life. Whose to say an alien organism couldnt have a diffrent process then the metabolism we know. And still be alive?

I think it's safe to assume that certain processes, certain physics or chemical reactions are the same across the universe. That might not hold in all circumstances, but it's safe to say that we should treat that statement as being true until such time as it's proved not to be.

Consequently, if there is a process going on then we would recognise what is happening and how it happens. If we have no idea what constitutes life, what processes are involved, then short of finding intelligent life then we'll never be able to identify it. Except by saying 'Hey, it looks different to the local environment'. Aka, we'll know it when we see it. Which is about as far from a scientific approach as you could possibly get. Why do you say it's alive? Well, it's different!

I did some searching and there's an interesting article that supports SelSim's position. That is, alien life could be so different that we'd need to rethink what we know about what constitutes it. And the author makes a strong case. With which I generally concur. But...he then goes on to say that, having said that, there are undoubtedly common aspects to life wherever it may be found. I've got it copied on a different device, so I'll paste it into the next post.

Now the guy does say that certain characteristics that he lists undoubtedly relate to Man. But the reason he's made the list is that he believes (and I agree) that they'll be common wherever you look.

And in passing, look at the example of a tongue that SelfSim gave earlier. Ah, it wasn't a tongue after all. Just some slimy mud. But the point I am making is that there would be a difference that could be detected in order for Self to be able to make that statement.

 

[Bradskii]

And here's part of the intro to that article that generally supports SelfSim's view. It's talking about definition of life:

"But beyond that, most of these definitions of life fall short in another, very subtle way: They are based on the origins of life on our planet. This means our hypotheses for what sentient and conscious aliens look like almost always reflect humankind".

From here: Our concept of life is too Earth-centric — alien life might look totally different

I have no problem with that. But note that he is talking about 'sentient and conscious aliens'. Not just life itself. And he goes on to list a number of characteristics that are undeniably required for life on earth and which could reasonably be expected to be requirements for life elsewhere.

"Yet, as far as we know, there are certain undeniable things that were important for the development of life on Earth, and therefore (we assume) for life in general. These are:

A need for energy. Nothing in the universe can move without having some way of obtaining energy. This is the first law of thermodynamics. In humans, this energy comes from metabolizing food.

Organization in membrane-bound cells. This one in particular seems specific to Earth, as all our living organisms are made of cells.

An ability to store genetic information. On Earth, DNA stores our genetic information, which serves as the blueprint for the development of every living thing. It would be pretty difficult to make life without a blueprint.

An ability to replicate with variation. Life would not be prosperous without being able to create offspring; the world would eventually return to being a wasteland after one generation of organisms died out. Producing offspring with variation goes back to the idea of Darwinian evolution. Being capable of evolution allows for population change over time, an important part of creating new forms of life.

The ability to grow and respond to stimuli. What distinguishes a human from a robot is our ability to synthesize information and use this information to make decisions that help us out in our environment. Life would not prosper without the ability to make changes, it would remain static. And static things rarely survive."

 

[SelfSim]

I think it's safe to assume that certain processes, certain physics or chemical reactions are the same across the universe. That might not hold in all circumstances, ..

.. and the physical environment is the primary 'circumstance'.

And in passing, look at the example of a tongue that {@SelfSim} gave earlier. Ah, it wasn't a tongue after all. Just some slimy mud. But the point I am making is that there would be a difference that could be detected in order for {@SelfSim} to be able to make that statement.

The 'difference that could be detected' there, came from instruments designed to measure and catalogue the background environment.

In my sci-fi story, those same instruments also went on and found that there was also something very unusual in the sample taken of the 'massive splodge of dusty methane rain, which landed on the camera, lens, when compared with other samples taken during the deluge, along with sample physical properties, taken from elsewhere in the background environment.

 

[SelfSim]

.. And he goes on to list a number of characteristics that are undeniably required for life on earth and which could reasonably be expected to be requirements for life elsewhere.

"Yet, as far as we know, there are certain undeniable things that were important for the development of life on Earth, and therefore (we assume) for life in general. These are:

A need for energy. Nothing in the universe can move without having some way of obtaining energy. This is the first law of thermodynamics. In humans, this energy comes from metabolizing food.

Organization in membrane-bound cells. This one in particular seems specific to Earth, as all our living organisms are made of cells.

An ability to store genetic information. On Earth, DNA stores our genetic information, which serves as the blueprint for the development of every living thing. It would be pretty difficult to make life without a blueprint.

An ability to replicate with variation. Life would not be prosperous without being able to create offspring; the world would eventually return to being a wasteland after one generation of organisms died out. Producing offspring with variation goes back to the idea of Darwinian evolution. Being capable of evolution allows for population change over time, an important part of creating new forms of life.

The ability to grow and respond to stimuli. What distinguishes a human from a robot is our ability to synthesize information and use this information to make decisions that help us out in our environment. Life would not prosper without the ability to make changes, it would remain static. And static things rarely survive."

Yes .. that is our generalised model of 'life' which has been distinguished from extensive objective tests, made within the context of our Earthly environment.

Whether or not that model is useful in non-Earthly environmental contexts, is unknown, or to be totally accurate: is currently evidenced as leading to 'ambiguous' results, at best. (Re: Viking Lander metabolism tests of the 1970s).

 

[SelfSim]

An ability to store genetic information. On Earth, DNA stores our genetic information, which serves as the blueprint for the development of every living thing. It would be pretty difficult to make life without a blueprint.

DNA molecules would be unable to accomplish that particular feat, in the surface environments on Titan .. yet self-replication there, is not (physically) unachievable, in theory.
I wouldn't have a clue about how 'difficult', (or not), it might be there, however ...
Which informed authority figure should I consult to cross-check your claim there?

 

[Bradskii]

Yes .. that is our generalised model of 'life' which has been distinguished from extensive objective tests, made within the context of our Earthly environment.

Whether or not that model is useful in non-Earthly environmental contexts, is unknown, or to be totally accurate: is currently evidenced as leading to 'ambiguous' results, at best. (Re: Viking Lander metabolism tests of the 1970s).

But as he says: 'and therefore (we assume) for life in general...'

To all intents and purposes we 'assume' the speed of light to be constant. Likewise the Hubble constant. Likewise that many other facets of science are the same elsewhere as they are here. So we don't go to Titan and wonder what the chemical composition of water might be there. We know what water is so we know what to look for. We know the half life of certain elements so we can age materials. We don't need to spend time recalibrating out instruments. And we know what constitutes life. So when we see it, we'll recognise it.

No-one is saying that we shouldn't expect something drastically different to what we have on earth. But physics is physics. Chemistry is chemistry. The processes that are involved in both will share the same characteristics on a distant planet as they do in your backyard. Life is simply specific processes that something will have that will differentiate it from innanimate materials. And those processes will be recognisable to us.

 

[Bradskii]

DNA molecules would be unable to accomplish that particular feat, in the surface environments on Titan .. yet self-replication there, is not (physically) unachievable, in theory.
I wouldn't have a clue about how 'difficult', (or not), it might be there, however ...
Which informed authority figure should I consult to cross-check your claim there?

I haven't made a claim. Other than I agree with the statement the guy made that some means of replication would be required. Dna is what we use. Alien life might use something different. What that might be is above my pay grade. Someone else could perhaps chip in. Something crystaline? But whatever it was, we wouldn't be looking specifically for dna. Dna was not one of the characteristics for life. Replication was. We'd be looking for a process that something might be using as a means to replicate information.

 

[Astrid]

But as he says: 'and therefore (we assume) for life in general...'

To all intents and purposes we 'assume' the speed of light to be constant. Likewise the Hubble constant. Likewise that many other facets of science are the same elsewhere as they are here. So we don't go to Titan and wonder what the chemical composition of water might be there. We know what water is so we know what to look for. We know the half life of certain elements so we can age materials. We don't need to spend time recalibrating out instruments. And we know what constitutes life. So when we see it, we'll recognise it.

No-one is saying that we shouldn't expect something drastically different to what we have on earth. But physics is physics. Chemistry is chemistry. The processes that are involved in both will share the same characteristics on a distant planet as they do in your backyard. Life is simply specific processes that something will have that will differentiate it from innanimate materials. And those processes will be recognisable to us.

And may this be the summary statement.

 

[SelfSim]

.. And we know what constitutes life. So when we see it, we'll recognise it.

What you actually mean there, is we only know what constitutes Earth-life, so therefore when we see it, we'll recognise it.

No-one is saying that we shouldn't expect something drastically different to what we have on earth. But physics is physics. Chemistry is chemistry. The processes that are involved in both will share the same characteristics on a distant planet as they do in your backyard.

The surface temperatures (and free energy availability) on Titan are nothing like those we have here .. nor are the dominating physical elements and their corresponding state behaviours anything like those we have here in our natural environment(s) here. How you think those differences affects the complex physics and chemistry outcomes there?

Life is simply specific processes that something will have that will differentiate it from innanimate materials. And those processes will be recognisable to us.

Yes .. that's your model for Earth-life there, yet again ..