SETI and the "oxygen bottleneck"

[Jayhawker Soule]

I find EurekAlert! : Is oxygen the cosmic key to alien technology? which notes:

The levels of oxygen required to biologically sustain complex life and intelligence are not as high as the levels necessary for technology, so while a species might be able to emerge in a world without oxygen, it will not be able to become a technological species, according to the researchers.​

​

“You might be able to get biology—you might even be able to get intelligent creatures—in a world that doesn’t have oxygen,” Frank says, “but without a ready source of fire, you’re never going to develop higher technology because higher technology requires fuel and melting.”​

​

Enter the “oxygen bottleneck,” a term coined by the researchers to describe the critical threshold that separates worlds capable of fostering technological civilizations from those that fall short. That is, oxygen levels are a bottleneck that impedes the emergence of advanced technology.​

So, how much is enough, and how common is this likely to occur among planets located in the so-called habitable zone?


,,

 

[Heyo]

I find EurekAlert! : Is oxygen the cosmic key to alien technology? which notes:

The levels of oxygen required to biologically sustain complex life and intelligence are not as high as the levels necessary for technology, so while a species might be able to emerge in a world without oxygen, it will not be able to become a technological species, according to the researchers.​

​

“You might be able to get biology—you might even be able to get intelligent creatures—in a world that doesn’t have oxygen,” Frank says, “but without a ready source of fire, you’re never going to develop higher technology because higher technology requires fuel and melting.”​

​

Enter the “oxygen bottleneck,” a term coined by the researchers to describe the critical threshold that separates worlds capable of fostering technological civilizations from those that fall short. That is, oxygen levels are a bottleneck that impedes the emergence of advanced technology.​

So, how much is enough, and how common is this likely to occur among planets located in the so-called habitable zone?


,,

Obviously a partial pressure of 0.2 bar is enough. (Earth condition at sea level.) But any significant level of oxygen or ozone is already a biomarker. Oxygen is highly reactive and won't stay in an atmosphere for long if it doesn't get replenished by photosynthesis (or other mechanism).

 

[Jayhawker Soule]

But any significant level of oxygen or ozone is already a biomarker.

Could you give me a sense of what constitutes s significant level and whether such a level could reflect abiotic sources?

 

[Heyo]

Could you give me a sense of what constitutes s significant level

Nope. I looked but found no number on that question.

and whether such a level could reflect abiotic sources?

Again, no numbers but yes, there are now hypothesis how
oxygen could form in a lifeless atmosphere.

 

[Jayhawker Soule]

... there are now hypothesis how
oxygen could form in a lifeless atmosphere.

I know. This is why I asked the question, given that you wrote:

But any significant level of oxygen or ozone is already a biomarker.

I recall the short-lived excitement back in 2020 when the news media were running headlines like ABC's

Alien life on Venus? Phosphene gas discovery is a potential game changer​

Sadly, it wasn't.

 

[Heyo]

I know. This is why I asked the question, given that you wrote:

I recall the short-lived excitement back in 2020 when the news media were running headlines like ABC's

Alien life on Venus? Phosphene gas discovery is a potential game changer​

Sadly, it wasn't.

Yes, I caught that one (reported by at least three channels I watch frequently) but that oxygen can be produced in measurable quantity from non biological sources somehow slipped by me.

 

[Pete in Panama]

I find EurekAlert! : Is oxygen the cosmic key to alien technology? which notes:

The levels of oxygen required to biologically sustain complex life and intelligence are not as high as the levels necessary for technology, so while a species might be able to emerge in a world without oxygen, it will not be able to become a technological species, according to the researchers.​

​

“You might be able to get biology—you might even be able to get intelligent creatures—in a world that doesn’t have oxygen,” Frank says, “but without a ready source of fire, you’re never going to develop higher technology because higher technology requires fuel and melting.”​

​

Enter the “oxygen bottleneck,” a term coined by the researchers to describe the critical threshold that separates worlds capable of fostering technological civilizations from those that fall short. That is, oxygen levels are a bottleneck that impedes the emergence of advanced technology.​

So, how much is enough, and how common is this likely to occur among planets located in the so-called habitable zone?

Somehow it seems that a lot of thought is missing here. What I'm getting is that Earths current 20% atmospheric oxygen is supposed to be what's not only necessary for life but it's also above the minimum for technology from life.

About 70 million years we had 30% oxygen which had been the norm for hundreds of millions of years. No technology. Oxygen falls to 20% for many tens of millions of years. No technology. Suddenly, we get technology for the last thousand years or so w/ no change in oxygen levels.

I don't see this oxygen theory supported by history.

 

[wellwisher]

I find EurekAlert! : Is oxygen the cosmic key to alien technology? which notes:

The levels of oxygen required to biologically sustain complex life and intelligence are not as high as the levels necessary for technology, so while a species might be able to emerge in a world without oxygen, it will not be able to become a technological species, according to the researchers.​

​

“You might be able to get biology—you might even be able to get intelligent creatures—in a world that doesn’t have oxygen,” Frank says, “but without a ready source of fire, you’re never going to develop higher technology because higher technology requires fuel and melting.”​

​

Enter the “oxygen bottleneck,” a term coined by the researchers to describe the critical threshold that separates worlds capable of fostering technological civilizations from those that fall short. That is, oxygen levels are a bottleneck that impedes the emergence of advanced technology.​

So, how much is enough, and how common is this likely to occur among planets located in the so-called habitable zone?


,,

Oxygen can form from water and CO2 via photosynthesis as it did on earth. Oxygen is inevitable for water based life with a sun, especially since chemistry is centered on water, oxygen and hydrogen. These three accounts for pH as well as oxidation and reduction potential, that can impact the rest of the atoms. The oxygen and hydrogen flame is more potent than any other natural or life reaction; upper bookend for life's energy bandwidth in water.

Once life becomes more advanced, you can still have tech advancement without oxygen; nuclear power and electric heat. Often with metal production we need to get rid of oxygen; oxidation. We add carbon to iron oxide; rust, to make carbon steel and CO2, with the carbon, as CO2, removing the oxygen of iron oxide to make iron.

We can still advance technology on the moon which has little atmospheric oxygen but plenty of oxygen in its minerals needing to be removed for pure metals and recycled for breathing air. With no appreciable oxygen in the moon's atmosphere building materials will not corrode and can last much longer.

 

[It Aint Necessarily So]

About 70 million years we had 30% oxygen which had been the norm for hundreds of millions of years. No technology.

Oceanic and atmospheric oxygen are necessary for a technological civilization, but not sufficient. We need oxygen for complex multicellular life to form: Oxygen triggered the evolution of complex life forms

This then evolves into intellectual animals, that is, animals able to conceive of and develop technology beyond fire, skinning animals, and stone tools. This is where the second role for oxygen comes in: for the oxidation of fuel to power machines. It's not really that different from what organisms had been using oxygen for for hundreds of millions of years. Life is a slow-burning, flameless fire, which is why your seat is warmed by you sitting in it and how we generate a fever. It's also why food is rated in terms of calories (calor is Latin for heat).

Suddenly, we get technology for the last thousand years or so w/ no change in oxygen levels.

We've had technology for longer than 1000 years, but your point is the same even if we say 50,000 years, 200,000 years, or a million years. Something was added to an oxygenated earth: intellect appears in apes, and with it, language, symbolic reasoning, and record keeping. These then are both necessary and sufficient for technology to appear.

 

[Jayhawker Soule]

Somehow it seems that a lot of thought is missing here.

Sorry.

 

[Pete in Panama]

...We've had technology for longer than 1000 years, but your point is the same even if we say 50,000 years, 200,000 years, or a million years. Something was added to an oxygenated earth: intellect appears in apes, and with it, language, symbolic reasoning, and record keeping. These then are both necessary and sufficient for technology to appear.

If you're calling the flint ax that was used by homo habilis there's some controversy there. That species existed for a million years w/ NO advances in technology. Some liken the making of the primitive stone ax to a bird building a nest. The nest is far more complex and the bird has a brain the size of a pea.

Regardless, none of this changes the fact that oxygen levels have been decreasing for millions of years, yet technology has appeared..

 

[Pete in Panama]

Sorry.

no problem...

 

[Dan From Smithville]

Somehow it seems that a lot of thought is missing here. What I'm getting is that Earths current 20% atmospheric oxygen is supposed to be what's not only necessary for life but it's also above the minimum for technology from life.

About 70 million years we had 30% oxygen which had been the norm for hundreds of millions of years. No technology. Oxygen falls to 20% for many tens of millions of years. No technology. Suddenly, we get technology for the last thousand years or so w/ no change in oxygen levels.

I don't see this oxygen theory supported by history.

I can't imagine anyone being able to put parameters around the speed at which technology should develop with or without oxygen, but I know that the oldest known stone tools are over 3 million years old.

You have to look at technology more broadly to capture all that is technology.

 

[Subduction Zone]

Somehow it seems that a lot of thought is missing here. What I'm getting is that Earths current 20% atmospheric oxygen is supposed to be what's not only necessary for life but it's also above the minimum for technology from life.

About 70 million years we had 30% oxygen which had been the norm for hundreds of millions of years. No technology. Oxygen falls to 20% for many tens of millions of years. No technology. Suddenly, we get technology for the last thousand years or so w/ no change in oxygen levels.

I don't see this oxygen theory supported by history.

You are not understanding it. It does not imply that technology will automatically arise once the oxygen levels hit a certain value. It is saying that technology is not possible until oxygen levels hit a specific level. Technology also takes the development of intelligence and though there are different degrees of it man appears to be the first intelligent life that could also use develop and use technology.

The oxygen bottleneck does not say that it is impossible for intelligent life to develop on other planets. It is saying that technology is only possible on planets where the oxygen levels are high enough so that certain advances, such as the metallurgical ones could occur..

Perhaps some of our chemists or if we have them, chemical engineers could explain how metallurgy could be developed without fire.

 

[Pete in Panama]

I can't imagine anyone being able to put parameters around the speed at which technology should develop with or without oxygen, but I know that the oldest known stone tools are over 3 million years old.

You have to look at technology more broadly to capture all that is technology.

It's possible that oxygen is necessary but not sufficient. There are others that insist that having a large moon w/ substantial tidal forces is necessary too. The list goes on and on.

 

[wellwisher]

There are already replacements for oxygen based manufacturing called electricity; plasma torch and arc welding. We can also generate energy, heat and electricity with nuclear; no oxygen needed.


There is a level of technical sophistication that benefits by oxidation reactions such as fire. But very advanced civilizations who wish to explore the universe will have to do it without oxygen, beyond what is needed for life; Colonize Mars. If we use the SETI definition we will miss the most advanced civilizations, but may find those closer to our own stage of sophistication. Colonies on Mars will have oxygen but it will be contained and not visible from space.

Where oxygen comes in is life. All the speculated solvents for life, except water, will meet their bottleneck when atmospheric oxygen appears. Only water can make fill use of the oxygen, and not be oxidized by it. We can burn all organic solvents in oxygen. That wipes all the speculated life based on dice and cards. SETI needs fresh eyes and better theory to get past science fiction.

 

[It Aint Necessarily So]

none of this changes the fact that oxygen levels have been decreasing for millions of years, yet technology has appeared.

OK. Why shouldn't it? What's your point?

Mine was that for an advanced technological society to arise, there needs to be animals with intellect, and it seems that this required an oxygenated world to permit the advent and subsequent evolution of eukaryotic (aerobic metabolism) life, and eventually, multicellular animal life with nervous systems and intellect. Twenty percent atmospheric oxygen levels appear to be enough to support terrestrial animal life. It doesn't matter if it was 30% at some time in the past before an animal existed capable of symbolic thought and explicit reason (in words).

So why do you think that its relevant that oxygen tensions used to be higher in the pre-human past? They were high enough when the time came for a species to begin to imagine touching the moon and then doing it.

There are others that insist that having a large moon w/ substantial tidal forces is necessary too. The list goes on and on.

That's an interesting topic - the requirements for humanity to have evolved over the lifetime of the earth. Earth's moon is unusual in two ways - being a lone moon, and being so large relative to its accompanying planet. As a result, it stabilizes the axis of the earth to prevent a kind of bobbing that would have the poles facing toward and away from the sun at times rather than roughly perpendicular to earth's orbital plane around the sun. This would lead to climatic instabilities that might impede the evolution of life.

The tides appear to be important to help make the oceans into mineral rich milieus. You probably know that earth's water came from the outer solar system. This was fresh water. Abiogenesis and later evolution in the seas would require a multitude of solutes be dissolved in the water. And I believe that it's also relevant that much but not all of the earth is covered in ocean, as there needs to be beaches and waves crashing onto the shore and into rocky structures to do that effectively under the influence of those tides. I don't suppose that there's much erosion on seafloors. Sediment, yes, but falling from above in the case of earth's oceans.

 

[Jayhawker Soule]

OK. Why shouldn't it? What's your point?

That's my question as well.

 

[Jayhawker Soule]

That's an interesting topic - the requirements for humanity to have evolved over the lifetime of the earth. Earth's moon is unusual in two ways - being a lone moon, and being so large relative to its accompanying planet. As a result, it stabilizes the axis of the earth to prevent a kind of bobbing that would have the poles facing toward and away from the sun at times rather than roughly perpendicular to earth's orbital plane around the sun. This would lead to climatic instabilities that might impede the evolution of life.

The tides appear to be important to help make the oceans into mineral rich milieus. You probably know that earth's water came from the outer solar system. This was fresh water. Abiogenesis and later evolution in the seas would require a multitude of solutes be dissolved in the water. And I believe that it's also relevant that much but not all of the earth is covered in ocean, as there needs to be beaches and waves crashing onto the shore and into rocky structures to do that effectively under the influence of those tides. I don't suppose that there's much erosion on seafloors. Sediment, yes, but falling from above in the case of earth's oceans.

Yes. That was essentially the point of my post:

Shall we thank mother Theia for our habitable world?​

 

[Subduction Zone]

There are already replacements for oxygen based manufacturing called electricity; plasma torch and arc welding. We can also generate energy, heat and electricity with nuclear; no oxygen needed.


There is a level of technical sophistication that benefits by oxidation reactions such as fire. But very advanced civilizations who wish to explore the universe will have to do it without oxygen, beyond what is needed for life; Colonize Mars. If we use the SETI definition we will miss the most advanced civilizations, but may find those closer to our own stage of sophistication. Colonies on Mars will have oxygen but it will be contained and not visible from space.

Where oxygen comes in is life. All the speculated solvents for life, except water, will meet their bottleneck when atmospheric oxygen appears. Only water can make fill use of the oxygen, and not be oxidized by it. We can burn all organic solvents in oxygen. That wipes all the speculated life based on dice and cards. SETI needs fresh eyes and better theory to get past science fiction.

The problem is that without the oxygen based technology and manufacturing before that how would a civilization get to that stage?

You brought up Mars. Put intelligent life on Mars right now and it will just die. Technology has to "evolve" with a civilization. The argument is that one cannot get from A to C without B. And in this case "B" is oxygen based manufacturing.