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Venus' Crust Heals Too Fast For Plate Tectonics
An anonymous reader writes in with an interesting look at how important plate tectonics may be to life and why the crust on Venus works differently than it does on Earth. "Without plate tectonics, carbon would build up in the atmosphere. Venus, which does not have tectonics, shows the results: an atmosphere that is 96 percent carbon dioxide. It's toxic. Yet Venus is about the same size and composition as our planet, so why doesn't it have plate tectonics? Some researchers made a model to explore how Earth initiated plate movements, and these same researchers made one model of its neighbor for comparison. A 1.5-billion-year-old Earth and a similarly aged Venus were modeled as a hot, mushy material made of tiny particles of rock. The model uses physics at the one-millimeter rock grain scale to explain how the whole planet behaves. According to David Bercovici, a geophysicist at Yale who was an author on the paper, the model also shows how plate tectonics emerged on Earth but not on her twin."
Is it very surprising that a completely different orbit around the sun and different composition result in different crust phenomena?
Hundreds of millions of plants would challenge the notion that carbon dioxide is toxic.
I believe I've read similar arguments some time ago in a book titled Rare Earth: Why Complex Life is Uncommon in the Universe. It was published a decade ago. So it's a slow news day again, I guess. ;-)
Ezekiel 23:20
Without plate tectonics, carbon would build up in the atmosphere
Why is that?
If Pandora's box is destined to be opened, *I* want to be the one to open it.
The geology department is trying to justify themselves again - "Some scientists think that plate tectonics are essential for life". What a load of crap!
What a dumb article, the dirt monkeys make this supposition: "Venus doesn't have life because there are no tectonics (we think)". Maybe it doesn't have life because it's being scorched by a nuclear furnace????
Yes, but call me Robert.
Table-ized A.I.
It doesn't make sense to you that a 96% CO2 atmosphere is poisonous? Really? How about Mercury? Does it have a molten surface? Why are there so many idiots and morons these days?
Poisonous is not always a question of composition but can be a question of amount.
Oxygen is toxic to humans if you bring the concentrations up high enough.
Increase the O2 even more and you have Apollo 1 all over again.
I want to see a model of a Venus carbon scrub. 96% CO2? Earth is 20% O2, 0.035% CO2. Venus has 3.5% nitrogen. If we brought the CO2 down to Earth levels, the atmosphere would be 1% CO2, 99% nitrogen. Obviously, instead, you'd have a ton of oxygen--but if you could find hydrogen, you could make vast amounts of O2.
I went to research this and ... someone has already worked it out. Bombarding Venus with hydrogen would produce a 3 bar atmosphere, 80% coverage with water, 10% of the water on the earth's surface but Venus is flat. Habitable. Probably not for humans, but we could continuously dump life there and it would eventually adapt. Building an ecosphere would be hard; it would be easier to seed with microbial life and wait a billion years. Rapid terraformation is hard; we could use a temporal bubble to do it, otherwise not so great.
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Plate tectonics is a theory (http://en.wikipedia.org/wiki/Plate_tectonics); one with a great many believers. Velikovsky writes Venus is hot because it is so young; having been a comet not that long ago, a theory too. An idea based upon another assumption, albeit one sold as fact, remains an idea.
A basic biology class will tell you that CO2 is poisonous to a great many things ... like everything that breaths oxygen.
http://en.wikipedia.org/wiki/H...
The rest of your post could be solved if you opened any 3rd or 4th grade science book ... not sure what planet you're thinking of, but its not venus, which has both an atmosphere and a solid surface.
http://en.wikipedia.org/wiki/V...
It makes no sense because you have absolutely no idea what you're talking about.
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ob. The Far Side reference
the preceding comment is my own and in no way reflects the opinion of the Joint Chiefs of Staff
If instead of yelling about how Mr. Bercovici's theory doesn't explain life, the Universe and everything we accept that he has provided a reasonable theory explaining one of the factors which led to the current difference between Earth and Venus, the conversation here might be more productive.
Yes, Venus gets considerably more energy from the Sun than Earth does. Yes, this alone could reasonably be expected to make it very different from Earth. Is that the only thing which caused Venus to be different from the Earth? If not, it might be interesting to know what other factors resulted in the differences we see - hence, the article exploring how plate tectonics may have contributed to the differences we see.
Oh, one last observation - Mr Bercovici has postulated a theory. I'm sure he started with a hypothesis for which he then sought supporting evidence, which he has provided. So far, sounds like good science to me.
there's a difference between something that's poisonous and something that suffocates you from lack of oxygen. for example, carbon monoxide is poisonous because it neutralizes your red blood cells, so you die even though the % is so low that it doesn't impact O2 %. So my question, is CO2 really poisonous or does it just cause suffocation?
heliocentrism is also a theory taken as fact, and notbody is even trying to disprove it any more. geocentrism ftw, it's the only one that makes any sense.
Though I don't know the exact mechanism, I'd say to watch Apollo 13. Watch how much effort they put in to the CO2 scrubbers, to remove carbon dioxide from the air. They had sufficient oxygen, it was the CO2 levels that were too high. That's what was making them sick.
From TFA:
the Venus model, which was a couple hundred Kelvin hotter,
So, how does it get so much hotter than Earth? It is certainly that much hotter now but that is attributed almost entirely to the greenhouse effect. However, the article earlier states:
Without plate tectonics, carbon would build up in the atmosphere. Venus, which does not have tectonics, shows the results: an atmosphere that is 96 percent carbon dioxide.
So, because plates did not form, Venus experienced a runaway greenhouse effect and high temperatures. But high temperatures are supposed to prevent plates from forming. A little circular, no?
Don't get me wrong: this is interesting work but it doesn't really answer the question of how Venus became the way it is . To close the gap, you need to assume that:
a) Venus started out 200K hotter though some other means (Proximity to the Sun is not generally considered sufficient for that)
-or-
b) Venus plate tectonics stalled early on for some other reason, allowing the greenhouse effect to take over.
http://upload.wikimedia.org/wi...
"The model uses physics at the one-millimeter rock grain scale to explain how the whole planet behaves."
A 3,000 x 3,000 x 3,000 grid is considered very large for modern scientific models. Assuming they are working on a cartesian grid, and an earth diameter of 12,000 km, their model would be 12,000,000 x 12,000,000 x 12,000,000; twelve orders of magnitude larger than the biggest physical model I've ever heard of.
This cannot be the case.
Since nobody was around billions of years ago, many assumptions have to be made about conditions on earth at that time. This is true even more so about Venus. About the only thing these “scientists” can say for sure is that the mathematics and programming of their computer models are likely correct. That is certainly not true about the original assumptions used as a starting point. As the saying goes: “garbage in, garbage out”.
A sufficiently advanced simulation is indistinguishable from reality.
"According to David Bercovici, a geophysicist at Yale who was an author on the paper, the model also shows how plate tectonics emerged on Earth but not on her twin."
I doubt the actual researcher said this. The model shows how plate tectonics could have emerged.
As the partial pressure of CO2 increases, your blood has trouble getting rid of the CO2 in it. This happens long before the oxygen gets displaced, and you wouldn't be able to live in an environment that had the same amount of oxygen but much higher CO2. In effect, a lot of CO2 acts parallel to carbon monoxide, just it takes a lot more.
I don't need to watch Apollo 13 because I watched gravity. also Apollo 11 was the more successful one so why would I watch a movie about the less successful one???
The atmosphere is 78% nitrogen, and we breath it just fine. But air of 5 - 10% carbon dioxide is far more than enough to kill you. This happens because carbon dioxide is toxic to humans and nitrogen is not. It has nothing to do with oxygen deprivation.
As anyone who has taken college level biology will know, the hemoglobin found in red blood cells has two functions. The first is to transport oxygen from the lungs to the rest of the body, because oxygen is needed for cellular respiration (mainly the electron transport chain). The second function is to remove CO2 from the body cells and send them to the lungs. CO2 is the byproduct of cellular respiration, so if red blood cells did not transport it out, it would quickly accumulate in the body and make it too acidic to function (carbon dioxide plus water makes carbonic acid). This is why it is so critical for hemoglobin to be able to transport CO2 out of the body. The problem is that since hemoglobin can bind both CO2 and oxygen, high CO2 levels will begin to "crowd out" oxygen and hog up all of the hemoglobin, leading to suffocation. But even though the atmosphere is 78% nitrogen, this does not happen with nitrogen because nitrogen is not able to bind to hemoglobin at all. Evolutionarily, there is no reason for hemoglobin to have this ability.
tl;dr It's not about lack of oxygen. CO2 is toxic, nitrogen is not even though there is much more of it.
Water in sufficient quantities is toxic. I don't even mean in the drowning sense, or the silly DiHydrogen Monoxide jokes, but if you have too much water, it can kill you.
Nitrogen also works this way. Nitrogen in air, normal pressure, is fine. Nitrogen under pressure can kill you.
Too much oxygen can make you space out.
There are a lot of things that follow this - if you think of normal doses of heat, or electricity, you're fine. If too much, you die. It doesn't take a lot of thinking to come up with examples.
I think most people here are taking issue with the journalist and not the researcher. She should read more Feynman if she really believes the tautological narrative presented in paragraph 3 and that simulation=reality as implied by the headline.
heliocentrism is also a theory taken as fact, and notbody is even trying to disprove it any more. geocentrism ftw, it's the only one that makes any sense.
We've known for almost 100 years that heliocentrism isn't accurate.
IANARS.
The problem is that since hemoglobin can bind both CO2 and oxygen, high CO2 levels will begin to "crowd out" oxygen and hog up all of the hemoglobin, leading to suffocation.
You lost me here. If CO2 and O2 both bind equally to hemoglobin, then what causes CO2 to be "released" in favor of O2 in the first place? (i.e. what causes the exchange during a given breath?)
Simple differences in concentration, combined with differences in binding strength between the two molecules.
When there is less 'free' CO2 than O2, more O2 will bind to the available receptors. (Especially as it binds preferentially.)
As CO2 levels rise, less and less O2 is available to 'find' and bind to the receptors on hemoglobin, resulting in less and less O2 being transported into the body.
CO, on the other hand binds *much* more strongly than O2, and as a result, it takes very high concentrations of O2, and/or long periods of time to flush CO from the bloodstream.
To add onto the other AC's helpful response, you can think about it as a sort of diffusion process. When blood reaches the lungs, it (and the hemoglobin within it) is rich in carbon dioxide while the lungs are rich in oxygen, so CO2 diffuses out of the blood and into lungs and oxygen flows from the lungs to the blood. When blood reaches body tissues, the body tissues have lots of CO2 and little oxygen compared to the blood, so the CO2 flows from the tissue to the blood and oxygen in the opposite direction. As the other AC already said, CO2 has a much higher binding affinity for hemoglobin than oxygen, which is why it can be a deadly poison even at low concentrations.
Fun fact: breathing is actually more driven by the need to exhale CO2 than the need to inhale oxygen. This is part of the reason that swimmers continue to exhale while they are holding their breath underwater.
Obvious troll is obvious. Go away, please.
Gravity is also a theory and yet hardly anybody argues about its existence.
https://en.wikipedia.org/wiki/Inverted_totalitarianism
CO2 also reversibly "neutralizes your red blood cells"; the reason we're alive is that it only does so at a much higher concentration than CO. Once the CO2 level goes above about 10% for more than about 15 minutes, you'll likely suffer brain damage and/or death, no matter how much oxygen there is in the air.
Just another example on how many factors affect a planet’s ability to support life not to mention sentient species and civilizations. The more we learn, the longer the list becomes (e.g. the right kind of star system with the right kind of star, the right planetary materials in the right zone, the right kind of magnetosphere, the right kind of moon, shepherd planets, the right kind of galaxy/cluster, the right place in place in the galaxy/cluster, the right kind of geological tectonics, the right kind of asteroid/comet hits, the right kind of mass extinctions and evolutionary histories, and so on).
The universe (not to mention a potential multiverse) certainly contains many planets capable of supporting civilizations, but the numbers are certainly bleaker than the old Drake equations.
The law of mass action, you oik.
Confucius say, "Find worm in apple - bad. Find half a worm - worse."
Velikovsky? How does his foolishness fit with your 'Electric Universe' foolishness?
"Think about how stupid the average person is. Now, realise that half of them are dumber than that." - George Carlin
Bob is that you?
Why are you so angry?
Watch this Heartland Institute video
Much as a broken clock is right twice a day, Velikovsky was the only one who predicted that Venus would be a furnace.
https://en.wikipedia.org/wiki/Inverted_totalitarianism
Or that Jupiter would have RF emissions.
They had a fairly good idea that the surface temperature was well above the boiling point of water by 1940, so I'd hardly say "the only one."
Just found out that Velikovsky was a proponent of the Electric Universe quackery as well. I guess if you're going to be wrong you may as well be extravagantly wrong.
"Think about how stupid the average person is. Now, realise that half of them are dumber than that." - George Carlin
Because we allowed their parents to breed.
Birds are not dinosaur descendants;birds are dinosaurs, for all useful meanings of "birds", "are" and "dinosaurs"
Probably the majority of life on Earth needs or can tolerate the presence of oxygen, if you measure it by tonnage of organisms. However if you measure by disparity (number of species and variety of metabolic processes) it's a much more balanced picture.
Birds are not dinosaur descendants;birds are dinosaurs, for all useful meanings of "birds", "are" and "dinosaurs"
Wellll ... actually, what CO does (NB : CO not CO2) is bond onto haemoglobin within the red blood cells and NOT release. So that molecule of haemoglobin becomes effectively useless. Oxygen will cycle onto and off the haemoglobin every couple of minutes (circulation time from lung to capillary and back to lung). CO will take hours on average to be released by the haemoglobin.
My diving text books when I was learning quoted that a cigarette with 0.5% CO would knock out between 5 and 10% of your haemoglobin. So don't smoke before a dive. (Yes, people have died to learn this lesson.)
CO2 does a number of things : it increases the blood's acidity, which messes up a lot of things including the ability of haemoglobin to pick up oxygen. AND it acts as an asphyxiant (suffocates you). Plus, it's rarely the only thing going on at the time. Most people who are exposed to excessive CO2 do so in the case of fire, when there's a lot going on. We use CO2 floods as a fire-fighting system at work, and the alarm systems are really serious about getting the fuck out of the area if the CO2 flood is going to be released.
Birds are not dinosaur descendants;birds are dinosaurs, for all useful meanings of "birds", "are" and "dinosaurs"