re: Edinburgh/MIT scientists to announce evidence for life in Venus’ atmosphere

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Why do you keep doubling down on this when a simple google search would return hundreds of results telling you it's wrong??

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Google results of experiments in space regarding artificial gravity. All attempts have failed. The concept of a centrifuge exerting force on earth is so ingrained as to be thought of as second nature in space. It simply is not possible.

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Real Artificial Gravity for SpaceX’s Starship

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Wow, such a misleading article. It starts off with “Real Artificial” gravity. That’s an oxymoron. It doesn’t get any better from there on.

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I want someone to quickly do the math on how much raw material would be needed to create a sphere that has a diameter of about 195 million miles, and then compare that to the mass of earth.

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Every time I see something reference a Dyson Sphere, this is my exact thought. How does anyone think that is realistic?

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A cool thread about potential evidence of life on Venus turned into a debate on creationism. Awesome work!

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let's get back on topic, y'all take the creation/evolution argument to another thread...please

with the papers released today, the follow up by others (not involved in the study) can begin, as expected and welcomed.

here is an article in ars technica today

LINK

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Assuming that analysis holds up, the big question becomes how phosphine got there. The researchers estimated how quickly it would be destroyed by the conditions in the Venusian atmosphere, and they used that to calculate how much phosphine would need to be produced to maintain the 20 parts-per-billion levels. And then they went searching for some sort of chemical reaction that could produce that much.

And, well, there isn't a plethora of good options. Under the conditions that prevail in the atmosphere, both the phosphorous and hydrogen will typically be oxidized, and there's not much of either around. While solar radiation could potentially liberate some of the hydrogen that is there, it would do so very slowly, and thermodynamics would indicate it's more likely to react with something other than phosphorus. Similarly, reaction pathways based on Venus' likely volcanism would fall short of producing enough phosphine by factors of roughly a million.

All of which leads the researchers to a somewhat frustrating conclusion: "If no known chemical process can explain PH3 within the upper atmosphere of Venus, then it must be produced by a process not previously considered plausible for Venusian conditions." Obviously, however, one of the implausibles that needs to be considered is the whole reason that people looked for phosphine in the first place, namely that it could be produced by living things.

But there's no shortage of implausibility involved with life on Venus. Nothing we'd recognize as life would possibly survive on a ferociously hot planetary surface that's bathed in supercritical carbon dioxide. The temperature in the upper atmosphere, where the phosphine signature originates, is much more moderate. But it would require some form of life that perpetually circulates in the upper atmosphere and somehow survives contact with the planet's sulfuric acid clouds.

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Life is an amazing thing, and would be pretty miraculous by what we understand about life for something to being living in that hellish of an environment with the extreme temperatures, atmospheric pressure many times greater than the earth, UV radiation, and poisonous gases in the region. I'd be amazed if we could collect a sample anytime soon to even confirm such a interesting hypothesis.

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In a local gravity field, yes, but not in microgravity.

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The presence of gravity (or lack thereof) has nothing to do with it. The only difference is that gravity makes it easier to start the rotation, for practical reasons. A person in a zero-G environment would need to secure themself to the spinning drum until it got up to speed. Beyond that - nope. They have to accelerate toward the axis of rotation in order to change their direction of movement as the drum spins. The only way for them to not accelerate would be to fly out of the drum.

Are you seriously arguing that centripetal acceleration can’t exist without gravity? Somebody should tell NASA, because they’ve proposed centrifuges as a means to simulate gravity as recently as 2011 - and last time I checked Einstein had already been dead for over 50 years by then.

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I admitted nothing of the sort. Einstein said that constant acceleration mimics gravity. It is hardly a substitute.

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Maybe from the standpoint of general relativity. But we are talking about the physiological effects of life in a zero-G environment. While there are certainly complications involved with using acceleration as a substitute, they have nothing to do with relativity.

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As you said, DSs are hypothetical. Science fiction even?

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But sentient artificial intelligence isn’t?

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My contention is that our purpose, as sentient biological creatures who have reached the zenith of our existence, is to design our successor species, machine intelligence. I dare say my idea is much more economical than yours.

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Sure, if you don’t care about the survival of our species. I dare say mankind as a whole probably cares more about this than you do.

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The presence of gravity (or lack thereof) has nothing to do with i

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Simple thought experiment: You’re floating in space in a giant circular spaceship tube that’s 5 kilometers in diameter overall with the tube itself being 50 meters wall-to-wall inside it (because a tube essentially has only one wall, let’s call the walls 1. Above you; 2. Below you; 3. Right of you; and, 4. Left of you. There are no divisions of the tube so nothing can hit you as the circle turns. The circular tube starts to turn. Faster and faster while you continue to float equidistant to the walls.

You contend that the spinning tube will generate a centripetal force or a centrifugal force to pull or push you to a wall within the tube. Centripetal means moving or tending to move towards a center. Centrifugal means moving or tending to move away from a center. These two forces are easy to understand when using earth-based examples. What happens in the microgravity of space?

The question of gravity’s role in defining these forces has been raised.

Back to the thought experiment. As the velocity of the tube increases, what will happen to you as its walls continue to slip past you, faster and faster? I contend that nothing will happen because the gravitational effect generated by your body’s mass and the gravitational effect generated by the spaceship’s mass are too weak to cause either a centripetal or centrifugal effect to occur. So, in effect, gravity has everything to do with it.

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A cool thread about potential evidence of life on Venus turned into a debate on creationism. Awesome work!

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Can’t wait until this thread turns into the best places to eat in Lafayette and on Venus.

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Simple thought experiment: You’re floating in space in a giant circular spaceship tube that’s 5 kilometers in diameter overall with the tube itself being 50 meters wall-to-wall inside it (because a tube essentially has only one wall, let’s call the walls 1. Above you; 2. Below you; 3. Right of you; and, 4. Left of you. There are no divisions of the tube so nothing can hit you as the circle turns. The circular tube starts to turn. Faster and faster while you continue to float equidistant to the walls.

You contend that the spinning tube will generate a centripetal force or a centrifugal force to pull or push you to a wall within the tube.

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NO. ABSO-frickING-LUTELY NOT.

THE FORCE MUST BE APPLIED TO THE HUMANS THAT WE ARE SIMULATING GRAVITY FOR. THEY MUST BE PUT INTO MOTION ALONG WITH THE CENTRIFUGE.

Christ, man. This is such a simple fricking thing. If the humans are at rest, they will stay at rest. We aren't creating gravity as you so dimly pointed out. We are simulating it. And in order to do that, the humans must have momentum. So if you set your centrifuge spinning, somehow, some way, the humans must make contact with the spinning body. Maybe they can blow in one direction to generate some thrust until they reach a side. Maybe they're attached to the fricking centrifuge to begin with. However it happens, they just need to be put in motion with the centrifuge. Once they are in motion, their bodies will try to continue in a straight line, which would keep them pressed against the inner walls of the centrifuge.

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Centripetal means moving or tending to move towards a center. Centrifugal means moving or tending to move away from a center. These two forces are easy to understand when using earth-based examples. What happens in the microgravity of space?

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The exact same fricking thing.

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The question of gravity’s role in defining these forces has been raised.

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And shot down as irrelevant on numerous occasions.

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Back to the thought experiment. As the velocity of the tube increases, what will happen to you as its walls continue to slip past you, faster and faster? I contend that nothing will happen because the gravitational effect generated by your body’s mass and the gravitational effect generated by the spaceship’s mass are too weak to cause either a centripetal or centrifugal effect to occur.

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Yeah no shite, but this only illustrates your complete misunderstanding of how a centrifuge would be used to simulate gravity. The humans, or anything you want to be held against the inner wall of the centrifuge, must be put into motion. This is as true in space as it is on earth.

Sorry you are resorting to insults. You must feel defeated. More discussion with you would be a waste of time. Good night.