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Member since: Fri Sep 9, 2005, 07:39 PM
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Can someone with real medical competence tell me why this weird idea wouldn't work?

This idea occurred to me a couple of years ago. It concerns the need for patients with lung damage, or fluid-filled lungs -- such as pneumonia patients or victims of smoke inhalation -- to maintain blood oxygenation, when the normal process of O2 absorption from their lungs is frustrated. I suppose someone, at some point, might have tried using a heart-lung machine to bypass the lungs in desperate cases, but I don't know for sure. With heart-lung machines being more complicated, more expensive, and less common than ventilators anyway, this wouldn't seem to be much help in the COVID crisis, so something simpler is needed. Unfortunately, I'm not a doctor, nor any sort of medical expert, myself, and I don't know who I could recommend this idea to for possible evaluation.

The idea comes from one very odd observation. Some turtles -- air-breathing animals which totally lack gills -- are able to survive hibernation underwater for months at a time. Of course, this is partly due to a drastic slowing of the animals' metabolism, a common ability among reptiles, but it's not enough by itself. Recently, investigators learned that these turtles are actually capable of "breathing" underwater -- through their butts. Now, technically, it involves the cloaca, an organ found in reptiles and birds, but not humans. Now, I realize turtles are not humans, and (with one prominent exception) humans are not turtles, and a human intestine is not the same as a cloaca. But consider what the intestines do -- they absorb nutrients, water, and salts from the contents of the digestive tract (water and salts apparently flowing both ways, as needed), at least partly by simple diffusion. To make this process rapid enough to be effective, the inner surfaces of the intestines are covered with tiny protrusions called villi, which increase the surface area available for diffusion, complementary to the way the airways of the lungs are ramified into many tiny alveoli for rapid diffusion of O2 and CO2. So couldn't an intestine serve as an alternative lung ? This is an idea which could be quickly be tested on dogs or pigs -- use a colonoscope or similar device to insert a tube deep into the colon, pass in O2-enriched air and allow it to pass out again through the anus. Then cut the animal's O2 supply (substitute pure N2, e.g.) and monitor the blood oxygen level. Even if this method is not as effective as normal breathing, it could still be very useful. It probably couldn't substitute completely for a ventilator, but might substantially augment oxygenation for patients in extreme pulmonary distress -- maybe enough to tip the balance. The equipment involved is not much more complicated than the high-flow nasal cannulas commonly in use, and much simpler than a ventilator. When ventilators run out, maybe it could even serve as a stopgap until a ventilator becomes available.

Again, I'm not a doctor, and don't have any in the family or my circle of acquaintances to discuss this with, but I'm just putting this out there to see if anyone can find merit in it, or improve the idea to the point it's more worth considering. Hope it helps someone, somewhere, somewhen.

(Possible later development -- use silicone or fluorocarbon fluids -- artificial blood -- in place of air. Might be of interest for deep-sea diving, or at least SF stories about same.)
Posted by eppur_se_muova | Tue Apr 7, 2020, 12:17 AM (10 replies)

**SIGH** Entropy must increase or stay constant WITHIN A CLOSED SYSTEM. (badly mistitled OP)

This is a FAR more important qualification than any requirement for equilibrium -- in fact the equilibrium argument is superfluous. Complex life evolved freely -- wantonly -- on Earth because Earth is anything BUT a closed system. The Sun constantly beams down a torrent of energy onto the Earth's surface. Virtually all of this radiation is eventually re-radiated back into space, where it expands virtually unimpeded into an effectively infinite volume, creating all the entropy that could ever be required, and allowing the local decrease in entropy that is absolutely characteristic of every living organism. In the process of being absorbed, flowing from one point to another, and eventually being lost again, that energy does useful work on the Earth's surface, including creating energetic molecules which plants and animals alike rely on for survival. That accumulation of 'negentropy' is perfectly allowed by the laws of thermodynamics in an open system. If we were to regard the Sun, the Earth, AND all the radiation emitted by the Sun as a closed system (it isn't perfectly, but close enough) then entropy is increasing massively overall, and the fact that a little turbulence in the flow of energy has produced all the complexity of life on earth is not even a jot in the entropy balance.

The suggestion that an impact is involved is also completely unnecessary. We have known since the days of the Miller-Urey experiment that radiation alone is sufficient. All the faddish theories about "life formed in outer space" will eventually be discarded as being as untenable as they are unnecessary. The attraction of these theories is romantic, not scientific -- there are no holes in any theories demanding an extraterrestial origin of life.
Posted by eppur_se_muova | Tue Jan 8, 2019, 10:53 AM (1 replies)

Use a two-part sail, which splits in two for the deceleration phase.


scroll to Fig. 5 on p. 8. This paper describes laser-pushed sails, but microwave-pushed sails would use similar principles. Interestingly, both electric and magnetic sails can be used for propulsion.
Posted by eppur_se_muova | Sat Mar 11, 2017, 11:10 PM (2 replies)

Quick answer to the question: Where does the radioactivity come from ? Basically, "radiobarite" ...

I.e., barite (BaSO4, the major barium mineral) containing small amounts of radium as RaSO4. Both have extremely low solubility in water (under normal conditions), so any radium salt that gets dissolved quickly precipitates back out, together with the more abundant barium, as soon as it encounters sufficient sulfate ions in solution. Here's a 2010 post on that:

Scaly precipitates on oil industry equipment may show the radioactivity as high as 103 Bq/g.


Note that's per gram, not per kilogram.
Posted by eppur_se_muova | Mon Jun 27, 2016, 05:03 PM (0 replies)

Stewart's response to this was absolutely epic -- watch the video !

Posted by eppur_se_muova | Fri Jul 31, 2015, 11:00 AM (0 replies)
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