Recent comments in /f/askscience
lubacrisp t1_j9tmhnr wrote
Reply to comment by Edd1148 in Why is urine yellow? by nateblackmt
The breakdown of aspargusic acid into sulphur products that readily evaporate. Sone people can't smell the smell and some people can't make the smell. Both genetic markers
OathOfFeanor t1_j9tm9gq wrote
Reply to It seems like we havent heard anything about carbon nanotubes for almost a decade. is there anything exciting involving those these days? by mintysmellshowntell
Carbon nanotubes help us make the best concrete imaginable right now. They provide significant increases in tensile strength which is hard to achieve in concrete.
Concrete people will tell you about how "fiber mesh" (macro sized fibers of steel or composites) helps concrete.
Carbon nanutubes work the same way on the nano scale. Think about velcro. Which will be the stronger bond: fifty × 2-inch long velcro strands hooked together, or fifty trillion × strands that are each nanometers long?
One of the coolest things to me is how many shapes they can assemble the carbon into and how it affects the performance.
There are single-walled carbon nanotubes, multi-walled carbon nanotubes of a variety of designs, partially unzipped multi-walled carbon nanotubes which I think are the coolest, it's just insane. You look at these shapes and sure you could design them in 3D software but how the heck are they arranging carbon atoms in this manner? Cool stuff
Downside: This is pretty much only used in the research phase, no contractor in your town is using carbon nanotubes today. Construction is a VERY slow industry to adapt to something like this. We will see it in this progression, if it continues:
- Research projects by Universities
- Experimental civil projects by government entities (usually highway/bridge related)
- Widespread use on civil projects
- Maybe the cost comes down
- Start to see it on commercial projects
- Maybe the cost comes down more
- Start to see it on residential projects
lubacrisp t1_j9tm4zt wrote
Reply to comment by sexualinnuend in Why is urine yellow? by nateblackmt
Their question was almost certainly about the mixing with oxygen causing it to turn yellow. Not even sure what question you think you're answering
AtrioventricularVenn t1_j9tlu18 wrote
Reply to comment by ThomasEdmund84 in How can Doctors tell if one of your kidneys isn't working? by FineLetMeSayIt
We do have two hearts, one for venous (low pressure) flow and one for arterial (high pressure) flow. Also, each "heart" has its own secondary pump as an additional failsafe mechanism. This is the reason why heart defects or acquired issues can go undiagnosed for several years while the individual still maintains a healthy function.
You can argue that you have at least 3 brains: left and right hemispheres, and the cerebellum. Specialization gives these 3 structures functions and architectures that blur their independence from their counterparts. Damage to any of these structures can be compensated by the others but, of course, the level of compensation varies between individuals and age.
The digestive system is a completely different story because of how embryonic development works. We (and most animals) develop around a whole that becomes our single digestive tube (or tract). We are basically worms with funny looking appendages with wiggly tiny tentacles at their ends.
oneAUaway t1_j9tlti0 wrote
Reply to comment by Edd1148 in Why is urine yellow? by nateblackmt
Asparagus contains a disulfide compound called asparagusic acid, whose metabolites produce the strong odor. Other foods with sulfur-containing compounds (such as cruciferous vegetables like cabbage and broccoli) can produce foul-smelling urine as well, though as u/Dubanx notes, there is a lot of variability in the production and experience of those odors.
riuminkd t1_j9tl1h6 wrote
Reply to comment by Shadowwynd in Do all thinking creatures on Earth use neurons? Does an example of non-neuron based biological "intelligence" exist? by Wun_Weg_Wun_Dar__Wun
Do you realize that "slime mold solving maze" is literally just following the steepest gradient of smell/taste of whatever it is in the middle? There is no intelligence involved. And i don't think memory is considered to be a sign of any high intellogence
tailuptaxi t1_j9tkuxo wrote
Reply to comment by [deleted] in Why is urine yellow? by nateblackmt
I also have no gallbladder. As I understand, its function was a reservoir for excess and it does not actually produce anything (except painful spasms when it has stones.)
The rest of the biliary system continues to function normally and the liver produces bile.
[deleted] t1_j9tktvb wrote
Reply to comment by veerKg_CSS_Geologist in What will be the environmental impact of de-orbiting 42,000 Starlink satellites every five years? (Explanation in post) by OvidPerl
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wannabe-physiologist t1_j9tkqe3 wrote
Reply to comment by FineLetMeSayIt in How can Doctors tell if one of your kidneys isn't working? by FineLetMeSayIt
Unilateral kidney failure is possible in cases of unilateral nephrolithiasis (kidney stones) however this would be painful enough to prompt someone to go to the ED where the imaging and labs others have mentioned will be done.
In the case of unilateral nephrolithiasis you would expect to see a patient with unilateral flank pain, CVA tenderness, and the urine studies would show red blood cells in the urine. This isn’t technically kidney failure per se, but is one of the ways someone without access to care may develop it.
[deleted] t1_j9tkaj6 wrote
Reply to comment by djublonskopf in After a surgery, what happens to the air that was inside the incision? by cimmic
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TutorStriking9419 t1_j9tk1e8 wrote
Reply to comment by berliniam in Why is urine yellow? by nateblackmt
Your example of beets reminded of one time when I hadn’t eaten beets in a while. Apparently my body doesn’t break them down well and I nearly ran to emergency.
[deleted] t1_j9tj6mc wrote
Reply to comment by [deleted] in Why is urine yellow? by nateblackmt
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[deleted] t1_j9tj5f5 wrote
Reply to comment by [deleted] in Why is urine yellow? by nateblackmt
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Alpacaofvengeance t1_j9tiyyt wrote
Reply to comment by berliniam in Why is urine yellow? by nateblackmt
> This urobilinogen oxidizes with air once you pee and converts to urobilin which has a yellow color
So is the pee in your bladder not yellow? Does this oxidation happen instantly while urinating? Or is there oxygen in your bladder which means the oxidation is happening there?
[deleted] t1_j9tituo wrote
Reply to comment by Unlikely_Plankton_11 in What will be the environmental impact of de-orbiting 42,000 Starlink satellites every five years? (Explanation in post) by OvidPerl
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Alphageds24 t1_j9tidor wrote
Reply to comment by Unlikely_Plankton_11 in What will be the environmental impact of de-orbiting 42,000 Starlink satellites every five years? (Explanation in post) by OvidPerl
Exactly my point, and ya totally feels like it's "ugh corporations", and targeting just starlink seems like it's an Elon attack and not at all looking at the satellite junk from many companies and governments.
Dubanx t1_j9ti5l8 wrote
It's important to note that viruses don't actually want to kill their host. A dead or excessively sick host is less likely to spread the virus to the next person. So viruses generally evolve to make its host sick without killing them.
The issue is that bats have a much heartier immune system than humans do. So when a virus adapted to living in bats jumps to humans, it's waaaay too virulent for the human body. It's not that bat viruses are more likely to infect humans than a cow virus or some other animal. It's just a lot more likely to be deadly when it does.
[deleted] t1_j9thf79 wrote
Reply to comment by berliniam in Why is urine yellow? by nateblackmt
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[deleted] t1_j9theg5 wrote
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[deleted] t1_j9theeu wrote
Reply to comment by berliniam in Why is urine yellow? by nateblackmt
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Alphageds24 t1_j9thcra wrote
Reply to comment by Minionmemesaregood in What will be the environmental impact of de-orbiting 42,000 Starlink satellites every five years? (Explanation in post) by OvidPerl
MIT did a study Study: Reflecting sunlight to cool the planet will cause other global changes
But it talks about aerosols in the air. So maybe burning them up the aluminum particles would be reflective aerosols?
A satellite reflecting sun back into space is probably very small amount of change, but with 30k maybe it adds up, I don't know.
Dubanx t1_j9th5x6 wrote
Reply to comment by Edd1148 in Why is urine yellow? by nateblackmt
Funnily enough, both the ability to smell asparagus pee AND whether or not your pee smells from asparagus is genetic.
Many people can't smell it, and many others don't have pee that smells. A lot of people don't produce a detectable smell after eating it, but the people who claim to smell it have been scientifically shown to agree on which samples smell and which do not. So it's not psychosomatic either.
k_alva t1_j9th35d wrote
Reply to comment by Sable-Keech in Why is urine yellow? by nateblackmt
The volume is a large part of that. If it's a little pee and a lot of water, it's quite diluted. As you pee more, the pee to water ratio changes
PastGround7893 t1_j9tgrnh wrote
Reply to comment by Monkfich in What will be the environmental impact of de-orbiting 42,000 Starlink satellites every five years? (Explanation in post) by OvidPerl
I don’t know much about metallic particle interaction, but I think it would be important to understand how aluminum interacts with Chlorine and copper piping/pvc piping because that’s where it will inevitably end up, making sure we understand how that affects the life span of copper piping particularly so we understand how much we affect our plans for infrastructure. It will undoubtedly shorten the life span of water infrastructure after enough enters water sources that are used for supplying homes/businesses with water. Not to mention the upkeep on the water plants before it enters main lines that will of course take more of a beating.
I don’t know the answers to that, let alone what kind of effects this has on an ecosystem, but I do know adding 28% to anything does indeed significantly change it.
fiendishrabbit t1_j9tmiei wrote
Reply to comment by lascivious_boasts in How can Doctors tell if one of your kidneys isn't working? by FineLetMeSayIt
Though not always. Had a colleague with hereditary PKD and an asymmetric progression (left kidney, non-functional and a huge amount of scar tissue. Enough that they had to remove it when transplanting. Right kidney had been pulling all the weight for the last few years and was now failing as well).