Recent comments in /f/askscience
[deleted] t1_j42o7h9 wrote
Reply to comment by Vazmanian_Devil in How do giraffes breathe? by NimishApte
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perta1234 t1_j42meit wrote
Reply to Is it possible that people born with genetic disorders is caused because humans are related to eachother in some way? by Skully_o7
Yes and no. It is bit complicated. Some disorders are combinations of variants of different genes, so there it is not the cause. Some are caused by dominant gene variants, so there as well, relatedness does not play a role. But then there are the recessive disorders, where you must inherit similar bad variant from mother and father, so there relatedness does matter.
Close relatedness of parents increases the proportion of genes, where the child has two identical variants. If some proportion of the genes are coding recessive disorders, one is more likely have an disorder. It is the mutation or the genotype that causes the disorder. Relatedness has impact on the genotype. So relatedness can have an indirect impact, but that depends on the existence of those mutations or gene variants.
Most disorders are of the recessive type or something that was beneficial in a different environment.
We are all "somehow related".
cailien t1_j42lxcq wrote
Reply to Is the uncertainty principle a general law, or just subjective to our own experience? by Turokr
This is unfortunately caused by the pop-science presentations of the uncertainty principle. To answer this fully, two different pieces have to be teased apart, and precision in language becomes important. There is a general confusion of two different phenomena. The uncertainty principle and the observer effect.
Observer Effect A phenomenon where measuring a system requires interacting with that system and changes the observables of that system.
The uncertainty principle Given an experiment where we can set the initial position of a particle to be at (0x, 0y, 0z, 0t) with a momentum p and we later measure the position and momentum of that particle a time t later, if we repeat that experiment for many particles, we will get a range of different final positions and momenta. The uncertainty principle holds that the product of the standard deviations of the distributions of final position and momenta, given a definite starting position and momentum, cannot be less than some limit. If one knows a particle's position and momentum now, one cannot predict both what its future position and momentum will be.
These two ideas (the uncertainty principle and the observer effect) are completely unrelated. Just because when a system is measured, it has to be interacted with does not mean that interaction is unpredictable. We can, in principle, fully account for all interactions and know how the measurement will affect the system and back out information about the system pre-interaction.
The uncertainty principle is orthogonal to measurement, and is related to what is possibly knowable about a system given full, perfect information. We can know perfectly where a particle is now, and what its momentum is now, and that will not allow us to accurately predict what its position and momentum is in the future.
The uncertainty principle is epistomological, it is a principle about what is fundamentally knowable. We can know everything there is to know about a system, we can fully specify its wavefunction and know how it will evolve forever and still not be able to predict the values of all observables about the system in the future. Knowledge of the future position of a particle is fundamentally incompatible with knowledge of its future momentum. Joint knowledge of future position and momentum are guaranteed to always be fuzzy with some spread in either or both observables.
There are often things reported about measurements "beyond the Heisenberg limit" which are breathlessly reported on, saying that they "broke the uncertainty limits" or whatever. Those are related to incorrect statements about the uncertainty principle and that it applies to any one measurement at all. To be clear, the uncertainty principle does not restrict what one can measure about a particle. You can perfectly measure a particle's position and momentum at any given time. The thing that the uncertainty principle forbids is using that information to know, with certainty, the future position and momentum of the particle.
> But as far as I'm concerned that is not a natural law but a restriction caused by our own inability to observe those data points without influencing the system ourselves.
To be very clear, it is a natural law that is not premised on experimental failures to observe things nor is it caused by our inability to observe without influencing. In mathematical models where all information about a system is known precisely, and all measurements are perfect, the results are the same. Future position and momentum cannot be known with joint precision below a certain limit.
[deleted] t1_j42lnwe wrote
Reply to How do giraffes breathe? by NimishApte
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know-your-onions t1_j42lghr wrote
Reply to comment by poorbill in Why do poultry producers kill their stock when they get bird flu, rather than keeping survivors to reproduce? by poorbill
Humans haven’t managed to develop immunity to flu viruses yet (and we don’t kill all the humans that get infected - in fact we go out of our way to keep them alive), so what makes you think birds would be different?
Chagrinnish t1_j42lbb2 wrote
Reply to comment by NimdokBennyandAM in How do giraffes breathe? by NimishApte
The googles say that a male giraffe average is 2628 lbs. Given that's about 13x the size of a human I'd expect a similar lung capacity; 8x seems small.
[deleted] t1_j42l96t wrote
Reply to comment by 4tehlulzez in How do giraffes breathe? by NimishApte
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[deleted] t1_j42kb1t wrote
Reply to comment by 4tehlulzez in How do giraffes breathe? by NimishApte
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h3rbi74 t1_j42ka84 wrote
Reply to comment by idiotcameltoilet in How do giraffes breathe? by NimishApte
True, a horse for example has a resting HR in the 20s-40s and for most domestic species, the smaller they are the faster they go, and vice versa. I have never heard that a giraffe can go 500 bpm and I can’t find a zoo reference manual on a quick search but several sources claim a normal HR for a giraffe is 150-170 bpm, which is insanely fast for something that huge. A relaxed house cat is frequently less than that.
Here is one source for giraffe HR that also has some cool BP info. https://iheart.polimi.it/en/the-incredible-cardio-circulatory-system-of-giraffes-a-challenge-to-gravity/
[deleted] t1_j42jui5 wrote
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[deleted] t1_j42jp6v wrote
Reply to comment by wene324 in How do giraffes breathe? by NimishApte
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[deleted] t1_j42jjtp wrote
idiotcameltoilet t1_j42ibm5 wrote
Reply to comment by wene324 in How do giraffes breathe? by NimishApte
I believe that was in reference to a mouse or a hummingbird. Generally speaking, larger animals will have much slower heart rates and smaller animals faster ones.
ScienceIsSexy420 t1_j42hpbb wrote
Reply to comment by [deleted] in Is it possible that people born with genetic disorders is caused because humans are related to eachother in some way? by Skully_o7
Mutations cause genetic disorders, but inbreeding increases the chances of inheriting those mutations. That's why you see things like the prevelance of Tay-Sachs in the Ashkenazi Jew population. Humans are especially vulnerable to inheriting genetic disorders due to inbreeding because of a lack of genetic diversity caused by previous population bottlenecks during prehistoric times.
NimishApte OP t1_j42gi04 wrote
Reply to comment by wene324 in How do giraffes breathe? by NimishApte
Don't larger mammals have a slower metabolism to avoid overheating?
Vazmanian_Devil t1_j42gbb2 wrote
Reply to comment by kalod9 in How do giraffes breathe? by NimishApte
yup, iirc, their skin is super tight around their legs to help get that blood to easily shoot up the neck.
[deleted] t1_j42fu20 wrote
Reply to How do giraffes breathe? by NimishApte
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wene324 t1_j42ey49 wrote
Reply to comment by NimdokBennyandAM in How do giraffes breathe? by NimishApte
I just watched Matilda (1995) today. She gave a factoid that giraffes had beat 500 times a minute, and sounds like a hum rather than a beat.
bitofrock t1_j42etdr wrote
Reply to comment by WhalesVirginia in Why are coastlines crinkly near the poles but smooth in the tropics? by emsot
Uhm, the thing about science is that the only way to improve on the science is more science.
An opinion or pointing out a possible flaw doesn't advance science, but may be a part of future science that advances things further.
But if you don't have a solid grasp on the science done so far, then you're just having opinions that are unlikely to make much of an impact or be considered unless you have substantial credentials in the field.
tbiko t1_j42emtg wrote
Reply to comment by NimdokBennyandAM in How do giraffes breathe? by NimishApte
"Dead air" or dead space is the volume of air that fills the space from your mouth/nose to the small airways of your lung that exchange oxygen and carbon dioxide. An above average height man may breath about 600 ml per breath and have about 200 ml be dead space. So only 400 ml air available for exchange. If he closed his nose and put is mouth around a large straw that held 600 ml of volume, he'd have to increase his breathing depth (and frequency) compensate, and would get pretty tired.
The OP likely just learned about dead space ventilation and the giraffe is a logical follow up question.
[deleted] t1_j42ej1d wrote
Reply to comment by 4tehlulzez in How do giraffes breathe? by NimishApte
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4tehlulzez t1_j42e90r wrote
Reply to comment by NimdokBennyandAM in How do giraffes breathe? by NimishApte
What's "dead air"?
WhalesVirginia t1_j42o906 wrote
Reply to comment by bitofrock in Why are coastlines crinkly near the poles but smooth in the tropics? by emsot
> Uhm, the thing about science is that the only way to improve on the science is more science.
The way to improve is not just more science. It's better science. Something like 80% of papers are never read after publishing, a surprisingly large number of papers are retracted. We have a quality problem, not a quantity.
>An opinion or pointing out a possible flaw doesn't advance science, but may be a part of future science that advances things further.
Being critical of models advances science. It shows where a model fails. My issue is with the politicization rising up science because it fits a narrative. There's plenty of great climate science, but there is plenty of kind iffy stuff that hits front page reddit on the daily.
> But if you don't have a solid grasp on the science done so far, then you're just having opinions that are unlikely to make much of an impact or be considered unless you have substantial credentials in the field.
Well obviously.