Recent comments in /f/askscience

MikeyXVX t1_j1ge42f wrote

Reply to Which medical procedures have a different application when treating a woman or a man? by ViejoOrtiva

The ridiculous part of this argument is that your medical records will already take this into consideration. If your clinician doesn't consider your anatomy, while still respecting your gender, they are bad clinicians. This is just an argument someone makes if they are either not a healthcare professional or they are just being disingenuous.

12

mrwolfisolveproblems t1_j1gdayr wrote

Reply to comment by FRCP_12b6 in How do fusion scientists expect to produce enough Tritium to sustain D-T fusion (see text)? by DanTheTerrible

So a 100kwh pack becomes 60kwh. A thousands of them together gives you 60MW for 1 hour. Peak load demand can swing 20-40,000 MW for 10+ hours at a time. That’s just peak demand, forget about base load, and that’s just in a regional area (say Texas for example) An extra 20,000 MW for 10 hours is 200,000,000 kWh. You would need 3.33 million old battery packs all tired together and synced to the grid. Not to mention every day they will lose capacity and eventually be useless even for grid storage.

TLDR: need to find a way to recycle them into new batteries like we do for lead acid batteries.

2

Lyndeead t1_j1gadxv wrote

Reply to Are people who live in certain climates less susceptible to the effects of the weather there? by dxrknxrth

As the two others have said, absolutely. We have severa morphological features that are different between populations of different climates.

  1. Body shape- individuals descended from cold climates are shorter and broader overall, this reduces the body’s surface area to volume ratio which promotes heat conservation. Alternatively, those from hot climates tend to have taller narrower bodies, which increases surface area to volume ratio which is better for evaporative cooling via sweating. Interestingly individuals from areas with monsoon seasons tend to be shorter but narrow overall, to reduce the body’s heat conservation and deal with the difficulties of sweating ineffectiveness. And lastly, populations that tend to be seafaring (Pacific Islanders etc) tend to have a tall yet broad body plan, to shed heat via sweat in the hot temperatures on land, but also cope with the cold breezes of the ocean winds.

2- limb proportions and crania shape follow similar trends to those above. These really refer to Allen’s rule and Bregman’s rules.

3- body hair distribution is larger in colder climates compared to populations in hot climates.

4- skin melanin content- in hot climates with greater radiation from the sun, the skin is more melanated than those climates with less solar radiation. Melanin is protective against solar UV radiation, but prohibitive of melanin production in the absence of sunlight.

5- nasal complex shape- there are climate associations, though the functional explanation has yet to be fully understood. The general thinking goes colder populations tend to have taller narrower nasal airways to promote heat transfer from the nasal mucosa to the cold inspired air to prevent injury to the lungs. This pressure is of no concern in warmer climates so the shapes is short and broad to maximize airflow or inspiratory and expiratory volume during breathing.

Anyhow, yes there are evolutionary adaptations in human populations to cope with the climate they and their ancestors descended from.

4

Tasty-Fox9030 t1_j1fy50w wrote

Reply to Are people who live in certain climates less susceptible to the effects of the weather there? by dxrknxrth

Among other things the basal metabolic rate of someone who's been exposed to the cold regularly for a while rises, and they tend to put on additional brown fat which produces heat. It might be interesting to see if the response is stronger in populations that have existed in cold places for s long time vs say, a population that lives near the equator. I suspect that there isn't enough time to evolve huge change in the capacity to alter the strength of this response though and people are actually really good at causing gene flow through all their different subpopulations even in antiquity.

7

kilotesla t1_j1fxjsd wrote

Reply to comment by Phat_Potatoes in which is more efficient, using the sun to boil water and generate electricity from team or using solar panals? by Phat_Potatoes

There was a lot of interest and excitement about it a while ago, maybe 15 years ago. What made people generally turn away from it was simply that silicon solar cells and panels got less expensive really fast, so even though when solar thermal electric power projects looked like they'd be competitive, by the time they were finished, the silicon solar cells were so much cheaper that they were no longer competitive.

However, the need for storage is leaving to renewed interest: storing heat can be cheaper than storing electricity.

5

SoylentRox t1_j1fxj19 wrote

Reply to comment by roguetrick in How do fusion scientists expect to produce enough Tritium to sustain D-T fusion (see text)? by DanTheTerrible

You have to absorb neutron flux regardless.

This is one argument in favor of aneutronic designs, that fusion may not ever be practical if the reaction emits a significant amount of neutrons. Hydrogen-B11 for instance. I understand it's immensely harder to do though, requiring much higher temperatures.

An aneutronic design could be designed to fail if someone tries to breed plutonium.

1

Tasty-Fox9030 t1_j1fvv2d wrote

Reply to Are fossils of deep sea life exceptionally rare finds? by Kronzypantz

You'd have to define deep I suppose. I think it probably IS fair to say that most fossil seabeds were not from what we'd call the Hadal zone nowadays.

Hmm. Actually, they have a pretty good idea of which plates were where at different epochs and I'm not sure there IS an exposed rock face that would have been Hadal, and I'm not sure that geologic processes are particularly likely to result in present trench communities to fossilize and then be exposed some time in the future. My general impression of most of the truly deep sites is that they're rifts at the bottom of subduction zones and rock that ends up sinking below a plate isn't coming out looking like it did when it went in. I THINK. I study evolution but not paleontology or geology. If someone does know of one I'd love to read about it!

You might find this interesting:

https://www.jstor.org/stable/20144263

That's a paper on a fossil anglerfish. Not all anglerfish live in the deepest parts of the ocean, but apparently they think the formation that one is from represents mostly fish from around 1000m. It certainly gets deeper than that but a lot of what you'd see living there would be "weird" compares to the fish most people are familiar with.

1

Mikeynolan t1_j1fuiqq wrote

Reply to Do we have to account for motion when receiving transmissions for things life planes and sattelites? by Acceptable-Lemonade

It happens with satellites all the time.

On the Huygens probe into Titan, it was realized that they had forgotten to account for the Doppler effect properly, and that the signal from Huygens would not be received. They figured out a spacecraft geometry that reduced the Doppler shift enough to avoid the problem. https://www.thespacereview.com/article/306/1

And of course that's how a radar gun measures how fast your car is going.

But yeah, radio communications with airplanes don't have to worry about it, as it's too small to matter and they can tweak the frequencies if they need to to stay locked on to each other.

2

Lyndeead t1_j1ftlf1 wrote

Reply to Which medical procedures have a different application when treating a woman or a man? by ViejoOrtiva

Radiological imaging particularly with larger radiation doses are not ordered on potentially pregnant individuals, a pregnancy test may not be offered to a male before imaging putting the offspring at risk. This is also true of some medications like accutane. Though there are reports a new medical recommendation will be including a question for the patients potential to be pregnant to all patients regardless of their sex reported on their file.

Then there are some anatomical differences in the location of certain blood vessels, glands, organs, that aren’t exactly visually apparent, but I can’t say this would be problematic in a surgical setting, maybe problematic in a diagnostic setting.

There can be differences in reported symptoms between sexes, and some medications maybe more effective for a particular sex than another.

9

Implausibilibuddy t1_j1fohz0 wrote

Reply to Can the Doppler effect make sounds inaudible by shifting frequencies out of human hearing range? Or vice versa? by IonnoFry

Not only can the doppler effect do this with sound, it works with light too. Red shift causes visible light waves to "stretch", lowering their frequency toward the red end of the spectrum. Due to the expansion of the universe the farthest and oldest light waves have undergone red shift so much that they're way past infrared into microwave territory. That's what cosmic background radiation is.

92