Recent comments in /f/askscience

annieselkie t1_jdd8sit wrote

Reply to comment by Dorocche in What’s the oldest know tortoise with a documented hatching date? by The_Real_Mr_F

😂 yeah tortoises probably didnt receive birth certificates then and werent that documented as modern zoo tortoises. In 1876 the german government started to do birth register and birth certificates, before it was churche's duty and pretty common even. In other countries it may have been in other times or not common at all and surely some people "fell through the cracks" and did not recieve one here as well.

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Dorocche t1_jdd7t6o wrote

Reply to comment by annieselkie in What’s the oldest know tortoise with a documented hatching date? by The_Real_Mr_F

I see what you mean; the oldest humans alive today were born in a time where the vast majority of people in the vast majority of places did not keep strict birth records.

The concept wasn't invented in 1910 (to pick a random date), you're right, but the ubiquity is the important part. Maybe there's a random tortoise or two out there who luckily happen to have good birth records.

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annieselkie t1_jdd7j3w wrote

Reply to comment by Dorocche in What’s the oldest know tortoise with a documented hatching date? by The_Real_Mr_F

>even the oldest humans alive today are "unverified" because they predate birth certificates.

I must object xD Birth documents are very old, in the "dark ages" churches eg had birth and death registers for the local population. And noble people always did care for their birthdate. And they weren't the first in ancient Rome birthdays (at least of important families) were registered, they had a calender and even wrote their own family history/tree (with some gods mixed in way back lol). Some of the oldest humans may have lost their certificate over time or were born in a place/time where noone cared for one for them or it gets unreadable etc. But we have many "oldest" humans verified by their birth certificate/ID/an equivalent of it, and registering birthdates and deathdates or at least times (month/year) is very old culturally.

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No_Constant8644 t1_jdd4p1j wrote

Reply to comment by ChemicalRain5513 in Do insects have "meat" like other animals? I know that grubs, mealworms, etc. are eaten in some parts of the world, but if, for instance, beetles were the size of cows, could you butcher one and make beetle steak? by 9RFCat9

There are different strains of E. Coli. The strain in your gut is suited to that location and is kept in homeostasis within your body.

A different strain would not necessarily be kept in check by normal body processes and your immune system would likely see it as an illness thus causing the immune response (a.k.a. Symptoms of illness)

The same thing happens with yeast infections (e.g. thrush) yeast naturally lives on us, but when something causes our body’s to get out of balance it can allow for the yeast to multiply and take over where it normally would not.

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Busterwasmycat t1_jdd3o8j wrote

Reply to Does the metal in the solid core of a rocky planet have any special properties? by VillagerNo4

Mostly iron because Iron packs really well under extreme pressure and temperature, which is really what drives the segregation of materials inside a planet. It is a matter of space/volume and not all compounds pack to the same extent so unit volumes vary, and will change even for a given compound as P and T vary. The amassing of iron in cores is just a response to the existence of pressure and temperature change with depth (other elements or compounds are less compatible with high pressure, basically, so they end up closer to surface than things that deal well with high P and T, and iron deals the best of them all, apparently.

On top of that density consideration are the chemical needs of each element. Most elements are not all that stable except when in a compound, but iron actually is fairly stable chemically, as a native element. Plus, there is a lots of iron around, with iron being the most stable element made by stars (heavier elements want to break apart, undergo fission, and lighter ones want to combine and make bigger atoms, undergo fusion).

The physical characteristics of iron at extreme pressure and temperature are not well known because it is really hard to study something several thousands of kilometers below a mass of silicate materials (study in place) and it is difficult to make even in laboratory, and then only in very tiny amounts, with even a problem of time duration coming into play (it won't stay the same if you ease off pressure or temp).

People are working on it. More near the frontier of knowledge than a well-characterized material. Even the nature (PT-conditions) of the transition from face-centered cubic to hexagonal close-packed structure is poorly defined from what I have seen about it.

Including minor nickel to make some sort of alloy, and its effects on behavior, is also still poorly understood.

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CrustalTrudger t1_jdd2wan wrote

Reply to With the extraordinary amount of precipitation that has fallen on California, would that weight have any effect on the tectonic plates/fault lines and could it cause a major earthquake? by barfly2780

The short answer is probably not, but it's complicated and any potential effects depend a lot on the details (i.e., where is the water, how much water, which faults, etc). We might expect some change in the statistics of microseismicity, but the likelihood that this would influence details of large magnitude earthquake is low.

For the longer answer, we need to establish that changes in surface loads from water (either rain or snow) and changes in the amount of water in the shallow subsurface (i.e., groundwater) can have an influence on earthquake statistics and details. There's not a single mechanism at play here though, so things get a bit messy. Some of the culprits at play are changes in: (1) primarily vertical normal stress magnitude from changes in surface water mass, (2) changes in strain rate from longer wavelength elastic responses to changes in water mass, and (3) various "poroelastic" effects that relate to more or less water within pore spaces at various levels within the upper crust.

The easiest one to wrap our heads around are the first, i.e., changes in normal stress. Basically if you have a shallowly angled fault, putting more weight on it will actually make it less likely to fail because, in a simplistic way, you're increasing the friction. For example, in portions of the Himalaya, there appears to be excess seismicity in the winter, with the idea that large loads imposed by the summer monsoons increase the normal stress on faults making them less likely to fail in the summer (e.g., Bollinger et al., 2007, Panda et al., 2018). Similar things are seen in Taiwan, though the signal is a bit messy (e.g., Hsu et al., 2021). Alternatively, in Japan, the opposite is found with some areas potentially experiencing more earthquakes in summer with the normal stress provided by snow suppressing earthquakes in the winter (e.g., Heki, 2003). Given this, we'd kind of think that heavy rains (i.e., more water mass) would actually decrease the likelihood of earthquakes, but critically, these examples are mostly focused on shallowly angled faults (i.e., shallowly dipping dip-slip faults), whereas in California, most of the faults of concern are close to vertical.

With reference to California, we've recognized that there is seasonal modulation of earthquake statistics (mostly for microseismicity, i.e., small earthquakes) thought to be related to changes in both surface and grounwater mass and related effects, i.e., those long-wavelength elastic and poroelastic ones mentioned above (e.g., Johnson et al., 2017). A variety of follow up work has filled in details (e.g., Kreemer & Zaliapin, 2018, Kim et al., 2020, Carlson et al., 2020), which highlight that the potential earthquake response depends on where the change in the water mass is in relation to specific faults and the type of faults. Heavy precipitation, depending on where it is, can make earthquakes slightly more likely for some faults and less likely for others depending on the details. Also, as discussed in some of the papers, some of these effects can have a significant (several month) time lag. Mostly again, this is considering small earthquakes and changing statistics not total energy release, but there are some indications that some of these water mass related changes could allow for larger earthquakes (e.g., Kreemer & Zaliapan), but this specific suggestion was for when faults in a particular location were experiencing fault normal extension due to an elastic response to less water.

Ultimately, what this suggests is that, especially given the large amounts of both snow and rain, this added water mass will likely influence some aspects of earthquake statistics, but the likelihood that this directly relates to a large earthquake is pretty low. Also, importantly, we don't generally understand these systems well enough to use this information to make useful or actionable forecasts for the details of changes in earthquake statistics we might expect, but I fully expect there will be papers in the coming years considering what effect these storms had on details of crustal strain and impacts of those changes in crustal strain.

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ndraiay t1_jdd1tf9 wrote

Reply to comment by PyroSAJ in Do insects have "meat" like other animals? I know that grubs, mealworms, etc. are eaten in some parts of the world, but if, for instance, beetles were the size of cows, could you butcher one and make beetle steak? by 9RFCat9

A friend offered me fried silk worms. Tasted like a cross between a peanut and a potato chip. It is one of those things that most people would like if they didn't know it was a silk worm.

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noirxgrace t1_jdcyo3l wrote

Reply to What happens when we die? by darsenalmex11

Sight is the last sense to go
Brain is the organ that survives the longest amongst all other organs
In short, you turn pale; all the blood in your body settles down on the area closest to ground creating bruises; then body goes cold no heat signature; then rigor mortis sets in i.e. your joints become rigid and position of body cannot be changed; then all organs in your body liquify and bloat your body from inside with fluids and gases; then you start decomposing with scavengers of the the society like maggots, insects and animals feeding on you and breaking you down until you turn in bones

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