John Cuthber

Yes and no. The molecule absorbs energy and some electrons get shuffled round. But ordinarily, those electrons manage to transfer their energy to vibrations of the molecule and it's dissipated as heat. So the molecule isn't usually permanently damaged. We deliberately chose molecules for their ability to stand up to this process even when it's repeated many times. Most fading by sunlight is actually caused by UV rather than visible light. UV photons carry enough energy to break bonds and that's not so easy to recover from. On the other hand, as has been pointed out, those are clay tiles. The pigment is essentially iron oxide and even if that molecule gets damage, the only plausible products are iron and oxygen. If any iron is produced, it wont be long before it rusts back to the original orange/ brown colour. So it's pretty much permanently light fast. The discolouration is probably, as SJ says, efflorescence. (I can't absolutely rule out leaching by acid rain or something if the place is in a chemical works or something.)

There are two interesting* things; 1 the USA seems to be doing badly, in spite of paying more for healthcare (And it has got worse). Maybe they should change the system. 2 there are differences between various bits of the population. I'd be interested to see what other factors are in play. How does maternal age relate to maternal death rate? How about number of previous births? (And come to think of it, how to those relate to infant mortality). * I'm not saying they are only interesting; they may also be scandalous or frightening, but they are interesting. https://en.wikipedia.org/wiki/List_of_countries_by_maternal_mortality_ratio

The simple answer is buffering. https://en.wikipedia.org/wiki/Buffer_solution If you have 5 ppt of citric acid in one wine and 5ppt of citric acid and also 5 ppt of sodium citrate in another wine they will have very different pH values but (relatively) similar tastes. Or, at least that's what I'm told about the tastes; I never checked.

Oops! Someone changed the rules while I wasn't looking.

An important factor is that stronger wines are more expensive (for tax reasons) and also more harmful to health.

In case anyone wondered, yest this does belong with the jokes. The Equipment The equipment used in these two sports is another major difference between them. For a start, the pin pong table, about 3.7 mm in diameter, is slightly larger than the table tennis court, which is only 3.4 mm. Source: https://pingpongacademy.org/ping-pong-vs-table-tennis/ I'm just not sure if it's deliberate.

I must have been half asleep when I posted that or something. The longitude- almost exactly 30 degrees- is the one that matters . The time difference should be almost exactly 2 hours. Today I think the answer is 3 hours, but that 's largely political.

That seems sensible to me. Even if the materials have the same viscosity to start with, a mixture may have a different viscosity (anyone who has seen an engine where water has got into the oil will know that; the product is much more viscous than the components even though no chemical reaction takes place). So, if the viscosity is homogeneous, the mixture must also be. But there's a catch 22 here. If your model doesn't work, then using a modeled property- like viscosity- won't be a good test. If you could model the density (which is usually "better behaved"than viscosity) it would be better.

7/8 and, had I been a Victorian schoolkid, I might have swotted up on lowest common multiples. That might not have been a time zone. It's pretty close to exactly 4 hours. " St Petersburg, Russia Lat Long Coordinates Info The latitude of St Petersburg, Russia is 59.937500, "

Thanks for the warning I will seek to avoid eating insulating materials.

Can we haul it out, dry it and burn it for fuel?

To a very good approximation, the effect of temperature on the density of air and helium is the same (in percentage terms). The balloon floats because its average density (including the walls of the balloon)is less than that of the air. As the balloon rises the air gets less dense. There comes a point where the density of the balloon and the surrounding air are the same and, at that level, it stops rising. It's made slightly more complicated by the fact that the balloon changes volume (and thus density) as it rises.| With mylar balloons, once the envelope is "full", the volume stays pretty much constant (until they burst). High altitude balloons are launched looking rather empty, to allow for expansion as they rise. https://www.forbes.com/sites/elizabethhowell1/2019/07/05/google-affiliated-company-sends-high-altitude-balloon-aloft-for-223-days/?sh=484528407edf

Note that not all epoxy resins are food-safe. Essentially the OP's question is like going into a large DIY store and asking "which is the best paint?". You might get an answer - but it might not be the information you were seeking.

Not really. Ivory is a combination of mineral material (largely hydrated calcium phosphate, I think) and proteins (largely collagen). Collagen isn't hard to get; nor is the calcium phosphate. But combining them is impractical/ impossible. The good news is that the only thing that ever needs ivory is an elephant, and it can make its own.

Yes, it is. What's to discuss? https://en.wikipedia.org/wiki/Cell-free_protein_synthesis

The wood preservatives industry would not see it that way.

Yes. It's called "air travel".

I think we might as well treat the OP's "message" as spam.

When you get cold enough for spin energy to be significant, most things (including nitrogen) have already frozen solid. So you don't get the same effects that you see with hydrogen and deuterium (and, I guess, tritium if you have any).

To be fair, that's a population size bias.

And you picked "beige" from all of them.

Did they look at the right time, i.e. before they knew there was an outbreak? Did they look in the right place, i.e. at every (susceptible) animal there? One odd case in some animal that passed the bug to a store-holder before becoming someone's cooked dinner would be all it took. Obviously, you can't rule out a lab mistake as the "source" but you have to ask how the virus got into the lab. It must have been in the environment somewhere. How easy is it to rule out the idea that, rather than coming from the lab, it came from the tyre of the car that carried the sample to the lab? Lab escapes happen. https://en.wikipedia.org/wiki/2007_United_Kingdom_foot-and-mouth_outbreak And they knew they were dealing with a dangerous (Cat 3, I think) organism. The only way in which you can "blame China" is if you can be sure that they deliberately made a lethal human pathogen in what is- as you say- pretty much a school laboratory.

It depends on how hot you get them and for how long. it does not depend on whether you heat them in a microwave or not.

Which would be the appropriate control measures for a bat virus, and vastly more than those in a wet market.

Water is black to UV with a wavelength below about 200 nM. But so is air, so it doesn't usually matter.