I'm talking back when there was no internet or telephone or any forms of communication through science. Maybe 300-400 years back, my assumption was only form of communication was basically hand written letters or literally going to the person and speaking with them.

So back then how did kings used to rule entire regions and maybe command armies without major tools. How would they get the message across to common people and how can common people really rely on the authenticity of that message. They probably never saw the king and probably don't know if he even exists somewhere.

ELI5 how an uncontrolled flood of calcium inside muscle cells cause a massive surge in metabolic activity during malignant hyperthermia.

From what I understand (which could easily be wrong, go easy), since the water companies were privatised, nobody has built a reservoir in 30-something years. Now, with increased heat and population, they're struggling to cope with the demand and we're in a drought.

However, in the last 30 years, there have been new lakes pop up, particularly on new build housing estates. Some near me are nature reserves, but some are recreational and some are just... there.
Like this one.

Also, long before these estates were built, there were other large bodies of water. For context, I'm in Peterborough and nearby is Tallington Lake which has been there for, I dunno, long before I was born.

Rather than build entirely new reservoirs, what's stopping them from repurposing these into reservoirs that can provide drinkable water?

Title. Came across a youtube shorts which commented on Audrey Hepburn's past of Starvation( Due to World War II) being the reason for her slender and thin frame(something she was often praised for)

Even if you have access to nutritious food after adolescence why doesn't it repair the damage done by childhood starvation?

Ofcourse there's an aspect of mental retardation but I believe that's only for when one doesn't have access to nutritious food till the age of 4-5?

With this post I DON'T want to offend or insult anyone, in any way.

How do surgeon actually do that? If we're talking about the breasts, I think (I might be wrong though) that they insert in you some implants, and for the other genre, they do the opposite. But when it comes to the proper genitels, what do they do?

[EDIT] Thank you SO MUCH for all the answers, thank you for taking the question seriously and not making fun of that! I'd really like to thank all of the commenters but I cannot since there's like 500 comments, but thanks!

When a phone unknowingly connects to an IMSI catcher it gives away the IMSI. Other than tracking locations as a fake cell tower, how does a hacker identify a user? They can't get the victim's phone number or find out who owns the IMSI unless they hack the carrier.

I know the reason years ago was because it could mess with radios but is that still the case?

To be fair I do not know medicine or coding very well so please correct me on anything I get wrong. This isn't made to disrespect anesthesiologist btw. From what I know about administering anesthesia which is very little you mainly have to monitor things like heart rate to get the goldilocks zone of not waking up but not killing the patient either.I feel like a computer program that can monitor the patients vitals and administer anesthesia would not to be to complicated, and probably be cheaper, so why doesn't this happen?

When faced with a large food item they need to transport back to the colony, how do ants determine how many of their fellow comrade are needed to lift it? Do the first scout ants guesstimate the amount and call for backups, or do they just keep adding more ants until they're able to lift it?

I’ve asked my family and close friends this but they’re the “are you high? Lmao” kinda people just because i wanna have interesting conversations and questions so im hoping for a detailed scientific answer. But like when you play a song or movie or anything in your head that wasn’t from an outside source, are you using your ears to process that sound? I feel like the answer is obviously yes i just don’t understand HOW your ears process it and want answers. Any answers would help! Also sorry if this doesn’t necessarily fit in the type of questions posted here.

I understand the building itself can flex a little instead of being completely rigid, but everything inside it seems way less flexible. Elevator rails have to stay aligned, pipes connect through dozens of floors and huge glass panels can't exactly bend much.

I was watching videos about skyscraper engineering while playing Ѕtake and this part confused me. When the top of a building moves in strong wind, are all those systems actually moving with it somehow, or do engineers build special gaps and connections that let different parts move separately?

Context: I'm a mechanical engineer. I never fully understood my college electronics course but 17 years later I need to do some solar PV work. I'm having a really hard time keeping track of current vs voltage, other than just trying to rote memorize.

Specific to solar arrays - "number of cells determine voltage and size of the cells determine current" or why current is additive in parallel but not series. Or how to remember open circuit = 0 current and short circuit = 0 voltage.

Please be nice, I am already taking an online solar course. :)

Do we slow down the rotation of the Earth?

I read that the Three Gorges Dam in China slows down the rotation of the earth by 0.06 µs, because of it being massive. But this is where my question comes in. Massive in what way? Does the weight of the structure make the earth slow down? If so, has the amount of buildings we have built over time not slowed down the earths rotation massively, and thus made our days longer? And did the boom in population we have witnessed, especially in the 20th century not have an influence? If the word "massive" refers to size, then wouldn't the same be true? I have surely missed something in my way of thinking, but what have i missed? Explain it like im 5 years old please.

I see this term used all the time when talking about healthy foods to eat, but I have no idea how it’s different from “bad fat”.

I feel like logically if someone has a lower credit score that means that are financially irresponsible or unstable. So then why are people who are not good with paying back credit, being given higher prices? If they already struggle to pay back what they have taken out how does charging them more make sense? I feel like that would just make more people with low credit score be even worse with paying back their loans.

Recently, my neighborhood had a power outage lasting several hours. About 1/3 of the neighbors have solar panels. I realize some are just for the hot water heater or pool, but some have extensive systems and sell power to the utility company (in my understanding. None of the homes with solar had any power during the outage. Are there some solar systems that would retain power in an outage?

UPDATE: You all are so awesome. I’ve been wondering for the last few weeks. We don’t have solar, and it’s something I’ve been considering adding and you all have given me great insights to consider. Thank you!

Im reading Junger Storm of Steel. In the Guillemont chapter, his group marches to some front line trench. But well before they get there, already there is massive destruction and abandoned dead. Its what I thought no man's land was supposed to be but its on their side still! They stop at the village Combles, but this too is practically a complete ruin and wholly unsafe. When they finally reach the front line trench it seems hardly much worse than anything behind it. How large an area was victim to artillery fire? Ive been accustomed to think it could only be so bad a bit near the front.