Recent comments in /f/explainlikeimfive

Roobar76 t1_j6g4tb9 wrote

There’s a bit of confirmation bias there. Rural areas developed where there was water and didn’t where there wasn’t. So where there is a long farming history there is generally surface or ground water, and the bits that ended up in national parks/reserves it’s either deeper or not there.

4

ninetentacles t1_j6g4hqr wrote

Ah, was just wondering because it's often at lower heart rates when I feel my heart pounding particularly forcefully, but I think my oxygen transfer may be a bit out of whack cause rona.

Will deconditioning cause your resting heart rate to go back up? Or if you're less active will you still maintain your low RHR past the point where whatever damage people think you're going to cause yourself by not pushing yourself to exercise til you drop through something like long COVID?

1

explainlikeimfive-ModTeam t1_j6g4927 wrote

Please read this entire message


Your submission has been removed for the following reason(s):

  • ELI5 requires that you search the ELI5 subreddit for your topic before posting.

Please search before submitting.

This question has already been asked on ELI5 multiple times.

If you need help searching, please refer to the Wiki.


If you would like this removal reviewed, please read the detailed rules first. If you believe this was removed erroneously, please use this form and we will review your submission.

1

Whitehatdvl t1_j6g42su wrote

What's weird to me is if you read stuff from the WWII era and before, it was common for people to refer to Japan as Nippon, and they called Japanese people Nipponese (if they weren't using a pejorative). It's kinda crazy that everybody says Japan now in English instead of Nippon, which is what the Japanese say.

22

saywherefore t1_j6g3tn3 wrote

There are advantages to building statically determinate structures beyond the simplicity of analysis; mostly related to the lack of prestress which means you can get away with larger manufacturing tolerances.

However in practice it is hard to achieve a truly determinate structure, and in many cases it is not necessary to even attempt it. There are analysis techniques that apply to indeterminate structures so it’s not like we just build those blindly and hope for the best.

1

explainlikeimfive-ModTeam t1_j6g3t7a wrote

Your submission has been removed for the following reason(s):

Loaded questions, or ones based on a false premise, are not allowed on ELI5 (Rule 6).

If you would like this removal reviewed, please read the detailed rules first. If you believe this was removed erroneously, please use this form first. If you believe this was removed erroneously, please use this form and we will review your submission.

1

Parkour63 t1_j6g3n4i wrote

Hand surgeon here. I’ve repaired my fair share of tendons.

I assume you’re referring to a surgery where a tendon is ruptured or cut, and needs repair.

Repairs are pretty straightforward. You make a cut, find both ends, and suture them together.

If a tendon tore from its attachment to the bone, you usually need to drill a hole into the bone and attach it with an anchor of some kind. (There are a wide variety of implants and techniques for this, so it’s hard to give more detail.)

Surgery is usually easier if you get it done sooner, so the tendon doesn’t retract or get covered with scar tissue.

Similarly, as soon as it’s safe, you’ll want to start gently moving, so the tendon doesn’t get stuck in scar tissue. Especially in hands!

If it isn’t clear, this is all very simplified, and is not a substitute for talking to a doctor in person if you think you need surgery!

If you give me a more specific question, I may be able to help you better.

1

saywherefore t1_j6g38dm wrote

The time is not spent by the machine communicating with the card. When you do chip and pin the card machine is communicating with the bank or credit card provider, and checking that the card is genuine and can afford the payment. This takes non-negligible time. In a contactless payment the vendor doesn’t check the card and just takes a risk that it isn’t genuine. The transaction will be settled up at the end of the day. This is why there are generally limits on the value of transaction that you can do contactlessly; it protects the vendor from being left out of pocket for a large sum.

Edit: this answer is Eurocentric. I understand that the technology may be different in other places, though in that case I doubt there would be a noticeable difference in speed.

77

breckenridgeback t1_j6g31kd wrote

> Wouldn't your heart need to beat more forcefully to move the same volume of blood completely around your body at 60bpm than at 100bpm, though?

No. You don't need as much blood flow when your blood is more efficiently carrying oxygen, and it doesn't have to push as hard when it's not getting as much resistance from your arteries.

> And are these your own actual numbers, or are people more likely to see a more modest decrease in resting heart rate, like from 70bpm to 60? 100 seems awful high for "resting"!

It is high, yes. It's typical of someone with poor physical fitness, but not healthy. 60 bpm is a fairly normal healthy resting pulse. But the thrust of the explanation - that the heart does less work by having mild stress during exercise and less stress the rest of the time - stands either way.

3