Please note that in aerodynamics, “lift” is any aerodynamic force that acts perpendicular to the relative wind on an object, so it’s lift whether it pushes a plane up, down, left, right, or pushes a sailing boat across the wind.
Also the keel of the boat that keeps it sailing in a straight line is technically providing lift in the water, although that “lift” is sideways. Also it isn’t aerodynamic lift, but hydrodynamic. The general field is called fluid dynamics, which covers both gasses and liquids.
You’ve got some good answers, but the problem with the air bouncing idea is that it ignores the air on top of the wing, or to the leeward side of the sail. The sail is pushed on by the windward air, and pulled on by the leeward air. (Edit: technically not pulled on, but you can model it that way if you take atmospheric pressure as 0 and anything lower than that as negative; it will give you correct results)
A better way to think about it is flow turning - as the wind moves past the sail, its flow is turned and the momentum change causes an equal and opposite change in momentum of the boat: www.grc.nasa.gov/www/k-12/…/right2.html
So ideally the leading edge of the sail should be parallel to the oncoming wind, and the trailing edge will be by definition parallel to the outgoing wind. The difference in velocity between these two winds multiplied by the mass of air passing over them over time will give you the force acting on the sail.
If the leading edge isn’t parallel, the air’s transition from free flow into contact with the sail will not be smooth, and will cause losses that reduce the efficiency of the sail.
In practice, the way to achieve this parallel flow is to let out the sail until you see “luffing”, which is just the leading edge flapping a bit in the wind. Then you tighten it until the luffing disappears, at which point the sail should be correctly trimmed. As you carry on you can occasionally repeat this process to check that you’ve still got the right angle, as minor shifts in wind or boat direction can change the ideal angle of attack.
This is also called “setting” the sail. So when a ship “sets sail” it’s referring to the fact a skipper would order the crew to “set sails”, which would start them moving. Now the term also means to commence a voyage.
In some bigger boats you have strings called “telltales” on the surface of the sail. If you see them flapping you know the air flow is turbulent, and you can trim the sail until the telltales on both sides of the sail are blown into a smooth line along the sail. If you tighten the sail too much, the leeward telltales will flap. If you let it out it too much, the windward telltales will flap.
A flat surface is much less efficient as it will cause a lot more turbulence on the leeward side. A lot of work has been done to make sails form the most efficient shape, and they are always deliberately curved. The shape will change depending on the tightness of the sheet (the rope that sets the sail) and on its manufacture, but ultimately your sail shape was basically set when it was made. Different sail shapes will be optimised for different types of tack and different tasks, but I don’t know enough about that to explain more. Mainly I know that spinnakers are made for running downwind and the other sails usually have to make do for the rest of the situations, but this article tells you a lot more: en.m.wikipedia.org/wiki/Sail_components
I only just found that article, so if it disagrees with anything I’ve said here I’d defer to it.
Very high performance sails and setups can do some cool things, like racing catamarans with their very sleek hulls and optimised sails allow you to sail in a close haul within 30-something degrees of the wind, whereas most normal sailboats can’t get much closer than 45 degrees.
Edit: This seems like a decent resource for first time sailors, and gives some more in depth explanation of how to set your sails correctly: www.cruisingworld.com/learn-to-sail-101/
This is also where I learned what telltales are called. I’ve never sailed bigger boats much tbh.
Okay, I think that’s most of what I can info-dump on the basis of your question. You landed on an intersection of two of my special interests lol :)
Seems like the way for reddit to “solve” this is to just close bad subs.
But that’s easily exploited, if people migrate to other subs and start protesting the sub closures, those subs get worse and they need to be closed…
Oh no, reddit, did you just discover that you relied on your users to make your site good and by screwing them over you’ve made your entire business unsustainable at scale?
Also, somewhat related, is there a short snappy name for lemmy communities? Some people call them subs out of habit but I don’t wanna do that, and “communities” is four whole syllables, and ain’t nobody got time for that.
Idk who downvoted you, I guess people who think the problem with Musk is that he’s cringy or like a cartoon supervillain. No, all billionaires are evil. If you think Gates is a good guy that’s because you don’t understand what it takes to be a billionaire, what he does with his “charity”, or the history of how he’s run his business or destroyed antitrust purely because he was embarrassed at how bad he looked under cross examination. He has the charity specifically to launder his image, and as a result he’s found ways to be evil using it as cover that he wouldn’t have found back in his embrace, extend and extinguish days.
EDIT: Also behind the bastards did episodes on both these absolute jackoffs:
It’s not because 69 is all that funny, but because it’s not very funny. It was a low effort joke that Elon dragged into the toilet and pissed all over, so it belongs in there with the rest of them.
You’re fucking the guy, he likes his name being said and it turns you off? How’d you get to that point? You don’t have a nickname? I don’t care if your name is Rumplestiltskin, if you want me to say your name I am making deep eye contact and saying it and I will mean it. I will moan it. Nothing is better than knowing what my partner wants so I can give it to them.
If you go through his old videos you’ll see him doing exactly that. There’s a non-zero chance your computer’s guts are in there in excruciating detail.
“Gay coated” is just an amazing eggcorn that I have never heard before.
So eggcorns are misheard phrases that are then reinterpreted in a way that still makes sense in context, and that video makes the point that they’re not actually wrong, and sometimes they can compete with the original phrase.
The original term is “gay coded”, as in the creators have used commonly recognised “code” to signal that the characters are gay.
But I actually love the idea that they’re just slathered in the gay, just lubed up head to toe.
Memes. They hijack pop culture and turn it into a dogwhistle, like if you’ve seen people randomly saying “is that a jojos reference?” underneath some worryingly bigoted comment on youtube, they’re trying to indicate that they’re a fellow right wing asshole. For a long time “subscribe to pewdiepie” was used. Both references had some nazi connection, like jojos had a nazi character, and pewdiepie flirted with nazi stuff in a deniable way.
The point is that it’s silly and innocuous so that if anybody tries to call it out then they can just gaslight them and point out how silly it is, and they’re clearly making something out of nothing.
Idk if you had intelligent talking people-rats like in the movie then being excluded from whole industries just because people think they’re icky would actually be pretty bigoted.
Right but that’s fragile. All it takes is one group to break the ice and suddenly they’re all talking.
Also, is the theory that we could live in a dark forest because every single species is insular enough to be afraid of such a threat? That means they all have to believe in the threat and yet also no species is aggressive enough to become the threat. But none of them thinks, “Wait, either we’re alone or everyone is hiding. If everyone is hiding, then the threat can’t exist, so we may as well say something.”
Again, it’s fragile. I find it completely unconvincing.
The Prime Directive concept is way more believable to me, as is the idea that life is just sparse.
I was once at a talk by someone in that company and he straight up said that open sourcing it was a mistake. I assume because that meant they couldn’t sell us a thousand versions of it like Skyrim.
No word of whether its ongoing popularity was at all caused by open sourcing it.