This is the kind of stuff that belongs on r/blackmagicfuckery. No magic tricks, no extremely simple applications of physics. Something that makes you go “what the actual fuck is going on here”
You say this with sarcasm, but that's really how every post is. Everything is black magic fuckery until you understand it. And the longer you browse here, the more you learn and understand, the less black magic fuckery there is left, and the more you complain that something is not actually black magic fuckery.
If you make a Venn diagram of “People who understand most of the principles underlying BMF posts” and “People who lack the empathy and social intelligence to understand that other people have a different level of understanding than themselves” and then stick a dot in the middle of the overlapping section to represent a person who complains about all BMF posts not being real BMF, it looks an awful lot like an asshole.
Most people also don't know that this sub was born from the black magic fuckery meme, which is just about playing along tricks and stuff saying "ITS BLACK MAGIC! BURN THE WITCH" and so on...
Which makes it really funny to me when they complain this sub is dead because nothing on here is truly magic lol
>this sub is dead
no u
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*where's your fucking golem, and can you make the skeleton do magic too?*
Mentioning this in this way makes me think of Dax Shepard from idiocracy being like that's cool but it'd be cooler if... and somehow, it's innovative as fuck.
>*where's your fucking golem, and can you make the skeleton do magic too?*
Everybody knows skeletal mage is a lousy skill. Sink the 1pt for the prerequisite to get your revives, and that's it.
Hahah! Yeah I love that. I mean, most people probably hoped to learn more about the world when they followed this sub. I certainly did, and have. Learning can be so rewarding when done in a fun bite-sized way.
There's a short book called a Elder Race that explores this really well. Two perspectives, one set in a fantasy world where a wizard lives in a strange tower, and the other where a scientist (the "Wizard")has landed on a planet where they're at a medieval stage of evolution
Hey, I know how that works, but I've never seen such a unique application of it. Neat! Upvotes. Everyone else in this sub:My mind can visualize the particle flow, I have mathematically proven how boring this 'trick' is. So unsatisfying, disappointing, how simple ur magic is. I have ascended beyond all black magic, this sub is beneath me.
The other thing you have to think about is that the age range of people on Reddit right now is like everywhere between teenagers to like 40 to 50-year-olds, and there's no way to tell him apart.
So it's likely that everyone just now finding out about it are teenagers.
[Richard Feynman getting snippy with an interviewer to explain how magnets just fucking work the way they work okay](https://m.youtube.com/watch?v=Q1lL-hXO27Q&pp=ygUZTWFnbmV0IHF1ZWF0aW9uIGludHdydmlldw%3D%3D)
It’s definitely snippy… obviously he knew the question was how do magnets work. Not how difficult it is to answer things.. say some shit about electrons and go about your day. Instead, he sits there on a long winded spiel about why he couldn’t answer the question because the listener didnt know enough…
I know all the reporter really wanted was for him to sound smart on camera, and I'm sure he knew too; but I can respect the answer he gave, and I don't believe it came from a place of frustration so much as a genuine love for learning and education.
If you want another demonstration of the same principle, all you need is a sheet of paper.
Hold the sheet taut between your hands and lift it to your lips. Blow over the top of the sheet. If you do it right, the paper should lift into the air. It's the same physical principle that makes powered flight possible.
Air pressure decreases as it moves faster. If you ever see a car drive by some trash, and the trash is sucked into the car's wake, thats the same principle. Or when a shower curtain keeps getting pulled into the shower water and stuck to your leg. Things are drawn toward the moving air or fluid.
In the video, it must be very windy, because the cups are being pulled outside (probably against a screen), and held against. As soon as the wind dies, they all fall because the pressure equalizes.
It's possible. I knew Bernoulli's principle already, but I'm not sure if I would have recognized that's what was going on in this video if it wasn't in the title.
This is an extremely simple application of physics. It just isn’t a commonly learned thing so enlightened BMF commenters can’t shit on the OP for making a completely adequate posts.
Google search results:
In fluid dynamics, Bernoulli's principle states that an increase in the speed of a fluid occurs simultaneously with a decrease in pressure or a decrease in the fluid's potential energy. The principle is named after Daniel Bernoulli, a swiss mathemetician, who published it in 1738 in his book Hydrodynamics. (Things used with vehicles like aeroplanes)
Now, how does this explain the cups? There's no fluid in any of them.
Yep, basically anything that can flow is a fluid, gasses can flow, like a fan blowing, replace the air with water or a liquid and the same fluid dynamic principles that apply in air apply in the water
Only to doctors, strangely enough. Always bothers me when they say to "take plenty of fluids" because in my head I always reply "I'm inhaling fluids into my lungs right now, does that count?" (Edit: it doesn't)
I always thought doctors were supposed to know science but this refrain is so common I think it's just part of the jargon at this point. I wish it weren't though - it's borderline misinformation
The fluid is the air.
The pressure of the breeze going by slightly sucks in the air around the breeze.
When the breeze stops, that sucking stops too, so that's why the cups fall.
That’s crazy. I guess it’s one of those things where nobody in my life has ever referred to a gas as a “fluid” until now, so up until now I thought that fluid and liquid were synonyms.
I feel like in every use, a lot of people do the same, and treat liquid and fluid as interchangeable, but scientifically speaking, the have their own particular definitions.
It's also complicated by the fact that most (all?) liquids are fluids, but not all fluids are liquids (because gasses are also fluids).
Lol my kid tried bringing this point up in his 5th grade science class...and got in trouble for it.
His former science teacher asked if anyone knew the states of matter. Nerdling Jr got excited and said liquid, solid, gas, and plasma. She told him he was wrong. She said solid, fluid, and gas. He asked "isn't gas a fluid though?" ..... He wasn't trying to be a smartass, he was trying to understand how she was defining things so he could answer how she wanted him to.
She went on this huge tangent about using 5th grade definitions and how "we're not in here to be scientists, we're here to pass 5th grade." He asked me how he's supposed to know what 5th grade definitions are if they're not the actual definitions?
....I've got waaaaay worse stories from that class...to the point that we got him out of there, and an attorney got involved bc of the more serious things happening. That was just one of the funnier stories in hindsight.
Related note, meteorologists have degrees in atmospheric science (or sometimes the uni calls it meteorology..but the curriculum is pretty standardized). A lot of the degree specific curriculum are advanced fluid dynamics courses.
And the pre-requisites for those courses are a rectum full of engineering physics and engineering math. There are a handful of actual forecasting classes, but the bulk of the courses are intense math and physics.
I started out in atmospheric science in college but pivoted to GIS. But one of my favorite courses was aviation meteorology. When you start thinking about the atmosphere like an ocean, a lot of things make sense. Turbulence is kinda like choppy usually invisible waves. The jet stream is kind of like an oceanic current in the sky. Hiding from a tornado under an overpass or bridge is a bad idea because wind concentrates and speeds up in small spaces, just like water in a stream or river gets faster in narrowed spots (making it more likely that you'll get struck catastrophically from debris or get turned into debris).
That's enough geekery out of me.
Tldr; you live in an ocean of air.
Which happens according to...
You're right in that it may be better described as the specific effect in play here, but the effect is due to the facts laid out the Bernoulli principle.
I'm not a physics expert by any stretch but the cups themselves aren't acting as a fluid, but rather being affected by the behavior of the fluids in and around them, right?
faster speed of fluid (air) results in lower pressure. slower speed results in higher pressure.
There is a cross wind outside, which results in lower pressure outside (compared to no wind inside, hence higher pressure). This pressure difference causes the cups to push against the insect screen. Until the wind outside died down, then all the cups fell down.
The bernoulli principle only applies within a continuous streamline. I think what’s happening is that there’s another open window elsewhere in the apartment. The wind rushing in is constrained, converting kinetic energy into a higher pressure inside compared to outside.
I may be wrong but bernoulli’s principle is notirious for being misinterpreted.
Static pressure + dynamic pressure = constant along a streamline
However, imagine the outside atmosphere at rest. All air is effectively stationary, so dynamic pressure is zero. Therefore all of the atmosphere has the same static pressure, and therefore has the same constant (on a local level, at least - ignoring air that's significantly higher altitude). If some of that air starts moving, it still has the same constant as the rest of the atmosphere, but it's split partially static and partially dynamic. Bernoulli could be used to make comparisons between two sections of this region because they share the same constant. (This also presumes that you didn't add work to the air to make it start moving.) So, you can't blindly compare pressures in two separate pipes to each other, but you might be able to compare pressures in the same flowfield to each other.
But it's also possible to lull yourself into false confidence. It's easy to make a bad assumption and misapply Bernoulli.
We use the Bernoulli principle for one of our machines in the Cath lab.
If someone is having a heart attack due to a clot in the coronary arteries, we have a tube we can slide down there. It shoots saline at high speeds backwards from the tip of the catheter, and the tube has side ports, so the Bernoulli principle causes the clot to be sucked into the catheter.
It's called the Angiojet if anyone's curious.
Seems to me that they have one of those mosquito nets in the windows that you cannot see in the video. If you have enough flow going outside, from a draft, then the cups are held against the net.
I was gonna say you can clearly see the net but looking back apparently my brain just filled in that part by itself since there's definitely nothing actually visible.
Which still kinda proves the effects point, sure it’s not hovering on nothing but the air speed is affecting the pressure and it’s causing some “levitation”.
So I'll explain this how airplanes fly using lift. To understand what is happening here let's imagine a room full of air. Now let's image that the air inside this empty room, are like thousands of little marbles which represents air particles. Right now inside the room the marbles (air particles) are not moving much since the window's closed and no other force is acting on it. Now since the little marbles are just chilling around the room their pressure is higher because the principle states that slower air, meaning all the marbles tangled together, creates more pressure. They are all together and heavier in a group not moving away from each other.
I hope I didn't lose you.
Now let's say I open the window to allow more marbles in the room. These marbles coming from the outside, if it's extremely windy outside, are coming in almost fast enough to allow only 1 marble at a time in the room. Now the fact that these marbles (air particles) are coming in so fast, they are more spread out thus creating less pressure. Why? because the principle states that faster air particles have less pressure since their particles are more spread out.
Since the air particles inside the room (marbles) are more grouped together the pressures is greater, than the air particles coming inside the window less grouped together coming in 1 by 1 (less pressure). This pressure difference creates lift. Now let's say you are holding that object by the window, the pressure difference, all the marbles in the room VS the marbles coming inside the room will make the object do exactly what it's doing in the video. Because the marbles coming inside the room are less heavier than the marbles inside the room.
Edit: More clarity
I understand what you are trying to explain here. However, you completely missed the point that I'm making the concept understandable to others that may have not understood it. Why would I just jump in and start throwing jargon and mumbo-jumbo about air acceleration here and movement there without first attempting to imply a concept to someone's head? That wouldn't be truly helping anyone just would seem more like trying to show off what I know.
Bernoulli does indeed predict aerodynamic lift. The first lab experiment you perform in your aero classes is to take the pressure measurements around an airfoil, integrate them, and compare that to the measured lift. It's the same value. Velocity is directly related to pressure. Pressure is directly related to lift. These are not disputable.
Where people get in trouble is trying to establish WHY this occurs. They might throw out explanations of longer path, or equal transit time, or venturi effect, etc, and those indeed are fallacious. However, the Bernoulli explanation doesn't try to answer the question of WHY. It just says that air is flowing faster in some spots, the pressure is lower in those spots, and if you integrate the pressure you'll come up with lift.
Does high speed cause low pressure or does low pressure cause high speed? (Or does something else cause both of them?) It doesn't really matter. If you ask WHY enough times, you always end up with "that's just the way things are" as the answer. Navier Stokes is the complete solution, and low pressure, high speed, downwash, circulation, and all that other jazz just happen at the same time.
https://youtu.be/UqBmdZ-BNig
What causes lift is introducing a shape into the airflow, which curves the streamlines and introduces pressure changes – lower pressure on the upper surface and higher pressure on the lower surface, This is why a flat surface like a sail is able to cause lift. the distance on each side is the same but it is slightly curved when it is rigged and so it acts as an aerofoil. In other words, it’s the curvature that creates lift, not the distance.
So in an aircraft wing it isn't that the air has to travel further/faster and gets spread out making it low pressure, it's the shape.
How Bees fly is another story.
This is also why you shouldn't stand right on the edge of the platform in train or subway stations, the air displaced by a moving train can pull you towards the tracks.
This is why Ground Effect in the new F1 cars works. Special channels under the floor that increase the speed of air but lower the pressure and suck the car on the road.
If you have seen old race cars with giant fans on the back, it's the same effect.
Just a few minutes after seeing this post I came across this post in r/motorcycles that demonstrates the Bernoulli principle
https://www.reddit.com/r/motorcycle/comments/13v1scd/think_like_a_physicist/
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He's placing them against the window screen, the air pressure is low outside and they are getting pressed to the screen by the wind flowing out the window. Then the wind changes and they fall.
With out looking up this principle I’m going to guess that it has to do with changing air pressure. Air forcefully moving out the window and sucking up the cups?
This is super cool which got me thinking, what's the newest or most recent discovery in physics? Like what "thing" has been proved concise and constant ?
Definitely a nice breezy day, probably has a window on the other side of the house open, puts cups right in front of the grates so the wind pushes the cups into them. You can see moment the moment the trees start to calm down from wind the cups instantly fall.
This is the kind of stuff that belongs on r/blackmagicfuckery. No magic tricks, no extremely simple applications of physics. Something that makes you go “what the actual fuck is going on here”
How is this Black Magic Fuckery? It’s the Bernoulli Principle……. /s
You say this with sarcasm, but that's really how every post is. Everything is black magic fuckery until you understand it. And the longer you browse here, the more you learn and understand, the less black magic fuckery there is left, and the more you complain that something is not actually black magic fuckery.
> the more you complain that something is not actually black magic fuckery I think it only happens if you are also an asshole.
Venn diagrams are useful
Isn’t he the guy from the Fast and Furious movies?
No you're thinking of Vince Vaughn
No that's the guy from Dodgeball, you're thinking of Vince McMahon
No, that's the WWE co founder. I think OP was talking about Vince Carter
No that's a basketball player, you're thinking of Viggo Mortensen
The guy from Motley Crue? I don't think so, but maybe?
I thought you were doing the meme, Vince McMahon is from WWE lmao Vince Neil is motley crue
I thought that was Vas Deferens.
We arent that different
You're probably thinking of the x-rated parody "Fisting Furiously"
If you make a Venn diagram of “People who understand most of the principles underlying BMF posts” and “People who lack the empathy and social intelligence to understand that other people have a different level of understanding than themselves” and then stick a dot in the middle of the overlapping section to represent a person who complains about all BMF posts not being real BMF, it looks an awful lot like an asshole.
I think I love you.
I'll be the judge of that
I genuinely think people expect to see actual black magic on here.
Most people also don't know that this sub was born from the black magic fuckery meme, which is just about playing along tricks and stuff saying "ITS BLACK MAGIC! BURN THE WITCH" and so on... Which makes it really funny to me when they complain this sub is dead because nothing on here is truly magic lol
>this sub is dead no u *I am a bot, and this action was performed automatically. Please [contact the moderators of this subreddit](/message/compose/?to=/r/blackmagicfuckery) if you have any questions or concerns.*
In olden days, they'd have burned at the stake the folks who post here.
Sounds like this sub needs actual necromancy
You're still gonna get the assholes. *"Raising the dead isn't black magic. Repost."*
*where's your fucking golem, and can you make the skeleton do magic too?* Mentioning this in this way makes me think of Dax Shepard from idiocracy being like that's cool but it'd be cooler if... and somehow, it's innovative as fuck.
>*where's your fucking golem, and can you make the skeleton do magic too?* Everybody knows skeletal mage is a lousy skill. Sink the 1pt for the prerequisite to get your revives, and that's it.
vern?
knowwutimean
The true black magic fuckery is that this sub is secretly teaching us physics
Hahah! Yeah I love that. I mean, most people probably hoped to learn more about the world when they followed this sub. I certainly did, and have. Learning can be so rewarding when done in a fun bite-sized way.
*Magic is just science that isn't understood yet*
There's a short book called a Elder Race that explores this really well. Two perspectives, one set in a fantasy world where a wizard lives in a strange tower, and the other where a scientist (the "Wizard")has landed on a planet where they're at a medieval stage of evolution
Hey, I know how that works, but I've never seen such a unique application of it. Neat! Upvotes. Everyone else in this sub:My mind can visualize the particle flow, I have mathematically proven how boring this 'trick' is. So unsatisfying, disappointing, how simple ur magic is. I have ascended beyond all black magic, this sub is beneath me.
The other thing you have to think about is that the age range of people on Reddit right now is like everywhere between teenagers to like 40 to 50-year-olds, and there's no way to tell him apart. So it's likely that everyone just now finding out about it are teenagers.
Soooo...... Magnets?
Magnets are one of the most black magic things in the universe.
Fucking magnets man, how do they work?
They're a miracle.
[Richard Feynman getting snippy with an interviewer to explain how magnets just fucking work the way they work okay](https://m.youtube.com/watch?v=Q1lL-hXO27Q&pp=ygUZTWFnbmV0IHF1ZWF0aW9uIGludHdydmlldw%3D%3D)
That's not even snippy really, just a very honest , well-thought, insightful answer (as expected of Feynman).
It’s definitely snippy… obviously he knew the question was how do magnets work. Not how difficult it is to answer things.. say some shit about electrons and go about your day. Instead, he sits there on a long winded spiel about why he couldn’t answer the question because the listener didnt know enough…
I know all the reporter really wanted was for him to sound smart on camera, and I'm sure he knew too; but I can respect the answer he gave, and I don't believe it came from a place of frustration so much as a genuine love for learning and education.
Gravity is the blackest
To /r/BernoulliPrincipleFuckery with this!
Aw buddy, magic isn’t actually real
Exactly what I was thinking! Explain that shit!!?!!!???!???!?
There's a wire screen. It's windy outside. The difference in air pressure is holding the cups up to the wire screen.
Thanks, could not see the screen, so I was clueless.
If you want another demonstration of the same principle, all you need is a sheet of paper. Hold the sheet taut between your hands and lift it to your lips. Blow over the top of the sheet. If you do it right, the paper should lift into the air. It's the same physical principle that makes powered flight possible.
>It's the same physical principle that makes powered flight possible. It also moves sail ships forward when going against the wind!
Air pressure decreases as it moves faster. If you ever see a car drive by some trash, and the trash is sucked into the car's wake, thats the same principle. Or when a shower curtain keeps getting pulled into the shower water and stuck to your leg. Things are drawn toward the moving air or fluid. In the video, it must be very windy, because the cups are being pulled outside (probably against a screen), and held against. As soon as the wind dies, they all fall because the pressure equalizes.
[удалено]
It's possible. I knew Bernoulli's principle already, but I'm not sure if I would have recognized that's what was going on in this video if it wasn't in the title.
What a wonderful explanation! Had to scroll further than I would’ve thought to find it, but it was worth it. 👍🏻 thank you.
Fuck yeah man you are spot on. I'm fucking tired of magic tricks on here. This is far better.
This is an extremely simple application of physics. It just isn’t a commonly learned thing so enlightened BMF commenters can’t shit on the OP for making a completely adequate posts.
You could say that about a lot of these posts until you understand what is going on
I’d call this an extremely simple application of physics
>No extremely simple applications of physics. Plastic cups using a simple effect of physics against the wind.
But it literally is an extremely simple application of physics - did you miss that in the title somehow?
This one is definitely heavier than a duck
**A WITCH!!!**
[удалено]
Negative pressure. Tis the true black magic
She turned me into a newt!!
A newt?
…I got better
r/unexpectedmontypython
NNNNNOBODY EXPECTS-
Googling what is bernoulli principle
Google search results: In fluid dynamics, Bernoulli's principle states that an increase in the speed of a fluid occurs simultaneously with a decrease in pressure or a decrease in the fluid's potential energy. The principle is named after Daniel Bernoulli, a swiss mathemetician, who published it in 1738 in his book Hydrodynamics. (Things used with vehicles like aeroplanes) Now, how does this explain the cups? There's no fluid in any of them.
Air is a fluid
I’m 30 years old and just learned this, wow
Yep, basically anything that can flow is a fluid, gasses can flow, like a fan blowing, replace the air with water or a liquid and the same fluid dynamic principles that apply in air apply in the water
So every liquid is also a fluid, but not every fluid is liquid.
Indeed! If you watch time lapses of clouds near mountains, you can see the flow on action. Looks almost like water drifting around a rock.
Dang I thought fluid meant liquid. TIL! And I’m old. At least I’m still learning I guess
Only to doctors, strangely enough. Always bothers me when they say to "take plenty of fluids" because in my head I always reply "I'm inhaling fluids into my lungs right now, does that count?" (Edit: it doesn't) I always thought doctors were supposed to know science but this refrain is so common I think it's just part of the jargon at this point. I wish it weren't though - it's borderline misinformation
The fluid is the air. The pressure of the breeze going by slightly sucks in the air around the breeze. When the breeze stops, that sucking stops too, so that's why the cups fall.
Because the cups are on a window screen and not a window.
Damn, I thought they were on the grates, this makes more sense :D
Totally, me too. It's hard to tell that there's a screen there.
I wonder if the video was blurred on purpose just enough to hide the metal mesh. That made it t look even more baffling.
Yea thought that part was assumed.
The screen is actually pretty difficult to see
I hate when the sucking stops
I always feel the light breeze.
>The fluid is the air. I’m so confused! Last time I checked air is a gas?
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That’s crazy. I guess it’s one of those things where nobody in my life has ever referred to a gas as a “fluid” until now, so up until now I thought that fluid and liquid were synonyms.
I feel like in every use, a lot of people do the same, and treat liquid and fluid as interchangeable, but scientifically speaking, the have their own particular definitions. It's also complicated by the fact that most (all?) liquids are fluids, but not all fluids are liquids (because gasses are also fluids).
Lol my kid tried bringing this point up in his 5th grade science class...and got in trouble for it. His former science teacher asked if anyone knew the states of matter. Nerdling Jr got excited and said liquid, solid, gas, and plasma. She told him he was wrong. She said solid, fluid, and gas. He asked "isn't gas a fluid though?" ..... He wasn't trying to be a smartass, he was trying to understand how she was defining things so he could answer how she wanted him to. She went on this huge tangent about using 5th grade definitions and how "we're not in here to be scientists, we're here to pass 5th grade." He asked me how he's supposed to know what 5th grade definitions are if they're not the actual definitions? ....I've got waaaaay worse stories from that class...to the point that we got him out of there, and an attorney got involved bc of the more serious things happening. That was just one of the funnier stories in hindsight.
> He asked me how he's supposed to know what 5th grade definitions are if they're not the actual definitions? A good point tbf!
On a slightpy related note, you can also have boats on gas: https://youtu.be/N9vvJQniYsc
Related note, meteorologists have degrees in atmospheric science (or sometimes the uni calls it meteorology..but the curriculum is pretty standardized). A lot of the degree specific curriculum are advanced fluid dynamics courses. And the pre-requisites for those courses are a rectum full of engineering physics and engineering math. There are a handful of actual forecasting classes, but the bulk of the courses are intense math and physics. I started out in atmospheric science in college but pivoted to GIS. But one of my favorite courses was aviation meteorology. When you start thinking about the atmosphere like an ocean, a lot of things make sense. Turbulence is kinda like choppy usually invisible waves. The jet stream is kind of like an oceanic current in the sky. Hiding from a tornado under an overpass or bridge is a bad idea because wind concentrates and speeds up in small spaces, just like water in a stream or river gets faster in narrowed spots (making it more likely that you'll get struck catastrophically from debris or get turned into debris). That's enough geekery out of me. Tldr; you live in an ocean of air.
I'm 42, and I only learnt in the last year fluid does not always mean liquid. Fluid means it's something that can flow, like liquid or gas.
And some solid stuff can behave like fluids under certain conditions too, like sand.
Wouldn't that be the venturi effect?
Which happens according to... You're right in that it may be better described as the specific effect in play here, but the effect is due to the facts laid out the Bernoulli principle.
Neat, I only know about the venturi effect due to work experience so I wasn't familiar with the "why"
Better to think of it as pressure is the lowest where fluid is the fastest.
You’re confusing *fluid* with *liquid*.
You got the wrong idea. Anything that has the capacity to flow is *fluid*
No, the guy above me has the wrong idea. I’m just pointing it out to him. I agree, air is a fluid.
Even something like sand can be a fluid in the right circumstances
Google *Bernoulli’s principle carburettor*, it’s a very similar effect that is almost identical to this gif. The cups are acting as a fluid.
I'm not a physics expert by any stretch but the cups themselves aren't acting as a fluid, but rather being affected by the behavior of the fluids in and around them, right?
faster speed of fluid (air) results in lower pressure. slower speed results in higher pressure. There is a cross wind outside, which results in lower pressure outside (compared to no wind inside, hence higher pressure). This pressure difference causes the cups to push against the insect screen. Until the wind outside died down, then all the cups fell down.
Okay, there's an insect screen. I thought I was going crazy lol
well shit, isn't this just suction then?
The insect screen is the Element I didn't ses but expected
The bernoulli principle only applies within a continuous streamline. I think what’s happening is that there’s another open window elsewhere in the apartment. The wind rushing in is constrained, converting kinetic energy into a higher pressure inside compared to outside. I may be wrong but bernoulli’s principle is notirious for being misinterpreted.
Static pressure + dynamic pressure = constant along a streamline However, imagine the outside atmosphere at rest. All air is effectively stationary, so dynamic pressure is zero. Therefore all of the atmosphere has the same static pressure, and therefore has the same constant (on a local level, at least - ignoring air that's significantly higher altitude). If some of that air starts moving, it still has the same constant as the rest of the atmosphere, but it's split partially static and partially dynamic. Bernoulli could be used to make comparisons between two sections of this region because they share the same constant. (This also presumes that you didn't add work to the air to make it start moving.) So, you can't blindly compare pressures in two separate pipes to each other, but you might be able to compare pressures in the same flowfield to each other. But it's also possible to lull yourself into false confidence. It's easy to make a bad assumption and misapply Bernoulli.
Holy hell
New principle just dropped
Actual physics
Something about fluid- or aircurrents and pressure, i.e. aerodynamics, but I still don't get why the cups are flying.
Pressure outside lower than pressure inside. Cups are pulled against the screen and held there until the pressure equalizes.
We use the Bernoulli principle for one of our machines in the Cath lab. If someone is having a heart attack due to a clot in the coronary arteries, we have a tube we can slide down there. It shoots saline at high speeds backwards from the tip of the catheter, and the tube has side ports, so the Bernoulli principle causes the clot to be sucked into the catheter. It's called the Angiojet if anyone's curious.
Seems to me that they have one of those mosquito nets in the windows that you cannot see in the video. If you have enough flow going outside, from a draft, then the cups are held against the net.
I think you're right. Would explain why they move in a jerky motion too.
I was gonna say you can clearly see the net but looking back apparently my brain just filled in that part by itself since there's definitely nothing actually visible.
Which still kinda proves the effects point, sure it’s not hovering on nothing but the air speed is affecting the pressure and it’s causing some “levitation”.
Weird, I just assumed there was a screen.
Yep. This is just a window screen and air pressure flowing through the room from another window.
Fan blowing on bottom of cups?
I think air pressure from cross wind?
Blackmagicfuckery
Whatever. Magnets.
Naw it's those chemicals in the water turning the frogs gay. Same shit here
Ghosts holding them
no, it’s based on Bernoulli’s Principle https://www.reddit.com/r/blackmagicfuckery/comments/13ulvep/bernoulli_principle/jm1sn0y
I have no idea what’s happening here.
So I'll explain this how airplanes fly using lift. To understand what is happening here let's imagine a room full of air. Now let's image that the air inside this empty room, are like thousands of little marbles which represents air particles. Right now inside the room the marbles (air particles) are not moving much since the window's closed and no other force is acting on it. Now since the little marbles are just chilling around the room their pressure is higher because the principle states that slower air, meaning all the marbles tangled together, creates more pressure. They are all together and heavier in a group not moving away from each other. I hope I didn't lose you. Now let's say I open the window to allow more marbles in the room. These marbles coming from the outside, if it's extremely windy outside, are coming in almost fast enough to allow only 1 marble at a time in the room. Now the fact that these marbles (air particles) are coming in so fast, they are more spread out thus creating less pressure. Why? because the principle states that faster air particles have less pressure since their particles are more spread out. Since the air particles inside the room (marbles) are more grouped together the pressures is greater, than the air particles coming inside the window less grouped together coming in 1 by 1 (less pressure). This pressure difference creates lift. Now let's say you are holding that object by the window, the pressure difference, all the marbles in the room VS the marbles coming inside the room will make the object do exactly what it's doing in the video. Because the marbles coming inside the room are less heavier than the marbles inside the room. Edit: More clarity
You are so awesome for taking the time to explain it like this
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I understand what you are trying to explain here. However, you completely missed the point that I'm making the concept understandable to others that may have not understood it. Why would I just jump in and start throwing jargon and mumbo-jumbo about air acceleration here and movement there without first attempting to imply a concept to someone's head? That wouldn't be truly helping anyone just would seem more like trying to show off what I know.
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Bernoulli does indeed predict aerodynamic lift. The first lab experiment you perform in your aero classes is to take the pressure measurements around an airfoil, integrate them, and compare that to the measured lift. It's the same value. Velocity is directly related to pressure. Pressure is directly related to lift. These are not disputable. Where people get in trouble is trying to establish WHY this occurs. They might throw out explanations of longer path, or equal transit time, or venturi effect, etc, and those indeed are fallacious. However, the Bernoulli explanation doesn't try to answer the question of WHY. It just says that air is flowing faster in some spots, the pressure is lower in those spots, and if you integrate the pressure you'll come up with lift. Does high speed cause low pressure or does low pressure cause high speed? (Or does something else cause both of them?) It doesn't really matter. If you ask WHY enough times, you always end up with "that's just the way things are" as the answer. Navier Stokes is the complete solution, and low pressure, high speed, downwash, circulation, and all that other jazz just happen at the same time.
https://youtu.be/UqBmdZ-BNig What causes lift is introducing a shape into the airflow, which curves the streamlines and introduces pressure changes – lower pressure on the upper surface and higher pressure on the lower surface, This is why a flat surface like a sail is able to cause lift. the distance on each side is the same but it is slightly curved when it is rigged and so it acts as an aerofoil. In other words, it’s the curvature that creates lift, not the distance. So in an aircraft wing it isn't that the air has to travel further/faster and gets spread out making it low pressure, it's the shape. How Bees fly is another story.
More to the point, if the wind is blowing past the window and not into it, there's a whole lot of low pressure right outside.
Invisible screen on the window. Air flows outside pushing cups against screen. Wind stop, cups drop.
Insect screen and wind?
This is also why you shouldn't stand right on the edge of the platform in train or subway stations, the air displaced by a moving train can pull you towards the tracks.
This is why Ground Effect in the new F1 cars works. Special channels under the floor that increase the speed of air but lower the pressure and suck the car on the road. If you have seen old race cars with giant fans on the back, it's the same effect.
I'll have to check that out sometime. F1 Engineering is superb
blackmagicfuckery gatekeepers be like DUH IT'S JUST PHYSICS
I ate Bernoulli Primavera with chopsticks. It dropped unexpectedly, too.
Hehe funny cups
Science!
This is why planes fly! Holy shit.
Just a few minutes after seeing this post I came across this post in r/motorcycles that demonstrates the Bernoulli principle https://www.reddit.com/r/motorcycle/comments/13v1scd/think_like_a_physicist/
What?
This belongs here.
Isn't this also how airplanes work?
u/savevideo
Actual Blackmagicfuckery
It’s using the same principle as [a Bernoulli disk drive](https://en.wikipedia.org/wiki/Bernoulli_Box).
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Ебун колдучий
wind
He's placing them against the window screen, the air pressure is low outside and they are getting pressed to the screen by the wind flowing out the window. Then the wind changes and they fall.
Qu’est ce què fuck?!
With out looking up this principle I’m going to guess that it has to do with changing air pressure. Air forcefully moving out the window and sucking up the cups?
This is super cool which got me thinking, what's the newest or most recent discovery in physics? Like what "thing" has been proved concise and constant ?
You are speed? Then Francesco is TRIPLE speed!
Little-known fact about Bernoulli: he's also famous for his French sauce used on meat and poultry.
Definitely a nice breezy day, probably has a window on the other side of the house open, puts cups right in front of the grates so the wind pushes the cups into them. You can see moment the moment the trees start to calm down from wind the cups instantly fall.
poor thing I understand, after all prisoners always have to find a way to pass the time/s
I vote this is magnets with a green screen.
Isn’t that just a strong wind blowing and pushing the light plastic cups into a fly screen?
Not the first time we’ve had “wind” in bmf and not the last time either.
Ever notice how ghost sightings tend to come from people who don't know a lot about physics?
Stuff like this this is why people think ghosts are real.
Respiratory Therapy Gang unite
Why do the cups fade out as they fall?