The history of the barometer (and how it works) - Asaf Bar-Yosef

[@Tombee2]

2:41 instead of a light bulb there is a candle which is historically accurate.

[@FluodioCin]

=)))))

[@booklover-hu9tw]

😂😂😂

[@Fulikia]

damn didnt realized that

[@shashikalaraju5769]

bulls eye.

[@aninditamukherjee8149]

True!

[@GuillotinedChemistry]

This is definitely one the best video I've found on barometers. Really nice job on explaining misconceptions about vacuums.

[@huzaifaarshadabbasi8744]

👍🏻

[@Sevalithi]

Oh these little scientist dudes are so cute!

[@satire9298]

No homo?

[@Sevalithi]

He feels like he needs a disclaimer whenever he compliments guys. Probably because he's not secure in his own sexuality.

[@marafradella2712]

Thank you!

[@intelX1000]

Kyle Sanchez This is what's called 'projecting'. You always check if your projection is correct before stating it, or you'll look like Kyle, the liberal.

[@timlang3852]

Kyle Sanchez o

[@MalaysianTropikfusion]

I have to say, the characters in this animation are the cutest I've seen so far. Love it!

[@smitasuhas7981]

I have experimented this with mug in bath tub (Some Indians can relate)

[@a.kzestos2085]

True

[@yashrathi6862]

the height of the water level at ground level is close to 9 meters, you can't do it with a mug unless you do it on high terrain.

[@shaunakn5881]

True lol

[@askhfbfns67589]

not Indian but i can relaten lol

[@RandomDudes710]

I think that's what we call a faulty barometer or just not a barometer at all

[@raniahussein7002]

I am from iraq,,,,I like this way to understand information in study,,,,,,great video

[@atiqueahmad3058]

Rania Hussein o

[@moej3386]

@@PhartingFeeting exactly-

[@xOxAdnanxOx]

Moe J what made you’ll go uncomfortable with it? lol

[@KaramYagan]

@@xOxAdnanxOx Chill. They are just pointing out that it is incorrect to use them this way. She should have put dots instead of commas, but.... Mehhh

[@twitwilight6087]

Hi Rania I'm pretty sure that you were in your first year in high school and having a trouble with studying physics and barometer when you wrote this comment, the same thing is happening 😂😂💔

[@meghanakankara2883]

Thanks for this video. I have been suffering to understand this concept but none was working but now this video with the explanation of the barometer and its history with splendid animation have helped not only me but many other students to understand the complexity and art of learning science. Thank you!

[@ssathe8273]

"Until necessity raised the issue " : such a deep and wonderful quote ❤️❤️

[@amyannaroy8357]

good job with the graphics and explanation....

[@boy.interlinked]

So weird, I actually have 2 notifications right now.

[@farzanaqalandari5615]

Pop

[@kilney2418]

Evangelista torricelli

[@MelihCANBOLAT]

3:23 The height should be measured from the surface of the liquid

[@Simon-mr6zy]

yes!

[@harsh2032]

good eyes sire!

[@terenceting26]

I had that question, thanks for confirming. Ted-ed should at least pin this comment. The graphical designers might not understand this.

[@eljison]

Not necessarily. You just need to measure the change in height from any known reference point. If you start with liquid (water or mercury) in the tube, you can make that the zero and calibrate it whatever pressure you want (1 atm, for example), then measure the height relative to that reference point.

[@hassaan1670]

thanks, i was wondering

[@kirstenkoch5920]

By far the best and simplest explanation I've seen. Good job with the graphics too!

[@shamunhaider2793]

yeah

[@ChanchalKotal]

This is my favorite channel so far because of the explanation and animation of each video. They are too good! Thank you Ted-Ed!

[@davidbooth3285]

Loved the way Torricelli had his lightbulb moment with a candle!!

[@jp4431]

So much knowledge we take for granted today were such brilliant discoveries back then

[@garydunken7934]

As usual, nice one TED! My 3 observations in this video: 1. At 1:34 Gasparo Berti pulled his idea from his arse, literally! Thanks for the funny animation. 2. Both Aristotle and Galileo behaved like jerks with regards to their knowledge of vacuum, albeit being good in other areas. 3. How brilliant both Gasparo Berti and Evangelista Torricelli were, for thinking outside the box (or tube like you mentioned in the video!)

[@PhysicsVlogs]

hahah u're right..

[@crashsitetube]

People also had a lot shorter legs back then. Between the Rubenesque women and short-legged men, it''s a wonder the human race has survived. But, enough inane silliness. Really good video. Thanks.

[@anugopan5]

CORRECT

[@dhanyak.j9618]

Awesome 😊😁😊😁😁😁😁😊😁😊😊😊👍

[@dhanyak.j9618]

Good morning. Good night. Good for the video 👍

[@abdulmalikalghazali8241]

I like the way how you make it easy to understand by making it enjoyable

[@tejasnimbkar694]

TED-ED team can you also make a you-tube video on Calculus Just beginning of it. It would be great

[@Blarmy_Korea]

Totally helpful! I was confused abt the barometer but saw this video and understood everything.. Thank you

[@AbidHasan-tg7jo]

3:23 the 76 cm height should be measured from the surface of the water.

[@STAR.C455]

I’m a little princess 👸

[@STAR.C455]

Hi

[@wonderman8537]

Bye

[@Sama-pl2pz]

Ya... Good observation🤝

[@Gojoft.sukuna]

True

[@MuhammadIqbal-dy5ks]

Nice way of teaching 😊😊

[@MuhammadIqbal-dy5ks]

Good

[@urvijain2823]

2:59 - I have a question here : If you change the amount of water in the tube will the water still drop to 10.3 m? Amazing video btw, my teacher brought me here and I understood the concept of barometers so much better after watching this :D

[@SydneyMadueke]

Yup it should. For example, if you repeated the experiment but with a 100meter tube, the water pressure in the tube is far greater than the surrounding atmospheric pressure so it would force the water out until the water pressure and atmospheric pressure are equal which would be when there is only 10.3 meters of water left in the tube. Correct me if I'm wrong KZbin

[@tiaxanderson9725]

Yes, it's the weight of the atmosphere that's 'pushing down' on the water and thus 'forcing it up the tube'. So even if you made a tube 1000 meters tall, all the water would spill out until it reaches 10.3m as 10.3m of water equals 1 standard atmospheric pressure. It's also why the mercury barometer is only 0.76 m tall as mercury is much heavier than water. (so 0.76 m mercury = 10.3 m water = 1 atm)

[@kokioto420]

I'm so thankful Ted Ed had a video on this, I needed this for my homework and this makes my homework more fun!

[@boofang10]

EXCELLENT video on the background of the barometer, especially the mercury barometer

[@alligrim]

Ted Ed saves my butt in my chem honors class every unit.

[@zaoshmakujina2215]

This cleared my doubts which arised in the chapter Mechanical properties of fluids thank u

[@superrandomuser]

same

[@briangardiner7574]

Use this video every year. Thank you

[@manallarrehemi5838]

I totally agree that the thinking outside the box " the tube " is always the right way to find solutions , even if the others do not agree with you THANKS FOR THIS VIDEO 🥰

[@billchoi2000lsc]

I love stories about challenging pre-existing theory and making major scientific breakthrough!!

[@kaushikpawar7508]

Amazing work team💯

[@josephcalabrese6337]

I'm watching this video because my new digital watch has a Barometer App. Knowledge is power.

[@russel4942]

This really helps a lot and well-explained compared in schools

[@twitwilight6087]

I'm from iraq , this way of learning is amazing 💗

[@DivineAgility]

رابع علمي؟

[@twitwilight6087]

@@DivineAgility اي

[@DivineAgility]

@@twitwilight6087 عاش اني هم

[@twitwilight6087]

@@DivineAgility الفيزيا ضيم مو ؟

[@priyalks1614]

its so so so lively and understandable pls try your luck in many more topics

[@godfreyxbrown1393]

Great explanation 🎉🎉🎉

[@memo6032]

3:33 I don't know if sb wondered about this or not but the reason why increasing the volume of water didn't affect the pressure of the it and it didn't need to go lower in the tube to be in equilibrium with the pressure outside the tube is because pressure of liquids only depends on their *density, height and gravitational field strength*. So since the two tubes are the same height, and the gravitational field strength didn't change and we are using water in both tubes (density of fluid didn't change) it doesn't matter. This may seem like it doesn't make sense but you can google to see the proof of it. And if you still don't understand, it's okay, if I wasn't taking phyiscs this year I wouldn't have understood either 😂😂😂

[@FailCant]

Truly fascinating

[@Peppermint1]

Worth mentioning that most times bad weather does not cause barometer drop. Small systems bring rain/snow without a drop in atmospheric pressure, actually sometimes the pressure may even increase. Mostly the large systems will cause a pressure drop. In other words., most of the time these barometers are worthless.

[@tueanhvu1627]

I can't understand the experiment until this. Thanks =)))

[@ytfrgaming632]

Amazing 😍😍😍

[@yashchaudhary9596]

I understood the concept of barometer bec of your video. THANKS

[@michaela9914]

Lovely explanation

[@drlefebvre8489]

Michaela what is mmhg

[@PeteGravell]

Nice video. But there is a small amount of mercury vapor in the space above the mercury, so it's not a perfect vacuum, and it does not prove Aristotle wrong. According to Wikipedia the vapor pressure of mercury at room temperature is about 1Pa.

[@Abdullahss1]

Pete Gravell i don't think that there is a mercury vapor in all cases

[@boeman6702]

Pete Gravell Aristotle was wrong in atomic scale as well...

[@jeremiahyolok6663]

very good and clearly explained

[@JoejoeReference]

"Fortunately, he turned out to be wrong" A phrase commonly heard when Aristotle is brought up

[@sayemshahariaprethebe]

Thank you so much

[@duckiie15]

Beautiful execution👏

[@naitikarora1694]

This helped me a lot... Thank you soo much

[@93mrravi]

Beautiful explanation!

[@pranshgupta4826]

Thank you I don't know much about vacuum but it did help me with atmospheric pressure so thanks..a lot!!..

[@ketfoen]

Thinking outside the box, I'm glad we have had people like that in the past. We have them today as well, but with so many public trolls around they don't get the chance to even speak.

[@popogast]

Nice and descriptive explanation.Well done.

[@muhittinselcukgoksu1327]

the other TED videos are not so ..They are very well.

[@malv4935]

This is awesome and so adorable, thank you :D

[@maulikshah28]

Great video, helped me understand the topic really well

[@miltonkumar1862]

It seems to me that, I also was the part of experiment. Nice way to explain 🙏🙏👏👏

[@sweetnasa1]

And that's also the reason "measuring units" of "pressure" is Torr or Pascal credited to the two celebrated scientists who helped us discover about Air Pressure. :)

[@pcg259]

This vacuum is the void of matter but it is filled with a liquid more mysterious than anything mankind has ever tried to understand.

[@andrewwarren3633]

There is a mistake at (or near) the 3:22) mark in the video. The dimension should be from the top of the pool of mercury, not the bottom.

[@priyankabhardwaj4590]

ted ed is the best!

[@Soneoak]

A vacuum exerts no force. It is the surrounding pressures that pushes the fluid into the tube to collapse the vacuum, and the weight of the fluid that establishes an equilibrium. The classic barometer is therefore a device that uses the weight(and hence pressure exerted by it) of a fluid to measure the opposing surrounding air pressure against it. As proper scientists, we always evaluate how our models would simulate the real world, and not the other way round. The world exists as it is. We merely describe it, not prescribe it. We propose models, then test them. Untested models are merely that, hypothesis, nothing more, but nevertheless, intrinsically valuable.

[@congnhaduong9047]

Scientists: Think outside the box Me: Hmm... Where is the box??

[@congnhaduong9047]

@AR7UN FF people nowadays tend to try to find something creative, but most of them dont really understand things in the box in detail

[@vijaychandra8550]

Thanks TED...nice explanation ever

[@shaziajehanzaib941]

Awesome animation and explanation

[@piggyparadiseplayz395]

This is a great video! thanks for the information!

[@abderrahimelboutaybi9018]

Thank you. Very clear and great explanation.

[@gurbakshkaur1213]

Its very helpful.😊

[@alyssatiangco7110]

thanks for helping me with my homework lol i knew nothing before this video

[@n8mail76]

thanks. must of us have only memorized these concepts taught to us. learning the mechanics behind how and why the concepts were developed bring a deeper understanding of the concepts.

[@ashenudayanga6359]

Thanks bro...... before i see this video, i have no idea about this exeriment.

[@analinagarcia]

Such a great video. Thank you.

[@Evan_Adams]

So.... what happened after 2007? How do we do it now?

[@stephensnell5707]

If you aren't aware Aneroid Barometers are now used and will be forever

[@yenlingleong]

Very nice! I've a question, at 3:22 , for the height of the mercury column (76 cm), is it measured from the base of the container or from the surface of the mercury in the container?

[@henhaliusaz5984]

It's measured from the surface of the mercury. By the way, if you put the tube deeper into the container, the volume of the vacuum would decrease, and vice versa.

[@melashop669]

el vídeo que necesitaba ver, muchas gracias

[@ahmetumutergen9927]

[QUESTİON]How did Torricelli know that a vacuum had been created when he made this experiment? Maybe some air came through the mercury and filled the empty space.

[@MukeshKumar-zv1wk]

fantastic way to learn

[@hemanjalihemanjali2896]

nice to understand easily

[@Shinywhite]

Very good explanation, tyvm.

[@chow143]

Extremely helpful

[@nileshvishvambhar6780]

It was Best explanation... Thankyou

[@PhilippKirchner]

Well made, and such nice animations ^-^

[@marafradella2712]

Thank you Philipp!

[@prashant.timilsina]

always such a wholesome videos✨

[@novakrypton5841]

I have a question.....if we put the barometer in a non inertial frame with constant acceleration upawards....will the level of mercury change due to pseudo force??

[@patriciayokelin9382]

I love the graphics of this video, the scientists are so cute!

[@janvigupta558]

Thanku so much this is really helpful🤗

[@georgekalemis7359]

Very nice video. Is there a way to contribute Greek subtitles?

[@vanshikha7179]

amazingly explained!

[@baharosman1416]

Thank you!!❤️❤️❤️

[@hannahhoag8571]

This is fascinating!

[@novachan69]

Thanks dude u cleared my doubts

[@Pineapple_extract]

Great explaination

[@أنسمحمدحسين-ي8ظ]

Great video. What is your reference?

[@unskilled_i_guess]

this helped so much

[@arnon-jaya]

3 apr 2020 5:57 pm edt:thanks 1:33 gasparo-berti 2:07 'galileo's idea' maybe should have been 'gasparo-berti's idea' ?

[@princessminnis-moss491]

verry helpful for my baby social studies

[@roidroid]

Aristotle wasn't wrong. The apparently "empty" bubble in a barometer is infact *not a vacuum*, it is filled with vapours of the liquid under it. The liquid surface under that empty gap boils away into the gap until the gap's pressure has raised to the liquid's vapour pressure, it's not a vacuum. Because - just as Aristotle said - nature really does abhor a vacuum. If you got 2 barometers, each filled with different liquids of the same density but differing vapour pressures, they will give different results. Weight (more accurately density) is not the only factor.

[@giovanniarmaroli8044]

There's more to it. Even in the Universe, where we consider to be "true" vacuum, vacuum does not exist. Quantum Field Theory predicts that particles are able to come out of nothing and return to nothing. For example a typical phenomenon is vacuum -> electron + positron -> vacuum. This may seem strange since it appear to violate the law of conservation of energy (and mass consequently). But actually conservation of energy does not hold if the time of such a phenomenon is "small enough". Where "small enough" is determined by the Energy-Time version of Heisenberg's uncertainty principle. This is not sci-fi, it is a known phenomenon that has been proven experimentally. For example at LHC they deal with it everyday in their Ultra High Vacuum particle accelerators.

[@randomfandom33]

@@giovanniarmaroli8044 You're kind of misrepresenting quantum theory. The particles don't come in and out of "nothing", that's just convenient language some scientists use, in fact the particles are just converted from the energy in the quantum field (because, as Einstein showed, matter and energy are basically two sides of the same coin). Energy in the quantum field is converted into matter, which appears in the 'vacuum', and then the matter of the particle is converted back into energy in the quantum field. So there's no "nothing" going on at all. The law of the conservation of energy does, in fact, apply to objects that are "small enough" and an accurate understanding of quantum mechanics such as above, instead of the internet misunderstands that you mentioned, show that virtual particles (which is what we call the particles that appear in and out of "nothing", where nothing is actually something, i.e. the quantum field) do not violate conservation at all.

[@giovanniarmaroli8044]

@@randomfandom33 Well, I was exactly using the "convenient language that scientists use" when I was talking about "nothing". We are on KZbin and I don't think it would make sense to talk too technical, but maybe I'm wrong. Anyway, I looked it up and I think you are right: energy is always conserved even in the so called quantum oscillations, but I think the explanation I gave was the most widely used until some years ago and I think it is still very used. Even my nuclear physics professor gave us this explanation, but he was an experimentalist so maybe he missed some subtleties that a theorist understands more deeply. Oh, by the way, I accept and appreciate criticism, but I am at my last year in my master degree in physics (experimentalist too), and I didn't like the "internet misunderstands" thing, so don't judge people just from 2 lines written on a KZbin comment.

[@randomfandom33]

@@giovanniarmaroli8044 OK, maybe I was too quick to say to you "internet misunderstandings", but it is *usually* that in my experience. What made me think you actually meant 'nothing' when you said 'nothing' is when you began arguing is that the presence of this nothing into particles doesn't violate conservation, which I still find unexplained if you were using the same convenient language.

[@brianshelley88]

Thank you. I was going to post this.

[@31896eneri]

Great story!

[@ceff01]

These are on planes for decision height altitude for anp/rnp landings in low visibility around mountainous areas

[@pcg259]

Well Aristotle wasn’t talking about matter ,he was referring to something more mysterious and unknown ,unseeable which human mind isn’t able to understand.

[@drdickqueso]

exactly. the presenter kinda trashed him a little by making him seem incorrect when it was instead a observation of reality. nature always tries to remove a vacuum.

[@salmamuhamed5728]

Great in a cute way. Love it. 👍

[@MrTheuploader123]

amazing but at 3:40 shouldn't the right barometer have more mercury on the tub because it has more mercury and the liquid level on the tub should be changed.

[@TheMediocreDev]

It should but that's irrelevant since the pressure is measured by the amount of REMAINING mercury in the tubes after the pressures equalize. The formula for fluid pressure is: Density of fluid x Height of remaining element x Gravity. Gravity is a constant & both tubes have mercury which is why the both stalled at the same height. (The part of the tube containing the remaining mercury is the same diameter thus they both have the same amount of mercury left over which is why they generate the same amount of pressure & stop at the same height)