Why is a kettle louder BEFORE it boils?
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- Опубликовано: 14 окт 2024
- So its always bugged the hell out of me why a kettle makes most noise before it boils, then becomes almost silent when it actually boils. However when you get a high speed camera on it, it becomes very obvious very quickly! The noise is actually made by the collapse of steam bubbles in colder water. At about 70 C you have the most number of these bubbles collapsing. As the temperature of the water gets higher, the steam in the bubbles doesnt condense as well, meaning the bubbles have a longer lifetime. Finally when the water boils, the bubbles dont collapse at all, and it becomes almost silent!
Cool stuff water does under vacuum:
• High speed camera reve...
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Thank you Thunderf00t, this is the content I subscribed to.
Same here, i was so close to end my subscription
Me too. The near-militant atheism videos are annoying, but the science, history, political, and fake science exposition videos are fantastic!
Lol. "near" militant.
Try full on armada.
Same here.. the rants are ok too.. but it seems they distract TF00t from videos like this one.
Yes, I too came for the science and if he could ramp it back up I would resub.
A long time ago when i was a kid, i remember asking myself where the bubbles in boiling water actually came from, but i never really got back to it. Now you´ve answered my unasked question.
Thanks Thunderf00t!
Evil. T-foot got it wrong. It's evil water leeches.
Cavitation is a really interesting effect and it would make an epic video - hint hint!
I've seen wrecked propellers after a single cross-Atlantic trip (at high speed). Also mantis shrimps create one right in front of the claw which "punches". It's so hot in the bubble it creates between it and its target that any moisture in the bubble apparently turns to plasma (think it's that way around. Don't have time to dig it out right now, but I usually remember what I've seen). It's only for a fraction of a second but the temp is the same as the surface of the sun.
(Any errors here I am blaming on Prof B Fox and possibly Sir David Attenborough. I may be mistaken but they are among the DVDs on science I watch the most!)
I've seen, more than once, pump impellers destroyed by cavitation. Actually seen time lapse microphotos of it occurring. Kind of weird when you see the bubble turn into a little donut. Who'd a thunk it?
Ooooh, in WATER.. and here I was wondering why would the propellers on an airplane get wrecked by cavitation just by flying over the Atlantic.
I have wondering why this happens since I was a child. 25yrs later I finally learn why. Great explanation! Thank you!
I have actually been wondering about that. Great video, thanks :)
I'm 32 yrs old and only just today stared at my electric kettle (almost the same one as yours) this morning as it was boiling water, and became overwhelmed by curiosity at this sound. Thanks for sating my curiosity! Don't know why I never pondered it before now.
In 30 years we may not remember everything, but we will stil know that a kettle makes noise because of poping small bubbles.
COLLAPSING BUBBLES!!!
How is bubble poped
Easy, all the bubble Cardinals get together in a secret conclave to nominate and vote on candidates. When you see the white steam rising, you know that a new bubble has been Poped.
Hehehe, well done.
Nice one, David! :D
I was just looking if someone already wrote something - couldn't have put it better myself :)
I was going to buy a new kettle because the one I've had for years is so loud and I'm sick of turning up the volume every time I make a coffee. You really burst my bubble.
Flat bottomed kettles make the rocking world go loud
but would a non flat kettle heat the water faster? or does it only depend on power input (for kettles usually around 1500watts)
I was just a skinny lad. Never knew good tea from bad.
Missed an opportunity - should have been 'knocking world' :) As in hydrodynamic knocking.
Ohhh, that was terrible. You are to spend 24 hours in pun jail.
Always the best content for science amateurs by far. Rare and common things explained simply but accurately. Thanks Tf00t. Keep up the good work.
"I'm British, and I'm a scientist... how can I combine these two facts?"
thanks for asking a question that has bugged me for years and for asking it in such a clear way that i realised the answer in the first 40s of the video.
well if the kettle used solar FREAKIN roadways it would make no noise.
because solar roadways dont make enough electricity to power a kettle. =] lol
This is why I love you Thunderf00t, I've had this question bug me for years. Asked loads of people about it but I've never really been convinced I heard the right answer. This is awesome, thank you!
I believe that if you make a kettle that follows the fluid dynamics with the convection currents, like that pan that “stirs itself “, I would make less noise.
It would also be slower to boil
Freedom Talk Media, why? If anything, it would boil faster. Less energy wasted in the form of sound waves (although the difference would be entirely negligible).
How would that stop vapor bubbles from forming and instantly collapsing?
Correct. Also, the heat would be removed faster from the element, going into the stirred water, which would result in a lower filament resistance, allowing for higher currents which in turn produces more heat. Yes, it may sound paradoxical (it really doesn't if your understanding of physics is intact), but a cooler filament heats the water faster! Simply by being enabled to produce the heat at a higher rate, it can do so with a lower temperature.
@Anvilshock Exactly
I always kind of wondered this, but never thought to look it up. Then I started binge-watching your videos, and look, an answer! Thanks for all the effort you put into your channel. Great stuff.
i like when you do science and not drama
cogor57 And not endlessly repeating content from older videos. e.g. solar roadways, Anita, hyperloop, etc.
just because it hurts your fefes doesnt mean its drama.
But science + drama = more better =)
Please check Thunderf00t's history. He's been doing "politics" and "drama" videos since the very beginning.
funny i just said the same :)
Thank you so much for this! This always bugged the hell out of me too. I was literally just thinking about this while making the food I'm eating while watching this.
I have a whistle on my kettle makes way more noise
Thanks for this very clear exaplantion. I've been wondering about this for years but could not think of any way of investigating it.
I suspect that the English spend a lot more time thinking about kettles than Americans...
we do, I've solved some great bugs waiting for it to boil. You don't get that from a barista!
It’s amazing how much tea they drink over there. The power has to be ramped up for commercial breaks on popular tv shows because of all of those electric kettles!
Imagine if us Americans had power demands like that, There’s roughly 10 times the population in the US. Super Bowl Halftime every weekday!
the uk has a population of 65 mil.. your saying there are 650 mil americans?
[Citation needed] on that information about the Invasion of Normandy please.
Maarten De Temmerman there’s 65 million people in England? Gotta read through the comments again... yep, no mention of UK.
This was a great explanation. And that visualization was totally amazing and new for me. People need this, because not everyone has a parent with a PhD.
I actually thought this today!
Chris Wouse
I thought of this every time I used one of these things... This video made my day, I never have to think about this again :p
Mind completely and utterly BLOWN!
Now this is good shit! And original content! Haven't seen this video anywhere else!
Thank you for answering questions I didn't know I absolutely needed the answer to.
Now make some nice soothing tea and get over your cold. :)
They water under a vacuum apparatus making those clunking noises is one of my favorite videos you've put out to date. Sooooooo cool!
yay an apolitical video with minimal clickbait!
Something I've always wondered but never thought to ask. Great video!
To really test to see if your theory is correct (which it most likely is) you should use software to analyze the frequency information from the mp3 that you recorded. You could correlate the frequency in Hz with the size of the bubbles and like learn new properties about water or something
"analyze the frequency information from the mp3 that you recorded" - Hint: Analysing the MP3 is NOT a good way to get accurate results ... You might as well analyse a black-and-white photo of a flower to find out its original smell ...
mp3 is not that bad for an analysis within humain hearing range, you will lose a bit of information but its not like mp3 change wich frequencie is being produce or if the mp3 was compress multiple time. and if he is the one who recorded it, he probably have the file in wav somwere.
I was mocking the appearance of the format MP3 apparently having replaced WAV as the one and only audio format in this guy's mind by both ubiquity and incompetence. Like, how some people perceive Facebook or Internet Explorer as "the internet". Especially since Tf never actually mentioned MP3 anywhere in his video, merely showing a waveform, and yet him immediately associating MP3 with it.
+Sagrotan Or at the very least create a proper audio spectrogram directly from the unmodified input source that should reveal all the frequency clusters, while the resonant frequencies will themselves change with temperature they should be a lot flatter with respect to time than the frequencies caused by the bubbles the lifetime of which changes by about an order of magnitude over just 10-20C or so. Most likely the sound from the bubbles would also be a wider band too as the lifetime of bubbles almost certainly follows a normal distribution whereas resonant frequencies are very specific.
Spectrographic analysis using a wav or mp3 would lead to almost identical results in this case bud. Also, take your head (and your fedora) out of your ass. You sound like the cringiest edgiest 15 year old trying too hard to sound smart on the internet. What went so badly in your life to where you sat down after a day of work just to mock me (a random person whom you do not know) on the internet for not specifying the "most correct" form of audio format to use when performing acoustic analysis. We get it dude, congrats on boasting your knowledge of the difference in quality between wav and mp3, you must pride yourself on being sooo smart. You seem to be good at negatively contributing to things, but not really good at positively contributing. Maybe you should work on that :)
I will never look at boiling water the same way again. I'm actually more impressed that you even noticed the strange behavior of heating water than I am with your fantastic explanation of what is going on.
If I had a dollar for every vídeo that TF starts with the word "So", I would...
Well, to be fair, that's just a normal English accent.
"So" is the latest science word. Seriously, watch a scientist being spoken to on the news (or more noticeably listen to the radio or a podcast), for example, and the majority of sentences (esp the start of an answer) will have "so" as the first word. It's a time-filler to make sure they have the correct answer in their heads before launching into the explanation. It used to be "well", "you know", "uh" or "um" or "I mean". There seems to be a fashion for them! 😋
Still annoying af!
I was very curious as a kid and used to watch water boil when my mum used to make tea on a gas stove using a glass kettle and I kinda figured it out back then why it’s making a lot of noise .. this video adds a lot to my existing knowledge and now I am more confidant sharing this knowledge with others...
#Britishpeopleproblems
Apparently it's surprising to some English people that 99% of Americans don't have a kettle.
US electrical outlets aren't really suitable for electric kettles that's why they are not as common. The maximum power for a UK outlet is 240V*13A=3.1kW. US is would be 120V*15A=1.8kW. 40% slower boiling time for 120V countries.
I doubt the number is anywhere near that high. They sell kettles in every general merchandise and housewares store. There are scores and scores of them online too. There are also several feet of tea sold in every grocery store. Mine has about 16 feet of tea.
As to Tom's comment about electric Kettles, those are also quite common in the US. They boil in a decent amount of time too. A google search for electric tea kettle, done from inside the US, brings up nearly 1.2 million results. If you click on the shopping link, there are approximately 320 electric tea kettles for Americans to pick from, on google alone.
+Freedom Talk Media While Tom does have a point that they would require a little longer to boil I doubt that an extra minute or so at most makes much difference to the average person that makes enough hot drinks to need one. Especially since one of the main advantages is the convenience of really not needing to monitor it to see when it's ready, just fill, switch on and do other tasks until it clicks so you are hardly paying much attention to it anyway.
Ah, but English aren't just 'the average person'... I don't think you appreciate quite how much they love tea... Are you suggesting waiting a whole extra minute? Might as well be a lifetime!
UK kettles are norm between 2000-2300w (more power at the start less once its heated up) usa ones probably have to be capped at 1000-1200w or even lower to not overload the socket
I have been wondering about this for a while too. Thanks for revealing the answer is such an aesthetic way.
wow an actual science video
The sound the water makes in that vakuum tube is so hauntingly beatiful. Also, great video!
from 18k to 30k... +- 15 +- 3 kek, don't approximate an approximation, please. How is that acceptable? Ok, its not a exp away but still.
its still within one order of magnitude approximation
Forget the numerals its the size that matters, compare XX with XXXXXX
I know, it's not an exponential away. I said it. :D
But it's still 50% over the final result. I mean... he said it anyway but I'm pretty sure there is a difference between 18k and 30k that is visually significant. why not 20k?
It's acceptable because 10k-30k wouldn't really make a difference to this project, and because considering it at 30k allows him to get a 10^(-3), which means roughly 1 milisecond.
These kind of approximations are normal. You've got different amounts of leeway when doing different things, for example, if you're doing trace determination for something, sometimes a 5% margin of error is way too much, while other times a 500% margin of error is perfectly acceptable ;)
I know... But yeah... I should get used to it. Thanks. :D
I've just recently started drinking more tea, and this question has been driving me nuts! Thanks for the video!
Why round 18,000 fps up to 30,000 fps in order to "keep the numbers simple"??.
Surely 20,000 fps is the obvious number to round up to..... 30,000 is almost double 18,000 though!. 18k is not a similar number to 30k. After saying lets round it up to 30k, he then references it as 20k..... wtf.... confusion.
I've noticed TF does this quite a lot in his videos, rounds things up to numbers that are far, far different than the original number to "keep it simple". In many cases the actual number doesn't really matter for the point he's trying to make, but at the same time, it causes problems when justification of the calculations he's made is required and just adds un-needed confusion, like in this case where he rounds up 18k to 30k but then references it as 20k.
He's had to make many an apology in the past for getting numbers wrong. I don't know why he continues to do this. It's not as if keeping the numbers as they are would make the math impossible to do, it'd just be ever so slightly harder.... something that should be quick work for a scientist.
Edit: And in this specific video, the FPS of the camera doesn't even matter - which just adds further confusion as to why it needs rounded up at all!!. The FPS has no bearing on the point he's making other than the fact we get to watch things happen at a slower rate.
I'd love an answer to this myself. It annoys me to no end, because it's just patently false. 18k is NOT 30k in any world. It's 15k or 20k, if you want to round it off. What's the scientific/academic reason for it?
It's actually pretty simple and is very useful as a teaching tool. The fewer numbers someone has to look at, the easier it is to comprehend. This is often used when calculating things like finance where there's no point in talking about amounts to the exact cent, or even dollar, when referring to a value in the 10 or 100 thousands. It's a tool used to convey "concepts", not a tool to conduct "accurate analysis". The fact that he rounded 18k to 30k puts the perspective of 30 fps vs 30k fps (obvious and quick calculation of 1000x). Otherwise, people can get stuck trying to math out the ratio 30:18k (or even 30:20k), which isn't necessarily difficult, but the former is simply "easier".
The fact he did in on something that had marginal significance actually helps warrant its use because it helps an audience/student/lay person to not dwell on the number for too long.
Hopefully this helps.
He tried to compare it to 30 fps in terms of orders of magnitude it has about 3 orders of magnitude difference to simplify it because it doesn't serve to calculate an exact number but to illustrate a point.
If you divide the FPS of the normal footage (30) and divide it by the FPS of the high speed footage, you can find out how much slower the high speed footage is. 30/30,000 will be 0.001. In other words each second of high speed footage is equivalent to one millisecond at normal speed. If you divide 30 by 20,000 or even 18,000 the result is only 0.0015 or 0.0016 respectively. Yes, 0.0015 and 0.0016 round up to 0.002, but for the purpose of the video just picking a value 1000 times greater makes it easy to just say it takes a millisecond.
if it doesnt matter then why are you getting worked up about it
For years I have been flicking off my
Kettle when it makes loads of noise. Thinking it was boiling and my kettle was just slow to respond to the temperate increase. (And turn itself off)
But in fact I have not been boiling my kettle for my tea at all.
Thanks!!!
I'm American so I don't use kettles,cool video though.
And as always some of us use both kettles and microwaves to boil water.
Don't see the point in using a microwave to boil water as the water can superheat, be > 100 C as liquid.
You just do it carefully.
I'm American and I use my kettle everyday.
French press coffee is best coffee.
This is the video I've liked the most of all of your's that I've seen. To the point and not padded by repeating the same thing over and over. And, yes, I always did wonder why water made more noise before it came to a full boil. It didn't really bug me because I assumed there was a physical explanation, but I did wonder. Thanks.
Now let's see just how fast RUclips dickheads will demonetize this video.
DHMO is dangerous stuff!
I've often puzzled over this one. Thanks TF
Easy, there’s way more small bubble activity at the loudest point
Yep, we all just watched the video too.
I'd often also thought about the acoustic differences of water being poured at different temperatures. This upload has made me revisit that observation.
Now, boil some water in a vacuum! XD
Yeah that's not how it works
ruclips.net/video/y4BGV7-1lhs/видео.html
I've wondered about this in a kind of peripheral way for a while...one less thing in the world drives me crazy...i feel better now. thanks
Okay, now something is bugging the hell out of ME. That glass apparatus of yours that makes the shockwave bubbles in the water when you shake it? You say that it's under vacuum; why is the water not boiling? I'm mystified. I thought that water in a vacuum boils at room temperature. Please, please enlighten me.
Craig Corson it’s at equilibrium. You heard him say that it wasn’t a vacuum in there, but water vapor at about .02 atm. This is the vapor pressure of water. If it were to boil it would raise the pressure thus making it less susceptible to boiling.
I do believe he means it's vacuum sealed. Being under vacuum conditions basically means the number of molecules per unit area is really really tiny.
I'm pretty sure he explains it in that video. In short: "Vacuum" is a bit misleading. He filled in water, then pumped the air out. After the glass is closed, the "vacuum" will be filled with water vapor. Boiling occurs when the vapor pressure of a liquid is higher than the atmospheric pressure. Boiling is the process of rectifying that imbalance. What you are looking at here is basically a post-boiling stage in which there is a liquid phase and a gaseous phase in equilibrium, both containing only water. It's still a very low pressure though, water has a rather low vapor pressure (about 2% normal atmospheric pressure).
You thought wrong, Craig.
Really? Try it some time. We'll see who's wrong.
Wonderful job Thunderf00t. You've got the answers to questions that I've never thought of. You must keep doing this!!
Super interessting, I even thought of it this morning when I made my tea. And I also had to think of you previous video you've shown. Keep the good work up!
Nucleation sites have become a popular topic in the past few weeks. Maybe I just notice the topic more after the first water/vacuum video. Thanks TF!
I had come up with the hypothesis on my own but I've had no way to confirm it by myself; thank you, Thunder Foot! 😀
Still my favorite channel. With the exception of perhaps Channel + Fireball.
OH MY GOD YES!
Thank you tf00t, i have wondered this myself for quite some time.
Wow. This thing really bugged me like a month ago. Great video!!
I HAVE always wondered this but always thought, "that's the way it works". Never thought about it very much. Thank you TF for this wonderful video.
Excellent content.
It's amazing how interesting the answers to seemingly innocuous questions can be.
Thank you. This is something that has bugged me for so long.
Very well made, this can also be a good guide for getting just the right temperature of water for tea making without a thermometer by hearing the noise level.
Love it - it always used to bother me and I used to assume it had something to do with the bubble formation process, but who would have thought that would be them imploding - cool!
I have noticed this and have wondered about it for a long time. Thanks for the explanation.
I've never thought about WHY a kettle makes noise, but I'm certainly aware enough of it that I could pretty accurately hear the sound of perfect tea temperature water. Thanks for helping me understand something I knew about, but never actively thought of.
Thanks for the vid. I couldnt figure why the bubbles made the noise but i did think it was because the surface on the bottom is still hot and the colder water on top was making some sort of pressure difference.
i asked myself that question so often thanks for clearing it up!
As soon as I saw your vacuum thingy... Wonderful!
This is a proper quality material! Very sexy footage as well! Thanks!
I was kinda ballpark guessing correctly why all the noise, but this vid is exhaustive!
AT LAST ! One of my greatest childhood (and later) mystery has been solved!!! Thanks Thunderf00t!!
Glad to have you around, peace and love man.
I love this one. Never really thought about it before, but thermodynamics is really interesting to me.
I can't say that I ever thought about this but this video was absolutely fascinating.
Great explanation. I was told the "first boil" was caused by the dissolved gasses.
one of the best science channels because it actually show you the experiment more or less first hand what going on keep it up
Here's the thing. Before this video I had always had issues with this. I stick the kettle on and I hear it getting louder and louder, so either a) I walk over to it as it gets loud and am amazed how long it still takes to switch off, or b) the noise gets quieter and then I don't hear it switch off and I forget about it. Thank you TF, now I know!
I've wondered this exact thing many times myself.
I suspected the cause was something very much like what you demonstrated - but actually being able to see it in action is really cool. The water being essentially incomprehensible probably helps a great deal in translating those resulting vibrations to the surfaces.
You make some of the most interesting science videos on the most mundane everyday things. 😉👍🏼
This is a really cool video. I knew why hot water sounds different when you pour it but I never really thought about the sound when you heat it.
Thanks Thunderf00t no more sleepless nights for me. Sir Edmond Hillary complained that the problem with climbing Mt. Everest was that you could not make a decent cup of tea because the water boiled at 70 deg C.
I've often wondered about that but never thought how to go about finding out experimentally. Thanks for doing this.
Love your videos on how random things like this work
Answering questions I never had, but happy to know the answer... Thanks man!
Glad to see the high speed camera going to good use!
Wow, this one really was interesting! One of the best ones i've seen from you yet!
Truthfully, I have never thought about it until you brought it up.
Hmmmmm, I wonder if this information could be used to make quieter or even silent kettles?
Great video, I had often wondered about this actually! Now I know, fantastic! :)
Reminds me of James Watt and the kettle. Still lots to learn from simple things.
This exact thing annoyed me too for awhile, so like a proper physicist i thought about it for a bit and came to the same conclusion. The way i did so was by noticing that the noise is much less if youve just cleaned out all of the calcium muck, lowering the amount of nucleation sites and thus lowering the amount of noise.
Oh, interesting!
We at home we're wondering the same thing receintly. Thanks for a great explanation thats more than meets the eye! Gread vid
This is one of the coolest videos I've ever watched. I am so glad I found your page. (thx to Big Clive!)
Great vid. Thank you Thunderf00t!!
Thank you, that question bothers me for almost 30 years 😀
I kinda suspected when you asked, but i did not think about this before. It is kinda like how a put put boat work.
By the way that thing you did with the overlapping video shaking the tube was really nice.
Sir, you just answered a question i've been asking my hole life. and for this i tip my hat and say thank you
Dude you are an amazing mind of science. Loved watching those cavitation bubbles reminds me of a pistol shrimp.
Thank you! I've been wondering this for ages!
This phenomenon has been bugging the S*** out of me forever. Curiosity satiated. Thanks.
This always bothered me so much. So thank you.
I really do enjoy these videos....guys like you make it more accessible for part time wannabe scientists like me....cardiff uk