[HN Gopher] Why you can hear the temperature of water
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Why you can hear the temperature of water
Author : mhb
Score : 153 points
Date : 2024-05-10 11:22 UTC (1 days ago)
(HTM) web link (www.nytimes.com)
(TXT) w3m dump (www.nytimes.com)
| PaulHoule wrote:
| Archived: https://archive.ph/ITRzw
| jerbear4328 wrote:
| And the audio clip (which doesn't work on the archive):
| https://static.nytimes.com/podcasts/2024/05/09/science/09tb-...
| GistNoesis wrote:
| https://www.youtube.com/watch?v=Ri_4dDvcZeM
| mikewarot wrote:
| I noticed the sound when making hot chocolate for my child. I
| figured there are a number of things at play... the leidenfrost
| effect when the water hits the much hotter edge above the
| waterline in a kettle(not in this video), the air over the hot
| water being more humid (and thus lighter), the much higher
| vapor pressure, the difference in surface tension, the
| dissolving of the hot chocolate powder, etc.
|
| Viscosity isn't something I considered... but it makes sense.
| kinow wrote:
| I thought I wouldn't be able to tell the difference, but when
| he told me to pause the video to try to guess, I listened to
| the audio of pouring water again, and thought about "which one
| sounds like when I pour tea", and that way I could identify the
| warm/cold water. Interesting!
| jaredhallen wrote:
| I can definitely hear when the shower gets hot. Cool to have some
| explanation behind it.
| KineticLensman wrote:
| Likewise. My shower takes quite a long time to run hot, and I
| can usually hear when it has reached the point where it is no
| longer too uncomfortable to get in.
| philipswood wrote:
| Yeah, my shower takes a a while to run hot, so I also listen
| for when the water is ready.
| Tanoc wrote:
| This is something I noticed as a kid. We had a creek in our
| backyard, which,depending on the temperature the water would be
| louder or quieter. This annoyed our dog, which after a number of
| times caused me to notice. Running water is louder and much more
| sharp when it's cold out, and quieter and muffled when it's hot
| out. In the same way sounds are louder in a colder environment
| because there's already a low level of ambient energy contained
| in the air and so the energy disperses much more readily but
| dissipates much more quickly. Essentially a difference between a
| quick "crack" and a lingering "whump" in terms of auditory
| impact. This effect also propagates to solid materials, as cold
| metals and ceramics transmit sound better than warm ceramics or
| metals. A church bell quite literally is louder on a cold
| winter's day.
| axxl wrote:
| My thought on the general "loudness" of cold months was due to
| reduced noise blocking or absorbing greenery like tree leaves,
| grass, etc. Which is then altered by a significant snowfall
| leading to sounds being softened again.
| ffsm8 wrote:
| Shouldn't that be an inverse relationship though? Without
| leaves on the trees you should get less reflection,
| consequently more of the noise should radiate upwards. Unless
| you're standing at the other side of a bush/greenery. In that
| case it definitely absorbs a lot
| CrazyStat wrote:
| Lots of small unaligned surfaces, like leaves, scatter the
| sound and make it interfere with itself. Reflection only
| makes the sound louder if you have large smooth flatish
| surfaces.
| Modified3019 wrote:
| Ah, I had never considered the interference aspect of
| sound reflections
| CoastalCoder wrote:
| I want to make a joke about the "three leaf" problem in
| acoustics, but I can't find a way to make it funny. Dang.
| tomrod wrote:
| You made me chuckle. Mission accomplished.
| kylebenzle wrote:
| HN is becoming worse and worse everyday :(
| CoastalCoder wrote:
| Assuming your comment is serious (rather than some quip),
| I think what we're seeing is differing visions for HN.
|
| One group (me included) enjoys some levity, as long as
| it's high quality and doesn't get in the way of
| substantial discussions.
|
| Another group would prefer that HN avoids that entirely.
|
| It mostly seems like a matter of taste / preference, so
| I'm not sure how we can come to one kind on this, shy of
| seeing the pro-humour approach clearly hurting the site.
| xattt wrote:
| The volume of water flow should/would also vary at different
| times of the year, based on how much the water table is
| loaded.
|
| Not sure how much of this would be complimentary to the
| acoustic effect of temperature. Either way, it's not a simple
| single-solution explanation.
| BurningFrog wrote:
| My guess is that frozen terrain is harder, which reflects
| more sound and makes hitting it noisier.
| xerox13ster wrote:
| Cold air is also more dense, less momentous, and can transfer
| sound energy more efficiently between particles than hot air
| where the particles are spread out and have their own
| momentum to maintain rather than the sound's.
| soulofmischief wrote:
| No one here has mentioned temperature inversion [0] which is
| responsible for a lot of the cold-induced amplification
| perceived in urban areas. It's quite a fascinating effect.
|
| [0] https://wisconsindot.gov/Documents/doing-bus/eng-
| consultants...
| quesera wrote:
| Could the audible difference be related to varying sound
| propagation through hot/humid vs cold/dry air?
| ajkjk wrote:
| I think it's this. Sounds are very different based on the
| temperature and humidity of air. I have a piano at home and
| the difference is huge and very apparent over time.
| CoastalCoder wrote:
| Does your piano have a wooden body and sound board?
|
| I'm sure piano techs are all over this topic, but (as a
| layman) I could imagine the wood's water content being
| quite relevant.
| bruce343434 wrote:
| Piano soundboards are almost always wood. There are a
| handful of companies that offer carbon fiber soundboards
| but they are very rare and expensive. As the soundboard
| gains moisture, it swells and buckles as it has nowhere
| to go, which makes it louder and also raises the pitch a
| bit as the strings are pushed a bit. When it gets drier,
| it goes flat (structurally and musically). If it has been
| too moist, the wood cells will be compacted and crushed.
| If it is then dried, it will form cracks as the wooden
| structure rips itself apart when shrinking again.
|
| A piano soundboard that has been built and kept in a
| desert for instance will not crack. But if you take a
| piano from a ~55% humid country and put it in a desert
| (or overly air-conditioned room! or right in front of a
| heat radiator!) it will die.
| CoastalCoder wrote:
| Does a swollen soundboard noticeably affect pitch even
| when the piano has a cast-metal harp?
|
| The one harp I've seen up close was in an upright piano I
| disassembled, and that harp was _solid_.
| bruce343434 wrote:
| The harp doesn't actually lie flush on the soundboard;
| there should be some space in between. The harp is just
| there to bear the tension of all the strings. The strings
| are connected to the soundboard via a wooden so called
| bridge, which is a raised wooden element glued onto the
| soundboard. It has pins in it which the strings are held
| against in tension. Bridges have a coating of graphite
| usually, and combined with the fact that most notes have
| 3 strings, it creates kind of a blocky pattern.
|
| Here you can see a soundboard, bridge, and hitch pins on
| the harp. The hitch pins on the harp can be seen up top,
| then in the middle the bridge and bridge pins, and then
| below that the soundboard. The hitch pins are located on
| the opposite side of the keys in a grand, or on the
| bottom of the piano in an upright. You can see on the
| right of the image that the harp has a structural element
| which floats over the bridge, with plenty clearance.
|
| https://www.chuppspianos.com/wp-
| content/uploads/2014/03/Stei...
|
| P.S. In some pianos you can really hear a metallic
| undertone produced by the harp, I find Yamaha pianos have
| a distinct sound that has it.
| 486sx33 wrote:
| It's important, and can change the tuning in spring and
| fall cycles
|
| most of the US is too dry in the home, and humidification
| is helpful for all wood in your home - to a point of
| course. Approx 55% is optimal
|
| Of course in the south it's the exact opposite - but A/C
| usually solves the problem.
|
| Every homeowner should monitor their indoor humidity,
| it's important for, wood floors, door trims, wood
| furniture, and our own health. Too much causes mold, too
| dry is hard on your respiratory system
| Wistar wrote:
| My piano has a Dammp-Chaser automatic humidifier and
| dehumidifier system that works well. My piano tech uses a
| moisture meter to check the soundboard at tuning time and
| the wood's moisture has been fairly stable for more than
| two decades.
| neom wrote:
| I'd imagine there may also be a component of sound bouncing
| off things? I think stuff contracts and expands when it hot
| or cold? So maybe something that is cold and contracted
| bounces the sound sharper too? Noooooo clue if that makes any
| sense, just a bunch of guessing from high school science
| class.
| YuccaGloriosa wrote:
| I don't think so. If I pour hot water into a mug from the
| kettle, it sounds different with cold water with all the same
| equipment, room etc
| dghlsakjg wrote:
| That's my feeling as well. I can hear when the hot water
| has reached my shower.
| grilledchickenw wrote:
| I hear the same with my shower, but I'd wager most of the
| change in sound would be to do with pressure change
| between the hot and cold source.
| schiffern wrote:
| That was what I thought at first too. However if it were
| pressure change, the sound would change when you move the
| knob, not when the hot water reaches the shower.
| nico wrote:
| Thank you for the great anecdote and explanation, it was fun an
| very illustrative to visualize the concepts while reading your
| comment
| morninglight wrote:
| The video is also excellent.
|
| https://youtu.be/9w3Zl3KBDpI
| nico wrote:
| The intro was hilarious! Thank you :)
| golergka wrote:
| I wonder how well it maps to notions of a "cold reverb" or
| "warm synth" in music production.
| wolverine876 wrote:
| You controlled for the volume / depth of water, which for the
| same mass would be greater when warmer, and the resulting
| changed interaction with objects ...?
| animal531 wrote:
| As the article mentions, most people know how to tell the
| difference by sound but if you were to ask them they would say
| no, it's impossible.
|
| That just makes me wonder how many other things there are that
| people subconsciously learns, without it ever becoming obviously
| noticeable for them?
| abyssin wrote:
| I'd say lots of behavioural cues, for instance related to
| dominance. Many people feel like they're behaving freely
| because they've completely internalized the constraints their
| social position imposes upon them.
| mbo wrote:
| I _think_ I can tell whether a car is an ICE / hybrid /
| electric just by the way their weight shifts around corners. My
| friends maintain they cannot, but under test conditions, I'm
| sure they'd be fine.
| YurgenJurgensen wrote:
| Are you sure it's weight distribution and not conducted
| engine vibration and gear shift patterns? Seems like it'd be
| difficult to control for (assuming we're already controlling
| for engine noise).
| xnx wrote:
| Many people can perceive polarized light.
| DoctorOetker wrote:
| There are many examples of humans being able to observe a
| difference, yet deny their capability to discern on the basis
| of abstract rational knowledge.
|
| Another example is frame rates: while its well known that the
| bandwidth of light sensitive cones on the retina is around 30Hz
| cycle frequency (and thus ~60Hz framerate), many gamers felt
| the difference of higher framerates, even though many of the
| same gamers denied observability of this difference on the
| basis of knowledge of this basic biological fact.
|
| The biological fact is not wrong: if screen pixel projects are
| at rest on the retina. But when the eye is rotating to follow a
| depicted object on the screen, then speeds higher than ~60
| pixels per second result in motion blur that would be absent
| when observing a real life object moving at the same angular
| speeds. The biological fact is still true, but simply not
| naively applicable in the context of motion blur due to
| eyeballs rotating while observing a display.
| ajuc wrote:
| It's more complicated than that, brain cuts out the blurry
| "in between" frames when you move your eyes. Which means it
| has to extrapolate the images from before the movement to
| fill the gaps. There's many weird effects of this hack - for
| example when you look at something moving very fast (like
| wheels of passing vehicles) but don't move your eyes - it
| looks blurry. But when you move your eyes - the frame in your
| brain "freezes" and you can notice non-blurry details on the
| fast moving things. There are even ways to force eyes to see
| stuff from the past (like seconds' hand on a clock moving at
| different rates depending if you move your eyes).
|
| You can't actually say that human eye has a strict fps, so
| the higher screen fps the less weird interactions with the
| ugly hacks in our brains.
| DoctorOetker wrote:
| when your eyes are motion tracking an object there is no
| cutting-out going on, that only happens when the brain
| intentionally decides to track a new object
| Kudos wrote:
| Your eyes being analog and the 60Hz display being offset from
| your own cycle frequency would play large roles in that.
| DoctorOetker wrote:
| the phenomenon I describe is much simpler, and is
| remediated by having the backlight of a 60 Hz display have
| a very short single on strobe. If they backlight remains on
| or flashes multiple times during a single frame then the
| pixel will draw a long streak on the retina (because the
| eye was rotating to track a depicted moving object)
| thfuran wrote:
| Sample and hold motion blur during smooth pursuit is far
| from the only visual artifact resulting from low frame
| rates.
| wizzwizz4 wrote:
| What are others?
| thfuran wrote:
| I'm not sure if you've seen them, but there are LED glow
| sticks that look normal when stationary but leave sort of
| a trail of distinct after images rather than a smooth
| blur when waved. I've seen LED Christmas lights that have
| a similar effect when you scan your eyes past them
| quickly. It's called the phantom array effect, and it's
| caused by a flickering light (LEDs lit with less than
| 100% duty cycle) moving rapidly across the visual field.
|
| Mitigating sample and hold motion blur by blacking out
| the display for some of the frame time turns your display
| into a flickering light source, so it can potentially
| produce the same effect for small bright objects on dark
| backgrounds when either the object moves rapidly on
| screen or you scan your eyes across the screen. It's
| fairly niche in that it'd only affect some rather
| specific scenes and even then can depend on how the scene
| is viewed (it won't occur if you track the only fast-
| moving bright object with your eyes, and it's much
| reduced in higher ambient light), but the flicker fusion
| rate is generally several kilohertz, so you'd need to
| boost the hell out of the frame rate to guarantee the
| effect is eliminated altogether.
|
| More generally, an object that is moving rapidly enough
| for its screen position to change by many pixels per
| frame can have its motion look jerky even without motion
| blur. And, in fact, motion blur can help disguise that.
| nico wrote:
| This is a very interesting concept
|
| Is there a way to sync the monitor's refresh rate to a
| different phase/offset?
|
| It would be cool to play with that setting and see the
| effects on our perception of the screen
| coffeebeqn wrote:
| Not much of an electrician but wouldn't the phase kind of
| randomly reset every time you turn the monitor on and
| off?
|
| Our eyes are good at adapting to all kinds of things -
| like really small red, green and blue lights in an array
| can look like anything to us
| nico wrote:
| That makes a lot of sense
|
| About turning the screen on and off, it's very slow if I
| want to change it in real time. It would be nice to have
| a little nob on the side and just change the phase one
| way or the other in correspondingly :)
| thfuran wrote:
| Eyes don't have a synchronous cycle. Every individual
| receptor has a relaxation time starting from the last
| excitation.
| Ferret7446 wrote:
| I think you're the one denying rational knowledge here.
| People are different, and there are in fact people who cannot
| tell the difference between higher frame rates, as shown in
| studies.
|
| Just because you can see it doesn't mean others can.
| smartscience wrote:
| The McGurk effect https://www.youtube.com/watch?v=2k8fHR9jKVM
| is another example, which might be described as people learning
| to lip read without them being aware that they have done so.
| plorkyeran wrote:
| Apparently I can't lip read, as I never heard anything other
| than "baa" even as the video was claiming that I should be
| hearing something different.
| CamperBob2 wrote:
| Yeah, I don't understand what I was supposed to be seeing
| or hearing in that clip, and they never bothered to explain
| it.
|
| The guy says "Baa" and we see his lips move accordingly.
| Then we hear him say "Baa" again, but this time he's
| obviously pronouncing something else, judging by his lip
| movements. We don't know what he's saying (or at least
| those of us without lip-reading skills don't), but nothing
| unusual or tricky seems to be happening.
|
| What am I missing?
| plorkyeran wrote:
| From making the same motions with my mouth I was able to
| figure out that the other thing he's saying is "faa", so
| I'm guessing some people literally hear "faa" even though
| the audio is "baa"?
| marmaduke wrote:
| > how many other things there are that people subconsciously
| learns, without it ever becoming obviously noticeable for them?
|
| 95%+? Stuff like how to jiggle keys on a keyring to get the
| right one for the door you're about to unlock? This only works
| for your keyring, it's highly kinetic, tactile, initial
| condition dependent etc, yet yet can usually be done
| unconsciously IME with the 6 keys on my keyring.
| rendaw wrote:
| Poor storytelling in modern cinema.
| nico wrote:
| There is a cool veritasium video in which they show we are
| sensitive to changes in the magnetic field surrounding us
|
| We can't consciously tell, but they can see our brain lighting
| up when sensing the changes
|
| Link to video: https://youtu.be/dg3pza4y2ws?si=-yXtwIu2n4QR_1Wi
| RicoElectrico wrote:
| AC electricity on painted metal objects can be felt by sweeping
| fingertips, even though there's no current path.
|
| You're absolutely right that people ignore whole lot going on
| around them in terms of sound, smell etc.
| tomsmeding wrote:
| I have felt this (?) often. Dragging fingers over a (metal)
| Mac Mini, some random laptop, a metal keyboard. Presumably
| this feeling triggers already at low power levels, otherwise
| I'd probably be dead.
| themoonisachees wrote:
| I don't think it's quite the same thing. Laptops in
| particular often have machined (?) surfaces that feel very
| weird to the touch, regardless of electricity. HP in
| particular is a regular offender, though I haven't touched
| many apple computers.
| rcxdude wrote:
| I've experienced it and it's markedly different how a
| laptop feels when plugged into the wall Vs not: it's
| because of a relatively high voltage (but also high
| impedance, so not dangerous, though sometimes painful if
| it focuses through a small point like a USB cable) hum
| you tend to see in the ground of most modern power
| adaptors due to noise reduction capacitors.
| jaggederest wrote:
| No, this is a different thing. It's leakage current from
| ungrounded power supplies (the two-prong apple power
| brick) and it's extremely noticeable. Couple hundred
| microamps, feels like licking a 9 volt battery.
| robocat wrote:
| Once you can feel it (say 50V) then you can have data
| problems with anything else plugged in.
|
| So often worth fixing even if you don't worry about getting
| a shock.
| proaralyst wrote:
| Is that explained by capacitance? I'm sure the capacitance of
| your finger through paint is pretty low but capacitors allow
| AC to pass
| goosejuice wrote:
| The woman who can smell Parkinson's comes to mind as a recent
| example.
| plusfour wrote:
| Most of your knowledge is implicit.
| inglor_cz wrote:
| Absolutely, yes. Pouring hot water into a cup sounds very
| different from pouring cold water into a cup. Even the flow looks
| visibly different, hot water is a lot more "lively". Noticed this
| as a kid, never made a mistake.
| is_true wrote:
| also the sound the cup makes when you hit it with a spoon while
| stirring
| eimrine wrote:
| Do you know how to download sound from nytimes.com? I can show
| the article on the website (not on archive one) and I would like
| to analyze the sound in audio software.
| perilunar wrote:
| If you wade through the (incredibly verbose) HTML you can
| eventually find a script with the source for the audio file,
| which is:
|
| https://static.nytimes.com/podcasts/2024/05/09/science/09tb-...
| kosolam wrote:
| Let us know the results please
| extragood wrote:
| It's easy enough to reproduce - may as well run a quick
| experiment and record that.
| wolverine876 wrote:
| You some controls: for example, the same mass/second of water
| - your water pressure might differ between hot and cold
| sources.
| ynniv wrote:
| Huh, I guess this is why movies never have convincingly cold
| water. Everyone is shivering, but it never _sounds_ cold.
| erehweb wrote:
| Googling, it sounds like cold showers are fairly common in
| movies
| https://www.reddit.com/r/explainlikeimfive/comments/dg52a5/e...
| YurgenJurgensen wrote:
| That kind of sound effect is usually added in post anyway.
| novaRom wrote:
| Also hard vs soft water may sound different, not just carbonated
| water. Soft water feels smoother and silkier on the skin because
| it contains less minerals.
| anfractuosity wrote:
| Someone appears to have made an android app to attempt to
| distinguish temperature from sound of pour -
| https://petter.saterskog.com/ai-thermometer/index.htm
|
| I thought I'd heard the 'stickiness' of the water affects how it
| sounds. Not sure if that is stiction or something else.
| Modified3019 wrote:
| From personal experience, walking on snow/ice sounds different
| based on temperature. From my time of walking to work at 6am in
| Michigan when I was younger, I could tell the temperature in
| approximately 10 degree F increments based on the sound. At least
| between 30F to -10F
| apitman wrote:
| As someone from Arizona I learned relatively late in life that
| ~15F is when my nose hairs start to freeze.
| zulban wrote:
| There's definitely many, many different sounds of snow and ice
| based on temperature, and probably humidity, pressure, etc. Or
| what those conditions were 2 days ago when the snow fell, what
| they were yesterday, and what they are now. I live in Canada,
| Quebec so maybe that makes me some kind of subjective
| authority.
| ubutler wrote:
| It surprises me that this is a surprise, I thought this was a
| given.
| extragood wrote:
| Yeah, I'm very certain that I've read about this phenomenon in
| the not so recent past. To the point where I've intentionally
| listened for the difference on many occassions since then.
| Wistar wrote:
| When running some water to warm up before turning on the shower
| head, I can tell when the hot water has arrived by the distinct
| change in the sound as it splashes on the shower basin. The
| splash sounds soften when the water starts to run hot.
| apitman wrote:
| This is the same context where I noticed this. One of those
| weird things that would be really easy to google but I never
| did. Wasn't expected to get that random mystery solved today
| but I'll take it!
| throwaway2562 wrote:
| Can anyone explain why hot water tastes different to cold water?
| Is taste not separable from temperature or is there another
| mechanism at work?
| datameta wrote:
| I would imagine it has with the biomechanics of our tongue as
| it relates to available dissolved minerals.
| ruined wrote:
| it makes sense to me that the chemistry of taste would be very
| sensitive to temperature. but often, heated water has more
| substances in solution
| thfuran wrote:
| I'd expect it has less. Usually minerals accumulate in the
| water heater.
| Arn_Thor wrote:
| Taste is absolutely linked with temperature. Cold vs hot coffee
| for example. Don't know exactly why. Most things tend to taste
| "more" when hot. Could be the intensity of molecular activity,
| which is what temperature is, that varies and so registers more
| or less strongly with our taste preceptors
| bassrattle wrote:
| Just look at the inside of any water heater. Usually
| disgusting! This is why we heat cold water up when we cook,
| rather than start with hot water
| hkpack wrote:
| A lot of things at play.
|
| 1) We actually can sense "coldness" or "hotness" as separate
| tastes. Think about mint candies or pepper for example.
|
| 2) Our receptors have different sensitivity based on the
| temperature. For example cold sweet drink feels much less
| sweet. That's why warm cola is disgustingly sweet for example.
|
| And water does contain a lot of dissolved salts which have a
| taste.
|
| 3) More than half of the taste we feel is actually coming from
| the smell, and warm water contains more vapour, and therefore,
| more smell.
|
| So our brain takes all these inputs from different sources and
| synthesises the feeling of taste in our brain.
|
| Source of this knowledge is from:
| https://www.cookingforgeeks.com
| 486sx33 wrote:
| Non paywall link ?
| flypunk wrote:
| https://archive.md/20240509203946/https://www.nytimes.com/20...
| amelius wrote:
| Yes, for sure, but at what resolution?
| 4RealFreedom wrote:
| I read about the viscosity difference in hot/cold water a while
| back. Every time I think about it while drinking water, I put my
| water down. I don't know why it bothers me so much but it does. I
| feel like I peered into the eyes of God and can never return to
| normal life.
| neltnerb wrote:
| It took a while to find the original source files [i.e. the ones
| the author published as supplementary information]
|
| Includes raw recordings as well as actual raw results for those
| of us without NYT subscriptions.
|
| https://osf.io/brp2a/?view_only=7f49783ebbf646b29af32ca64524...
|
| Audio comparison video, the fun part for me anyway.
|
| https://osf.io/brp2a/files/osfstorage/62fe7d9da06acd0f5b2db3...
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