How do you hear the difference between cold water and hot water?/TikTok/CuredEggYolk
You have a super cool ability that you probably didn't even know you had: you can tell the difference between hot running water and cold running water - with just your voice..
Yes. If you are like us, you probably didn't know that humans can tell the difference between hot and cold water just by the sound they make when they are poured. It turns out that there are differences in the sound that cold water makes compared to hot water when it is poured. A simple experiment involving a demonstration of pouring cold water and pouring hot water proved that it is even really easy to tell the difference between the two.
If you're a little skeptical, don't worry, there's an easy experiment you can do right now to prove you can really tell the difference.
This experiment only works if you don't lie or peek, then listen to the sounds of the pouring water and think whether you just heard the glass of hot or cold water. Just listen carefully and decide.
So what do you do to prove it? Tiktoker uploaded a video that has gained over 33 million views in which he holds two glasses of water - cold and boiling. He challenged his viewers and asked them to close their eyes and listen to the differences in the sound the water makes when it is poured into a glass. He then asked them to open their eyes and see it again.
Watch the proof video
why is it happening?
If you are wondering what the scientific explanation behind this is, don't worry because we have the answer for you.
Cold water is several times more viscous than hot water so while it produces the same sound frequency when poured - it does so at different intensities. This gives hot water and cold water slightly different sounds that the human ear can detect, so you can tell which is cold and which is hot just by the noise.
So it's all about viscosity, or the thickness of the liquid. It's easy to see the difference between the viscosity of hot and cold honey, because the hot stuff is more liquid (because it has a lower viscosity). When it comes to water, you don't really see the difference, but you can hear it.
Without going into too scientific explanations, we will explain that molecules in thicker and colder water have less energy, and therefore are less 'excited', meaning that they move less quickly and become stickier in a certain sense. There is also less bubbling in cold water for the same reasons. And this, as scientists explain, creates lower frequency sounds.
Conversely, warmer water produces higher-pitched sounds when poured into a mug or shower tray, because the molecules move more than in cold water.
The way temperature changes water—and virtually any liquid—has an effect on everything from global warming to the inside of our kitchen freezer, but scientists still don't understand all the secrets behind these phenomena.
On the sciencealert website they explained that what is happening is that our brain has unconsciously learned to pick up the differences between the two sounds from all the hot and cold drinks we have heard being poured throughout our lives.