You used a ceramic pot which slows down heat loss. You left the metal spoon inside pot. What if u do the same experiment with glass or aluminium pot same size? What if you remove the spoon? What if you have 2 pots and pour liquid from one pot to the other alternating? What if you put pot in fridge? What if you put pot inside pot with ice cubes? And what if put to chiller? If the coffee temp drops fast then it is not enjoyable to drink. The best is to use some isolated cup to slow down temp loss more than ceramic. Nice video.
What about pouring the coffee from one cup into another? And would the distance between the cups ( let's say two inches away versus twelve inches away) make a difference?
will be faster. But often you won't have an extra cup - on a caffe or something. That's why i didn't also test with a fridge or with ice cubes.
5 ปีที่แล้ว +2
Adding a second cup will soak some heat from the water alone - the cups are room temperature after all. The extra surface area when pouring will have a huge effect, since that gives you a bigger area for the liquid to evaporate from. Other than that the increased surface area, the effects of pouring are similar to blowing. Pouring further is like blowing harder - it falls through the air faster, so it exchanges heat more efficiently. I expect that pouring would be the fastest, but also the most cumbersome. Also, if you want to try to pour from one cup to another at 12 inches, expect spills.
I actually tested this lol. And yes you are right Mikkel - especially about the spills oh my god! I quickly glanced at the results but I think it’s about double as fast than blowing
One thing I do is that I use two cups and pour the hot liquid of one into the other and vice versa a couple of times, until it cools down. The hot liquid (coffee) exchanges heat with the cool air, forced convection put simply.
When you kept a hot body with a cold one the hot one liberate. Heat and cool. One absorb it. Real life example in some country the river will star freezing while surrounding becomes warm. It's the easy method
A more interesting observation is that if you put cream in your coffee first, and then wait 10 minutes, it will be hotter than it would be if you wait ten minutes and then put cream in it. This is because the rate of cooling is in proportion to the difference in temperature. So a very hot cup of coffee cools faster than a cup of coffee that is closer in temperature to the ambient temperature.
Great video. What temperature probe are you using? Seems like it performs well. I would like to do similar experiments testing kettles for thermal insulation/conductivity.
Since blowing on hot coffee for 20 min is something that few people want to do, I think lifting is a good alternative and is a realistic answer rather than just the results of the test.
5 ปีที่แล้ว +2
It hit the 60 degree mark after about 3½ minutes of blowing - half that of lifting - and you don't *have* to blow all the time. I'd blow over lift any day.
I made that already - with cold milk/creamer. It's in my SAW physics video ;) Here I'll link directly to the question, if you answer it correctly the explanation comes: th-cam.com/video/WCMMwcmY0IA/w-d-xo.html
Thank you for your reply!I am actually interested to find out the cooling rate of the coffee by stirring it with a spoon..so as I am considering stirring? Can I assume it to be a lumped parameter analysis? And how should I calculate h and put it into python code?
@@pranavipagala6150 there are too many parameters in the real world to define "stirring" I'm my opinion.. so just pick some meaningfully ones and stick with them. But I think it sounds like a very difficult problem to model 😅
Get an old pentium heat sink, (wash it), put it in the freezer, drop it in the coffee. Not cold enough? put it for a few seconds in cold running water, drop it in the coffee again.
Yeah i think this is faster as well. I made this test in order to know what is best given normal circumstances - it's rare you will have a sink available or liquid nitrogen :D
@@Higgsinophysics Okay, just a disclaimer I'm not a scientist and I have never tried this experiment. What I just said is a bit of a "false advertising" since this will probably never work on coffee but might work on water and under very strict idealistic conditions. What you will need for this to work is a gigantic vacuum chamber , an enormous amount of water and a lot of time (very precise measurements given, I know) . Also, the water needs to be insulated from any heat flow from the bottom. In these conditions it seems that by blowing your lungs out (which might literally happen since you're in a vacuum chamber ) (trough vigorous evaporative cooling) you can actually freeze the water. It is important that there is no air around since heat can flow back in from the air. One key fact is that the latent heat of vaporization is much bigger than the latent heat of melting, so each gram of water that evaporates should cool things enough to freeze more than a gram of water. That gives some room for heat leaks without stopping the process altogether. Hope this makes sense and please let me know if you find any mistakes in my explanation or have any other questions. Btw I really enjoy watching your videos! (side note: have you heard about the mpemba effect I think it is a pretty interesting phenomenon :) )
3:47 Sorry, but you explanation is incorrect. Since you are blowing onto the surface you are not going to lower the pressure enough to have any noticeable effect. Pressure on surfaces is lowered when air blows across them because the fast moving stream of air across the surface causes fewer molecules from reaching the surface. For example, Let's say students leave a classroom and try to walk across the hall to the stairwell. The fast moving students in the hall are going to drag some of the students along with them as they try to cross so fewer will reach the stairwell. Replace students with air molecules and you can understand the reason WHY the air pressure on the surface is lower. Fewer molecules reach the surface to strike it so the pressure is lower. The faster the air stream the more molecule dragged away and the lower the pressure. Your blowing into the cup f coffee is not going to accomplish that. The actual reason the coffee cools faster is because you are blowing away the warm humid air and replacing it with cooler drier air, so the rate of evaporation increases. It is the same you feel colder when the wind blows.
What? You would love to know more about heat exchange with coffee?? well let's talk entropy then th-cam.com/video/RJ7H6bKbp24/w-d-xo.html
Btw I just used all three methods at once,that's the fastest
U blow on it while stirring and pouring up and down
Let's be real, I prefer iced coffee 😂But the next time I feel like hot coffee I know what to do, thank you!
Hi, I am a big fan of yours.
Yeah, go and buy some dress, and then go to the kitchen.
Lmao at that last scene. Great work, as always, man! Glad to know I haven't been cooling down my coffee the wrong way all these years...
I was wrong, but the correct answer makes sense. Great video!
Thank you!
4:12 That's what he said
You used a ceramic pot which slows down heat loss. You left the metal spoon inside pot. What if u do the same experiment with glass or aluminium pot same size? What if you remove the spoon? What if you have 2 pots and pour liquid from one pot to the other alternating? What if you put pot in fridge? What if you put pot inside pot with ice cubes? And what if put to chiller? If the coffee temp drops fast then it is not enjoyable to drink. The best is to use some isolated cup to slow down temp loss more than ceramic. Nice video.
This was a fun video. Well done!
What about pouring the coffee from one cup into another? And would the distance between the cups ( let's say two inches away versus twelve inches away) make a difference?
will be faster. But often you won't have an extra cup - on a caffe or something. That's why i didn't also test with a fridge or with ice cubes.
Adding a second cup will soak some heat from the water alone - the cups are room temperature after all. The extra surface area when pouring will have a huge effect, since that gives you a bigger area for the liquid to evaporate from. Other than that the increased surface area, the effects of pouring are similar to blowing. Pouring further is like blowing harder - it falls through the air faster, so it exchanges heat more efficiently.
I expect that pouring would be the fastest, but also the most cumbersome. Also, if you want to try to pour from one cup to another at 12 inches, expect spills.
I actually tested this lol. And yes you are right Mikkel - especially about the spills oh my god! I quickly glanced at the results but I think it’s about double as fast than blowing
One thing I do is that I use two cups and pour the hot liquid of one into the other and vice versa a couple of times, until it cools down. The hot liquid (coffee) exchanges heat with the cool air, forced convection put simply.
When you kept a hot body with a cold one the hot one liberate. Heat and cool. One absorb it. Real life example in some country the river will star freezing while surrounding becomes warm. It's the easy method
A more interesting observation is that if you put cream in your coffee first, and then wait 10 minutes, it will be hotter than it would be if you wait ten minutes and then put cream in it.
This is because the rate of cooling is in proportion to the difference in temperature. So a very hot cup of coffee cools faster than a cup of coffee that is closer in temperature to the ambient temperature.
Great video!!
I see you had fun making this video
I did go full meme on this one
this is beautiful
Great video. What temperature probe are you using? Seems like it performs well. I would like to do similar experiments testing kettles for thermal insulation/conductivity.
Would love to see that! I used a Waterproof Temperature Probe Thermometer DS18B20
Since blowing on hot coffee for 20 min is something that few people want to do, I think lifting is a good alternative and is a realistic answer rather than just the results of the test.
It hit the 60 degree mark after about 3½ minutes of blowing - half that of lifting - and you don't *have* to blow all the time. I'd blow over lift any day.
Thank you 😍😍😍
np friend !
Now for the really stressed drinkers.
Can you make such an awesome video to show and explain adding cold water and ice to coffee to cool it down? =)
I made that already - with cold milk/creamer. It's in my SAW physics video ;)
Here I'll link directly to the question, if you answer it correctly the explanation comes:
th-cam.com/video/WCMMwcmY0IA/w-d-xo.html
Great experiment! May I know more about the coding part?
sure what are you interested in?
Thank you for your reply!I am actually interested to find out the cooling rate of the coffee by stirring it with a spoon..so as I am considering stirring? Can I assume it to be a lumped parameter analysis? And how should I calculate h and put it into python code?
@@pranavipagala6150 there are too many parameters in the real world to define "stirring" I'm my opinion.. so just pick some meaningfully ones and stick with them. But I think it sounds like a very difficult problem to model 😅
What about stirring AND blowing?
What if you blow and lift the spoon
Combination will be better :)
Get an old pentium heat sink, (wash it), put it in the freezer, drop it in the coffee. Not cold enough? put it for a few seconds in cold running water, drop it in the coffee again.
Yeah i think this is faster as well. I made this test in order to know what is best given normal circumstances - it's rare you will have a sink available or liquid nitrogen :D
@@Higgsinophysics watercool your coffee!
pour between two cups or just stir one block of ice.
Feels good to finally know the answer to that. But whos going to blow for 5min straight lol
Coffee cooled down after watching video :)
He's howtobasic.
Technically if you blow for *long* period of time you can actually freeze your coffee
How?
@@Higgsinophysics Okay, just a disclaimer I'm not a scientist and I have never tried this experiment. What I just said is a bit of a "false advertising" since this will probably never work on coffee but might work on water and under very strict idealistic conditions. What you will need for this to work is a gigantic vacuum chamber , an enormous amount of water and a lot of time (very precise measurements given, I know) . Also, the water needs to be insulated from any heat flow from the bottom. In these conditions it seems that by blowing your lungs out (which might literally happen since you're in a vacuum chamber ) (trough vigorous evaporative cooling) you can actually freeze the water. It is important that there is no air around since heat can flow back in from the air. One key fact is that the latent heat of vaporization is much bigger than the latent heat of melting, so each gram of water that evaporates should cool things enough to freeze more than a gram of water. That gives some room for heat leaks without stopping the process altogether. Hope this makes sense and please let me know if you find any mistakes in my explanation or have any other questions. Btw I really enjoy watching your videos! (side note: have you heard about the mpemba effect I think it is a pretty interesting phenomenon :) )
3:47 Sorry, but you explanation is incorrect. Since you are blowing onto the surface you are not going to lower the pressure enough to have any noticeable effect. Pressure on surfaces is lowered when air blows across them because the fast moving stream of air across the surface causes fewer molecules from reaching the surface. For example, Let's say students leave a classroom and try to walk across the hall to the stairwell. The fast moving students in the hall are going to drag some of the students along with them as they try to cross so fewer will reach the stairwell.
Replace students with air molecules and you can understand the reason WHY the air pressure on the surface is lower. Fewer molecules reach the surface to strike it so the pressure is lower. The faster the air stream the more molecule dragged away and the lower the pressure. Your blowing into the cup f coffee is not going to accomplish that.
The actual reason the coffee cools faster is because you are blowing away the warm humid air and replacing it with cooler drier air, so the rate of evaporation increases. It is the same you feel colder when the wind blows.
omg now i know the truth!
With great power comes great responsibility
I knew that I was right all the time 😂
First :P
Omg i was right its method blowing
@@AncientAccounts haha doing it the smart way
Of course I mean back and forth between cups for a few minutes, not just once.
Are you sure the blow person didn’t blow half the coffee ☕️ out of the cup?
yes
Before watching ...If i like this one i will subscribe you...after watching
Sorry will check your other video..
Actually i was expecting it to be better than this.once again thanks for your video...i liked your superconductors one,keep going
What's the 300 IQ studying where you concluded coffee is tastiest between 45-60C? BTW I agree with this statement.
did you also do I 300 IQ study? I noted which tempertures the coffee made me go: "yes"
Lol