When we touch something that is hot or cold, what are we actually sensing? Is it the temperature of the object, or the rate at which heat flows between the object and our hand?
Hahaha yeh. I totally get what Veritasium is getting at with these misconceptions. But I think most people don’t care at all, they are perfectly happy to hold false or contradictory beliefs.
we all to think we are the ones that know a logical enough answer better than the person in front of us... its hard to remember different logical reasons to things that we already think we know and understand and this happened to me recently in physics and i confused the crap out of myself until i asked the teacher to explain again but still i knew i didn't completely understand.
Stupid people are typically more prone to judgement. It's harder to accept new viewpoints if you don't even fully understand the opinions that have been impressed upon you by others. Once you internalize something you don't understand as a universal truth you're in effect giving up on your humanity. It's why religion has been such a smash hit for so long.
I really like your statement. A lot of people won't even fully understand what you just meant. In a way, this video is more about this statement above than whether someone believes or understands that the temperatures of the cake and the tin are actually the same. Heck, the lady at 1:31 argues that: "...the metal holds the heat longer and holds the cold longer...". The very opposite logic of this is the reason your hand gets burned - when you touch the tin the heat transfers very rapidly to your hand, and its also the reason the metal appears cold - the heat from your body transfers very rapidly to the metal object. These preconceived notions that "stupid people" typically have are arguably a result of a lack of knowledge or simply a willing to care. People are too busy with their lives to even consider an arguably shallow concept like this one. Just as their religion was injected into their life, whether it be from and early age or later in life, they simply knew it as others had told them. Why would they consider such a shallow concept such as: "God doesn't exist", when their bodies thought it real before their minds even understood, or could yet to understand?
Because our built in sensor system only registers temperature change of the sensor (nerve ending), so our body can´t distinguish heat flow from temperature.
@@paavobergmann4920 oi oi oi, mr. escobar your delivery is awaiting you in the basement. yeah, only temperature change. i think that's the reason why sometimes when i want to wash my hands in the winter it never feels like there is cold water coming out of the tap when my hands are cold... if i then drink it i know that it is indeed, cold
Lol I've also been subscribed for many years. However, I've seen this video before. YT has been suggesting lots of vids lately that are 5+ yo and acting like I've never seen them 😂
Matthew Smith it is a VERY stupid thing to say....its the exact opposite of what actually happens. paper doesnt absorb HEAT as well as metal and doesnt release it as well...as well.
Niels Rasmussen nothing...NOTHING absorbs cold...think of it like this...cold doesnt exists (the opposite of energy doesnt exist). only energy exists and we use the term "cold" to explain that something has little thermal energy when compared to another thing
***** Well, not exactly. You can't have an absence of energy, it's literally impossible. Cold is when something has less energy than what it has at the moment.
The other big misconception is that a fan will reduce the temperature of a room. I've seen people put a fan in a hot room, close the room and wait for it to cool down.
it does not reduce the temperature of the room but it does feel cooler for the same reason described here. when air is stationary its takes less heat off your body as the heat has to propagate through the air merely on the airs natural movement, but when then air is circulating due to a fan blowing it around more air is passing over your body and the new air has yet to absorb heat from you so it can absorb at a higher rate and as that heat blows around the room it distributes that heat all over and allows it to propagate into the walls, ceiling and floor much better due to a larger surface area to work with. so yea it does not cool the room down but it does cool you down. _though admittedly I don't think I did a very good job explaining it here._
right, but it would still cool the room, slightly, as moving air redistributes and disperses the heat better. In a perfectly sealed and insulated system, yes the heat would remain constant, maybe even increase with the fan generating heat due to motion, but a room is not a sealed system. This kinda ties into another common misconception that at all times all the air in a room is the same temperature, which is not true, there are pockets of hotter air and pockets of cooler air. and the heat wants to go into the cooler areas, such as the cooler pockets of air or the walls or out a window or whatever, but with stagnant air it has to travel through to adjacent air and repeat to get to the cooler locations, by moving the air it can travel more freely. as this hotter air passes cooler locations it bleeds off a bit of that heat, and cools down, then it gets back to the hotter section and heats back up cooling the hotter section of the room, it keeps cycling like this, making the temperature more unified and also bleeding some of the heat out of the room. so it would in fact probably lower the ambient temperature of the room, not as significantly as it would with say AC but a noticeable few degrees. kinda long winded I know.
Tenshi Strife I say it would heat it up by using the principle. Presumption is that outside is hotter than the inside of the room, otherwise why close it when you could just open the windows and let the cooler air in. :) "long winded" - air circulation pun?
i studied a lot of physics in high school but all of it didnt make full sense to me. So many things happened during that time that it was overwhelming and i didnt have enough time to think about all that i studied other than learning them to pass numerous tests. Now in uni i started questioning stuffs again and kept googling and learning and came across ur videos. TBH we are lucky that u have made all these type of videos and im so thankful. Ur videos feed my curiosity more and more and i want to read and understand all about such amazing concepts.
3:17 I love how your mother looks at you feeling very proud, even though you've just started your TH-cam career. Can't imagine how happy and proud she feels now.
For me it's like when someone says: "If you stick an umbrella up your anus and open and close it 10 times it'll cure your cancer." so no laugh as much as you want.
Titan Csokona people attribute properties to what they percieve and sense. If they feel a wall with less absolute heat than their hand they will have the sensation of "cold", they could then apply this observation to how objects retain "hot" and "cold". You are watching these videos, and that means that you are part of a specific group of people who are interested in science and learn about it in their spare time. So to assume everyone has the same interests as you and that the only reason they dont know as much about thermal conductivity is because they are stupid is ridiculous. So no, basing how the world works based on observations is not the same as your stupid example.
@@canatronYT it's common knowledge mate. You are taught this in schools. If you don't know this basic stuff I'm sorry but you must be only be able to work in McDonald's at the age of 50
That's a great example of how our perception can be deceptive, even if our senses are telling the complete truth. The problem isn't on the fingertips, it's in the brain. Our understanding of reality can't be perfect and should always be questioned.
But our understanding of reality is a primarily abstracted one. Since our senses *do* tell the truth it's quite often the case that our intuitions are correct, even if we don't understand them. A hot seatbelt buckle *will* burn you in the summer, whereas a nylon belt won't. Sitting on a metal seat in the winter will be significantly less pleasant than sitting on a polyester seat with foam in it. None of these are incorrect, which is frankly of infinitely more importance than an abstracted understanding.
@@RohannvanRensburg Senses and perception are obviously important, but they only get you so far. I would argue that understanding exactly why things feel hotter, and how material physics actually work on a molecular level and how heat transfer works is infinitely more important because without it we would not be able to design and build any of the modern technology that we use today in society.
I remember taking my first physics class in high school and learning about heat transfer, conductivity of heat through various media, many of things he touches on here. Had I not ever been exposed to that knowledge, I would be as confused about it as any of these folks.
PenguinCoalition yep.... The the stupidity of people hurts my head everyday. Sadly they outnumber the smart people and they're still allowed to vote 😏🔫
Air can only hold so much moisture content in a vaporized form. If it's at 100% saturation, then your sweat cannot evaporate, and thus can't help cool you off. If the vapor content goes above 100% it recondenses, which is why you get rain when the air is "too full of water vapor".
I remember when I first learned about specific heat and how I was blown away when you think about how metal object and a wooden object of the same temperature feel different temperatures. It was so mind boggling because of the incorrect way we define "temperature."
@Fergussonification haha - yes I thought about a thermocouple, and you may well be right about the emissivity - but I'm not sure this was the main source of uncertainty. I noticed a lot of variability in temperature around the cake, plus the temperature dropped remarkably quickly. The pan was down to 40C in under a minute.
A lot of smartasses in here. Thermodynamics isn't intuitive fellas. To fully understand this video you need to know about: 1. The definition of heat and the nonsense of "cold" 2. The definition of temperature 3. Zeroth law of thermodynamics : A being the metal, B the book and C the air... 4. Thermal comfort, which in turn requires some human biology, the first law of thermodynamics, psychrometrics, statistics, and heat transfer. (maybe I forgot something) Not easy. So please don't mock people and rather try to educate them with the knowledge you've got. Everyone is ignorant about many things, that isn't bad per se, being comfortable with ignorance is bad. The peope in this video showed willingness to learn something new, so what's wrong with that?
His methodology is that he starts with the misconceptions because then the person listening has to actively think about it and not just use old, often inaccurate, information. He wrote his PhD on this. Please type his name and ted ed in on TH-cam and you'll be able to see why he does it this way.
+mbk3986 I wasn't criticizing him, I get what he's doing. But take a look to the other comments, for a lot a "geniuses" the answer was quite obvious... I don't believe them.
Same thing is when you have cold hands and you wash your hands in warm water, you feel it like it's hot. But when you have hot hands you might feel that warm water is colder. :)
can u guys stop calling those people dumb... I know some of the answers were stupid but they are just people who are not into science... the fact that u r watching this video is because u like science.
+Obleddo yep, water is often warmer and air conducts less heat so thats why if youre wet and stand up you get the cold properties of both then the water conducts heat/cold from the air and shares with you
@@ch3z231 What does the hability to conduct heat faster from an object to another relate to heat capacity? The former is termal conductivity (what's the vid about) and the latter is the capacity to absorb a certain energy to change the temperature 1°. Those the definitions, but is there a relation between them? I just ask for curiosity since you mentioned heat capacity.
I recall first learning this concept decades ago from a book that explained why on a cold morning, bare feet on a bedroom carpet do not feel near as cold as bare feet on a tile bathroom floor. Both are in the same house, so they must be the same temperature, but one feels cold while the other does not. Thermal conductivity is the answer.
this is great, but a good part of the explanation around this is to mention that the human body is hotter than room temperature (due to the general chemical processes occurring within your body creating a lot of friction and heat within it. This means there is a difference in temperature between you and the book / you and the dvd player. Since the dvd player has a [higher?] heat capacity, it 'accepts' more of your heat, causing your hand to cool down faster. Other than missing this point, this video is spot on. [when you're 12 years late to appreciate a good video on time lol]
@elmepo232 the performance mic was a new purchase on my North American trip - I will be using it in interviews from now on. I should add that the purchase was inspired by comments like this one.
i know it has been 8 years but if somehow you read this i wanted to thank you because this was a question on my physics exam and i would've never guessed it without you
That infrared thermometer gun could be used for the best pick-up schemes.. (Enter attractive female) *Slightly tilts sunglasses and wields infrared thermometer gun. Aims at female and checks the reading* "Yep, she'll do"
Great video! I recently came across with your channel, and I really enjoy your approach on science topics. I still remember how hard and mindblowing it was to me to come up with a tangible idea of heat. In fact, we usually end up thinking about heat as "something" that flows from hot surfaces to colder ones, implicating a temperature variation. It was even more incredible when I learnt that it is actually possible for heat processes to occur at CONSTANT temperature... heat is weird stuff LOL.
I was preparing some coffee and it made me think about heat transfer. I immediately remembered this metal vs book analogy and came to look for this video. Just a classic and simple explanation! But didnt remember that Derek's mom was in it. They both look so sweet together. Cant believe that was 12y ago.
WOW the red rag hanging on the oven at 2:02 is so relatable. I've got the exact same hanging on mine as I'm sure everyone else does as well haha. Nice!
It is a very 'cool' demo. lay(wo)men or for that matter anybody has a misunderstood idea on temperature. Thermal equilibrium is not a well understood concept by all. Measuring the temperature of cake and container is very illustrative. My appreciation for Vertasium scientific invention.
It's surprising that many people have forgotten that metal is a great conductor of temperature, that's why metal feels hotter because it conducts heat very well.
yah i think there is a lot of confusion between temperature and heat. metal is a great conductor of heat not temperature. that why those guys probably assumed that the temperature would be different because they assumed heat and temperature are the same thing.
Incidentally, this is why outer space doesn't actually feel that cold. Since it is a vacuum, it can't conduct heat from your body. You will still lose heat through radiation, but it is a much slower process for our bodies. So the actual sensation of the 'temperature' of space would be quite pleasant when the sun is eclipsed behind the Earth (of course, the sensation of having all of the gases in your bodies forcibly expelled from all of your orifices at once and then blacking out from shock and asphyxiation will be decidedly less pleasant). If you were to somehow remain conscious but exposed to the vacuum of space, it would over time start to feel quite cold as you lose more and more heat. But it's far from the 'instafreeze' environment it's depicted in various media. But speaking of the sun, this is where it really starts to defy expectation. In space, you face the full, unfiltered radiation of the sun. The sensation of the sunlight without any cooler ambient temperature would feel akin to the sensation of sunlight in the Sahara desert (an extremely dry environment), plus unfiltered radiation in the ultraviolet spectrum will make the sensation even hotter and the dangers of sunburn far more immediately dangerous. In fact, the primary heat-related issue that had to be addressed for astronaut suits wasn't just keeping them warm in the coldness of space, but keeping them cool in the heat of the unfiltered sun. This applies to things like the space station and probes as well. Their electronics and processes create heat, which sometimes cannot be radiated out into the vacuum of space faster than the heat is being generated. This is referred to as "waste heat" (it applies to normal machinery here on Earth as well, but it's bigger problem in space due to the heat conduction issue) and is another consideration in designing vehicles, machinery, and electronics in space.
First off, i'd like to say that i really love your videos. I'm always interested in seeing and comparing techniques for teaching people non-intuitive physics and math concepts. Great Ghu knows this world needs so much more of decent instructors. Specifically here, though, I sort of wonder - conduct *enough* of these random interviews here, and *eventually* you're going to run into somebody who responds with something like "Hmm, well, as soon as I actually *grab* the book and hard drive case, I substantially change the surface boundary conditions that you have to solve the Laplace Equation (or , oh crap, I've got blood flow, and can sink heat, so maybe that's not good enough and we need Poisson's) for, and most likely, the different heat conduction properties of the two also implies that *at the point my finger sensors are measuring*, the temperature of the two objects really is different. Lets look at them with a FLIR camera after I let go!". When you eventually run into that person, will you find a way to edit them into your video? :-)
i tell this to my mom and she doesn't trust me...i also have to keep insisting with her that letting a fan run inside a room won't make the room cooler, if anything it'll make it hotter. I guess i'll have to end up buying an infrared thermometer to actually prove these facts to her
+mos ab A fan will make the room cooler if it's pulling air from a cooler place into a warmer place. Insulated houses can retain heat faster than the outdoors, so running a fan can pull air from the cool night air into the still-warm house.
Depends, if it is just a fan alone it will make you hotter since it is blowing hot air to your face at a faster rate and is direct, but if the interior of the fan is designed to cool hotter air to cooler ones, it should cool you down.
They probably didn't have the opportunity to study thermodynamics. in quiet a lot of countries thermodynamics isn't taught until college, so if your major doesn't involve science you'll probably never learn smthg such as "thermoconductivity" and so can't answer his questions accurately. Point of my comment is: don't mock people :)
Nah, it's other people being ignorant and not paying attention or remembering their science lessons from when they were at school. Mums specialise in making tasty cake; schoolkids specialise in remembering thermodynamics... :D
Hey Derek, the cake and the tin are NOT the same temperature, for an entirely different reason than what you're demonstrating. The cake has water in it, so it can't heat above 100℃. All the water would have to turn into steam first. The surface can be slightly hotter because it's dry, but the close contact with the inside still keeps it around that point. Metal cookware has no such limitations. The reason your readings were so close is because you measured the surface of the cake and a part of the tin that was in direct contact with - and therefore cooled by - the cake. Had you measured the inside of the cake with a Thermapen for example, it would've been below or at 100℃. More importantly, measuring a part of the tin that's not in contact with the cake, such as a handle, could possibly have resulted in a much higher reading, up to the oven's set temperature. I respect your work tremendously and learned a lot from your videos, but I don't think this particular demonstration proves your point very well!
haha out of all the smart asses here Adam you're the only one that got it right, I've looked at dozens of comments and they pretty much consist of people calling the ladies idiots and "humanity is doomed" when in fact the inside of an unburnt cake is indeed significantly cooler than the metal surrounding it.
I think you could teach us a lot abut being patient, which is one of the most important aspects of socializing, which is one of the most important aspects of being a human.
The “I’ll take your word for it” lady is the reason I can’t be bothered to discuss/debate with most people. So many seem stubbornly ignorant yet arrogant.
Another nice demonstration of thermal conductivity affecting the perception of heat is if you heat a wet wooden spatula in the microwave. It feels hot to the touch when it comes out, but after 5 seconds or so, it'll only feel warm immediately after being touched, but keep the grip on and the perceived temperature ramps up
Two problems with using an Infrared thermometer, you are measuring the steam coming off the surface of the cake, and the difference in reflectivity between the cake and the metal pan affects the emissivity of Infrared waves.
My favourite part of the video was 5:07 when the lady finds the physics interesting and says she learned something. Proves exactly the point Derek made about learning when people criticise his intention of "making people look stupid" for his own ego.
Yes, but the human brain is more interested in th amount of heat exchanged between body and the environment. It isn't interested about the temperature.
this is good comedy material. but to be fair i was confused by this same phoenomenon before i was properly introduced to the concept of heat transfer in...i don't remember which grade.
true statement and i didnt know our skin didn't feel the temperature when it was the nerves or something but well if you put a paper in the frezzer its going to get cold it was just so obvious i couldnt not laugh
Alex Wong I suspect the huge amount of force delivered to the face from the palm of the hand was so great, it pushed the whole head backwards, breaking the neck that the head was attached to.
I would love to see you revisit this subject, but introduce a space shuttle thermal protection tile into the mix. It would make for an interesting video.
Actually, the metal feels colder because, upon touching it, it IS colder. The instant you touch the paper, the paper you are touching becomes the temperature of your hand. This is because the other paper in the area is bad at conduction. So what you are feeling is NOT the apparent temperature, you are feeling the actual temperature, only not of the object as a whole, but of an extremely localized area. It's like a skin effect on the paper. Only one layer will heat up to your hand's temperature.
Correct: the metal conducts the heat from your hand quickly The paper insulates and allows the heat of your hand to be collected at the surface OR in other words REFLECTS the energy of your skin temperature.
Harold Geodesic Mhmm... I'm not sure anything is being 'reflected'. I would say that, because the paper is a poor conductor, not very much is happening in terms of energy transfer. And, because not very much happening, you do not perceive much change in your finger tip - bearing in mind that you are only directly sensing the warmth of your own tissues.
Hey Derek, could we please have a video about the working of that infrared thermometer? Its kinda cool how it measures the temperature without any contact. Thanks!
Pfft, he knew that meat thermometer wasn't going to work from the start. He just wanted an excuse to eat two cakes.
aviation_nut what if I told you... the cake is a LIE!!
100th like
Jonatha De Sousa I'd say you like Portal, and GLADoS!
sure he did...
munchies
“I’ll take your word for it.” She was fed up with that interview and just wanted to move on 😂
Hahaha yeh. I totally get what Veritasium is getting at with these misconceptions. But I think most people don’t care at all, they are perfectly happy to hold false or contradictory beliefs.
She's made a fool of herself and wanted it to end.
@@Pingwinho she isn’t a fool, she just doesn’t know much of the physics, ignorance does not make someone a fool.
@@AvenFurness it's an idiom.
@@AvenFurness Fools are fools because of their ignorance.
"Paper doesn't absorb cold"
I paused then just to see if someone else found it incredibly stupid
same
Alex Edwards lol
epic
Ok it absorbs liquid nitrogen
This guy has an insane amount of patience.
not patience, respectfulness.
apart from in that first bunjee jump vid.
it is so funny to see these people answer these questions like he is the stupid person in the conversation
we all to think we are the ones that know a logical enough answer better than the person in front of us... its hard to remember different logical reasons to things that we already think we know and understand and this happened to me recently in physics and i confused the crap out of myself until i asked the teacher to explain again but still i knew i didn't completely understand.
Stupid people are typically more prone to judgement. It's harder to accept new viewpoints if you don't even fully understand the opinions that have been impressed upon you by others. Once you internalize something you don't understand as a universal truth you're in effect giving up on your humanity. It's why religion has been such a smash hit for so long.
I really like your statement. A lot of people won't even fully understand what you just meant. In a way, this video is more about this statement above than whether someone believes or understands that the temperatures of the cake and the tin are actually the same. Heck, the lady at 1:31 argues that: "...the metal holds the heat longer and holds the cold longer...". The very opposite logic of this is the reason your hand gets burned - when you touch the tin the heat transfers very rapidly to your hand, and its also the reason the metal appears cold - the heat from your body transfers very rapidly to the metal object. These preconceived notions that "stupid people" typically have are arguably a result of a lack of knowledge or simply a willing to care. People are too busy with their lives to even consider an arguably shallow concept like this one. Just as their religion was injected into their life, whether it be from and early age or later in life, they simply knew it as others had told them. Why would they consider such a shallow concept such as: "God doesn't exist", when their bodies thought it real before their minds even understood, or could yet to understand?
I love the way his mom keeps smiling at him, she seems so proud
I think she has ever reason to be!
well. duh.
she's a good mum. is she australian?
@@stoneskull no
@@stoneskull south african
I think people can't distinguish phrase "it's cold" from "it feels cold".
+Danon W I think of hot and cold and warm, that kind of stuff as a perception.
+Danon W there is no such thing as hot or cold in the first place
@@viyusavery248 and there are no humans, trees or cars, its all just atoms
Because our built in sensor system only registers temperature change of the sensor (nerve ending), so our body can´t distinguish heat flow from temperature.
@@paavobergmann4920 oi oi oi, mr. escobar your delivery is awaiting you in the basement.
yeah, only temperature change. i think that's the reason why sometimes when i want to wash my hands in the winter it never feels like there is cold water coming out of the tap when my hands are cold... if i then drink it i know that it is indeed, cold
paper doesn't absorb cold... it all makes sense now
+SkizzlePiano Thats what i thought
+jamiepie123 i dont know if you can tell +SkizzlePiano is sarcastic but theres no such thing as absorbing cold
+Jose Ting I Know i was just going with the joke
+SkizzlePiano It's technically not too far off. If by "not absorbing cold" you meant "a worse conductor of heat", the statements are quite similar.
+LimitedWard one just sounds really stupid and the other does not
Why did the algo dump me here in 2024
I mean... I've been subscribed to Veri. for maaany years. But I haven't watched this before either.
Lol I've also been subscribed for many years. However, I've seen this video before. YT has been suggesting lots of vids lately that are 5+ yo and acting like I've never seen them 😂
Facts
0:53 When she said paper doesn't absorb cold I literally smacked my forhead.
It's not that much of a stupid thing to say, paper is a good insulator and metal isn't.
Hahaha wtf?
Matthew Smith She also says that "metal holds the cold longer" which makes zero sense.
Skyfire Did you knock yourself out cold?
Matthew Smith it is a VERY stupid thing to say....its the exact opposite of what actually happens. paper doesnt absorb HEAT as well as metal and doesnt release it as well...as well.
the only time I bake a cake is when I want to prove a point too! the point being that cake is delicious.
I don't believe you. You're going to have to prove it to me. (chocolate please).
hi
"paper doesn't absorb cold"
I literally slammed my head on the desk
Niels Rasmussen nothing...NOTHING absorbs cold...think of it like this...cold doesnt exists (the opposite of energy doesnt exist). only energy exists and we use the term "cold" to explain that something has little thermal energy when compared to another thing
alex sun I know! It bothers me too!!
***** Well, not exactly. You can't have an absence of energy, it's literally impossible. Cold is when something has less energy than what it has at the moment.
I love you
my reaction to "jet fuel can't melt steel beams"
Thermodynamics: *exist*
Some person: "paper doesnt absorb cold"
Thermodynamics: geuss im just a joke
The other big misconception is that a fan will reduce the temperature of a room. I've seen people put a fan in a hot room, close the room and wait for it to cool down.
lol. True.
it does not reduce the temperature of the room but it does feel cooler for the same reason described here.
when air is stationary its takes less heat off your body as the heat has to propagate through the air merely on the airs natural movement, but when then air is circulating due to a fan blowing it around more air is passing over your body and the new air has yet to absorb heat from you so it can absorb at a higher rate and as that heat blows around the room it distributes that heat all over and allows it to propagate into the walls, ceiling and floor much better due to a larger surface area to work with.
so yea it does not cool the room down but it does cool you down.
_though admittedly I don't think I did a very good job explaining it here._
Tenshi Strife I think he means an empty room, as in nobody in it.
right, but it would still cool the room, slightly, as moving air redistributes and disperses the heat better.
In a perfectly sealed and insulated system, yes the heat would remain constant, maybe even increase with the fan generating heat due to motion, but a room is not a sealed system.
This kinda ties into another common misconception that at all times all the air in a room is the same temperature, which is not true, there are pockets of hotter air and pockets of cooler air. and the heat wants to go into the cooler areas, such as the cooler pockets of air or the walls or out a window or whatever, but with stagnant air it has to travel through to adjacent air and repeat to get to the cooler locations, by moving the air it can travel more freely.
as this hotter air passes cooler locations it bleeds off a bit of that heat, and cools down, then it gets back to the hotter section and heats back up cooling the hotter section of the room, it keeps cycling like this, making the temperature more unified and also bleeding some of the heat out of the room. so it would in fact probably lower the ambient temperature of the room, not as significantly as it would with say AC but a noticeable few degrees.
kinda long winded I know.
Tenshi Strife I say it would heat it up by using the principle.
Presumption is that outside is hotter than the inside of the room, otherwise why close it when you could just open the windows and let the cooler air in.
:)
"long winded" - air circulation pun?
i studied a lot of physics in high school but all of it didnt make full sense to me. So many things happened during that time that it was overwhelming and i didnt have enough time to think about all that i studied other than learning them to pass numerous tests. Now in uni i started questioning stuffs again and kept googling and learning and came across ur videos. TBH we are lucky that u have made all these type of videos and im so thankful. Ur videos feed my curiosity more and more and i want to read and understand all about such amazing concepts.
Agreed, the real word experiments really question our education of physics
3:17 I love how your mother looks at you feeling very proud, even though you've just started your TH-cam career. Can't imagine how happy and proud she feels now.
Is it bad that I laughed when she said metal absorbs cold?
Absolutely normal
For me it's like when someone says: "If you stick an umbrella up your anus and open and close it 10 times it'll cure your cancer." so no laugh as much as you want.
Titan Csokona people attribute properties to what they percieve and sense. If they feel a wall with less absolute heat than their hand they will have the sensation of "cold", they could then apply this observation to how objects retain "hot" and "cold". You are watching these videos, and that means that you are part of a specific group of people who are interested in science and learn about it in their spare time. So to assume everyone has the same interests as you and that the only reason they dont know as much about thermal conductivity is because they are stupid is ridiculous. So no, basing how the world works based on observations is not the same as your stupid example.
I am sorry, and that was so good I literally shed a tear. (When I wrote it I had a really bad day)
@@canatronYT it's common knowledge mate. You are taught this in schools. If you don't know this basic stuff I'm sorry but you must be only be able to work in McDonald's at the age of 50
''And what if I told you these are the same temperature''
''No I don't *agree* with that''
lol
A very polite way to say that. This you got to count in her favor :P
Real question is: how good was the cake ?
That's a very good question.
Charlie Tango
D: THE CAKE IS A LIE
lol
+Vynyl Welsh maybe the mom was raised in Britain while he was raised in the mid-northern United States
Very good
That's a great example of how our perception can be deceptive, even if our senses are telling the complete truth. The problem isn't on the fingertips, it's in the brain. Our understanding of reality can't be perfect and should always be questioned.
But our understanding of reality is a primarily abstracted one. Since our senses *do* tell the truth it's quite often the case that our intuitions are correct, even if we don't understand them. A hot seatbelt buckle *will* burn you in the summer, whereas a nylon belt won't. Sitting on a metal seat in the winter will be significantly less pleasant than sitting on a polyester seat with foam in it. None of these are incorrect, which is frankly of infinitely more importance than an abstracted understanding.
@@RohannvanRensburg Senses and perception are obviously important, but they only get you so far. I would argue that understanding exactly why things feel hotter, and how material physics actually work on a molecular level and how heat transfer works is infinitely more important because without it we would not be able to design and build any of the modern technology that we use today in society.
Just like when you reach for your seat belt in 100 degree weather and the metal buckle burns you but the nylon belt doesn't.
its caust the belt doesnt absorb the cold
Or the cheese on pizza burns the top of your mouth and the crust doesn't.
Jonathan Lowe that's because the crust is on the bottom sort burns ur tung. Der 😁
Chris aka Schulbus nice
100 degrees????? No where on earth is that temperature. Highest was like 56??
I remember taking my first physics class in high school and learning about heat transfer, conductivity of heat through various media, many of things he touches on here. Had I not ever been exposed to that knowledge, I would be as confused about it as any of these folks.
yeah and im doing this in grade for XD
3:14
"but i could be wrong"
yeah right..
Exactly, it's what those people couldn't even consider saying, so annoying tbh
He just wanted cake ;)
value of pie 3.14......................................
Lost it when she said "Paper doesn't absorb cold."
Hello
You meant to tell me this whole time I could have been insulating my thermos with paper in order for it never to get warm!
Who else was shouting "THE METAL CONDUCTS HEAT BETTER!!!!!"?
+PineapplePenguin55
me
+PineapplePenguin55 Calm down minecraft boy
+PineapplePenguin55 Anyone who actually did went to school, I guess.
+jur4x but apparently you did not went to grammar class. :P
PenguinCoalition yep.... The the stupidity of people hurts my head everyday.
Sadly they outnumber the smart people and they're still allowed to vote 😏🔫
Great question. Just wanted to know your thoughts on why sweating wouldn't work in the humid environment.
Air can only hold so much moisture content in a vaporized form. If it's at 100% saturation, then your sweat cannot evaporate, and thus can't help cool you off. If the vapor content goes above 100% it recondenses, which is why you get rain when the air is "too full of water vapor".
@@LtFoodstamp I like that explanation. Makes sense.
Sweat is used to transfer heat(evaporate) humidity slows down heat transfer. Takes more btu for change of state (laten heat) in a high water colum
I remember when I first learned about specific heat and how I was blown away when you think about how metal object and a wooden object of the same temperature feel different temperatures. It was so mind boggling because of the incorrect way we define "temperature."
Your channel is at the present time the most interresting channel I know on TH-cam. Thank you for your work !
You should check out Vsause He does stuff like this too. Very interesting :)
justplainskill he's more of a theory then experiment guy
Still interesting enough
"Paper doesn't absorb cold. "
ROFL xDD
@Fergussonification haha - yes I thought about a thermocouple, and you may well be right about the emissivity - but I'm not sure this was the main source of uncertainty. I noticed a lot of variability in temperature around the cake, plus the temperature dropped remarkably quickly. The pan was down to 40C in under a minute.
"Nah, I don't agree with that" LOL
A lot of smartasses in here. Thermodynamics isn't intuitive fellas. To fully understand this video you need to know about:
1. The definition of heat and the nonsense of "cold"
2. The definition of temperature
3. Zeroth law of thermodynamics : A being the metal, B the book and C the air...
4. Thermal comfort, which in turn requires some human biology, the first law of thermodynamics, psychrometrics, statistics, and heat transfer. (maybe I forgot something)
Not easy.
So please don't mock people and rather try to educate them with the knowledge you've got. Everyone is ignorant about many things, that isn't bad per se, being comfortable with ignorance is bad. The peope in this video showed willingness to learn something new, so what's wrong with that?
+carlos k absolutly nothing.
+carlos k stuff yourself
His methodology is that he starts with the misconceptions because then the person listening has to actively think about it and not just use old, often inaccurate, information. He wrote his PhD on this. Please type his name and ted ed in on TH-cam and you'll be able to see why he does it this way.
+mbk3986 I wasn't criticizing him, I get what he's doing. But take a look to the other comments, for a lot a "geniuses" the answer was quite obvious... I don't believe them.
+Harrison C ¿?
Same thing is when you have cold hands and you wash your hands in warm water, you feel it like it's hot. But when you have hot hands you might feel that warm water is colder. :)
can u guys stop calling those people dumb... I know some of the answers were stupid but they are just people who are not into science... the fact that u r watching this video is because u like science.
This is great! Standing in a 10°C room is no problem. Standing in a 10°C pool causes me to swear. Water conducts heat better than air :P
+Obleddo yep, water is often warmer and air conducts less heat so thats why if youre wet and stand up you get the cold properties of both then the water conducts heat/cold from the air and shares with you
Water has a higher heat capacity.
@@ch3z231 What does the hability to conduct heat faster from an object to another relate to heat capacity? The former is termal conductivity (what's the vid about) and the latter is the capacity to absorb a certain energy to change the temperature 1°. Those the definitions, but is there a relation between them? I just ask for curiosity since you mentioned heat capacity.
No it is bcs water takes more heat to raise its temperature thus causing extra loss of heat from your body
You sweat from 10 degree water? You must be an eskimo.
I recall first learning this concept decades ago from a book that explained why on a cold morning, bare feet on a bedroom carpet do not feel near as cold as bare feet on a tile bathroom floor. Both are in the same house, so they must be the same temperature, but one feels cold while the other does not. Thermal conductivity is the answer.
this is great, but a good part of the explanation around this is to mention that the human body is hotter than room temperature (due to the general chemical processes occurring within your body creating a lot of friction and heat within it.
This means there is a difference in temperature between you and the book / you and the dvd player. Since the dvd player has a [higher?] heat capacity, it 'accepts' more of your heat, causing your hand to cool down faster.
Other than missing this point, this video is spot on. [when you're 12 years late to appreciate a good video on time lol]
"paper doesn't absorb cold"
I literally jumped out of my 3 story apartment window and slammed onto the sidewalk head first.
0:52-0:54 Facepalmed so hard I needed a moment to recover.
It’s so funny how Derek suddenly gets his Australian accent back when he’s with his mum.
"What if I told you they were the same temperature?"
"I'll take your word for it"
"Paper doesn't absorb cold" I'm starting to question the sanity of the general public
@elmepo232 the performance mic was a new purchase on my North American trip - I will be using it in interviews from now on. I should add that the purchase was inspired by comments like this one.
Do you ever interview people that actually know what you are talking about and you just have to edit them out?
His point is to show the basic misconceptions, so he has to show the people who got it wrong
Zane Crabtree I think 50% of the people he interviews nail it, but if he shows them too then the whole video becomes pointless
Well obviously some people will get it, but I'm sure the vast majority of Adults and elderly won't
Ik
His own mother didn’t get it either
3:28 I hate my mind 😂
I also hate your mind lmao
1:42 Derek's reaction is priceless 🤩🤩
I want a t-shirt that just says "Absorb the cold"
The Australian accent has really changed a lot in 10 years.
i know it has been 8 years but if somehow you read this i wanted to thank you because this was a question on my physics exam and i would've never guessed it without you
That infrared thermometer gun could be used for the best pick-up schemes..
(Enter attractive female)
*Slightly tilts sunglasses and wields infrared thermometer gun. Aims at female and checks the reading* "Yep, she'll do"
My gun says you're hot.
The feeling that you get when you know the answer before this genius guy tells it... Oh man, so satisfying.
Better than taking an A on a math test.
+Yosyp Ha what a nerd.
+Yosyp ik :D i love basic physics
Soooo satisfying.
What you just described is 12 year old me - only that this video didn't exist back then and I never felt that joy...
I learnt something as well, I knew metal was a heat conductor, but never thought those two objects would be at the same temperature. Thanks Derek.
Great video! I recently came across with your channel, and I really enjoy your approach on science topics. I still remember how hard and mindblowing it was to me to come up with a tangible idea of heat. In fact, we usually end up thinking about heat as "something" that flows from hot surfaces to colder ones, implicating a temperature variation. It was even more incredible when I learnt that it is actually possible for heat processes to occur at CONSTANT temperature... heat is weird stuff LOL.
1:32 She got that entirely backwards. Metal transfers heat better than almost any other substance which means it doesn't hold heat well at all.
THE IGNORANCE... IT BUUURRRNS!!!
Cold burns >:3
+Lord Geezmo Clearly it's warmer than a book.
........................................................
feel the Bern.
"Freezer Burn" ?
I was preparing some coffee and it made me think about heat transfer. I immediately remembered this metal vs book analogy and came to look for this video. Just a classic and simple explanation! But didnt remember that Derek's mom was in it. They both look so sweet together. Cant believe that was 12y ago.
WOW the red rag hanging on the oven at 2:02 is so relatable. I've got the exact same hanging on mine as I'm sure everyone else does as well haha. Nice!
It is a very 'cool' demo. lay(wo)men or for that matter anybody has a misunderstood idea on temperature. Thermal equilibrium is not a well understood concept by all. Measuring the temperature of cake and container is very illustrative. My appreciation for Vertasium scientific invention.
Wait a second, the one in the red jacket is the one from the Shadow Illusion video!
On the same day!
The idea of making a physics video about misconceptions is brilliant.
Amazing to see how far Derek has come (I mean the science is just as interesting but I mean in terms of video quality etc.)
It's surprising that many people have forgotten that metal is a great conductor of temperature, that's why metal feels hotter because it conducts heat very well.
yah i think there is a lot of confusion between temperature and heat. metal is a great conductor of heat not temperature. that why those guys probably assumed that the temperature would be different because they assumed heat and temperature are the same thing.
Incidentally, this is why outer space doesn't actually feel that cold. Since it is a vacuum, it can't conduct heat from your body. You will still lose heat through radiation, but it is a much slower process for our bodies. So the actual sensation of the 'temperature' of space would be quite pleasant when the sun is eclipsed behind the Earth (of course, the sensation of having all of the gases in your bodies forcibly expelled from all of your orifices at once and then blacking out from shock and asphyxiation will be decidedly less pleasant). If you were to somehow remain conscious but exposed to the vacuum of space, it would over time start to feel quite cold as you lose more and more heat. But it's far from the 'instafreeze' environment it's depicted in various media.
But speaking of the sun, this is where it really starts to defy expectation. In space, you face the full, unfiltered radiation of the sun. The sensation of the sunlight without any cooler ambient temperature would feel akin to the sensation of sunlight in the Sahara desert (an extremely dry environment), plus unfiltered radiation in the ultraviolet spectrum will make the sensation even hotter and the dangers of sunburn far more immediately dangerous. In fact, the primary heat-related issue that had to be addressed for astronaut suits wasn't just keeping them warm in the coldness of space, but keeping them cool in the heat of the unfiltered sun.
This applies to things like the space station and probes as well. Their electronics and processes create heat, which sometimes cannot be radiated out into the vacuum of space faster than the heat is being generated. This is referred to as "waste heat" (it applies to normal machinery here on Earth as well, but it's bigger problem in space due to the heat conduction issue) and is another consideration in designing vehicles, machinery, and electronics in space.
I really love and appreciate such eye-opening videos.
First off, i'd like to say that i really love your videos. I'm always interested in seeing and comparing techniques for teaching people non-intuitive physics and math concepts. Great Ghu knows this world needs so much more of decent instructors. Specifically here, though, I sort of wonder - conduct *enough* of these random interviews here, and *eventually* you're going to run into somebody who responds with something like "Hmm, well, as soon as I actually *grab* the book and hard drive case, I substantially change the surface boundary conditions that you have to solve the Laplace Equation (or , oh crap, I've got blood flow, and can sink heat, so maybe that's not good enough and we need Poisson's) for, and most likely, the different heat conduction properties of the two also implies that *at the point my finger sensors are measuring*, the temperature of the two objects really is different. Lets look at them with a FLIR camera after I let go!". When you eventually run into that person, will you find a way to edit them into your video? :-)
i tell this to my mom and she doesn't trust me...i also have to keep insisting with her that letting a fan run inside a room won't make the room cooler, if anything it'll make it hotter. I guess i'll have to end up buying an infrared thermometer to actually prove these facts to her
but, wind chill.
+mos ab A fan will make the room cooler if it's pulling air from a cooler place into a warmer place. Insulated houses can retain heat faster than the outdoors, so running a fan can pull air from the cool night air into the still-warm house.
Nudedragon you are just being a schmuck and you know it
Depends, if it is just a fan alone it will make you hotter since it is blowing hot air to your face at a faster rate and is direct, but if the interior of the fan is designed to cool hotter air to cooler ones, it should cool you down.
5 seconds in:
"I thought I understood science, but I am utterly lost."
6 seconds in:
"Ah... Heat conduction... Freaking Veritasium man."
My life. ._.
It's cool that Derek has gone back to making classic science videos instead of trying to chase clout in the style of Mark Rober and Mr Beast
I will say that when I first grasped this concept my sophomore year of high school, it changed my outlook on life almost as much as calculus did.
Wow, some people... I am speechless!
Yup, "Paper doesn't absorb cold!" I bet they thought they were smart, because they said a "sciencey" word like "absorb". -_-
They probably didn't have the opportunity to study thermodynamics. in quiet a lot of countries thermodynamics isn't taught until college, so if your major doesn't involve science you'll probably never learn smthg such as "thermoconductivity" and so can't answer his questions accurately.
Point of my comment is: don't mock people :)
Laurelindo It's not so much the lack of knowledge, it is more the general stupidity. Like laughing at a dog that runs into a lamppost.
Max Lindner I know about thermodynamics. I am just 13 and have known about thermodynamics for years but I am a nerd.
Nah, it's other people being ignorant and not paying attention or remembering their science lessons from when they were at school. Mums specialise in making tasty cake; schoolkids specialise in remembering thermodynamics... :D
Hey Derek, the cake and the tin are NOT the same temperature, for an entirely different reason than what you're demonstrating. The cake has water in it, so it can't heat above 100℃. All the water would have to turn into steam first. The surface can be slightly hotter because it's dry, but the close contact with the inside still keeps it around that point. Metal cookware has no such limitations. The reason your readings were so close is because you measured the surface of the cake and a part of the tin that was in direct contact with - and therefore cooled by - the cake. Had you measured the inside of the cake with a Thermapen for example, it would've been below or at 100℃. More importantly, measuring a part of the tin that's not in contact with the cake, such as a handle, could possibly have resulted in a much higher reading, up to the oven's set temperature. I respect your work tremendously and learned a lot from your videos, but I don't think this particular demonstration proves your point very well!
I think people would be touching the surface of the cake, though, and base their estimate of its temperature on that.
Adam Hosman btw the water would of turned to steam by the time that the cake finished baking
haha out of all the smart asses here Adam you're the only one that got it right, I've looked at dozens of comments and they pretty much consist of people calling the ladies idiots and "humanity is doomed" when in fact the inside of an unburnt cake is indeed significantly cooler than the metal surrounding it.
I think you could teach us a lot abut being patient, which is one of the most important aspects of socializing, which is one of the most important aspects of being a human.
Everyone’s heard of “gotcha journalism”, but this is “gotcha science education”
Mind blown
Didn't realize people still think cold exists.
Isnt it like there is no such thing as cold only absence of heat?
The “I’ll take your word for it” lady is the reason I can’t be bothered to discuss/debate with most people. So many seem stubbornly ignorant yet arrogant.
Another nice demonstration of thermal conductivity affecting the perception of heat is if you heat a wet wooden spatula in the microwave. It feels hot to the touch when it comes out, but after 5 seconds or so, it'll only feel warm immediately after being touched, but keep the grip on and the perceived temperature ramps up
2:40 oh boy these have become so common
when that woman said that "paper doesn't absorb cold" I don't know how he didn't burst out laughing XD
Two problems with using an Infrared thermometer, you are measuring the steam coming off the surface of the cake, and the difference in reflectivity between the cake and the metal pan affects the emissivity of Infrared waves.
My favourite part of the video was 5:07 when the lady finds the physics interesting and says she learned something. Proves exactly the point Derek made about learning when people criticise his intention of "making people look stupid" for his own ego.
New favorite channel.
Yes, but the human brain is more interested in th amount of heat exchanged between body and the environment. It isn't interested about the temperature.
Bro you came soooooo far since then...
I love this video. Well done. They feel like different temperatures but are in testing the same!
this is good comedy material.
but to be fair i was confused by this same phoenomenon before i was properly introduced to the concept of heat transfer in...i don't remember which grade.
In Germany that would be somewhere around year 6 to 8. Does this compare to wherever you are?
i laughed so hard for 3 mins when she said paper does not absorb cold
true statement and i didnt know our skin didn't feel the temperature when it was the nerves or something but well if you put a paper in the frezzer its going to get cold it was just so obvious i couldnt not laugh
Even I didn't know anything like stuffs that heat travels rather than cold. Moreover, I never used to think these kind of things. ;)
@@KartikayKaul Plot Twist: There is no cold! Only heat.
Ruthless. Even sets up his own mother for that wicked burn.
"I'm right, you're wrong. You gotta bake me another cake now."
How to get your teacher mad: 0:53 the law of thermodynamics: paper does not absorb cold.
Paper doesn't absorb cold? LOLWHAT?
I facepalmed so hard that i broke my neck
I thought you would break your face, not your neck.
Alex Wong But your face is much stronger than your neck.
Alex Wong I suspect the huge amount of force delivered to the face from the palm of the hand was so great, it pushed the whole head backwards, breaking the neck that the head was attached to.
K
I think I'm impressed with your patience more than the fact that you make these fun and watchable videos.
I would love to see you revisit this subject, but introduce a space shuttle thermal protection tile into the mix. It would make for an interesting video.
those people actually helped us to learn something so stop insultig them
Actually, the metal feels colder because, upon touching it, it IS colder. The instant you touch the paper, the paper you are touching becomes the temperature of your hand. This is because the other paper in the area is bad at conduction. So what you are feeling is NOT the apparent temperature, you are feeling the actual temperature, only not of the object as a whole, but of an extremely localized area. It's like a skin effect on the paper. Only one layer will heat up to your hand's temperature.
Correct:
the metal conducts the heat from your hand quickly
The paper insulates and allows the heat of your hand to be collected at the surface OR in other words REFLECTS the energy of your skin temperature.
Harold Geodesic
Mhmm... I'm not sure anything is being 'reflected'. I would say that, because the paper is a poor conductor, not very much is happening in terms of energy transfer. And, because not very much happening, you do not perceive much change in your finger tip - bearing in mind that you are only directly sensing the warmth of your own tissues.
Exactly.
You pretty much said the same thing as he did, just in a different way.
Wtf, drowning in pseudoscience here
When the lady is so confident with her answer i laughed hahaha
It's not the heat that gets you, it's the humidity.
People really don't know any science. Its boggling.
Am I the only one who thought when Derek said Master Baker but thought MastorBater?P.S. I have problems
+Peter Black Had to scroll way to far for this ^
You're not.
Hey Derek, could we please have a video about the working of that infrared thermometer? Its kinda cool how it measures the temperature without any contact.
Thanks!
Love your videos, watching them all and definitely subscribed.