Fun fact for anyone revisiting this gem: Thermal conductivity also directly relates to Electrical conductivity. This means that things that are good at transferring electricity also conduct heat a lot better (usually metals), and why insulating materials both feel warmer and usually are used for electrical insulation (i.e. plastics or rubber). There are however some outliers and exceptions, like for example: Mica is a good conductor of heat but a bad conductor of electricity. It means mica has a very capable dielectric function, making it ideally suited for applications that require an effective heat conductor and electric insulator. There are a few good electrical insulators that conduct heat (e.g. mica, diamond, water, oil, wax, glass, ceramics) but the opposite is rare. It’s unlikely (apart from superconductors) since in many materials the electrons that conduct electricity also conduct heat. For metals, the thermal and electrical conductivity are related (by the Wiedemann-Franz Law). Berkeley scientists have discovered that electrons in vanadium dioxide can conduct electricity without conducting heat, an exotic property in an unconventional material. The characteristic could lead to applications in thermoelectrics and window coatings. Hope whoever comes across this, enjoys reading it!
Could Vanadium Oxide be applied in cabling for Quantum Computers? Quantum Computers are cooled in several "stages", which need to be thermally insulated from each other. Less thermal conductivity in these cables would help a lot.
@Soheil-ev6ls sounds like a good idea, im pretty sure it is doable. It would quite indeed have a positive impact on the cooling rate. How big obviously would depend on a lot of other factors like cable size, density, diameter, etc.
I did enjoy, thank you. Side note, I'd always assumed diamond was a good electrical conductor, considering most forms of pure carbon are. Interesting that this isn't the case.
Does that mean thermal conductivity is measured by free electrons? Not sure if remember correctly, but I think conductivity has to do with free electrons.
Two normalies next to me was lost watching this... I explained it as thermal exchange between the two things...think they were like the woman who said I believe you...
I was sitting the whole time wondering where he found adults who doesnt know about thermal conductivity, or at the very least, know that while metals feel colder they actually aren't (somehow even the ppl that said metals usually feel colder said they thought the harddrive _was in fact colder_ :o). I expected at least some to rather than being entirely out in the left field, throw out the explanation usually given to kids when they ask why metals/stone feel colder than wood: "because they suck heat right out of your body!" It would also be wrong, but it is nevertheless the explanation most ppl grow up with until either school or 5 minutes of thought about the subject corrects it.
@@feha92 Now i know that is true but many people still don't have/had any interest in knowing it so we can't blame them . It seems hard to believe but that is exactly how i feel too when i tell someone of the very basics of coding or general aptitude (like how can someone not know what an array is). Meh i used to be surprised but then there's a lot of stuff i don't know either , very basic stuff for someone like chemical composition of dust or how to repair an engine or how to smith a simple knife from metal. But yea, someone dum if they dont know how to know something, in my case google.
These videos make me realize how fortunate we are to have access to so much knowledge inapplicable to our daily lives. I knew why but only because I love physics and have watched so many science related videos. Its only within the last 20 yrs that we've been able to access so much content on anything our minds question.
@@brendankohler1000Yes, because it’s gotten to the point where (lots of people on average) expect information to be so readily available for them in small packaged doses, that they don’t go out and find out more about it, and they just take whatever is easiest for them to digest. Influenced by short form content like you said. The other day I was in class and someone said “where’s the little text telling me the answer” 😬 Even though there were multiple different sources of information on their screen, they were used to the summarised version telling them the easy answer. And I think it’s just gonna get worse until it (might) get better… something would have to change..
i think thermal conductivity was taught to us in higher-primary school (when we were between 11-14 years old) in Hungary what's amazing is how other countries can get away with having so many basic-science-illiterate ppl
@@obonyxiam it is a testament to Veritassium dude’s abilities. Surely without online platforms, he would have still been a film maker. Video production was a different beast prior to the modern web.
this is so mind blowing to me! I love itt, I like Derek way of pulling out the curiosity out of people before explaining the true concept of temperature . it just make me understand and remember the concept a LOT better
Well, at least it's a thought process. It's going in a wrong direction, but if he'd continue to follow that path, he'd notice it's wrong and search for another explanation. I prefer that to simply standing there flabbergasted thinking you've witnessed some sort of magic and not wasting a thought at all.
Yet, fields of science like anatomy were pioneered by artists to improve their art, meanwhile, Einstein developed his theory of gravity based on a daydream he had. The interconnectedness of intellectuals and creatives is great, and everyone goes on about how an unintelligent artist cannot make valid art, but we don't talk often enough about how an uncreative scientist cannot do valid science. It's how we end up pigeon holed into conclusions about things we clearly dont understand yet.
This was neat to discover when I did some time ago. A topic about metal railings etc. I've also concluded that we're much more sensitive to temperature changes than we think. A change of merely a few degrees directly on the nerve endings can feel incredibly chilly or warm, but those endings don't actually feel the temperature of the object unless it's like aluminum or water etc because we're still feeling mostly our own temperature plus a fraction of the difference due to lack of thermal conductivity.
Are you a Bangladeshi? It is really hot here, and somehow TH-cam algorithm understand it (though I have never searched a video about temperature), and bring the video to my feed.
the guy in the beanie is mvp. "A hard drive is a lot colder than the book. I don't know, 'cause the books got more knowledge?" "I think science might be able to answer that. And I'm not a scientist!" "Could aluminium be bad for the environment?"
It sounds like a dumb question but I appreciate this guys willingness to engage his mind and draw conclusions. With some guidance this dude might actually learn something :)
@@jeremyphelps5140 Yeah you are right scientific questions seem dumb but experiments always have to do with conclusion and what went wrong in between that led to some other result, which makes us learn even more
Great video, physics concepts made easy to understand and/or to realize, ….. I think almost everyone that attended at least high school, knew the concept of thermal conductivity, but along the time, we forgot the application of those concepts in everyday life. You also made lots of videos that is understandable for most of us common people, even for the way more complicated astrophysics concepts like the blackhole images created from radio waves, the concept of speed of light etc …… thank you very much
Just watching this for the first time 11 years after it was made...been following his work for about 5 years now and this is probably my favorite video so far...even though the graphics suck
@@archi-mendel while I agree with you, I also think many people give nonsense answers or just make things up instead of admitting they don't know something. That was my point. You can't learn anything if you pretend that you already know everything.
"In a time where everyone knows it better than experts, this guy my hero. " This happened all the time troughout every period and will always happen until we alter our brain with something like neural implants. Its normal, we didn't evolve to "know" our perceptions trought sense are not reliable. Reason and the acknowledgement of the necesity of the scientific method is an extra effort that doesn't come naturally to 99.9% of the people.
He didn't undeniably prove his claim though. It still takes some amount of belief. Because someone can make something up, have it sound reasonable, and give fake evidence.
@@Borg8 Agreed, there are people out there that denies concrete facts. When they're presented with real evidence, they simply ignore them and go on with their delusions.
Flubadubdub The Great Most people's purpose in our society is to work and don't ask questions. Why would those things matter to them? It's how our society produces cheap work force.
Metalbirne Because those things do not matter to them, they get fooled into paying their tax money for dead-born projects, increasing the number of milllionairs and billionairs and enriching the existing ones. The dumber the people are, the better they can be fooled and ruled. As Julius Caesar said over 2000 years ago: "Give the people bread and games and they belong to you." It's still valid today - gladiator arenas then, sport and brainless internet entertainment now ...
In my high school physics class, my teacher did something similar. He told us to touch the metal bar of our desk and our textbook. He asked if one was colder than the other. After we answered, he asked us to think deeper. They've both been sitting in the room for a long time. We realized they both have to be at room temperature. He then explained that the metal conducts thermal energy better than the book, so we feel the energy leaving our body as cold.
On my first day of Physics class in high school, I blew up a paper clip by bending it in half and flicking it into an electrical outlet. There was a loud POP and a small mushroom cloud rising above me. I just sat there like I had no clue about what the hell just happened. That was a number of decades ago, nobody asked too many questions back then. (I call it "life before rules", you should have been there). Totally irrelevant, but just wanted to share the memory! I'm pretty sure the statute of limitations has expired!
I think it would be good to accept what the class says but emphasize where it comes from - write it down as the metal *feels* colder, which is correct and is a good stepping stone on the way.
@@mayorb3366 I connected bike lamp to 230V socket. When I was about 5, home alone. It went bang and scared the hell out of me. Now I`m surprised how it didn`t blow up. Cuz the bulb inside was made for 6V dinamo.
@@MEGAsporg12 Thermal conductivity is something everyone knows without realising they do know it. Kids know the concept maybe not the reasons behind it. Thermal conductivity is the reason why there are wooden spoons for cooking and so many cooking utensils in plastic. Even if there are metal utensils they usually have a plastic or a wooden handle. The reason you grab oven mittens to take something out of the oven is becuz you know they are heat insulators and will prevent you from burning your hand. You know about thermal conductivity since you are a kid, you just don't know the scientific name and it never really registered in your brain that you actually know it.
A good tip I always remember is if you're looking for a good conductor/insulator in a hurry, touch it and if it feels cold it's generally a good conductor, and if it's warm/room temp it's generally a good insulator. Metals are notorious for being good thermal conductors due to their metallic bonding, which is basically where you have a sea of electrons loosely bound to their atoms and can move freely (electron gas). This is one reason for such high electrical conductivity in metals, but also means those electrons carry kinetic energy or heat, and so since there are tons (1e20/cm^3 +) bouncing around at mean speeds of 1e6 m/s (just from electrostatic forces) you can imagine the heat transfer of those electrons is very significant. Wood is basically a polymer but has it's electrons more tightly bound with covalent bonding, resulting in a lower thermal conductivity. Another way of looking at it is metals have a low specific heat capacity (J/gK) which means the energy required to heat up 1 gram of metal one degree kelvin is much lower than in other materials. Metals feel cold to the touch since they are able to transfer the heat from your fingers much faster than other materials, ultimately to achieve some sort of equilibrium. But the case is reversed for something very cold like liquid nitrogen, where heat is being transferred into the LN at a faster rate than the wood. Tldr: metals are cool
Cool stuff. Yes, it is the heat conductivity - or heat flow. I really got a dose of this in my few years doing R&D. The plastic is a thermal/heat insulator, and so is the paper in the book. Metals tend to have over ten times the heat flow conducted. Real world: For one experiment, I was looking for the best insulator I could find for use in some tooling, to keep hot oil heat energy away from cooling water channels. I ended up with a strange plastic called Polybenzimidazole, used in rockets' nose cones and in firefighter clothing. It took two days in an electric furnace to get it up to 450°F. When I took it out, I knew intellectually that I could pick it up and not get burned. But I almost didn't test it. I was freaking out. When I did, I did not get burned. It STILL read 450°F. It felt room temperature to me. Years earlier, I worked for Ferro Corporation. I had a nice company brochure, and in it was a photo of a guy holding a SPACE SHUTTLE TILE in his bare hand, A glowing red hot space shuttle tile. Space shuttle tiles, their purpose is to NOT let heat flow into the metal of the shuttle. They do a great job of it. When they are knocked off, it ain't pretty. Temperature is NOT what burns you. It is the heat flow. The thermal conductivity. The heat energy cannot hurt you if it is not able to flow into your skin. Stopping the flow is stipping the burn. Polybenzimidazole, BTW, does not burn, and it does not melt.
Joe Alias but at the same time i feel good coz i worked that out kinda on my own, through background knowledge about thermal conduction and stuff but nobody ever telling me or asking the question
Joe Alias It probably is also frustrating to not know the answer, and watch this. The suspense kills you, doesn't it? I was perplexed to learn this for the first time, 15 years ago.
They both are at evened out outside temperature, but the harddrive will feel colder because its chassis is made out of some kind of metal that has a low heat capacity and as such the thermal conductivity is high, so the heat will transfer quickly. For example your warm hand will transfer heat onto the harddrive chassis quickly and since you're losing heat, it'll feel cold. Furthermore you can really mess with your head by having a freezing and very hot bowls of water and an object, sink your hands in the bowls and then touch the object that you know is at the same temperature as the room. It feels completely different in each hand. Our body just wasn't made for accurately assessing temperature, but proxies that are more important to our function than temperature itself. And this is why it was useful to finally get the thermodynamics class done in my engineering degree. One interesting question was related to sauna. What's the heat of the stove? What about the air? The wooden walls? The wooden bench? The nail on the bench? What if the bench was made of metal? How about if it's been only a little time versus a couple of hours? The temperature of each thing in the sauna in relation to their thermal conductivity and time was something really worthwhile to thinkg about. Another interesting thought experiment was geothermal heat. Like you'd think it was the fact that earth gets warmer the deeper you get, but the system is probably not even 100 metres deep in the ground so that makes practically no difference on the temperature of the ground. So does the heat come from the bottom? No, it comes from the sides of the bore hole.
Although it's nothing new for me I like the way he demonstrates and explains things. Those experiments were quite good to show what's happening and made the people think about it. That's what should be more done in schools.
During my exams, i know all these answers but in my day to day life i forgot these concepts and then comes you giving such a type of explaination which i never gonna forget 😵🧢💙
I wonder if he actually encountered anyone who knew the answer, except they were edited out for effect. Once you understand how it works, what seems counterintuitive at first now seems common sense. As such, I didn't realize that the questions he was asking would stump most ordinary people. I thought the answers were common sense.
I really hope he had to edit out several right answers. Very surprising to me that people actually thought the book was warmer and were surprised that it wasn't.
@@gameface6091 Yeah right! Like who havent handled aluminum and noticed it ''suckes'' heat right out of you while other stuff in the same room or temperature dont. Its the same thing with styrofoam but oposit. If you just hold it, you will feel your hands are getting hoter
He did a video a while back defending his use of this formula of asking people, having them answer wrong, then explaining the answer. I think it did a good job of realizing why people don’t like it and a bad job of justifying it in the face of alternative methods for presenting the dichotomy of common sense vs facts.
I pause these videos seconds before you explain, to have conversations with my girlfriend to see if we understand the physics behind these, Ive usually got a pretty good understanding so it's so much fun!
For most peolpe in the world, school doesn't teach them this. It will probably be a covered subject, but the education is so bad that the students only learn how to answer the exam questions (and then forget even _that_ after the exam), without acquiring any actually useful knowledge such as an intuitive understanding of how thermal conductivity works.
Big Boss In other words, liberal arts majors, not (insert any science major here). What did the liberal arts major say to the engineer? ... "Want fries with that?"
this is so messed up. I hope Dr. Muller isn't too depressed for trying to do this with a general population. It'd be terrible if he was the one to come up with a weapon to annihilate humans, yet perfectly reasonable after an experience like this.
Before having seen the episode (just his question to the people), both objects should have the same temperature if they’ve been in the same temperature environment long enough (he didn’t pull one out of a cooler/oven). The objects will feel different because of their material differences in how they exchange/conduct heat. One way you can tell if a countertop is granite instead of particle board and laminate is that the granite will feel cool to the touch. The ambient temperature is the same but the materials are different.
2:14 is the only reasonable thing that was said by the interviewed in this video. He just explained that they were the same temperature and all the others just went with their instincts again and stated that it would melt quicker on the "hotter" plate. The lady in pink is the only one who concluded something from the first experience, eventhough it was a wrong conclusion at least she used her brain.
Technically we don't know that he demonstrated the equal temperature to all of them. So they might still have no particular reason to doubt their instinct.
+Captain Hindsight hence Engineers are generally disliked and have poorer social skills because they have god complex mentality and can't relate to the average joe
cherubin7th yeah, exactly. Science in general should be skeptical of everything, but on the personal level, we often have to just trust some people, organizations, theories. Nobody has time to fact-check everything
Well, he didn't quite explain it correctly either. The real answer is that there is no such thing as cold. It's really just one having more heat (energy) than another. What we perceive as "cold" is really just heat (energy) leaving our body and what we perceive as "hot" is heat (energy) transferring to our body.
Though can't an object have more heat than another and still feel colder? For instance, lets say the hard drive has more heat than the book and they are the same temperature. The hard drive still feels colder because as he said, the heat in your body is able to be transferred through the hard drive faster, so an object with more heat than another doesn't necessarily mean that it feels warmer. I guess it's just kind of misleading to say that objects with more thermal energy will feel warmer: an entire ocean will feel the same temperature as a bucket of the ocean's water. Things can feel warm without thermal energy being transferred into you as is the case with the book. The temperature is quite important because water that is 20 C is going to to feel much warmer than an ocean that is 10 C even though it has much less thermal energy. And even in this situation, the energy will be leaving your body and not entering it.
Don't know why i was recommended this old video of Veritasium but it reminded me that i came to the answer for this very question myself. The only difference was that I wasn't thinking of metal and other material but i asked myself 2 questions: "Why is it that my body temperature is 36.6 but i feel hot at 20+ degrees?" and second question i wondered was "Why is it that when air and water temperature are same and i enter the water it's freaking cold?" I realized answer for second question relatively fast because we clearly had two different substances to compare. Even though this gave me half of answer for the first question it took me about 2-3 days of thinking to answer it to myself. I remember being proud of myself for understanding it. Later i asked myself another question "If Earth's core produce heat that propagate from inside and we also get heat from the sun from outside, how come our planet isn't increadibely hot?" Even though answer is similar to the body temperature question it was much more difficult to grasp because unlike our body, Earth is isolated by vacuum and the only way to lose heat was due to radiation. Answer to this question i had to google though.
Very good demonstration. But IR temperature sensors are not always very good at measuring temperature. Emissivity is different for different materials and even different surface finishes. On electronic boards the solder joints always measure as cooler then the board right next to them. But when measuring objects near room temp / error is small. So for your demonstration is no problem. Second problem with IR thermometers is that sometimes you get a reflection of another object included in what you are trying to measure.
"Humans are to a large degree sensitive to energy fluxes rather than temperatures, which you can verify for yourself on a cold, dark morning in the outhouse of a mountain cabin equipped with wooden and metal toilet seats. Both seats are at the same temperature, but your backside, which is not a very good thermometer, is nevertheless very effective at telling you which is which." -Craig F. Bohren and Bruce A. Albrecht, Atmospheric Thermodynamics (Oxford University Press, New York, 1998).
two scientists interested in "atmospheric thermodynamics" apparently spent time on a mountain everyone knows they're speaking from *personal experience* with that outhouse seating
"What's the torch for?" "2000 degrees, Mick. Enough to turn steel into butter. It won't hurt at first. It's too hot, you see? The flame sears the nerve endings shut, killing them. You'll go into shock and all you'll feel is... ...cold."
About that, i noticed how bad of a thermal conductor air is when i went out to the snow for the first time this year. The place I was in had no airflow and the air was -4c. It felt warmer than outside my house at 10c Wind is what makes you loose heat, not static air. Wind is what makes you feel cold outside It also has to do with humidity as my house is in a very humid region while the snow was in a much drier ambient
And since you changed the avatar to that awesome doge, you had to mention it so others would understand my comment. xD or not, who knows. Kinda helpes me in a way anyway, so ty. :)
Better way to have explained this is the tell them that the way we feel heat is the transferring of it. If something feels cold, it's because it is taking your heat. And if it is REALLY cold, it's because it is taking your heat really fast. And while that rate can be affected by how cold it is, that rate can also be affected by the material. Metals give and take much faster than say wood or plastic, in the same way that more cars pass back and forth on a highway than on a street.
YES! and maybe one of them would have hypothesized that they could make the metal and plastic feel identical if both were at body temperature (or hand temperature), and *also* if the plastic was much warmer than the metal, at an appropriate ratio that compensates for their differing conductances.
Some very arrogant commenters here. Not everyone retains every science fact from school. The whole point of the video is that there are common "misconceptions about temperature". This is why Derek is a good science communicator.
black leg genji - the effect of bare skin touching something is the same regardless of the temperature. A good example would be thermal insulation tiles, like those used to protect the space shuttle as it re-enters the atmosphere. Those tiles conduct heat so slowly that they can even be handled by their edges with bare hands (and great care) even if they are heated to over 500 degrees! Yet a piece of steel at 500 degrees would burn bare skin black in an instant, because steel conducts heat very, very well. But a thermal insulation tile would just feel very hot at 500 degrees, but the heat moves so slowly into bare skin that it won't burn instantly, like steel. Your skin senses the _transfer rate of heat_ from what you touch, but it does not feel the actual temperature. I hope that makes sense?
MrAnperm The only think that bothered me was when some of them said „I’m not a scientist how should i know that“ you don’t have to be a scientist to learn/listen in school.
I'd like to add that due to individual circumstances this may have actually not been covered in school. I had physics as one of the two prime subjects for my A levels, and I am absolutely certain we have not covered heat conductivity during the last six years at gymnasium. The reason in my case is that for one, the physics of heat was more or less left out during the earlier four of these years, and during the final two (during which you prepare for your A levels) our physics teacher consciously omitted thermodynamics from our curriculum as he knew beforehand that thermodynamics would not be a topic in our final exams; thusly, he chose to use the limited time to prepare us for the topics we would actually face. In any case, the ignoramus in question may not be responsible for that, so one should not be quick to judge (as in general).
@@kylewaddle7592 Well, it sounds almost the same, "mo" and "mal", so I can't know for sure. But if you want to find out more about the concept, the term is "thermal conductivity".
@Veritasium actually, the relevant physical quantity for how an object feels depending of the material it's made of is its thermal effusivity, and not its thermal conductivity.
This is like basic material conductivity, I'm actually a bit surprised at how clueless these people were. Nice vid though, you're really good at presentation.
You shouldn't be surprised. One in four Americans, for instance, don't know the earth revolves around the sun (seriously). www.npr.org/blogs/thetwo-way/2014/02/14/277058739/1-in-4-americans-think-the-sun-goes-around-the-earth-survey-says
***** Picture this... religious nuts would have you burn 500 years ago if you came talking about thermal conductivity. And people ask me why I don't like religion and its bigots.
Andres .C Religion and Science are just ways we invent to explain things. Science simply has more examples that support it. I think both are cool btw, no wars wanted. Also, in the past, they were idiots, not their fault for not knowing really. Still idiots though.
Ok one has feedback. The other doesnt. You propose, you see if youre right, you believe. The other works in a more colorful manner: you believe, you invariably see that youre right, you propose patches just in case, in the event of failure you then return to step one.
I knew the answer to this. My Chemical Engineering degree wasn't a complete waste of time. The bit with the ice cube on the blocks was a nice touch and a great teaching aid
It's a good thing that you're you and not them, and their opinions about their own selves doesn't in any way impede your progress. Now go be awesome, unhindered by others. Including me.
Walsh2571 I rolled my eyes and said, "shut up!" out loud to myself when she said that. I really hate the term, "a creative" to describe one's self. For some reason it grosses me out and I'm "a creative" apparently. Ewww. Self important douchery.
What a great experiment. I know it’s hard for people on the street to come up with any conclusions on the spot. I’m sure you jogged their memories of science class. Sitting in my chair watching similar videos, it came to me that it was about conductance of heat very early on. If I was out at street party it would be hard for me to think back to what I’ve learned about the subject.
I feel like he glanced over a crucial factor that will make this more clear to most people when explaining this effect. Body temperature. Since the objects being touched are colder than the body temperature but warmer than melting temperature of water, the metal/aluminium feels colder to touch while also melting the ice cube faster. If the book and the metal is warmer than body temperature, it would have the opposite effect where the metal feels warmer than the book.
well, one of the experiments i knew what would happen before it happened, because i've spent enough time working with electronics i know a few things about thermal conduction. You should have done the trick where you take two metal tubes, one that's warm to the touch, the other is cool to the touch (neither enough to feel unpleasant) then have them hold both tubes in the same hand and see how it suddenly feels extremely hot/cold because it's not just the thermal conductivity that determines how we perceive temperature, but also the difference between two substances (which is also one reason you feel colder when you have a fever, even if the air temperature around you is the same as always; the other reason being you have the heat being transferred out of your body faster because the temperature difference is greater)
If you ever get the opportunity to have some thin piece of silver like a knife, try cutting ice with it. Silver having the fastest conductivity of any element makes it so that a silver knife can cut through ice because it melts it so fast on contact.
@veritasium, hello and thank you for your mesmerizing videos, i always enjoy them. After watching the one about entropy, i think we need one (similar in quality) explaining temperature, how it does transfer, etc. Thanks again. (For example, in space, if you put a hot cup of coffee, it will freeze ? But since the space is empty, to where did that heat transfer ?) Some say that temperature is like a kinetic energy of the atoms, let’s trap one atom and heat it, what happens inside when getting heat and how does temperature transfer in and out it and what actually transfers ?)
If he asked you, how it FEELS, of course you say, the aluminum FEELS colder than the book which is correct. The problem now when he asked if they had the same temperature though which is pretty confusing for someone who just said it FEELS colder.
….but you can have too much of a good thing While people with too little earwax are likely to experience itchy ears that are more prone to infection, an ear canal blocked up with earwax can cause earaches, mild deafness, a sensation of fullness in the ear, tinnitus, infections and other problems. Your earwax says a lot about you There are actually two kinds of earwax - wet and dry. Wet earwax is more common among Caucasian and African people and is typically dark yellow and sticky. For those with East Asian or Native American ancestry, ear wax is typically light in colour, dry and flaky.
You should make a video on why thermal velocity, responsible for temperature, is different from normal velocity and therefore why different units are used to measure temperature and velocity (degrees vs m/s). I am having trouble understanding it
Derek: "It's about thermal conductivity!" Everyone: "oh of course!"
“Just what I was thinking!!”
Simply put, that is why we use metal for cooking rather than any other materials.
@@JackSuperFly Really? I thought we use metal for cooking, because it doesn't burn from the heat.
@@Shogoeu well that too lol but metal heats up so fast that it's perfect for cooking.
I mean I thought of that as soon as he said they’re both the same
"We are creatives, not intellectuals."
"Then create an answer for me."
REKT
Swiit Lime It’s just a joke, buddy. You would get that... but “You’re clearly not an intellectual either.”
Well this was a better comeback than the original one.
@Swiit Lime There's an old Spanish saying that translates to "Ignorance is daring". You offer a perfect example.
@Swiit Lime scientist already knows the answers? You couldn't be more etong
The only problem is that people of this generation are not keen to learn. They are only interested in playing Fortnite.
Fun fact for anyone revisiting this gem:
Thermal conductivity also directly relates to Electrical conductivity.
This means that things that are good at transferring electricity also conduct heat a lot better (usually metals), and why insulating materials both feel warmer and usually are used for electrical insulation (i.e. plastics or rubber).
There are however some outliers and exceptions, like for example:
Mica is a good conductor of heat but a bad conductor of electricity. It means mica has a very capable dielectric function, making it ideally suited for applications that require an effective heat conductor and electric insulator.
There are a few good electrical insulators that conduct heat (e.g. mica, diamond, water, oil, wax, glass, ceramics) but the opposite is rare.
It’s unlikely (apart from superconductors) since in many materials the electrons that conduct electricity also conduct heat. For metals, the thermal and electrical conductivity are related (by the Wiedemann-Franz Law).
Berkeley scientists have discovered that electrons in vanadium dioxide can conduct electricity without conducting heat, an exotic property in an unconventional material. The characteristic could lead to applications in thermoelectrics and window coatings.
Hope whoever comes across this, enjoys reading it!
Could Vanadium Oxide be applied in cabling for Quantum Computers?
Quantum Computers are cooled in several "stages", which need to be thermally insulated from each other.
Less thermal conductivity in these cables would help a lot.
@Soheil-ev6ls sounds like a good idea, im pretty sure it is doable. It would quite indeed have a positive impact on the cooling rate. How big obviously would depend on a lot of other factors like cable size, density, diameter, etc.
I did enjoy, thank you. Side note, I'd always assumed diamond was a good electrical conductor, considering most forms of pure carbon are. Interesting that this isn't the case.
Makes sense, I’ve set Mica on fire a good few times on RDR2 so can confirm that he is definitely a good conductor of heat.
Does that mean thermal conductivity is measured by free electrons? Not sure if remember correctly, but I think conductivity has to do with free electrons.
Anyone else just getting this recommended to them in 2024?
Yes and I love 2013 Derek
I got a science exam 😭😭😭😭
😂 I got it, but it’s one damn interesting fact that I didn’t know
Me
Twice recommended
“Well you see *thermal conductivity...* “
Everyone: **windows shutdown sound*
literally
Two normalies next to me was lost watching this... I explained it as thermal exchange between the two things...think they were like the woman who said I believe you...
I was sitting the whole time wondering where he found adults who doesnt know about thermal conductivity, or at the very least, know that while metals feel colder they actually aren't (somehow even the ppl that said metals usually feel colder said they thought the harddrive _was in fact colder_ :o).
I expected at least some to rather than being entirely out in the left field, throw out the explanation usually given to kids when they ask why metals/stone feel colder than wood: "because they suck heat right out of your body!" It would also be wrong, but it is nevertheless the explanation most ppl grow up with until either school or 5 minutes of thought about the subject corrects it.
@@feha92 exactly..
@@feha92 Now i know that is true but many people still don't have/had any interest in knowing it so we can't blame them . It seems hard to believe but that is exactly how i feel too when i tell someone of the very basics of coding or general aptitude (like how can someone not know what an array is). Meh i used to be surprised but then there's a lot of stuff i don't know either , very basic stuff for someone like chemical composition of dust or how to repair an engine or how to smith a simple knife from metal.
But yea, someone dum if they dont know how to know something, in my case google.
The looks on their faces when he starts explaining the science is priceless. They just immediately lose all interest.
Ikr
How can anyone hate science?
+Michael Sporzynski Goddammit those people have an effect on government policy because of inherently amoral "lack of knowledge."
kaitengiri yep they are probably all 'highly successful managers'.
jagara1 No they are 'creators' as one of them said, highly successful managers are pretty smart
A pound of feathers is warmer than a pound of steel.
...because it is bigger.
@@TroyQwert no none of them are warmer of colder, they just conduct the heat from differently, which is why the steel feels colder to us
@@Sophia-MarieSchoffel whooooosh
But steel is heavier than feathers!
@@LtPowers , no kidding! 😵
These videos make me realize how fortunate we are to have access to so much knowledge inapplicable to our daily lives. I knew why but only because I love physics and have watched so many science related videos. Its only within the last 20 yrs that we've been able to access so much content on anything our minds question.
Agree, and yet society seems to be getting dumber. I blame tiktok and fb.
@@brendankohler1000Yes, because it’s gotten to the point where (lots of people on average) expect information to be so readily available for them in small packaged doses, that they don’t go out and find out more about it, and they just take whatever is easiest for them to digest. Influenced by short form content like you said.
The other day I was in class and someone said “where’s the little text telling me the answer” 😬 Even though there were multiple different sources of information on their screen, they were used to the summarised version telling them the easy answer.
And I think it’s just gonna get worse until it (might) get better… something would have to change..
i think thermal conductivity was taught to us in higher-primary school (when we were between 11-14 years old) in Hungary
what's amazing is how other countries can get away with having so many basic-science-illiterate ppl
2:32 That guy has best logic for the climate change.
+How To Make Yeah... he was the funniest of all as well :)
Could have been D.Trump ^^
lol
yes. climate change is cause by too many soda cans in the world!
wrong.. D. Trump would have said that aluminum is good for the environment
“Okay, I believe you” translation: I couldn’t be less interested, let me leave.
sadly, youre 100% correct
"I'm proud being ignorant and not understanding how things work"
Nah, it's joke
@@mrnarason ""I'm proud being ignorant and not understanding how things work""
or maybe some people don't want to be lectured at that very moment...
@@Red4350 That's clearly not the case, and you know that
Amazing how this video 9 years later still holds up pretty good in production quality and content is still top tier
Well 9 years ago was 2015, well into the Web 2.0 and modern tech.
@@tommyjones1357 your point does kinda stand, but the video is from 2013 and what was a really small channel at the time
@@obonyxiam it is a testament to Veritassium dude’s abilities.
Surely without online platforms, he would have still been a film maker. Video production was a different beast prior to the modern web.
@@tommyjones1357 oh absolutely, but your first comment implies that the video's ability to stand the test of time isn't impressive
@@obonyxiam it is a shame that the TH-cam algorithm should make that decision rather than the audience.
Evergreen content is the best.
this is so mind blowing to me! I love itt, I like Derek way of pulling out the curiosity out of people before explaining the true concept of temperature . it just make me understand and remember the concept a LOT better
"Aluminium is bad for the environment, because it's melting the ice faster" Where did you go to record this? :)
Well, at least it's a thought process. It's going in a wrong direction, but if he'd continue to follow that path, he'd notice it's wrong and search for another explanation. I prefer that to simply standing there flabbergasted thinking you've witnessed some sort of magic and not wasting a thought at all.
That made me laugh our loud at 4am
Pretty sure he joked.
@@Querez8504 yeah he was joking the entire time
that one was golden
"We are creatives, not intellectuals."
"Then create an answer for me."
Well that proves the man's an intellectual.
Smart
Uno reverse at its FINEST!!! xD
there is not creativity without knowledge.
That's absurd because
Science and creativity are interdependent.
Yet, fields of science like anatomy were pioneered by artists to improve their art, meanwhile, Einstein developed his theory of gravity based on a daydream he had. The interconnectedness of intellectuals and creatives is great, and everyone goes on about how an unintelligent artist cannot make valid art, but we don't talk often enough about how an uncreative scientist cannot do valid science. It's how we end up pigeon holed into conclusions about things we clearly dont understand yet.
This was neat to discover when I did some time ago. A topic about metal railings etc.
I've also concluded that we're much more sensitive to temperature changes than we think. A change of merely a few degrees directly on the nerve endings can feel incredibly chilly or warm, but those endings don't actually feel the temperature of the object unless it's like aluminum or water etc because we're still feeling mostly our own temperature plus a fraction of the difference due to lack of thermal conductivity.
The TH-cam Algorithm will bring us here again.
And it has.
And it did, today for me
Welcome 2024 people
Are you a Bangladeshi? It is really hot here, and somehow TH-cam algorithm understand it (though I have never searched a video about temperature), and bring the video to my feed.
@@kamrulhasanraihan3769 I'm Indian, welcome back again everyone
the guy in the beanie is mvp.
"A hard drive is a lot colder than the book. I don't know, 'cause the books got more knowledge?"
"I think science might be able to answer that. And I'm not a scientist!"
"Could aluminium be bad for the environment?"
"Could aluminium be bad for the environment ... well it's thawing out the ice a lot quicker, isn't it?" made me laugh for a solid 5 minutes
It sounds like a dumb question but I appreciate this guys willingness to engage his mind and draw conclusions. With some guidance this dude might actually learn something :)
But most hard drives can hold way more knowledge than I book
@@jeremyphelps5140 Yeah you are right scientific questions seem dumb but experiments always have to do with conclusion and what went wrong in between that led to some other result, which makes us learn even more
@@jeremyphelps5140 I agree! That's a mind for science 😄
Everyone: wondering why ice is melting quicker on the block that feels colder
Me: Why does he have ice cubes in his pockets?
to run a social experiment.
imagine if he casually always carry ice in his pocket
Good question 😂
I see you are asking the big questions here!
This verges on philosophy.
Where was that in the video?
Great video, physics concepts made easy to understand and/or to realize, ….. I think almost everyone that attended at least high school, knew the concept of thermal conductivity, but along the time, we forgot the application of those concepts in everyday life. You also made lots of videos that is understandable for most of us common people, even for the way more complicated astrophysics concepts like the blackhole images created from radio waves, the concept of speed of light etc …… thank you very much
Just watching this for the first time 11 years after it was made...been following his work for about 5 years now and this is probably my favorite video so far...even though the graphics suck
"I think science might be able to answer that. And I'm not a scientist!"
In a time where everyone knows it better than experts, this guy my hero.
For real. Let's normalize humility and honesty. Nobody can know everything. There's nothing wrong with saying "I don't know."
@@nickmetts 100%. He’s on the right track by asking questions and thinking things through
There is no need to be a scientist to understand fundamental things about of our world. Like there is no need to be linguist to speak English.
@@archi-mendel while I agree with you, I also think many people give nonsense answers or just make things up instead of admitting they don't know something. That was my point. You can't learn anything if you pretend that you already know everything.
"In a time where everyone knows it better than experts, this guy my hero. "
This happened all the time troughout every period and will always happen until we alter our brain with something like neural implants. Its normal, we didn't evolve to "know" our perceptions trought sense are not reliable. Reason and the acknowledgement of the necesity of the scientific method is an extra effort that doesn't come naturally to 99.9% of the people.
(Explains just everything)
- I BELIEVE YOU
Lol i hate when people believe things rather tjan understanding them
He didn't undeniably prove his claim though. It still takes some amount of belief. Because someone can make something up, have it sound reasonable, and give fake evidence.
@@PurpleViking221 understanding > belief > faith (in terms of proof needed)
She could say "I don't believe you", so let us be glad about what we have.
@@Borg8 Agreed, there are people out there that denies concrete facts. When they're presented with real evidence, they simply ignore them and go on with their delusions.
This is a best elaboration of anything which is misunderstood.
Please keep this with constant speed.
Thanks
Imagine someone coming up to you on the street and pulling out ice cubes from his pocket.
That's not science, it's magic!
Excuse me sir, wny do you have ice cubes in your tots pocket?
That moment he said "Thermal Conductivity", the look on their faces, they have no idea what he just said
Again, our "glorious" educational system, keeping people dumb.
I believe the problem is apathy, people do not realise why these things matter. I wish humans were more efficient.
Flubadubdub The Great
Most people's purpose in our society is to work and don't ask questions. Why would those things matter to them? It's how our society produces cheap work force.
Metalbirne
Because those things do not matter to them, they get fooled into paying their tax money for dead-born projects, increasing the number of milllionairs and billionairs and enriching the existing ones. The dumber the people are, the better they can be fooled and ruled. As Julius Caesar said over 2000 years ago:
"Give the people bread and games and they belong to you."
It's still valid today - gladiator arenas then, sport and brainless internet entertainment now ...
Thermospecialist
yeah, that's what i said (atleast try to say anyway).
I feel really good that I actually already kinda knew this like this: you can only feel the temperature of 1 thing, your skin.
I learned that metal is more thermoconductive last year (maybe 2019) in chemistry class so I was also feeling pretty good. Christ do I love science.
Your best video Derek. Such a basic concept yet we experience it daily. Showed it to my kids already.
In my high school physics class, my teacher did something similar. He told us to touch the metal bar of our desk and our textbook. He asked if one was colder than the other. After we answered, he asked us to think deeper. They've both been sitting in the room for a long time. We realized they both have to be at room temperature. He then explained that the metal conducts thermal energy better than the book, so we feel the energy leaving our body as cold.
On my first day of Physics class in high school, I blew up a paper clip by bending it in half and flicking it into an electrical outlet.
There was a loud POP and a small mushroom cloud rising above me. I just sat there like I had no clue about what the hell just happened.
That was a number of decades ago, nobody asked too many questions back then.
(I call it "life before rules", you should have been there).
Totally irrelevant, but just wanted to share the memory!
I'm pretty sure the statute of limitations has expired!
I think it would be good to accept what the class says but emphasize where it comes from - write it down as the metal *feels* colder, which is correct and is a good stepping stone on the way.
Yeah I remembered when my physics teacher taught me temperature, and the difference between Celsius and Fahrenheit. Good times, then we cooked.
@@mayorb3366 I connected bike lamp to 230V socket. When I was about 5, home alone. It went bang and scared the hell out of me. Now I`m surprised how it didn`t blow up. Cuz the bulb inside was made for 6V dinamo.
@@mayorb3366 You, too, eh?
The thing with videos like these are that, if you answer right in the interview they won't put you in the video.
Exactly!
I would have recked this bloke, and I'm an idiot!
Right, thermal conductivity is something you learn about in pre school
@@shaney54st YOU DO? what the hell
@@MEGAsporg12 Thermal conductivity is something everyone knows without realising they do know it. Kids know the concept maybe not the reasons behind it. Thermal conductivity is the reason why there are wooden spoons for cooking and so many cooking utensils in plastic. Even if there are metal utensils they usually have a plastic or a wooden handle. The reason you grab oven mittens to take something out of the oven is becuz you know they are heat insulators and will prevent you from burning your hand. You know about thermal conductivity since you are a kid, you just don't know the scientific name and it never really registered in your brain that you actually know it.
@@MEGAsporg12 right i learn it when 17
A good tip I always remember is if you're looking for a good conductor/insulator in a hurry, touch it and if it feels cold it's generally a good conductor, and if it's warm/room temp it's generally a good insulator. Metals are notorious for being good thermal conductors due to their metallic bonding, which is basically where you have a sea of electrons loosely bound to their atoms and can move freely (electron gas). This is one reason for such high electrical conductivity in metals, but also means those electrons carry kinetic energy or heat, and so since there are tons (1e20/cm^3 +) bouncing around at mean speeds of 1e6 m/s (just from electrostatic forces) you can imagine the heat transfer of those electrons is very significant. Wood is basically a polymer but has it's electrons more tightly bound with covalent bonding, resulting in a lower thermal conductivity. Another way of looking at it is metals have a low specific heat capacity (J/gK) which means the energy required to heat up 1 gram of metal one degree kelvin is much lower than in other materials. Metals feel cold to the touch since they are able to transfer the heat from your fingers much faster than other materials, ultimately to achieve some sort of equilibrium. But the case is reversed for something very cold like liquid nitrogen, where heat is being transferred into the LN at a faster rate than the wood.
Tldr: metals are cool
Nice comment
3:05 That moment when you realize you've not only been sucked in, but you're not having fun anymore.
the ice caps are melting because of aluminium haha
+eamonnd1 Because of environment too...
***** w8ers are not gonna h8 they are gonna w8 for h8.
+eamonnd1 aluminium actually uses an enormous amount of electricity to produce, so it has some truth to it
***** Ahh! spider! *Stabs and breaks the screen* :(
+hey7328, so does cement (use lots of energy). plus it releases co2 just to convert from limestone (caCO3) to (CaO).
"I believe you" The sign, the girl simply isn't interested anymore.. lol
Or just dumb
I wouldn’t say they’re dumb, but it is disappointing that more people are not interested in science and how the world works. Sad.
@@quicksilver3431 blegh, r/imverysmart
Cool stuff. Yes, it is the heat conductivity - or heat flow. I really got a dose of this in my few years doing R&D. The plastic is a thermal/heat insulator, and so is the paper in the book. Metals tend to have over ten times the heat flow conducted.
Real world: For one experiment, I was looking for the best insulator I could find for use in some tooling, to keep hot oil heat energy away from cooling water channels. I ended up with a strange plastic called Polybenzimidazole, used in rockets' nose cones and in firefighter clothing. It took two days in an electric furnace to get it up to 450°F. When I took it out, I knew intellectually that I could pick it up and not get burned. But I almost didn't test it. I was freaking out. When I did, I did not get burned. It STILL read 450°F. It felt room temperature to me.
Years earlier, I worked for Ferro Corporation. I had a nice company brochure, and in it was a photo of a guy holding a SPACE SHUTTLE TILE in his bare hand, A glowing red hot space shuttle tile. Space shuttle tiles, their purpose is to NOT let heat flow into the metal of the shuttle. They do a great job of it. When they are knocked off, it ain't pretty.
Temperature is NOT what burns you. It is the heat flow. The thermal conductivity. The heat energy cannot hurt you if it is not able to flow into your skin. Stopping the flow is stipping the burn.
Polybenzimidazole, BTW, does not burn, and it does not melt.
Fascinating. I assume there's an excessive cost or major pollutant output in the process of manufacturing this to explain why it isn't in common use?
This channel is a gem 💎
Aaah it so frustrating to know the answer and watch this...
Joe Alias haha, agreed
Joe Alias but at the same time i feel good coz i worked that out kinda on my own, through background knowledge about thermal conduction and stuff but nobody ever telling me or asking the question
Yeah so annoying
Joe Alias true, true
Joe Alias It probably is also frustrating to not know the answer, and watch this. The suspense kills you, doesn't it?
I was perplexed to learn this for the first time, 15 years ago.
you want the answer?
YES PLEASE
its about thermal conductivity...
*sad Linus faces*
OH GOD
They thought it was a magic trick lmao
leidenfrost effect
@@landi76 that’s not the leidenfrost effect
haha sad linus face 😂😂
i love his video though
The video is very cool and informative. Also the interviewees seems very natural and intellectual (as if they were actors/actresses)
They both are at evened out outside temperature, but the harddrive will feel colder because its chassis is made out of some kind of metal that has a low heat capacity and as such the thermal conductivity is high, so the heat will transfer quickly. For example your warm hand will transfer heat onto the harddrive chassis quickly and since you're losing heat, it'll feel cold.
Furthermore you can really mess with your head by having a freezing and very hot bowls of water and an object, sink your hands in the bowls and then touch the object that you know is at the same temperature as the room. It feels completely different in each hand. Our body just wasn't made for accurately assessing temperature, but proxies that are more important to our function than temperature itself.
And this is why it was useful to finally get the thermodynamics class done in my engineering degree. One interesting question was related to sauna. What's the heat of the stove? What about the air? The wooden walls? The wooden bench? The nail on the bench? What if the bench was made of metal? How about if it's been only a little time versus a couple of hours? The temperature of each thing in the sauna in relation to their thermal conductivity and time was something really worthwhile to thinkg about.
Another interesting thought experiment was geothermal heat. Like you'd think it was the fact that earth gets warmer the deeper you get, but the system is probably not even 100 metres deep in the ground so that makes practically no difference on the temperature of the ground. So does the heat come from the bottom? No, it comes from the sides of the bore hole.
Although it's nothing new for me I like the way he demonstrates and explains things. Those experiments were quite good to show what's happening and made the people think about it. That's what should be more done in schools.
Here in germany they often do such experiments
@Southeastern777 This is not true.
@Southeastern777 Modern schooling has many flaws, political correctness is not one of them.
@Southeastern777 Do you have any tangible proof that our entire education system holds any of these beliefs? Analogies are not a form of evidence.
@Southeastern777 The burden of proof lies on the claimant.
"Answer this question for me"
" *Actually answers* "
"You're not supposed to do that"
Nah, he'd have just said you're right/good job/etc, and not included you in the video.
During my exams, i know all these answers but in my day to day life i forgot these concepts and then comes you giving such a type of explaination which i never gonna forget 😵🧢💙
I wonder if he actually encountered anyone who knew the answer, except they were edited out for effect. Once you understand how it works, what seems counterintuitive at first now seems common sense. As such, I didn't realize that the questions he was asking would stump most ordinary people. I thought the answers were common sense.
I really hope he had to edit out several right answers.
Very surprising to me that people actually thought the book was warmer and were surprised that it wasn't.
@@gameface6091 Yeah right! Like who havent handled aluminum and noticed it ''suckes'' heat right out of you while other stuff in the same room or temperature dont. Its the same thing with styrofoam but oposit. If you just hold it, you will feel your hands are getting hoter
@@alexwilk2491 ñ
He did a video a while back defending his use of this formula of asking people, having them answer wrong, then explaining the answer. I think it did a good job of realizing why people don’t like it and a bad job of justifying it in the face of alternative methods for presenting the dichotomy of common sense vs facts.
I thought so as well.
The best place to find people to interview who'll definitely not know the answer?
*Hippie festival*
Sure, Nascar or rodeo people will know the answer...
@@MrFlyingPanda nascar people could know cuz of the races and tyre wear 😂
🤣👍🏼
Honestly anywhere away from a school or college or doctor in my experience
@@gabemerritt3139 What do you mean by doctor? like a surgeon? And what experience do you have with this?
Love the way these people smile when they learn something new. It's honestly heartwarming.
Is that meant to be a pun? I hope so.
It's not warming your heart... it only feels like it, because it's less heat conductive than your body???
such a good comment
Googelplus Sucksys
lmao underrated
You probably wanted to say that this video has high thermal conductivity because it melts hearts faster
Brillant choice of topics! Wonderful demonstration and explanation !!!!
I already knew this before the video started but I've never seen it explained so well!
I pause these videos seconds before you explain, to have conversations with my girlfriend to see if we understand the physics behind these, Ive usually got a pretty good understanding so it's so much fun!
Confirmed: 3% of the population actually paid attention in school
they developed spoke ability, as lawyers, etc
For most peolpe in the world, school doesn't teach them this. It will probably be a covered subject, but the education is so bad that the students only learn how to answer the exam questions (and then forget even _that_ after the exam), without acquiring any actually useful knowledge such as an intuitive understanding of how thermal conductivity works.
@@leandrog2785 I hate that I agree with you
They know
But they forgot😑
Also that 3% of the population are missing in the video
I don't think half of them understood the reasoning :P
+Big Boss but the point is that they believed him!
+v3le but that's not science, "question the authority!!"
Yeah they were probably just thinking "k k okay stfu already I have to go places"
It's because they're creatives, not intellectuals!
Big Boss In other words, liberal arts majors, not (insert any science major here).
What did the liberal arts major say to the engineer?
...
"Want fries with that?"
as someone with no formal qualifications, i am glad i worked this out straight away!
This is a very illustrative experiment. Thank you.
As a creative, I am annoyed he did not allow me to express an explanation through the medium of interpretive dance.
Looooooooool
Haha
Brilliant comment!
I will use this
Lol, they more often said "I believe you" than "I understand".
nice observation
True :D
this is so messed up.
I hope Dr. Muller isn't too depressed for trying to do this with a general population.
It'd be terrible if he was the one to come up with a weapon to annihilate humans, yet perfectly reasonable after an experience like this.
omg I can't even believe this channel has been around for so long
Before having seen the episode (just his question to the people), both objects should have the same temperature if they’ve been in the same temperature environment long enough (he didn’t pull one out of a cooler/oven).
The objects will feel different because of their material differences in how they exchange/conduct heat.
One way you can tell if a countertop is granite instead of particle board and laminate is that the granite will feel cool to the touch. The ambient temperature is the same but the materials are different.
2:14 is the only reasonable thing that was said by the interviewed in this video. He just explained that they were the same temperature and all the others just went with their instincts again and stated that it would melt quicker on the "hotter" plate. The lady in pink is the only one who concluded something from the first experience, eventhough it was a wrong conclusion at least she used her brain.
Technically we don't know that he demonstrated the equal temperature to all of them. So they might still have no particular reason to doubt their instinct.
Yeah videos are edited AF
As an engineer, I found this video hard to watch without yelling at my screen.
+Captain Hindsight I'm not even an engineer and I am disgusted by people's stupidity here.
+Captain Hindsight Same thing here...
+Captain Hindsight hence Engineers are generally disliked and have poorer social skills because they have god complex mentality and can't relate to the average joe
ImpetuousFire Ignorantly stereotyping is just as bad,
ImpetuousFire I have a background in thermodynamics, not a god complex.
Next time try calling me a nerd and see if it hurts my feelings.
Maan this old stuff is epic, on multiple levels, just epic.
Wow. I always learn something new on this channel.
"I believe you"
And that is called not understanding what science even is.....
she clearly wanted to show him a little acknowledgement. - Didn't work to well though^^ :D
Scientists don't fact check everything.
cherubin7th
But they should
cherubin7th yeah, exactly. Science in general should be skeptical of everything, but on the personal level, we often have to just trust some people, organizations, theories. Nobody has time to fact-check everything
Actually the vast majority of science is creed and beliefs.
How many chemical or physical experience did you replicate by yourself ?
It funny when he explains conductivity to them, they clearly don't have any idea what he's talking about and pretend they understand
lul
"Hurrr ITS JUST THERMALCONDUCTIVITY GUYS!"
3:09 "mmhmm, okay. I believe you." (I'm done holding these things in my hands and I lost interest in this conversation.)
Well, he didn't quite explain it correctly either.
The real answer is that there is no such thing as cold. It's really just one having more heat (energy) than another. What we perceive as "cold" is really just heat (energy) leaving our body and what we perceive as "hot" is heat (energy) transferring to our body.
Though can't an object have more heat than another and still feel colder? For instance, lets say the hard drive has more heat than the book and they are the same temperature. The hard drive still feels colder because as he said, the heat in your body is able to be transferred through the hard drive faster, so an object with more heat than another doesn't necessarily mean that it feels warmer. I guess it's just kind of misleading to say that objects with more thermal energy will feel warmer: an entire ocean will feel the same temperature as a bucket of the ocean's water. Things can feel warm without thermal energy being transferred into you as is the case with the book. The temperature is quite important because water that is 20 C is going to to feel much warmer than an ocean that is 10 C even though it has much less thermal energy. And even in this situation, the energy will be leaving your body and not entering it.
Don't know why i was recommended this old video of Veritasium but it reminded me that i came to the answer for this very question myself. The only difference was that I wasn't thinking of metal and other material but i asked myself 2 questions: "Why is it that my body temperature is 36.6 but i feel hot at 20+ degrees?" and second question i wondered was "Why is it that when air and water temperature are same and i enter the water it's freaking cold?"
I realized answer for second question relatively fast because we clearly had two different substances to compare. Even though this gave me half of answer for the first question it took me about 2-3 days of thinking to answer it to myself. I remember being proud of myself for understanding it.
Later i asked myself another question "If Earth's core produce heat that propagate from inside and we also get heat from the sun from outside, how come our planet isn't increadibely hot?" Even though answer is similar to the body temperature question it was much more difficult to grasp because unlike our body, Earth is isolated by vacuum and the only way to lose heat was due to radiation. Answer to this question i had to google though.
Very good demonstration. But IR temperature sensors are not always very good at measuring temperature. Emissivity is different for different materials and even different surface finishes. On electronic boards the solder joints always measure as cooler then the board right next to them. But when measuring objects near room temp / error is small. So for your demonstration is no problem.
Second problem with IR thermometers is that sometimes you get a reflection of another object included in what you are trying to measure.
"Humans are to a large degree sensitive to energy fluxes rather than temperatures, which you can verify for yourself on a cold, dark morning in the outhouse of a mountain cabin equipped with wooden and metal toilet seats.
Both seats are at the same temperature, but your backside, which is not a very good thermometer, is nevertheless very effective at telling you which is
which."
-Craig F. Bohren and Bruce A. Albrecht, Atmospheric Thermodynamics (Oxford
University Press, New York, 1998).
its the best way to explain it .lol
omegalulz.
Thanks but it would take time for the seat to Heat up
two scientists interested in "atmospheric thermodynamics" apparently spent time on a mountain
everyone knows they're speaking from *personal experience* with that outhouse seating
"What's the torch for?"
"2000 degrees, Mick.
Enough to turn steel into butter.
It won't hurt at first. It's too hot, you see?
The flame sears the nerve endings shut, killing them.
You'll go into shock and all you'll feel is...
...cold."
About that, i noticed how bad of a thermal conductor air is when i went out to the snow for the first time this year. The place I was in had no airflow and the air was -4c. It felt warmer than outside my house at 10c
Wind is what makes you loose heat, not static air. Wind is what makes you feel cold outside
It also has to do with humidity as my house is in a very humid region while the snow was in a much drier ambient
But wind is made of air🧐
I love the editing and feel of these older videos. I feel like I'm watching one of those old science shows on cable tv
"the book's hotter because it's got more knowledge"... omg
I think you missed the joke
@B
He didn't say that he didn't understand the joke… he's just pointing that the joke was so bad it was good
@@SreenikethanI Exactly what i was thinking
The guy who said that must be cold af
Dmitriy Timchuk goteem
3:13
'I don't care about the world around me, now let me get back to facebook.'
spot on
Your avatar fits so well into your comment, meme correctly(ish) used.
Sarinmoon that's funny you saw that jackie chan meme, only had it set for 5min before i changed my mind
And since you changed the avatar to that awesome doge, you had to mention it so others would understand my comment. xD or not, who knows. Kinda helpes me in a way anyway, so ty. :)
Sarinmoon yw =]
Better way to have explained this is the tell them that the way we feel heat is the transferring of it. If something feels cold, it's because it is taking your heat. And if it is REALLY cold, it's because it is taking your heat really fast. And while that rate can be affected by how cold it is, that rate can also be affected by the material. Metals give and take much faster than say wood or plastic, in the same way that more cars pass back and forth on a highway than on a street.
YES! and maybe one of them would have hypothesized that they could make the metal and plastic feel identical if both were at body temperature (or hand temperature), and *also* if the plastic was much warmer than the metal, at an appropriate ratio that compensates for their differing conductances.
This might be my favorite video of yours
Just watched this video back again after several years. I wish Dereck would make these kind of video's again, i love this concept.
Some very arrogant commenters here. Not everyone retains every science fact from school. The whole point of the video is that there are common "misconceptions about temperature". This is why Derek is a good science communicator.
Reminds me of the hilarious South Park episode "The Smug".
so basically when we touch things hotter we could know which one is hotter, but if its colder than us, we can never know?
black leg genji - the effect of bare skin touching something is the same regardless of the temperature.
A good example would be thermal insulation tiles, like those used to protect the space shuttle as it re-enters the atmosphere. Those tiles conduct heat so slowly that they can even be handled by their edges with bare hands (and great care) even if they are heated to over 500 degrees!
Yet a piece of steel at 500 degrees would burn bare skin black in an instant, because steel conducts heat very, very well. But a thermal insulation tile would just feel very hot at 500 degrees, but the heat moves so slowly into bare skin that it won't burn instantly, like steel.
Your skin senses the _transfer rate of heat_ from what you touch, but it does not feel the actual temperature.
I hope that makes sense?
MrAnperm The only think that bothered me was when some of them said „I’m not a scientist how should i know that“ you don’t have to be a scientist to learn/listen in school.
I'd like to add that due to individual circumstances this may have actually not been covered in school.
I had physics as one of the two prime subjects for my A levels, and I am absolutely certain we have not covered heat conductivity during the last six years at gymnasium.
The reason in my case is that for one, the physics of heat was more or less left out during the earlier four of these years, and during the final two (during which you prepare for your A levels) our physics teacher consciously omitted thermodynamics from our curriculum as he knew beforehand that thermodynamics would not be a topic in our final exams; thusly, he chose to use the limited time to prepare us for the topics we would actually face.
In any case, the ignoramus in question may not be responsible for that, so one should not be quick to judge (as in general).
I’m continuously astounded by how little most people know about basic physics and the properties of common matter.
i am astounded how few people know such simple and basic science. this world is heading full steam ahead towards idiocracy
"How could aluminium be bad for enviroment?"
"Well its thrawing the ice quicker isnt?"
Well this is not old
hahahah
Ok i believe you
Posted 9 years ago
It's nice thinking though
aaaaannnnndddd ..... you no longer get to vote.
The second he said Thermal conductivity , everybody got pissed off 😂
Edit: so many likes ...
Edit: Okay y'all can stop liking it ;-;
thermal* conductivity
at least we reinforced our knowledge :)
Who said thermo conductivity and when did they say it
@@kylewaddle7592 Well, it sounds almost the same, "mo" and "mal", so I can't know for sure. But if you want to find out more about the concept, the term is "thermal conductivity".
@@buttonasas I know thank you though. I just didn't know if someone actually said that
@@kylewaddle7592 Well, Derek said it at 2:41.
And, like you said, the reactions look almost like they are pissed off :D
I'm seeing more and more of your really old back-catalog content showing in my feed.
@Veritasium actually, the relevant physical quantity for how an object feels depending of the material it's made of is its thermal effusivity, and not its thermal conductivity.
When she said "I believe you" I felt like she also said: but I don't understand you.
This is like basic material conductivity, I'm actually a bit surprised at how clueless these people were. Nice vid though, you're really good at presentation.
You shouldn't be surprised. One in four Americans, for instance, don't know the earth revolves around the sun (seriously).
www.npr.org/blogs/thetwo-way/2014/02/14/277058739/1-in-4-americans-think-the-sun-goes-around-the-earth-survey-says
He films people who are clueless for us to learn quicker. I am sure there are people who understood what was going on.
***** Picture this... religious nuts would have you burn 500 years ago if you came talking about thermal conductivity. And people ask me why I don't like religion and its bigots.
Andres .C Religion and Science are just ways we invent to explain things. Science simply has more examples that support it. I think both are cool btw, no wars wanted. Also, in the past, they were idiots, not their fault for not knowing really. Still idiots though.
Ok one has feedback. The other doesnt. You propose, you see if youre right, you believe. The other works in a more colorful manner: you believe, you invariably see that youre right, you propose patches just in case, in the event of failure you then return to step one.
Gives scientifique explanation... I beleive you. Its like showing a painting to someone and they say wow it smells great.
I knew the answer to this. My Chemical Engineering degree wasn't a complete waste of time.
The bit with the ice cube on the blocks was a nice touch and a great teaching aid
"We're creatives not intellectuals" - this comment insults my ambition to become a creative physicist
It's a good thing that you're you and not them, and their opinions about their own selves doesn't in any way impede your progress. Now go be awesome, unhindered by others. Including me.
If life gives you lemons, go burn the bitch house!!!
I'm both a member of Mensa and a professional artist. You are not necessarily one or the other. Be what you choose to be.
***** YES
Walsh2571 I rolled my eyes and said, "shut up!" out loud to myself when she said that. I really hate the term, "a creative" to describe one's self. For some reason it grosses me out and I'm "a creative" apparently. Ewww. Self important douchery.
What a great experiment. I know it’s hard for people on the street to come up with any conclusions on the spot. I’m sure you jogged their memories of science class. Sitting in my chair watching similar videos, it came to me that it was about conductance of heat very early on. If I was out at street party it would be hard for me to think back to what I’ve learned about the subject.
If you're the kind of person that watches this channel, you probably knew this already.
I feel like he glanced over a crucial factor that will make this more clear to most people when explaining this effect.
Body temperature.
Since the objects being touched are colder than the body temperature but warmer than melting temperature of water, the metal/aluminium feels colder to touch while also melting the ice cube faster.
If the book and the metal is warmer than body temperature, it would have the opposite effect where the metal feels warmer than the book.
"OK I believe you." means she still don't understand. 😂
well, one of the experiments i knew what would happen before it happened, because i've spent enough time working with electronics i know a few things about thermal conduction. You should have done the trick where you take two metal tubes, one that's warm to the touch, the other is cool to the touch (neither enough to feel unpleasant) then have them hold both tubes in the same hand and see how it suddenly feels extremely hot/cold because it's not just the thermal conductivity that determines how we perceive temperature, but also the difference between two substances (which is also one reason you feel colder when you have a fever, even if the air temperature around you is the same as always; the other reason being you have the heat being transferred out of your body faster because the temperature difference is greater)
If you ever get the opportunity to have some thin piece of silver like a knife, try cutting ice with it. Silver having the fastest conductivity of any element makes it so that a silver knife can cut through ice because it melts it so fast on contact.
@veritasium, hello and thank you for your mesmerizing videos, i always enjoy them.
After watching the one about entropy, i think we need one (similar in quality) explaining temperature, how it does transfer, etc.
Thanks again.
(For example, in space, if you put a hot cup of coffee, it will freeze ? But since the space is empty, to where did that heat transfer ?)
Some say that temperature is like a kinetic energy of the atoms, let’s trap one atom and heat it, what happens inside when getting heat and how does temperature transfer in and out it and what actually transfers ?)
im amazed as i take this for granted and im blown away that so many people dont realise this..
When he starts explaining
*ok now it's not fun anymore*
That dude in the green hoodie is a true intellectual with knowledge we could never even begin to grasp.
This experiment reveals a lot more than people's lack of knowledge on temperature.
yes, epic stuff exactly because of what you say. So basic and so complex - so epic!
If he asked you, how it FEELS, of course you say, the aluminum FEELS colder than the book which is correct. The problem now when he asked if they had the same temperature though which is pretty confusing for someone who just said it FEELS colder.
2:32
Me: my ice melting in the air,
*cOuLd aiR bE bAd fOr tHe eNvIroNmEnT?*
….but you can have too much of a good thing
While people with too little earwax are likely to experience itchy ears that are more prone to infection, an ear canal blocked up with earwax can cause earaches, mild deafness, a sensation of fullness in the ear, tinnitus, infections and other problems.
Your earwax says a lot about you
There are actually two kinds of earwax - wet and dry. Wet earwax is more common among Caucasian and African people and is typically dark yellow and sticky. For those with East Asian or Native American ancestry, ear wax is typically light in colour, dry and flaky.
@@GreenGoblinCoryintheHouse I've heard that it's actually fatal to humans and everyone who has ever breathed it has died roughly 75 years later
@@benjaminrogers9848 actually that's true. Oxygen "ages" you faster.
The sun is warming the earth, does that mean the sun is bad for the environment?
Mr. Nice Man yeah it is called global warming, yes this air is bad for environment (at least its temperature 😁)
You should make a video on why thermal velocity, responsible for temperature, is different from normal velocity and therefore why different units are used to measure temperature and velocity (degrees vs m/s). I am having trouble understanding it
Love you finding this answer for an half hour