Heat and Temperature

We all know what it's like to feel hot or cold. But what is hot? What is cold? What is heat? What does temperature really measure? Don't pretend like you haven't lost sleep over this. Well you don't have to fret any longer, Prof Dave will take you through the details.
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[@professor_m_gibbons]

@3:03 - the transfer of heat energy will NOT always alter the temperature of a system, such as when a phase change is occurring at a constant pressure. Very common misconception, so watch out.

[@ProfessorDaveExplains]

Yes good point, that was a misspeak on my part.

[@professor_m_gibbons]

@@ProfessorDaveExplains It's true 99% of the time we're talking about solid objects though, so I understand. Thanks for the reply!

[@10anjalinarayan60]

@@ProfessorDaveExplains u can pin her comment

[@localverse]

@@professor_m_gibbons Does that mean the heat's energy temporarily stops going into kinetic energy and instead goes into breaking bonds at the instance of phase change (with constant pressure) then switches back to affecting kinetic speed of molecules after the phase change?

[@smaran353]

One question: Isn't the expression "heat flows from" misleading and incorrect? Instead, the expressions "thermal energy flows from" or "heat flow occurs from" are actually correct, isn't it?

[@morrainn815]

man,,, this dude really be saving my grades. thank you professor jesus

[@samyukta4746]

jesus😂😂

[@kingboi7856]

jesus LOL

[@leagodalle995]

yooo look at the top of his head!

[@dalemalunes1100]

Wtf QHAHAHAB

[@AnthaxPhotoworks]

Hello

[@pritchardsangai3288]

I love the explanations, thank you very much.

[@alias40anon]

Excellent short and simple explanation.

[@joserobing661]

Thanks for your clarity of ideas and simple presentation

[@vivianasierra1]

thank you I needed this video for my end of the year test!!! :)

[@SW-nx4jz]

Omg your the best! Thermochemistry is so confusing to me but your making it alot easier. I can't say thank you enough for these quick video!

[@paramitam4002]

teen Titans go Can we feel temperature kzbin.info/www/bejne/qXzLlJSiZqaVf8k

[@kedarparab8001]

Man you actually explained nicely and scientifically than other videos

[@chrispieG]

Professor Dave. You're the man!!! My Gr. 10 class finally gets it.

[@ShyaMKumAr-bo1ji]

*GREAT EXPLANATION* 🙏

[@jorostuff]

I love when he says: "Let's check comprehension." I LOVE IT!

[@Jen-gl1hn]

Ikr!! Like it helps me a LOT

[@aedenthegreatyt]

My Chem. Honors teacher had me watch this video for an assignment. I was not disappointed.

[@carolarentz3208]

Thanks so much for the video it helped A LOT!!!! :)

[@aedenthegreatyt]

Any hard science concept: *exists* Dave: *Understandable, have a great day*

[@retsepilemothepu1396]

My Physics improved from 50% on semester test 1 to 97% on semester test 2🎉🎉 Thank you sir, I have nothing to offer. I’ll thank you properly in the future.

[@geramaerosales572]

Great Video! very useful as a resource material

[@voltdragneel1052]

after 10 hours I have my chemistry test and I was reading thermodynamic when I see notification of your video lol and yhea you're videos are useful

[@ProfessorDaveExplains]

more thermo all next week!

[@prisminc158]

Is that Kaneki/Haise?

[@controlequebrado4455]

your*

[@niceguy4801]

Thankyou professor dave!

[@raedibrahim9409]

I love your lectures 😍

[@subhashishbehera2424]

Sir you're explaining things really good

[@kevinlapulapu8651]

thankful for your lecture

[@nirupamam2814]

All of your videos are very very very very nice....

[@rajpanigrahi7008]

Hello Dr Dave... you explain everything in very easy way, so anyone can understand it easily...I am the first to watch and comment on this video.

[@binabonmary.marbaniang6456]

Love the explanation👍👍👍

[@eyobwendmagen849]

I rely understand Difference of Temperature and Heat. I like your explanation system. It is easy and nice.

[@cbtaylor303]

I have a question that has troubled me for some time (making the link between the atomic world to the macroscopic). What happens if we have a spaceship in outer space, and let’s say it’s a perfect vacuum (so no friction will occur). If we accelerate the spaceship, it now has higher velocity and so higher kinetic energy. You could say therefore it has higher temperature? After all the average kinetic energy of all the particles has increased? This doesn’t make sense though. Is temperature relative? Another similar problem, say if the earth sped up due to a gravitational force, does that mean our individual temperature increases, after all our kinetic energy has increased.

[@kurage_medusa]

Kinetic energy is based on velocity and velocity is relative, so temperature is too. If you accelerate an object in space relative to something else, I believe that it would count as increasing the average temperature of the system, as there would be more kinetic energy available. It would not increase the temperature of the object itself however, since relative to itself the average kinetic energy of its particles is the same.

[@shirohanna]

Great video and visuals. Thank you! Follow up question: The high specific heat capacity of water is due to strong covalent bonds of Hydrogen and Oxygen molecules INSIDE each water atom? Or, strong bonds between water molecules? Thank you, again!

[@jilliandavenport9404]

Taking my last CSET and need to know this info. Clear ,concise and very helpful! Thank you!

[@user-fi8pi3eo5s]

Great explanation!

[@Ethan-uo6fv]

2:22 Not all phases of matter expand with higher temperature. Water for example, is at its densest at 3.98 ⁰ C (according to the internet). Contraction upon heating in solids is called "negative thermal expansion."

[@lowall]

i like very to the point and easy to understand :D

[@hindutva2685]

Outstanding explaination sir

[@ghazalabibi9570]

@Professor Dave Explains I love all your highly educational videos that you do here on KZbin. I have a question! How come cold temperatures have a limit of around -273 C and warm temperatures can go well over 10,000 C or even can be over 1 million degrees? Please explain - THANKS.

[@ProfessorDaveExplains]

that's absolute zero! a total absence of kinetic energy

[@kotishjaiman8231]

Just like you can take away only 1 liter of water from a 1 litre beaker but you can keep adding water to it eventually leading it to overflow and you can still just add more. Atoms have a definite amount of energy so you can take away only that small amount, whereas you can give it a lot of heat but after a point its structure will be affected maybe bonds will break (in case of molecules) and after a point you will get plasma.

[@oliverbrunncarstens4215]

Thank you Dave!

[@mohammadhafeezullah1846]

thanks for my completing the first question of my assignment

[@binadam9459]

I love you man, you are brilliant

[@hari8654]

Thanks you sir most conceptual video

[@alriktimo644]

Can I say that any system has no need to transfer its energy to the other one in contact but as a natural consequence of action and reaction the energy gets distributed, eventually making the whole system reach equilibrium. Doesn't necessarily imply that energy is transferred from hot to cold and not from cold to hot it is just that the former does the transfer with a faster rate than the latter. Correct my intuition if I am wrong.

[@Jihad_Sakib]

Man, your are so amazing 💗 , thank you 😊

[@howitzerm777]

i just saw the intro and was instant subscribe push!

[@crazygamers9574]

तुला जास्त येतय का वेड्या

[@po4187]

wtf his intro is cringe asf

[@fooliery6216]

I ended up here after watching the first 4 videos in the "Math and Science" channel -chemistry 1. It become paid to see at the same point where Prof. Dave here pics up the topic. Thanks for not making me Pay to Learn Dave. I wanna learn for free

[@katrinamae3510]

The song at the checking comprehension is so calming lol

[@ghost0_01]

Wow thank you so much!

[@SamiUllah-bg2br]

You have no indeed explained it very well sir

[@danielcastagna1941]

Thank you so much Dave Grohl \m/

[@user-dg6lo9fn8u]

Thank you sir!

[@ahappyimago]

U da man, dave!!

[@robertolara3820]

great man!!!! thanks!!!!

[@mahmoudhalawa5588]

Thanks so much ❤️😊

[@abdullahalhabsi9302]

I have an assignment due next week hope similarity doesn’t go high 😅 thank you professor

[@abutaymiyyahlectures]

this lecture was mind blowing ngl

[@asifmandal9758]

Thanks :) Professor Dave

[@narender6464]

Thank you so much 🥰

[@rekhadevi9672]

Helpful..!

[@abrarmohammed6735]

Thanks 😊

[@kabouch]

The covalent bond stretching and bending is an example of potential but not kinetic energy, am I right?

[@subikshayakumar9779]

Thank you sir

[@raizenvillagracia7644]

Thankyou professor

[@tokahuissen6615]

it is really good

[@richardfraussen1057]

Wish I had professor Dave videos during my studies, 55 years ago.

[@aksharasbhat6480]

hi professor dave ,i have one question,if temperature is nothing but kinetic energy why is it considered a base quantity

[@TheLivirus]

Explain to me the process by which temperature (the average kinetic energy of molecules/atoms) converts into thermal radiation over time.

[@princerao6525]

can u made a video on optics complete theory...plzz

[@incrediblestudios5609]

I love you Professor Dave

[@akrm2944]

Is it better to use High/Low than More/Less kinetic energy in 4:00?

[@ProfessorDaveExplains]

eh, either way!

[@brianfrancis5548]

"all phases of matter expand with higher temperature" actually not always true. the density of water decreases as the temperature increases from 32F to 39F

[@Meringue_Pie]

saved my life and my science test, thank you

[@EricPham-gr8pg]

Is pressure and intensity or decibel and compression of space elasticity

[@angeliemaebonaobra4448]

Professor Dave! Thank you!

[@rajthegamerz7118]

so long suker

[@rajthegamerz7118]

hey

[@christianmgbike6188]

When two objects or things are in thermal equilibrium, are their molecules vibrating or moving at the same speeds due to same temp?

[@turnitinplagiarismreportch1973]

i have a question what is relationship between heat and flame if you get my point please clarify me!

[@nugget...]

You are just great❤

[@bellaferreir6732]

UR THE BEST!

[@ProfessorDaveExplains]

you are!

[@ohmy9261]

You're the man dave

[@IEleMenTIx]

1:20 faster moving particles with higher temperaure ... is correct for gasses and liquids, but not a sufficient expression and explanation for temperature changes in solids. One could misinterprete the statement and think that the atoms will vibrate more often, which is one of the most frequent misconseptions I have read about on scientific websites and forums about atomic motion. Every molecule, molecular solid or atomic solid has characteristic vibration frequencies in the range of 10^13 Hz due to their mass and force interactions. For example: If the frequency of a radiation source matches a molecules or atoms natural resonant frequency it begins to vibrate stronger, not more frequently! Now the energy of those vibrations can be transferred in solids due to whole lattice vibrations called phonons. I'm not trying to give a lecture here. But its such a common misconception that people say if you heat stuff, the frequency of the atomic vibrations increase, which is absolutely NOT true. It's the amplitude of the vibrations that gets larger. Of course this explanation was viewed at with classical mechanics, quantummechanically everything has to do with probability waves and distributions... but the probability of finding a particle will shift towards a higher distance if we give the system more energy. If you look at the asymmetric potential curve you get the idea... The frequency of atomic oscillations simply do not change, otherwise IR-Spectroscopy would not work, as peaks would shift around all the time being a strongly temperature dependant measurement method, which it is not! One thing you can get is overtones of vibrations at higher temperatures... The frequencies which change will eventually be those of the whole macroscopic lattice due to thermal expansion and changes in the elastic modulus of the solid. I think why most people think that atoms change their vibration frequencies is due to incandescence... simply speaking if the amplitude of a vibrating system increases but the vibration frequency stays the same, the particles have to travel a longer distance in the same amount of oscillations. Thus ultimately your statement is correct that the particles have to move faster. Faster moving particles means that more energy is involved... Electromagnetic radiation is generated by the movement of charged particles in space, so at temperatures of around 800 Kelvin our eyes begin to see dim red light emitted from that object depending on its emissivity. At these temperatures the atomic vibrations are so intense that the strong acceleration and deceleration leads to the incandescent effect emitting red light. Plancks law, Wien's displacement law and the stefan boltzmann law are responsible for the shape of the function, the maximal emitted wavelength at a certain temperature and the intensity of the radiation... OK sorry this has escalated to become a lecture ;)

[@ProfessorDaveExplains]

interesting! i see your point with IR, that makes sense. at any rate, this was a little more in the context of gases, but this is excellent supplemental information.

[@IEleMenTIx]

thanks :)

[@sandk7969]

Sound energy make air particles to vibrate and so does solid object.. do sound have some kind of temperature? I mean will sound energy transfer faster in high temperature condition and do otherwise in lower temperature.

[@pram5532]

That has to be the longest KZbin comment I've seen - and not read.

[@xOxAdnanxOx]

Praveen M the longest “ useful “ youtube comment I have ever seen.. u should read it

[@maxamuudsagaar5405]

Good idea

[@iqrayousaf6898]

My question is if any object having 37 celsius temp and our body has also d same then we will feel any cold or hot sensation or not

[@ProfessorDaveExplains]

if they are at the same temperature there should be no heat transfer.

[@carolarentz3208]

YOU SHOULD BE MY TEACHER!!!!!!!!

[@AlexKnauth]

(2:17) "all phases of matter expand with higher temperature, whether solid, liquid, or gas" What happens with Water when it's at the freezing point? Or just above it about to freeze? Ice is less dense than water so how does that work?

[@carultch]

That's a special condition in a substance that is a special case. Throughout the majority of water's heating from absolute zero to vapor form, it expands when adding thermal energy to the system.

[@btsblackpink957]

I have a question.... If temperature measures the flow of heat then why do we not have any unit for say flow of pressure, potential,charges etc. Why only flow of heat gets a whole new SI unit

[@waffles_1823]

This is damn useful I even subscribed

[@tsehayenegash8394]

what is the differnce between work done on the system and work done by the system

[@shvel1648]

Very didactic! Congrats... By the way, what kind of tools do you use to create your videos?

[@ProfessorDaveExplains]

adobe after effects!

[@sdvsdv4833]

Best lecture

[@amishakahar1282]

your video helps

[@mamathashaik2452]

Sir ur just awesome sir ur the best sir

[@markjones6133]

Temperature is a proportional measure of the average translational kinetic energy of the random motions of the constituent microscopic particles in a system (such as electrons, atoms, and molecules); Wikepedia. This definition contradicts the definition in the video. Which one is right?

[@ProfessorDaveExplains]

My definition specifically says "relates to the average kinetic energy of the molecules in the system". How are you seeing a contradiction? They are the same, mine is simply more intelligible to the average viewer.

[@pencilman7474]

So that means that for heat to exist there needs to be molecules, which means in an absolute vacuum, there can't be heat because there is nothing to absorb, which is why supposedly there is not much of a problem with heat in space, and this is why light(photons) could travel really far distances? Ok, and this means more dense objects have a higher warming capacity, which means it is able to absorb more, and this is why light molecules have low warming capacity/get hotter and colder faster, ok thanks for the information!

[@ThePhoenixSlayer]

Thanks Dave for all the informational vids you've been making over the years! I know you sometimes still read the comments of your old vids, and I have a question. In my science class, our teacher was talking about heat and temperature. She mentioned heat energy, but then corrected herself, calling it "warmth" energy. I'm not sure if my translation works perfectly, as I'm not learning in english, but as far as I can see it's accurate. Could you think of any reason for this change, or are these terms sort of interchangable?

[@gamingammar3838]

Thanks

[@jolynemalone]

uh thanks my school book gives a explanation on this subject but it was not very good

[@playingsometimes7290]

Nice i can understand it Wow

[@littletin8453]

the intro is the best i have seen

[@DoubleMrE]

Yay Dave!

[@shahrukhkhankhan6264]

If we take two molecules of a monoatomicgas in a cylinder.why they have not contain same kinetic energy.but we know they should come be In thermal equilibrium

[@guidomista3570]

Professor Dave is the Oversimplified of science, change my mind

[@abdullahbaloch8013]

Will you make a video on how infrared radiation increases kinetic energy of particles

[@mechanicalvibes7927]

@1:07 temperature is not the measure of heat energy available for work in a system

[@kimsahl8555]

Is heat the reason for motion of molecules/is the motion of molecules the reason for heat?

[@sowmyatirunagari1434]

Very helpful..

[@christinetorres8075]

Yea it is

[@srenbohn4904]

Please explain "work in a system", This is the only part I don't understand what means 🙂