Dear Doc Schuster, I have come to a conclusion. This is my 4th time watching your videos in my 4th period tech class, and this is my 4th time enjoying watching your videos. After multiple discussions with my peers I have made the final decision to subscribe to this channel. Yes, subscribe. By this day I’m proud to say I’m not Tim, but I’m Doc Tim Jr.
"it's great to be known for two sentences way to go Carnot" lol I gotta say your sense of humor and casual way of explaining things goes a long way. I wish my professors knew how to communicate this informally while still being specific and correct with their analogies or metaphors!
Absolutely fantastic as always. I am studying a Natural Sciences: Physics degree at distance with the British Open University and your videos are pretty much my only lectures en route. Thank you very much.
great video! I am doing a problem that involves a furnace to surrounding then a pump back into a house. When I set up my equation for the pump into the house (Qh is given) I get a negative Win. This doesn't make sense because I use Qh to be negative (since it LEAVES the pump and enters the house). My professor put up the equation as (Qc/Qh= -(Tc/Th) and this gives me the correct answer using the sign convention that work on surroundings is NEGATIVE.
distributed renewable energy... somethat is in nearly everyone's home and makes energies lol I have always been fascinated by alternate energy sources. I have tinkered with some hydrogen playing around. I got a couple weird contraptions I wish I could build to test... Thanks for the lesson.
I understand in theory why the cold reservoir is required but why is it really? Get rid of the cold reservoir and all the heat from the hot reservoir gets converted into work except for whatever little is lost to the surroundings.
adugnaw yehuala Downloading a video from youtube is stealing from me and from youtube. Do you hate us that much? Is it even moral to steal from those you hate?
That is, if an engine converts heat into work under isothermal conditions (no cold reservoir, Th=Tc), the second law of thermodynamics is violated. Unpublished notes written in the period 1824-1832 reveal that, at the end of his (short) life, Carnot discovered the first law of thermodynamics and immediately started doubting the second: www.nd.edu/~powers/ame.20231/carnot1897.pdf Sadi Carnot: (p. 225) "Heat is simply motive power, or rather motion which has changed form. It is a movement among the particles of bodies. Wherever there is destruction of motive power there is, at the same time, production of heat in quantity exactly proportional to the quantity of motive power destroyed. Reciprocally, wherever there is destruction of heat, there is production of motive power." (p. 222) "Could a motion (that of radiating heat) produce matter (caloric)? No, undoubtedly; it can only produce a motion. Heat is then the result of a motion. Then it is plain that it could be produced by the consumption of motive power, and that it could produce this power. All the other phenomena - composition and decomposition of bodies, passage to the gaseous state, specific heat, equilibrium of heat, its more or less easy transmission, its constancy in experiments with the calorimeter - could be explained by this hypothesis. But it would be DIFFICULT TO EXPLAIN WHY, IN THE DEVELOPMENT OF MOTIVE POWER BY HEAT, A COLD BODY IS NECESSARY; why, in consuming the heat of a warm body, motion cannot be produced." I think that, almost 200 years later, Carnot's question is still relevant. Isothermal heat engines are possible in principle (that is, the second law is wrong) but they are so slow and powerless that experimental demonstrations (perpetuum mobile of the second kind) are virtually impossible.
Doc Schuster I don't think I understand the question - if you elaborate I may be able to answer it. Meanwhile let me show you something interesting. Consider FIG. 1 and FIG. 2 in: pages.csam.montclair.edu/~yecko/ferro/papers/Fundamentals/Brevik_ElecMagnFluids.pdf Can. J . Phys., 60. 449 (1982), Fluids in electric and magnetic fields: Pressure variation and stability, I. BREVIK: "FIG. 1. Two charged condenser plates partly immersed in a dielectric liquid. (...) FIG. 2. The hydrostatic pressure variation from point 1 to point 5 in Fig. 1." FIG. 2 shows that the hydrostatic pressure between the plates of the capacitor is much greater than that in the rest of the liquid. Therefore, if we punch a small hole in one of the plates, somewhere between "3" and "2" in FIG. 1, water will constantly flow through the hole, pushed by the pressure between the plates: energythic.com/usercontent/3/DIEPHOPU_caphole.gif It looks like the second law is violated, doesn't it? More references: www.amazon.com/Introduction-To-Electromagnetic-Theory-Perspective/dp/0763738271 Introduction to Electromagnetic Theory: A Modern Perspective, Tai Chow, p. 267: "Calculations of the forces between charged conductors immersed in a liquid dielectric always show that the force is reduced by the factor K. There is a tendency to think of this as representing a reduction in the electrical forces between the charges on the conductors, as though Coulomb's law for the interaction of two charges should have the dielectric constant included in its denominator. This is incorrect, however. The strictly electric forces between charges on the conductors are not influenced by the presence of the dielectric medium. The medium is polarized, however, and the interaction of the electric field with the polarized medium results in an INCREASED FLUID PRESSURE ON THE CONDUCTORS that reduces the net forces acting on them." farside.ph.utexas.edu/teaching/jk1/lectures/node44.html "However, in experiments in which a capacitor is submerged in a dielectric liquid the force per unit area exerted by one plate on another is observed to decrease... (...) This apparent paradox can be explained by taking into account the difference in liquid pressure in the field filled space between the plates and the field free region outside the capacitor."
Amazing how a good teacher can make a concept so understandable.
Dear Doc Schuster,
I have come to a conclusion. This is my 4th time watching your videos in my 4th period tech class, and this is my 4th time enjoying watching your videos. After multiple discussions with my peers I have made the final decision to subscribe to this channel. Yes, subscribe. By this day I’m proud to say I’m not Tim, but I’m Doc Tim Jr.
"it's great to be known for two sentences way to go Carnot" lol I gotta say your sense of humor and casual way of explaining things goes a long way. I wish my professors knew how to communicate this informally while still being specific and correct with their analogies or metaphors!
That's nice of you to say - I'm totally shooting for that balance of silly and right.
hero’s engine is a spinny bong of sorts
Ahh, I found the perfect video..! Unfortunately I did my exam already, so understanding this now isn't helping me that much :P
This is so helpful! I'm so glad I found your videos! (also your sense of humor is great)
Dude these videos are really helpful. Thanks for keeping it simple and and making the concepts understandable.
I like your style. Thank you for the video ! !
You are great at explaining stuff! Thank you so much
Thanks alot for the video
Absolutely fantastic as always. I am studying a Natural Sciences: Physics degree at distance with the British Open University and your videos are pretty much my only lectures en route. Thank you very much.
you explain things so well, thank you so much! ♡
very impressed after just watching 1 video, subscribing and going to watch more!
You are simply awesome
according to carnot theorem "NO CYCLOE CAN BE MORE EFFICIENT THAN A REVERSIBLE CYCLE OPERATING BETWEEN THE SAME TEMPERATURE LIMITS
Thanks sirji
Can you do a video on Stirling engines and Ericsson engines?
great video!
I am doing a problem that involves a furnace to surrounding then a pump back into a house. When I set up my equation for the pump into the house (Qh is given) I get a negative Win. This doesn't make sense because I use Qh to be negative (since it LEAVES the pump and enters the house). My professor put up the equation as (Qc/Qh= -(Tc/Th) and this gives me the correct answer using the sign convention that work on surroundings is NEGATIVE.
Hi Doc, just wondering, what's the cold reservoir in Hero's engine?
Jade Tan-Holmes Wonderful question. Same one used by automobile engines - the atmosphere.
You are amazing. Better than Khan for sure. Wish you had more videos tho
Daniel Ray Thanks, Dan! Where should I go next?
maybe some more physics concepts? or physics real-life applications?
tysm
Hi continue these videos
What does a reversible process mean?
distributed renewable energy... somethat is in nearly everyone's home and makes energies lol I have always been fascinated by alternate energy sources. I have tinkered with some hydrogen playing around. I got a couple weird contraptions I wish I could build to test... Thanks for the lesson.
I understand in theory why the cold reservoir is required but why is it really? Get rid of the cold reservoir and all the heat from the hot reservoir gets converted into work except for whatever little is lost to the surroundings.
I am not able to understand why a reversible process is more efficient?
Please download
How to download?
adugnaw yehuala Downloading a video from youtube is stealing from me and from youtube. Do you hate us that much? Is it even moral to steal from those you hate?
That is, if an engine converts heat into work under isothermal conditions (no cold reservoir, Th=Tc), the second law of thermodynamics is violated. Unpublished notes written in the period 1824-1832 reveal that, at the end of his (short) life, Carnot discovered the first law of thermodynamics and immediately started doubting the second:
www.nd.edu/~powers/ame.20231/carnot1897.pdf
Sadi Carnot: (p. 225) "Heat is simply motive power, or rather motion which has changed form. It is a movement among the particles of bodies. Wherever there is destruction of motive power there is, at the same time, production of heat in quantity exactly proportional to the quantity of motive power destroyed. Reciprocally, wherever there is destruction of heat, there is production of motive power." (p. 222) "Could a motion (that of radiating heat) produce matter (caloric)? No, undoubtedly; it can only produce a motion. Heat is then the result of a motion. Then it is plain that it could be produced by the consumption of motive power, and that it could produce this power. All the other phenomena - composition and decomposition of bodies, passage to the gaseous state, specific heat, equilibrium of heat, its more or less easy transmission, its constancy in experiments with the calorimeter - could be explained by this hypothesis. But it would be DIFFICULT TO EXPLAIN WHY, IN THE DEVELOPMENT OF MOTIVE POWER BY HEAT, A COLD BODY IS NECESSARY; why, in consuming the heat of a warm body, motion cannot be produced."
I think that, almost 200 years later, Carnot's question is still relevant. Isothermal heat engines are possible in principle (that is, the second law is wrong) but they are so slow and powerless that experimental demonstrations (perpetuum mobile of the second kind) are virtually impossible.
Pentcho Valev Love it. But could you get closer by making an enormous number of very small ones?
Doc Schuster
I don't think I understand the question - if you elaborate I may be able to answer it. Meanwhile let me show you something interesting. Consider FIG. 1 and FIG. 2 in:
pages.csam.montclair.edu/~yecko/ferro/papers/Fundamentals/Brevik_ElecMagnFluids.pdf
Can. J . Phys., 60. 449 (1982), Fluids in electric and magnetic fields: Pressure variation and stability, I. BREVIK: "FIG. 1. Two charged condenser plates partly immersed in a dielectric liquid. (...) FIG. 2. The hydrostatic pressure variation from point 1 to point 5 in Fig. 1."
FIG. 2 shows that the hydrostatic pressure between the plates of the capacitor is much greater than that in the rest of the liquid. Therefore, if we punch a small hole in one of the plates, somewhere between "3" and "2" in FIG. 1, water will constantly flow through the hole, pushed by the pressure between the plates:
energythic.com/usercontent/3/DIEPHOPU_caphole.gif
It looks like the second law is violated, doesn't it? More references:
www.amazon.com/Introduction-To-Electromagnetic-Theory-Perspective/dp/0763738271
Introduction to Electromagnetic Theory: A Modern Perspective, Tai Chow, p. 267: "Calculations of the forces between charged conductors immersed in a liquid dielectric always show that the force is reduced by the factor K. There is a tendency to think of this as representing a reduction in the electrical forces between the charges on the conductors, as though Coulomb's law for the interaction of two charges should have the dielectric constant included in its denominator. This is incorrect, however. The strictly electric forces between charges on the conductors are not influenced by the presence of the dielectric medium. The medium is polarized, however, and the interaction of the electric field with the polarized medium results in an INCREASED FLUID PRESSURE ON THE CONDUCTORS that reduces the net forces acting on them."
farside.ph.utexas.edu/teaching/jk1/lectures/node44.html
"However, in experiments in which a capacitor is submerged in a dielectric liquid the force per unit area exerted by one plate on another is observed to decrease... (...) This apparent paradox can be explained by taking into account the difference in liquid pressure in the field filled space between the plates and the field free region outside the capacitor."