A better description of entropy

The reason that train isn't moving is because the driver wants to postpone the heat death of the universe by not increasing entropy.

Sir, you are a huge clump of energy and enthusiasm!

First watched this video when I was in high school, found it absolutely fascinating and was at a time in my life where videos like yours were interesting me into pursuing STEM education. Now, years later, doing my MEng degree and learning about thermodynamics, stirling engines, etc in university, so I came back here to recap (you explained it a lot better than my lecturer). Thank you for your contribution to the educations of myself and so many others <3

This really bridged the gap for me between the statistical “ping pong ball” analogies ive heard, and the teachings of physically irreversible processes when describing entropy. Great video!

This particular way of describing entropy is why you always find your earbud cords always tangled up: there’s only 1 way to have the cords straight and untangled but, as you jostle them around in your pocket or backpack, there’s a myriad of ways for them to become tangled.

Entropy increases and so does my understanding of entropy, thanks to this video!

Yes! This is what am talking about. Entropy is increasing not about disorder it's about fair even distribution or spread out. And this also applies to abstract things, for example a high entropy random generator is well spread out evenly. A high entropy checksum is also well spread out that a small change in input make much of the checksum to change into any possible value.

I have a degree in mechanical engineering from a respectable university. I did thousands of thermodinamical calculations using entropy. Yet, you helped me understand entropy better... thank you!

I want someone to look at me the way Steve looks at his Stirling engine

So they had Stirling engines but no ice? One weird train indeed.

You make complex subjects simple and fascinating . I can’t ask for more than that.

I like the ping-pong ball box analogy, as it's also useful for explaining Chaos. You could fill the box with half red and blue balls in the same way, and use a machine to precisely shake the box, then note the position of the balls. Put the balls back in their half/half configuration, and repeat the exercise. The chances are the balls will settle into a different position every time, and you never effectively predict where the balls will land. This system is chaotic. Now I think that arguably, if the balls are set up precisely enough, and the box is maintained precisely enough, and the machine shakes precisely enough, and the temperature is precisely maintained, and it can be isolated from all external interference, perhaps you could predict the outcome of the test, and get the same result each time. However even the tiniest change in any factor will produce wildly different results, such that we cannot conceivably engineer such precise conditions to make the outcome predictable, even if we had an inconceivable amount of analytical computing power. That is chaos.

I'm an Aerospace Engineer, studied at the University of Maryland.  This is by far the best explanation of Entropy I've ever heard.  You get into another level of complexity when solving for Entropy (S) as a function of heat transfer (Q) and absolute temperature (T), but having this foundational understanding gives context to really comprehend your solution.  Good stuff!

I finally understand, after so many videos and articles - now, the clumped energy of my frustration has been dispersed! Thank you!

Thank you so much for this video Steve! Studying thermodynamics at uni right now, and this video is the ONLY one that I have understood. Physics, nature and our universe is just so beautiful, and your video made that ever more clear to me!

I just recently purchased a Sterling Engine model (and a Tensegrity Table) to Science educate my grand-kids (they'll face challenges greater than I've faced, and I'll be 'gone' in 20-30 years, optimistically). In the course of exploring, THIS post was suggested... and I've shared. Thank you!! I feel it was brilliantly explained and worthy of interest. Just sitting on a train, in a station, not moving yet... and an 11 minute compilation of Brilliance I just discovered when I needed it.

As far as I know, out of all entropy videos, only this one mentions why the concept of entropy was introduced and gives a clear reason as to why entropy always increases. You are doing god's work my man. AWESOME explanation. :)

I watch this video before and after my thermodynamics class. Now I understand the video better but I have to say that you explain better than my professor!

Absolutely great video! Not only your definition of entropy is, in my opinion, a lot better than the "measure of disorder" one, but also yours was the very best explanation of how the Stirling engine works (I love Sterling engines). Your way to explain stuff is second to none. Thank you.

Always watch Steve's videos until the very end. Don't ever leave the video thinking it's basically over.