The Misunderstood Nature of Entropy

Entropy and the second law of thermodynamics has been credited with defining the arrow of time.

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Entropy is surely one of the most intriguing and misunderstood concepts in all of physics. The entropy of the universe must always increase – so says the second law of thermodynamics. It’s a law that seems emergent from deeper laws – it’s statistical in nature – and yet may ultimately be more fundamental and unavoidable than any other law of physics.

Hosted by Matt O'Dowd
Written Matt O'Dowd
Graphics by Grayson Blackmon
Assistant Editing and Sound Design by Mike Petrow

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[Valdagast]

My cat goes out into the cold, then comes in to warm himself in my bed. He is a sort of engine for moving heat out of the apartment. I don't know if he does any useful work, though.

[thomascorbett]

Now that I'm 70, I have a clear understanding of entropy when I look in the mirror .

[yuccapalme]

"keep beeing that brilliant macrostate that is you" ... noone has ever given me a better compliment ☺️

[observing]

Holly crap, this was my Astronomy professor last semester. Thanks for the lessons 👌🏻

[UnidentifiedAerialPhenomena]

""Welcome to Entropy Burgers - may I take your order?"
"I put in disorder a long time ago. The service here is getting worse all the time."
"My experience Gibbs me reason to believe you."
"I know the waitress who asked that, too. Her name's Ellen Omega. She really made me thermally dynamic. So, I asked her out. I tell you, when she don't like you, she really Boltz, man. Women like that are never distributed normally among the population."
"What kind of Poisson would say something like this?""

[Minecraftster]

IN THIS HOUSE WE OBEY THE LAWS OF THERMODYNAMICS

[MostlyPennyCat]

I prefer the sand castle analogy.
There's trillions of arrangements of sand particles that define the macro state "lump of sand"
But there's only millions that define the macro state "pretty sand castle"
That's why the wind turns sand castles into lumps of sand, not lumps of sand into sand castles.
Straight probability.
And it shows you the "arrow of time"
What I've always wondered is, does increasing entropy create the arrow of time?
Or does the arrow of time increase entropy?
Does time even exist?

[FrntRow]

It blows my mind how good Matt is at presenting! Explaining the most complex physics and topics science has, every time I watch I feel like I understand something, for a Atto second, then he says something else and it's gone.
Your the best Matt keep it up, I might be able to hold on to some of your conversation soon enough.

[DutchDeLorean]

I spent a semester in college writing a research paper on entropy. That's what it took to get me to wrap my head around the subject...

[suneperera]

thanos:"i am inevitable

2nd law of thermodynamics:"hold my beer"

[KafshakTashtak]

Regarding all air atoms being in one half of the room, does that mean if a tree falls in the other half, there is a chance it does not make a sound?

[Jacktrack]

I've been trying to understand Entropy for a couple of years by now, I watched the video... I still don't get it xd

[rDnhey]

I'm going to reverse entropy, hold my beer... yportne.
Done.

[judgeomega]

i think this is my favorite space time episode. revealing how a law arises out of possibilities is just mind blowing.

[BrendanSteffens]

Really well explained. The gou board analogy was a brilliant touch.

[davnape]

This guy looks like he's got two personalities: a calm, academic one for the cameras and wilder one for the pub with his mates lol

[meleardil]

There is just one thing I would like to add. In every episode you state things, and draw conclusions in a very elegant and simplified way. It would be just a nice touch to emphasize every time, what was the fundamental assumption on which the whole model is standing, and what would be the consequences if that axiom would not be true. In this case the fundamental assumption is that ALL possible physical states are EQUALLY probable. It is possible to change the outcome of a phase propagation by messing up the probabilities. Also, even when you keep the "equally probable" axiom, the macro probabilities are highly dependent on the definition of the micro states. That is also a good filter for messed up theories. Not to mention that the infinite improbability drive is the MOST powerful machine that anyone can construct, as it practically means omnipotence.

[thenotflatearth]

If my room is the entire universe, heat death has already happened

[rceby]

Although I rarely comment on a YouTube contents, this made do so. Just wow! Finally, the best explanation for entropy. Thank you for this!

[WildsDreams]

I'm obsessed with the idea of entropy. Thanks for this!