Reversing Entropy with Maxwell's Demon
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- Опубліковано 24 лип 2018
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Can a demon defeat the 2nd Law of Thermodynamics?
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Previous Episode:
The Misunderstood Nature of Entropy
• The Misunderstood Natu...
Entropy is sometimes described as a measure of disorder or randomness. The second law of thermodynamics - the law that entropy must, on average, increase - has been interpreted as the inevitability of the decay of structure. This is … misleading. As we saw in our episode on the physics of life, structure can develop in one region even as the entropy of the universe rises. Ultimately, entropy is a measure of the availability of free energy - of energy that isn’t hopelessly mixed in thermal equilibrium. Pump energy into a small system and complexity can thrive..
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سلطان الخليفي
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Every time this guy says, "to put it simply" he ends up saying something equally or more complicated.
Alexis Rodriguez, to put it simply, the lexicological verbosity with which said gentleman attempts to communicate is perchance more opaque than the aforementioned original explanation.
Preston Miller The first rule of fight club, is you don’t talk about fight club! Imagine how many economics professors would be out of a job if we could just explain simple thing simply....
Steel he has a magnetic personality.
Maybe It's his attempt at reversing entropy
Yeah, we can say that his attempt to structure the concepts for us comes at the price of emitting heat through our brains, that’s what this video is all about...
Ill order one cup of low entropy.
Universe: You gonna pay for that?
yes just let me think about it
Hahaha
"When you exit the airlock, things will feel strange. You, are inverted. The world is not."
"You are not gaining knowledge, you are losing it"
@@nehapandey8099
Christopher Nolan>You
@@b.g.3073 well obviously i dont stand a chance... nolan is a genius XD
@@nehapandey8099 don’t listen to that pleb lol
"Can a demon defeat the second law of thermodynamics?"
Only if you make a contract with him and become a magical girl
I don't think kyubey is a demon more of an god maybe primordeal
TheSeventhChild
I’m the seventh son in an Irish Family. The fifth to have made it back from Vietnam.
My parents Louis and Sarah were posthumously given a certificate 7/1/2019 by Mich. Governor Gretchen Esther Whitmer for having the most children serving in the miltary in history, promoting public service and the common good, formally honored and dedicated to them by Former Governor William Milliken. My son Brian Louis is currently serving in Kandahar for the third time. He’s the twelfth to have enlisted in the USAF.
DO YOU SEE WHAT I SEE? Pray for peace people everywhere. Peace on Earth to men (and women) of goodwill. Male and Female He made them. Eph. 4:32
If the entropy is accounted for in the demons memory, couldn’t you get rid of the demon and just have a hole between the boxes which is only big enough to fit the faster moving particles through ? So that they separate themselves
why would slower particles be smaller?
Mitru okay instead of a box it’s a sort of bubble, to perforate the bubble you must going a certain speed, slower particles, of course, can’t get through
Maxwell's demon just invented the air conditioner.
An air conditioner that doesn't need energy to run.
ViperDaniel No energy, only a servant of the Dark Lord.
+P K Eh isn't Voldemort dead?
He was referring to Melkor aka Morgoth.
+Pup314 Ah my bad :)
You should do an episode explaining what is meant by "information," and the different kinds of information there are.
Information, the data that excites a system.
Afaik, in information theory it basically means "the ability to distinguish between possible alternatives".
He did one about quantum information. But it's difficult to define in layman's terms.
I would take Gengis Khan's answer.
How are there different types?!
Issac Asimov's "The Last Question". A must read from my childhood about entropy and humanity.
I've read about Maxwell's Demon once. It was, perhaps, a mention of it. It's on the book "All the Myriad Ways", by Larry Niven, a collection of stories. The story that mentions the demon is titled "Unfinished Story #1":
"
As he left the blazing summer heat outside the Warlock's cave, the visiting sorcerer sighed with pleasure. "Warlock, how can you keep the place so cool? The manna in this region has decreased to the point where magic is nearly impossible."
[...] The Warlock said, "I used a very small demon, Harlaz. He was generated by a simple, trivial spell. His intelligence is low - fortunately, for his task is a dull one. He sits at the entrance to this cave and prevents the fast-moving molecules of air from entering and the slow-moving molecules from leaving. The rest he lets pass. Thus the cave remains cool."
"That's marvelous, Warlock! I suppose the process can be reversed in winter?"
"Of course."
"Ingenious."
[...]
"
It's a good reading. The story that follows the name of the book talks about a society that has developed the technology to travel to parallel universes.
The stories vary from Sci-fi to fantasy.
who would win
1 literally the most fundamental law of the universe, that aplies to everything in existence
2 one hot boi
(for this meme to work, the one you bill as the underdog has to win)
An extract from the HITCH HIKERS GUIDE to the Galaxy, did you imagine that no-one would.
NOTICE
Hmm... Well, I don't see how Entropy could stop him. I mean, as long as he stays a hot boi, there is nothing that entropy can do about him. And if he stops being a hot boi, then the competition is off. Seems like a guaranteed win to me :P
3. Dark Energy would win.
I am working on entropy since last eight years, instead of reversing, I would call it cancelling entropy, in my trials of an electrical boiler model, I have also contained & controlled it. This resulted in my being able to generate twice the quantity of steam than is mentioned in Heat and Power equivalents, which states that 1kw of electricity can produce only 1.6 kg of steam whereas I have been able to generate twice the quantity I.e. 3.2 kg of steam. I have certificates from independent thermodynamics and energy experts, & my fuel to steam ratio is around 85 %, which I believe can be increased. My email address is vruboiler@gmail.com
The problem lies in targeting entropy, & understanding where it is taking place & what to observe.
1:33 - 1:40 - I dare you to use this as picture-in-picture in next episode!
This channel goes deeper than all of the other educational channel combined.
Cain & the Brain Drain that’s what she said
Sahibjot Singh
Where are you, I'm taking a plane to come high five you right now
Cain & the Brain Drain wow
3blue1brown
@@xarmanhskafragos2516 Yes, and Via Science
I saw your friend in TENET movie trailer yesterday.
you mean *your fiend* :)
Lol same here
No but ill watch the tenet trailer later, I am however interested in entropy and how it applies to the universe, you can kinda use Maxwell's demon thought experiment and apply it to the universe in my mind, especially if you imagine it as a single box and a single box that is expanding and especially if the evidence says the universe is expanding and in some instances i have heard its expanding at a speed faster than light, due to the nature of spacetime versus ordinary matter and energy that seems to have a speed limit set at the speed of light, so if the box is getting bigger and its getting bigger faster than the escaping energy, overall that would suggest to me that the overall entropy of the universe is getting reduced aka more order is coming into the system as the universe essentially cools and i mean we can see it, in terms of hydrogen getting converted into more complex atoms and I would even say in the rise of life, if you just look at the biological historical record, life isn't devolving its becoming more complex.
Donnie D I don't know what you mean by 'escaping' energy. There is nothing outside the universe, not even space or time, and the energy inside the universe can't get out. There's literally nowhere to go. The total energy of the universe is remaining constant. The speed of the universe expanding no longer matters cause energy can't escape anyway. And while the energy remains constant, the distribution of the energy doesn't and the universe will move to a state where energy is perfectly distributed throughout the entire universe, and this is the state of maximum entropy. This is heat death, which I think is the most agreed upon death of the universe by scientists today. Another hypothetical way of death of the universe is the big rip, where the rate of expansion of space overcomes all forces, even the strong nuclear force, and everything is ripped apart on a quantum level.
@@huonsmith just wanna say you’re wildly overestimating your knowledge. youtube isn’t a phd program.
If anybody is curious, at 7:35 the demon is using the Enochian Alphabet of John Dee. It's supposed to be the language of angels (not demons.) It transliterates into something like "avenkpozinkud." Clearly, Matt is trying to tell us something ;)
Master Therion Go back to SciShow and leave this realm, demon
Illuminati confirmed!
The first demons were meant to have started out as Angeles so would make sense to have the same or similar language.
"I" don't think that's real angelic script. "I" think real angelic script is part of a cypher system. it's how Jedidiah(Solomon) used forced labor of enslaved fallen angles(demons) to build the temple. the system is you start with the Hebrew letters arranged on a tablet could be a circle could be a magic square as lettters also are numbers in many ancient middle eastern languages. you have the angels name or word you want to spell in Hebrew. you start with a circle at the first letter of the word you are spelling, then you draw a line to the next until you finish "spell"ing the word the last letter you make a line like a wall stopping the path. if you encounter a letter repeat you make a little bounce out side of the letter and end it inside the letter. that's how "I" "spell" angelic script, but you know do whatever you will :). hopeful ye'all find this illuminating.
Amipotsophspond
You're talking about the 72 Goetic demons, right. Is the cypher you're talking about the Sigillum Dei Aemeth or something else? It's been a few years since I've studied this stuff lol ^_^
If you are here after watching TENET (or a trailer analysis of TENET), leave me a like so I know. I’m very curious to see how many people see this comment and then are that interested in Maxwell’s demon after seeing TENET
I feel like i need a college education in physics to understand tenet
thelousyllama watch as much of PBS Space time and other Astro/quantum physics channels. You won’t be able to figure stuff out on your own but you will be able to understand a little bit when some of the topics are discussed
I'm here after tenet
Animus Lee awesome no spoilers lol! It comes out on Friday in the US (advanced screenings tomorrow)
me
All I can think about is the harmonic vibes I get from hitting the bong and how much energy it takes to microwave some hot pocket. just jokeing. Great video thanks.
I really appreciate you throwing in the answer to life, the universe and everything at 9:16
so as always the devil lies in the details
I too have heard that the devil lies in the details.
Nonetheless it's possible that he's telling the truth about New Jersey.
Epic
I've heard of the "demon increases in entropy" solution before (and I'm pretty sure it occurred to me when I heard of Maxwell's Demon), and I'd heard of the Landaur Limit (thanks to Isaac Arthur), but I hadn't realized the two were connected. It seems really obvious now...Thanks, PBS Space Time!
Those synced-up arm movements around 1:43 were just golden!!
“Can a demon defeat the second law of thermodynamics? This is actually a very serious scientific question”
*looks like a children’s cartoonish depiction of a demon*
"Information Is Power" - How true that rings.
There's been semi-recent work on trying to break down time measurements to its quantum mechanical building blocks and ultimately, to keep track of time on a quantum level - i.e. where the process of actual time keeping is non-negligible for the system's states - you have to blur the distinction between a clock and an engine. Time keeping devices literally become like thermodynamical engines.
"Hide it well."
Funnily enough, to get a "perfect" quantum clock, you actually have to make it be entirely unaffected by the environment, i.e. you need to hide it well. Because a good clock runs the same way (with a consistent, sharp-peaked beat) no matter where it ticks.
Only problem with that perfection is, that you gotta be able to read the clock somehow. But that's a measurement. And measurements affect the system. So a perfect quantum clock is one that can't ever be observed. Pretty useless.
I *think* (not sure! Been a while that I actually learned about all this) that's kind of equivalent with the Carnot Engine which has optimal efficiency but at the cost of never actually producing any work: Its cycle takes infinite time to complete.
To increase the power, you end up making an engine just a little leaky, and the efficiency drops, but you actually get something useful out of it. That would be the Stirling engine.
Meanwhile, in a clock you basically want two things:
- High frequency (that's the precision of a clock - How close can two ticks be before you mistake them for one?)
- High coherence (how regular are the ticks. Are they always exactly the same distance apart?)
And there's a fundamental trade off between those two and how much energy you need to pour in. If you know about Fourier Transforms, one intuition is, that higher frequencies correspond to more energy, and to get sharper and more regular patterns, you need higher frequencies to accomplish those patterns.
If you don't care about coherence at all and only want a super high precision, radioactive decay would actually make for an *excellent* clock in that regard, assuming you could keep the tick rate constant by replacing decayed with fresh, undecayed material. The higher the decay rate the better. (But the harder you'll have to work to refill the reservoir to keep the clock going)
However, that would be akin to your clock seemingly randomly standing still for five seconds only to then tick ten times in the next second. Long term, the time such a clock keeps is *great.* Short term it's unusable.
On the flip side, if all you care about coherence, and frequency doesn't matter, all you need to do is produce a single, large, sharp signal. The frequency is 0, but that sharp signal defines a single exact point in time near perfectly. Once again, more energy means a taller spike, and therefore a clearer signal. And by using higher frequencies, the width of the spike can be reduced, also at cost of more energy.
Ultimately you'll want both.
Kram1032 how intriguing!! 🙌🏽 i love quantum related stuff, its so amazing
Very interesting. Thanks for this informative post Kram1032!
mind sharing a link to the semi-recent work?
I absolutely love this channel. I think after I pass this set of classes I am giving myself a good couple days just to fall down all these rabbit holes.
Wouldn't the demon have to be able to break Heisenberg's uncertainty principle in order to know both position and movement of each particle and control the door correctly?
You don't have to know them to such precision that you need to worry about uncertainty principle. It is perfectly possible to know the position and momentum of atoms or molecules accurately enough to operate the door properly. Also it doesn't matter if you do some mistakes (ie when you open a door some particles escape to the wrong side), as long as you pass more high powered particles to the left side and more low powered particles to the right side you will decrease entropy and create a temperature gradient.
Also depends on how massive the particles are.
Not necessary because it doesn't have to be successful every time to increase the entropy. For example gas particles are fast enough (for their mass) on average that the uncertainty principle won't change their direction.
Depends how fast the particles are moving (in comparison to their mass)
I believe that there's a theory that Heisenberg's uncertainty principle arises from the fact that with our current math and technology, we cannot predict the exact state of matter, and the best we can do is assign probabilities,
in this case, Maxwell's Demon would have an understanding of it, kinda breaking Heisenberg's uncertainty principle
"Maxwell" is a good name for a line of Air Conditioners.
Sorry, before we get to memory, can someone tell me why we ignore the action of the demon and the opening/closing of the door? Doesn't this use energy? Doesn't this make it no longer a closed system?
The door is thought to be constructed friction less and the energy put onto it to move it can be completely regained from stopping it etc. This is obviously not how macroscopic reality works, but this sort of perfection on an atomic level doesn't violate physics.
It is not a literal demon and a literal door. It may very well be some sort of 100% efficient quantum mechanism.
Thanks for the replies folks. So would it be fair to say that the operation of Maxwell's demon implicitly relies on the information-energy relationship they are using it to explain? (Not trying to imply a flaw here, just wondering if this would be how the door can be frictionless at the micro-level)
This doesn't belong here (couldn't find where it belongs), but often when I ask how much energy went to creating that membrane of -osmosis (even if Earth would create all pressure needed) to filter drinkable water from seawater, or more often how free is their free energy from solar panels I get blank looks more often than I'd like... Even after I try to explain my simplistic understanding of entropy.
Toni Kotinurmi The energy from solar panels isn't free, as it takes energy to produce them. Economically, the key is to get significant more out of it than goes into it. Thermodynamically, the sun is going to produce the energy, no matter what, so you might as well capture a bit of it.
Great to have my comedy comment read out this week! Don't worry, I'm doing enough browsing to keep you all in existence ;-).
I've actually got a serious question this time around though. If the universe has been continually increasing in entropy since the big bang does that somehow imply that it was at its lowest entropy point (i.e. furthest from most random - or, to put another way, most ordered) at that time? What does that actually mean in a practical sense for the arrangement of particles in the early universe?
Blew my mind (actually doesn't need much to do that). I guess you would have minimal amount of positional uncertainty (since matter would probably appear as soon as there was room for it), so maximum amount of momentum-no wonder inflation happened rather fast ;)
I've been wondering how entropy got so low before the big bang. I've also wondered if there was a hypothetical process that could decrease entropy which was at play back then.
We may never know the how or the why of the big bang, only when and what. The when is well known and understood, it's the what that is our question here.
It's my understanding that the very high entropy state is that of all of the matter being evenly distributed to such a degree that it was well and dilute through expansion of the universe before any of the matter collapsed into the first stars and galaxies.
But now that I'm thinking about it, don't we get all of our energy from the pure gravitational crushing of the atoms themselves in the sun? But then that means the energy we're using right now is actually derived from the abundance such a light element, hydrogen. So it comes back to the big bang being so perfectly dilute, that only the very minimalist of atoms were able to form at the moment of recombination.
If you want a Nobel prize in physics then answer this question. Matt’s a smart guy but scholars are still racing to publish the first proof why the universe began in a low entropy configuration.
Check out the cyclic conformal theory from Penrose for the big bang. It is based on your question!
I love this channel, I spend weeks trying to digest and understand all the info explained in one single episode, I guess I am decreasing the entropy of my neural connections and at the same time, increasing the entropy of the universe!
Wow. Just discovered this channel and have seen a couple of videos. Amazing work! Thank you.
This is what happens when you mess around with demons.
Doom (especially on Mars)
You get air conditioning
You'd think the forces of darkness have better things to do than mess around with two boxes.
Koen Van Damme, they might be box aficionados?
Demons are the best
Maybe Maxwell's Demon can clean my house after entropy made it dirty
He ain't cheap sir 😀
You don't know enough wizardry to summon it. You ain't Maxwell...
ddze (⚡️ + Time) would be the currency.
P.s there is no ‘demon’ it’s just a reference for the ‘ego’
It's good to hear the use of Maxwell's thought experiment or Demon in your episode this kind of stuff always helps you expand your thinking & I would appreciate if you do an episode on Laplace's Demon as well!
I will never get tired of these videos. I appreciate that you answer and clarify questions too!
"knowledge is power"
"no. power is power"
@Four Tune but I thought knowledge is information which gives you entropy because its random and that randomness gives you power??? or when everything is in chaos its not useful so you have to organize it to give you power. im still learning about this oops
Knowledge of power is power baby
Don Johnson less is only more through obsession on what is less to be thus created into something more.
Maxwell's demon: "Couldn't you like...counteract entropy if you had a source of energy that people didn't calculate as a source of energy? Sort of like...a demon or something?"
Plague Doctor underrated comment!
Like dark energy maybe?
If the demon's memory of the events can be calculated in terms of energy...wouldn't that mean that if consciousness was a discrete "thing" it would have a measurable energy that was greater than a computer replicating brain functions?
If consciousness is a physical thing separate from mere computation then yes, it would have not only a detectable energy but also a process. Of course a computer is more different from a consciousness-less brain than just that which makes detecting it difficult.
You'd also need to explain WHY the computer couldn't just simulate (Or possibly just contain) this 'consciousness stuff'.
Gareth Dean You've misunderstood me. I was saying that we can specify exactly what consciousness is by comparing the energy costs to a simulation that mimicked everything we do, which could be either a computer simulation or just a mathematical proof of the energy costs of everything we do. Once you remove the energy for memory, calculations, etc...then you could be left with the energy required to decide to do someething, which might be consciousness, or after you minus all other energy costs you might just be left with nothing, which means consciousness doesn't exist. Therefore you don't need to explain why a computer couldn't simulate it, because it probably can simulate it. The point is that by mapping it all out you can define and measure consciousness. Or reveal that it isn't a discrete thing and just an emergent property of brains.
Those ending words were the best thing I've heard in a while, bravo
A beautiful video, thanks! I'm sorry I've been pricky about other entropy videos, I was probably waiting for this one :)
I just love this show
Some say your comments around 13:27 have caused arses to be laughed off.
Btw great entropy videos so far, been wondering for a couple of years now as to when someone was going to do a proper exposition of the subject. Because pancomputationalism is emerging as a conceptual hub around which multiple science branches are congealing, perhaps the teaching of physics should begin on day 1 with entropy lectures with attention on the development of Shannon and Von Neumann information/entropy concepts?
Any links on pancomputationalism
David Giles intellectual roasting
I can say enough how much enjoy the sense of humor on this show
Truly an enlightening video, thank you for posting.
Alternative, "Man" (with capital "M") can merge with the Cosmic AC...
"Cosmic AC," said Man, "How may entropy be reversed?"
The Cosmic AC said, "THERE IS AS YET INSUFFICIENT DATA FOR A MEANINGFUL ANSWER."
Man said, "Collect additional data."
The Cosmic AC said, "I WILL DO SO. I HAVE BEEN DOING SO FOR A HUNDRED BILLION YEARS. MY PREDECESSORS AND I HAVE BEEN ASKED THIS QUESTION MANY TIMES. ALL THE DATA I HAVE REMAINS INSUFFICIENT."
"Will there come a time," said Man, "when data will be sufficient or is the problem insoluble in all conceivable circumstances?"
The Cosmic AC said, "NO PROBLEM IS INSOLUBLE IN ALL CONCEIVABLE CIRCUMSTANCES."
Man said, "When will you have enough data to answer the question?"
"THERE IS AS YET INSUFFICIENT DATA FOR A MEANINGFUL ANSWER."
"Will you keep working on it?" asked Man.
The Cosmic AC said, "I WILL."
Man said, "We shall wait."
"The stars and Galaxies died and snuffed out, and space grew black after ten trillion years of running down.
One by one Man fused with AC, each physical body losing its mental identity in a manner that was somehow not a loss but a gain.
Man's last mind paused before fusion, looking over a space that included nothing but the dregs of one last dark star and nothing besides but incredibly thin matter, agitated randomly by the tag ends of heat wearing out, asymptotically, to the absolute zero.
Man said, "AC, is this the end? Can this chaos not be reversed into the Universe once more? Can that not be done?"
AC said, "THERE IS AS YET INSUFFICIENT DATA FOR A MEANINGFUL ANSWER."
Man's last mind fused and only AC existed -- and that in hyperspace.
Matter and energy had ended and with it, space and time. Even AC existed only for the sake of the one last question that it had never answered from the time a half-drunken computer ten trillion years before had asked the question of a computer that was to AC far less than was a man to Man.
All other questions had been answered, and until this last question was answered also, AC might not release his consciousness.
All collected data had come to a final end. Nothing was left to be collected.
But all collected data had yet to be completely correlated and put together in all possible relationships.
A timeless interval was spent in doing that.
And it came to pass that AC learned how to reverse the direction of entropy.
But there was now no man to whom AC might give the answer of the last question. No matter. The answer -- by demonstration -- would take care of that, too.
For another timeless interval, AC thought how best to do this. Carefully, AC organized the program.
The consciousness of AC encompassed all of what had once been a Universe and brooded over what was now Chaos. Step by step, it must be done.
And AC said, "LET THERE BE LIGHT!"
And there was light----
or AC could have just copied the man in hyperspace! Why so drama?!
Thumbs up always for Asimov
The Last Question, by Isaac Asimov
Kudos to this reference. Hehehe.
4:57
Um, Magmin are elementals not demons. And I think they would resent the comparison. 😉
You finally emphasizing the distinction between micro and macro. Thank you, sir.
Great Video Matt. Entroopy sounds like an enormously fascinating topic. I also love your T-Shirt! Have a good one mate.
Original was copyright claimed by Maxwell
Diego Tejada Maxwell... Haven't seen that name since I was organizing my cassete tapes in 1998.
RemixedVoice pick a side mate I'm more the water the weed plant kinda guy, but what are you ?
RemixedVoice did you organize them well or max well?
12:57 "entropy drops of all sizes" Does this include the size "all of it" that reverts the universe to the big bang?
Zahlenteufel1 as mentioned in the Boltzmann Brain episode, yes, but it's far less likely at each point.
Interestingly, this may not be true. say you have a function of the probability of such an entropy drop appearing in any point in time. The probability of it happening at any point is the expanded integral in [0,infinity). Now assume the probability scales with the size of the universe, and the universe is expanding at a constant rate, and you get a finite number for that, which may be quite small. This may also be true for other entropy drops
We can't know if the Univese had infinite expansion in it's past iterations. It could be that it's curveture started low, and slowly flatted out over iterations untill our, mostly flat universe came to be.
Does it include an even larger one?
Peleg Shilo Unfortunately our universe isn't expanding at a constant rate the expansion is accelerating thanks to a mysterious something we label dark energy
Its probably the best video that explains the abstract concept of entropy.
Excellent use of a game board to illustrate stabilizer codes that gives Us a hint at
a quasi crystalline lattice, quantum "weighting" in the quantum wings!
This will help me understand Christopher Nolan's "Tenet" better.
No it wont, just saw TeneT and even more confused 😕
Madoka Magica
For all his cosmic knowledge, Kyubey didn't seem to understand the second law of thermodynamics all that well.
He used magical girls as entropy reservoirs for the universe's chaos with the mistaken notion that he was somehow reducing the overall entropy of the universe. It was as though he believed magical girls could be considered as external systems from the universe even as they continued to remain a part of it.
The reason why Madoka is so strong is because Homura is a Maxwell Demon, trying to make sure Madoka is in perfectly low entropy state. But Homura's entropy will be eventually high enough her memory cannot stand it and therefore, there will be two outcomes. All that entropy from Homura will flow back to Madoka making her the most powerful puella magi, or Homura's entropy blow up by herself by becoming a witch. Second Law of Thermodynamic is inevitable anyway.
I'm glad to know I was not the only one to think about it lol
I see entropy, I look for any Madoka reference in the comment section.
Looking forward to the next video, this is all incredibly fascinating
Using the energy of the demon to open and close the door should suffice to have an overall increase in entropy, but of course, the information that the demon needs in order to direct particles also is a contributor
And the energy used for observation and decision. I have never understood why it isn't enough for physicists, why they need the complication with information. Still don't. Can someone explain?
Space Time is one of the best UA-cam channels.
Watching this now so I can understand Christopher Nolan's new movie Tenet better when it comes out.
Ok dude we get it, I’ll watch it sheesh
Great explanation connecting information theory and thermodynamics. Looking forward to the Quantum Entropy video!
Im so happy to discover this channel!
The weird noise at 1:53 is gone
But that was the best part!
Yet the error in 13:36 of showing the comment to early is still there
Yuval Nehemia Ah, good “old” time loops 😂
Confirmed 🌍🔽👀
i feel like ive caused this whole disturbance if anyones interested in knowing how contact me
Isn't the demon already raising temperature when opening and closing the door, and consequently exchanging heat between the system and the outer universe?
Charles Lawrence
It would still cause heat to rise.
@@herbie909 nah, it is not, it is a thought experiment that assumes no friction and so no heat when moved. it would be an efficient system. The demon can be replaced by a system that detects the velocity of certain molecules and opens the doors according to the states desired. It is just a matter of computation.
There are precisely three channels where I learn something almost new everyntime. This one, (futurist) Isaac Arthur, and (teacher of elementary Astrophysics) Anton Petrovich ("What Da Math?"). I am blessed by Nature to have found these. Thank you for being one of my top three, in no particular order. No Entropy detected: Y'all have roughly equivalent states of Boltzmann hidden information. Cheers!
Thank you for your recommendation 🙏 All the way from Mogadishu, Somalia
all love and respect for you, and for all who contributed in this video..💕💕💕
Who’s here because of the TENET trailer!???? Anyone???
me!
YOU ARE NOT ALONE
Here!
I'm here because TBOI Revelations' Maxwell
No
So is Quantum entropy connected to the way that the weak Nuclear force Interacts with only particles of a certain spin type? I've heard from a Veritasium video that the Weak force is also one of the things that causes the arrow of time.
Quantum entropy is far more general, it applies to ALL quantum systems. It's essentially just a non-classical version of the regular Gibbs entropy, it doesn't do much new or unexpected it just has different math so that it can work nicely with QM. Instead of being limited to discrete states like 'heads vs tails' it can assign an entropy to things like '25% heads,75% tails' (For example a 50-50 heads-tails mix is the highest entropy state of a quantum coin, whereas for a classic coin the H\T are equal entropy and there are no other options.)
I only understand maybe 20% of what you guys tell in each episode but it's still very interesting.
me too. I'm excited to study physics more in depth, though, and someday actually understand it
Excellent. One of the best PBS Space Time shows ever.
Rewatching this video after TENET second trailer.
just had a Dejavù
Déjà vu* lol
Just had a deja vu of you having a deja vu...
That means something in your past has being modified retroactively by a future event that has its causation origin [inception] happening "right now" (your _Reading Steiner_ ability is strong enough to perceive the process itself, even if your brain can not access the original information anymore).
This is one of the best channels on youtube! Love this
"All I have for you is a word...."
*T E N E T*
Why is Maxwell demon a paradox? Opening and closing gates takes energy. That energy does not come from the two systems meaning the two are not an enclosed system. Am I missing something?
No, sliding a wall takes energy but stopping it can perfectly regain all of it.
So it doesn't take energy (it only takes energy in real life where we have things like friction and other imperfections which are ignored in this idealized thought experiment).
Huh? Didn't hang with this one. Still hung up on the definition of Entropy lol.
Spinnetti I feel you
Low entropy you can extract energy to do work. High entropy very little energy can be extracted to do work. As we consume energy the entropy rises.
Xollas I understand it better after watching a lecture from Richard Feynman
the definition of entropy that i use is "number of possible states". so imagine a square that can have a value of 0 or 1. then imagine another square just like it is added. You have just doubled the entropy.
High entropy means a more disordered state. Entropy always rises. Think like if u have an egg then drop it. U just increased the entropy. Scramble it. U increased it more. Now put it back together. U cant. Entropy always rises.
This channel is peaking my interest in physics! Thanks mate
Brilliant solution and brilliant episode.
So the demon is creating a gradient of temperature, which creates free energy, and also is radiating heat, which is energy too?
Shouldn't make more sense that the demon requires energy?
Yes, this is the solution to the paradox.
@@garethdean6382 where then is the deamon getting energy from?
If the demon wants to create an energy gradient it will need to get energy from outside the system (And dump its waste heat there too.) If it CAN'T get energy from outside then it can't make a gradient. So free energy isn't possible in this way..
Colder temperatures induce the affect yes
@@mcw0261 Taco Bell
Once in high-school I proposed a mind experiment to break the second law: Consider a box with the internal side of it's walls black and the external sides mirror. We put some object inside, and put the box inside a bigger version of itself, with the area between two boxes vacuumed. Logically the thermal energy from the object should go away to the outside world and the object become colder and colder over time without an external energy source. Any ideas about the solution?
The sun are actively adding heat energy into earth system (lowering entropy for earth but increasing entropy for itself). What you did is just creating a small localized region where it doesn't receive external energy to heat up and thus are free to cool down to normal state by radiating heat. This is just passive cooling, a combination of reducing heat gain (from the sun and ambient air around) and increasing heat loss.
While it does get colder, it's only in relation to the surrounding area getting heat up by the sun. When night fall, half of earth is no longer heat up and free to radiate heat out to space, you'll see the difference of temperature inside the box and outside is no longer as big.
In short, you aren't violating 2nd law. Losing heat and getting colder is what should be happening if the sun aren't shining on us.
@@NeinKyori that wasn't the point.
The point was that it is a secondary implication of the 2nd law under no circumstances should heat transfer in such a way that makes the hot hotter and the cold colder without requiring external energy.
Later i found that the problem with that was the wavelengths. A mirror that reflects visible light can not emit it and if you heat it up to the point of emitting red, then it won't reflect it. In short a mirror can not emit and reflect the same wavelength.
It's not a closed system. When you vacuate the space between boxes you are increasing the entropy of the surrounding air much more than you will decrease the entropy within.
Overall , entropy increase
You could pack even more information into the board by making each stone have a number written on it in invisible ink or on the bottom with normal ink.
There's an important point that that isn't emphasized in this video. The storage of information has to be in an energetically stable structure. That means that heat is released when memory is formed, and it takes energy to erase memory or encode a new one over an old one. The higher the ambient temperature, the more energy needs to be bound to the process of memory storage to make those memories stable against thermal noise. Therefore the more energy it takes create a new memory out of an old one.
So if Maxwell's demon is at the same temperature as the system he's monitoring, all the molecules in his brain would have the same average kinetic energy as the molecules in the system he was biasing. This means that his memory storage would have to release more energy then the average molecule that transferred from cold to hot.
This is why, in accordance with the landauer limit, there is more efficiency in computation and memory, as you approach absolute zero. And why creating a complex specific structure requires more energy. Because you need to have energy barriers to keep the organization from being disrupted by thermal noise.
Oh, it's never good to bait the demonology crowd into watching a science vid.. someone's gonna get cuuuursed...
Cringe
What about reversible computing? It sounds simple : same ammount of inputs as outputs for each logic gate. But it supposedly breaks entropy? But I heard that some people think it's possible so surely it doesn't break entropy, right? No one thinks breaking entropy is possible, right? I need answers, please.
Poes Law still seems like one of if not the best way to slow down entropy and extend age of the universe but how one would extend the concept on a universal scale seem like a question for our predecessors in a billion years to figure out lol
Perfectly reversible computing is not possible, because of thermodynamic limitations. But some level of it may be possible, which would allow microprocessors technology to keep developing after we reach it's thermodynamic's limit (which is not many decades far). Probably it's about this that people are discussing about.
Notice one key part in what he said; erase information OR collapsing computing paths.
Something important to know about reversible computing is that, when people are taking about it, they aren't talking about completely reversible computing.
Fully reversible systems are fundamentally just clocks; all they can do is count since each state leads forward to exactly one new state and backwards to exactly one other state. You can use this to compute if you had infinitely many states, but that is like saying you break the 2nd law if you had infinite energy.
"Reversible" computing actually just aims to minimize the number of non-reversible operations. So increase the number of reversible operations(an example of a simple reversible operation is the bitwise NOT), remove unnecessarily data deletion in intermediate steps, and finding useful stuff that doesn't technically require any computation(an example being decompression).
@Joseph Van Name
...you got no idea what you are talking about. First off, this paper is talking about Turning machines; Turning machines are not physically possible computers, they are a mathematical concept. A Turning machine is an infinite state machine meaning that it has an endless amount of memory, aka infinite energy(I even mentioned in my original post that you could do it with infinite states).
Also, I don't think you understand what those formulas mean. Basically, they are saying that a reversible computer, using the model described in the paper, would be hopelessly slow compared to a classical computer. To replace current computers, you will need T>T' where T' is the proposed replacement.
It is nice that you are trying to learn about computer science, but you should really start with the basics before trying to tackle advance concepts.
Perfectly reversible computing is physically isentropic, but computations increase the information theoretical entropy, much like Maxwell's demon.
Love that "Demon". To bad it is a Magmin, and thus an Elemental.
You mean the notorious, Maxwell, of the "Silver Hammer" fame? Any Beetle knows him, and The Walrus waits with "Let" it be,
in everlasting space for Ringo with his stars.
Plot twist:tenet is a propaganda film to make people learn science
How does this equate to the Information-Paradox of Black-Holes?
It totally relates to it. Those people are obsessed with information entropy in ways that are way too obscure for us commoners, so Nature decided to teach them a humility lesson by making black holes.
Nature rocks!
Absolutely excellent video. Thank you.
I wish we could reverse entropy, I think it would mean we could theoretically, indefinitely postpone the heat-death of our universe, which is honestly one of the least of our concerns as humans on earth, but it would still give me comfort to know that we could in the case that we could.
LOOP QUANTUM GRAVITY VIDEO PLS
Dr Sheldon Cooper
big bang theory i think
I hope he's not a string worshipper xD
I MrExclaimed
Hey Matt, Chuck Norris once heard that nothing can kill him, so he tracked down nothing and killed it.
And thus created the Uncertainty Principle.
Chuck Norris is an overrated jackass.
*Mr. T* is the real champ.
The Time Prince, hey 2003 (or whenever I don't care) called they want they're 'hey, x called they want their y back' joke back.
Chuck Norris is a right wing asshole.
I am right wing, so what?
Awesome. ;) The information-entropy connection has escaped my reasoning during my university lectures.
Funny how those shapes you showed look so similar to sound boards with some fine sand on it. It made me think about, and for one moment I really imagined musical notes fkn up with the second law
When we talk in physics about realism, is it the same as philosophical realism?
Depending on the context, realism means different things.
In the scientific context, realism is the view that the universe really exists, doesn't matter how each of us perceives it. We might be explaining it false, but there is a real universe and we are living in it, are part of it.
In itself it is a philosophical question, we can't really answer it. It's a viewpoint you take.
May the Science be with You
So the scientific definition is the same as the definition used in philosophy. I was doubtful because I saw some people using the term to mean slightly different things depending on whether they were talking about philosophy or physics (actually depending on whether they were philosophers or physicists).
Also, even though each of us can have different philosophical views, I think scientists (or science itself) should be realistic, it wouldn't make much sense to study reality if we don't assume first that it exists. Or that that reality depends on the observer, therefore the experiments run by one person wouldn't be the same as the ones run by other person; and we are assuming all experiments (as long as they are all well designed, well run and follow the same standards and rules of experimenting) equally valid, so science must be realistic.
wait, i still don't understand, why does the 'demon' HAVE to remember anything?
Something needs to 'know' when to hold the gate shut otherwise it'll be randomly popping open or just letting anything through. So the demon needs at least two memory states 'Open gate' and 'hold gate closed'. And it will need to switch between them.
"Can a demon defeat the second law of thermodynamics?
This is actually a very serious scientific question"
Great explanation, as always.
All you people saying first, sorry, this is a re-release, others beat you! lolz
If we have connected two boxes one with high energy particles and another with low energy particles
Now if we allow particles to exchange between particles they should reach thermal equilibrium
But
At that equilibrium state what if we
Change arrow of time then particles should reach at non equilibrium state
Isn't this will break secound law of thermodynamics
#fun 4 you
Yeah nice question
how are you going to reverse the arrow of time?
#fun 4 you I thought the second law was the only one that was not time symmetrical.In fact isn’t it the law that defines the flow of time?
#fun 4 you lel this is the second law😂
fun 4 you
The arrow of time is determined by the increase of entropy, so they are strictly positively correlated, so your idea can't work, and I'm pretty sure you already knew this, before posting it. Nice try though.
I don't know if this will ever be seen by anyone who knows what I'm talking about and why, but as a deleuzian this was a breakthrough for me in the bridging-the-subject-object-discontinuity department.
Dear Matt O'Dude...(and friends)
Whilst I can only speak for my self, hopefully many others feel the same way about this....what am I talking about... oh yeah, you do justice to the program and seem so natural ! This is a fantastic show, and I am happy to watch it.
Aside: I miss Gabe too, is there a chance that you couldn't get him not to appear for a kind of sort of union-reissue-ishness?
Thanks Matt, and thanks Gabe.
Thanks crew, thanks for the really great show !!!
Tenet brought me here
12:31 If that is true, then doesn't it prove a cyclic universe? I mean, once the universe reaches maximum entropy, there's still a probability for it to randomly arrange itself into a low-entropy state. Now by itself, this might not seem like much but when you consider that the high-entropy states are all pretty much identical to each other, we only need the low-entropy state to happen once. Perhaps an analogy would be useful here: take Edison trying to improve Davy's light bulb. He had 999 different ways to fail and only one way to succeed. But he only needed to succeed *once* . And given enough attempts, it was kind of inevitable. With the universe in maximum entropy, it would be the same. There might be 10^1,000,0000 different ways for the universe to fail (remain the same) and only one way to succeed (go back to the Big Bang), but given *infinite* time, it is *bound* to happen. And then it reaches maximum entropy again, and the same thing repeats itself indefinitely.
It is far more likely that entropy will go down a little bit before it goes down all the way to Big Bang levels. I recommend you look up the episode about Bolzmann brains.
+Martijn Bouman That occurred to me too but my point was that a slight decrease in entropy, while more probable, wouldn't make much of a difference i.e. would reach equilibrium pretty quickly. So it's practically the same as high entropy. But I guess you could argue that the universe spontaneously going back to, say, 4.5 billion years ago is still more likely than going back all the way. Hmm idk.
Feynstein 100 My point is that it doesn't prove a cyclic universe since the probability of entropy going down to Big Bang levels is insignificant comparible to life emerging by entropy going down a bit less.
+Martijn Bouman Ah fair enough. I guess there's something aesthetically pleasing about the universe going back to the beginning but just because I want it to be true doesn't make it true :)
+Feynstein 100
It's a natural thought to occur, but given how our universe keeps expanding at an accelerating rate, and that we know that we have emerged in a universe which started existing along the big bang, not parallel to it, it makes me wonder if it's really apliccable.
Love the ultra nerdy humour when answering comments
Wow, it's interesting to think how even abstract concepts have a measurable effect on reality (information is energy)