There’s a concept that’s crucial

to chemistry and physics. It helps explain why physical processes

go one way and not the other: why ice melts, why cream spreads in coffee, why air leaks out of a punctured tire. It’s entropy, and it’s notoriously

difficult to wrap our heads around. Entropy is often described as

a measurement of disorder. That’s a convenient image,

but it’s unfortunately misleading. For example, which is more disordered – a cup of crushed ice or a glass

of room temperature water? Most people would say the ice, but that actually has lower entropy. So here’s another way of thinking

about it through probability. This may be trickier to understand,

but take the time to internalize it and you’ll have a much better

understanding of entropy. Consider two small solids which are comprised

of six atomic bonds each. In this model, the energy in each solid

is stored in the bonds. Those can be thought of

as simple containers, which can hold indivisible units of energy

known as quanta. The more energy a solid has,

the hotter it is. It turns out that there are numerous

ways that the energy can be distributed in the two solids and still have the same

total energy in each. Each of these options

is called a microstate. For six quanta of energy in Solid A

and two in Solid B, there are 9,702 microstates. Of course, there are other ways our eight

quanta of energy can be arranged. For example, all of the energy

could be in Solid A and none in B, or half in A and half in B. If we assume that each microstate

is equally likely, we can see that some of the energy

configurations have a higher probability of occurring

than others. That’s due to their greater number

of microstates. Entropy is a direct measure of each

energy configuration’s probability. What we see is that the energy

configuration in which the energy

is most spread out between the solids has the highest entropy. So in a general sense, entropy can be thought of as a measurement

of this energy spread. Low entropy means

the energy is concentrated. High entropy means it’s spread out. To see why entropy is useful for

explaining spontaneous processes, like hot objects cooling down, we need to look at a dynamic system

where the energy moves. In reality, energy doesn’t stay put. It continuously moves between

neighboring bonds. As the energy moves, the energy configuration can change. Because of the distribution

of microstates, there’s a 21% chance that the system

will later be in the configuration in which the energy is maximally

spread out, there’s a 13% chance that it will

return to its starting point, and an 8% chance that A will actually

gain energy. Again, we see that because there are

more ways to have dispersed energy and high entropy than concentrated energy, the energy tends to spread out. That’s why if you put a hot object

next to a cold one, the cold one will warm up

and the hot one will cool down. But even in that example, there is an 8% chance that the hot object

would get hotter. Why doesn’t this ever happen

in real life? It’s all about the size of the system. Our hypothetical solids only had

six bonds each. Let’s scale the solids up to 6,000 bonds

and 8,000 units of energy, and again start the system with

three-quarters of the energy in A and one-quarter in B. Now we find that chance of A

spontaneously acquiring more energy is this tiny number. Familiar, everyday objects have many, many

times more particles than this. The chance of a hot object

in the real world getting hotter is so absurdly small, it just never happens. Ice melts, cream mixes in, and tires deflate because these states have more

dispersed energy than the originals. There’s no mysterious force

nudging the system towards higher entropy. It’s just that higher entropy is always

statistically more likely. That’s why entropy has been called

time’s arrow. If energy has the opportunity

to spread out, it will.

Am I the only one who get more confused about entropy than the one I knew before this video?

I m ðŸ˜•

Best part about youtube videos is you can pause, rewind and rewatch! Watched it twice and finally understood it.

I was searching for the song, but ended up watching a TED-Ed video instead.

It looks a crazy ending for an anime

So… Etropy is like a type of energy-based balance on a molecular level?

So I am not gaining fame and power in this world because of entropy. I have to tell my parents now, that the problem is not in their genes but in physics.

So what you're telling me is that if I shot a bullet, there is a chance all the energy from it will go into the air, the bullet will just stop mid flight and create a gust of wind?

Achievement acquired : Air bending discovered

phew thanks a lot, now i understand what is enthropy all aboutðŸ˜„

Essentially, Energy and matter wants to scatter

Beautiful graphics does not mean beautiful explanation. I was hoping to understand, now I am even more confused.

0.0000000000003 is not zero; so we can't say it will never happen!

Did you notice the outro is just intro played backwards

Entropy is the inexistent of an energy that refuse to be a mechanical work.

If entropy is the unavailability of energy and provides more disorder, then the cup of crushed ice is absolutely more disordered due to the fact that it has less energy than water.

Does this means the same as "the universe is seeking for equilibrium"?

How are you getting 9,702 microstates? I failed to get that number when I applied the permutation formula both where repetition of the constituent objects (in this case quanta) matters and does not matter. 6! + 2! 6^6 6^8 none produce 9,702

Thank you. Am looking forward to your response

It's so useful when scientific concepts are illustrated!

Beautifully explained. Many hanks.

If the energy has the opportunity to spread out, it will.

Why is Adam Sandler in this video ?

Who had to watch twice?

The big problem here is equating entropy increase with energy spread and increase in probability like they are synonymous. Energy spreading out is always an increase in entropy but increase in entropy is NOT ALWAYS measurable as a spreading out of energy. ENTROPY IS NOT ENERGY! This comes from the fact that the microstates of any system are the set of all possible [position, momentum] pairs for all particles in the system. Position means GEOMETRY is also important. Consider two equal masses of glass, one a blob straight from the furnace the other formed into a delicate lace sphere 20 times the diameter of the blob. Let them both cool to the same temperature. Which has the highest entropy? According to Jeff Phillips it would be the last one. – WRONG! But note I am now talking about the ABSOLUTE ENTROPY of the glass and not the CHANGE in entropy during the process which got it there. Why is the large sphere lower entropy? Because the macrostate defined by that GEOMETRY has fewer microstates than the blob. So what's the definition of a macrostate? And this is the heart of the problem. In engineering thermodynamics macrostates are defined by P, V, T and N (number of particles). In truth all of these are only valid for gasses, then only P, T, N are valid for liquids and only T, N are valid for solids. But the whole set completely ignores internal structure or GEOMETRY. Why because it is of no interest in engineering and we can't calculate it anyway because we can't count the microstates. So we come back to what is a macrostate? I have not found this anywhere else to date! The Boltzmann equation for absolute entropy also tells us fundamentally entropy has no units. If you want to argue with R Feynman on that good luck.

A MACROSTATE IS A SET OF MICROSTATES WITH AN IDENTIFIABLE CHARACTERISTIC.

The real reason this definition is missing is because it raises the question of intelligence or subjectivity into physics. That is microstates are a given or natural but macrostates by the above definition are an intelligent choice. We decide on the geometry of the glass sphere and we decide the tolerances around any geometry (say a statue of Venus) which fall into our macrostate we call Venus or the beautiful sphere. That is why there will be fewer ways of arranging the particles in our chosen geometry compared to any random blob. Note something very important here the glass sphere may occupy a greater volume than the blob BUT the volume of the SYSTEM ie glass has NOT changed. This is why if we moulded the blob into a shape of equal volume but geometrically interesting the latter would still have lower entropy than the random blob.

That is why the definition of [ENTROPY: MEASURE OF DISORDER] is the only one that encompasses all possible cases ie always true. and to complete it we define [DISORDER: PROBABLE] and [ORDER: IMPROBABLE] which also gives us clear definitions of complex and simple.

[COMPLEX: IMPROBABLE] and [SIMPLE: PROBABLE] so we end up with..

LOW ENTROPY = COMPLEX = ORDERED = IMPROBABLE and visa versa that's it.

The absolute BEST and SIMPLEST statement of the second law is [Any system of particles will tend to move to its most probable state]. Here by system all I mean is identified in some way. We don't even have to say it is a closed system because it is the TENDENCY which is ALWAYS true. We only need a closed system to PROVE that entropy will increase for a statistically large system.

The subject is a mess because the naturalists who have hijacked all of science and education are uncomfortable with the suggestion of intelligence having any role in the universe. The truth about entropy and the second law proves they are wrong so they hide it.

Oh right . Now I get it ðŸ˜³ðŸ˜³ðŸ˜³

Advanced congratulations for 10m subscriber

So, the probability of all my energy having been transferred to my Great Granddaughters is high!!??

Uuuuh will Teded again upload this with an easy explaination and easy demonstration.

What the heck was that

So is my belly getting bigger, a spreading out of energy, the result of entropy?

Is obesity linked to entropy?

I can't believe I actually understood this!

Here because of Daniel Caesar.

It's an interesting way to understand Entropy

If we reverse the velocity of each and every particle in the universe, will the entropy still increase? Mathematically, reversing the direction is equivalent to reversing the time … I.e. the universe will go backwards in time mathematically….

Nope, still not getting it.

I would say entropy is rather measurement of ORDER than disorder. Because SPREAD OUT or SMEARED energy distribution, which entropy actually is, associate better with ORDER than disorder …

after fours weeks of combinatronics i can say i approve the 9702 microstates counting ðŸ™‚

At first i thought they are going to illustrate it with decaying matter or a radioactive substance. This seems to be just 'simply to put it' and its only cover the default environment on Earth. Would melting ice even deemed as Enthropy when it is as far as the orbit of Pluto where there is much absence of heat?

This was actually super helpful for my chem course, thank you

Speak English

my small brain just molt

… stuff spreads. Grass grows. And brother, this hurts my head.

Malardo malardo malardo malardo

I was hoping "(and why it useful)" would mean they would explain how entropy valuable for technology

My man got snapped at the end by entropy.

This video came at the right time, thank you. Doing Thermodynamics right now.

At some point, the universe will stop. Totally wild.

Evrendeki her ÅŸey dÃ¼zensiz olma eÄŸililimindeymiÅŸ. KÄ±rÄ±lan bir bardak tekrar eski haline dÃ¶nemez.

DaÄŸÄ±lmÄ±ÅŸ enerjiye ve yÃ¼ksek entropiye sahip olma yollarÄ±, yoÄŸunlaÅŸmÄ±ÅŸ enerjiye ve dÃ¼ÅŸÃ¼k entropiye sahip olma yollarÄ±ndan daha yÃ¼ksek olasÄ±lÄ±ÄŸa sahip olduÄŸu iÃ§in enerji daÄŸÄ±nÄ±k olmaya eÄŸilimlidir.

…

What?

Now day6's entropy trailer film makes a little more sense…

Here after Day6 drops teaser.

Fantastic

I came here because of Day6's comeback. Let's learn entropy guys. LOL

Came here after the trailer

Anyone came here because of day6?

came here because of DAY6 hahahahaha

S t a n D A Y 6

i'm here after day6 lol

Oh ok so this is how the universe came to be this how everything was created

wow now i am totaly confused what entropy is!!!!!!! btw thanks for confusing me hope i never click on interesting topics like this

Thanku tedx for such good explanation

So entropy is basically the way the energy distributes. So low entropy would be two things that arenâ€™t likely to level out with energy, and high entropy is two things that are already leveled out energy like the ice cubes are sharing the energy evenly, I think ?? Sum like that

If you understood this, leave a like…

How did you get those probabilities? This is not just a simple binomial, is it?

It's too

Easy to understand it , now….