The h Bar

So the total pressure is the sum of the pressure caused by the air molecules plus the pressure caused by the water molecules.

@JohnRennie Yeah, but don't they like average out as they collide to each other.

Physics Meta

0

Q: Proposed Tag: 'derivation'

Would a 'derivations' tag be useful? i.e. for questions asking about the derivation of established laws and equations. In my experience, understanding derivations (at least of college-level physics material) can be extremely useful and insightful---often far better than memorizing a result. A ...

Air and water molecules do collide with each other, but so what? That doesn't affect the fact the both exert a pressure on a surface by cbouncing off it.

4:07 PM

@JohnRennie Yeah, but i was thinking that as they collide to each other they end up on average both having the same partial pressure.

No. They both end up with the same kinetic energy.

@JohnRennie Oh, but that depends on the moles of the gas.

rob

@LuBu But the pressure is $p = nRT/V$

@LuBu Correct!

The pressure depends on the number collisions per second, and that depends on the density of the molecules.

@JohnRennie So when this partial pressure of the water vapor equals the external or atmospheric pressure in this case, we have what is called boiling.

@JohnRennie And this pressure is the pressure that is exerted on the gad-liquid interface.

4:12 PM

@LuBu Have a look at these posts

Kaumudi and I discussed this in some detail before Christmas.

@JohnRennie Yeah, i might look into that.

@JohnRennie I already read your discussion on osmosis, just because i got a little curious. And i have a question.

OK

@JohnRennie Have you got any pictures of college-boy Rennie?

I'm curious

@JohnRennie Ok so in this video: youtu.be/w3_8FSrqc-I?t=44s They say that the urea molecules interact with the water molecules and lower the concentration of water that way.

@JohnRennie But the interaction isn't needed is it? The simple existence of the molecules lowering the concentration should be enough, right?

@BernardoMeurer I think my Mum has some photos from that era. I don't have any.

4:23 PM

@JohnRennie Did you have a mustache?

I thought about this walking home today

Now I want to know :P

@BernardoMeurer :-) No. The one and only time I grew a beard was when I was in that amateur operatics group.

@BernardoMeurer You walked home and wondered whether JohnRennie had a beard in college?

That's...oddly specific

@JohnRennie A shame, it looks cool on you

I didn't like having a beard and shaved it off as soon as the show had finished.

@ACuriousMind Yeah well, my mind is weird

4:25 PM

I had long hair as an undergrad ...

I feel like my experience with all you guys on PSE has given me a new perspective on how I'd like to see physics taught

@LuBu Correct. Just the presence on the urea is enough.

@CRDrost Physics should be taught by random lunatics with baseball bats

Maximum effectiveness

@JohnRennie I think the interaction part is a bit misleading then. I've also seen it in another video.

imagine a set of pamphlets (~A4 paper folded in thirds, written on on both sides): (a) each introduces one topic, a few definitions, one or two major laws/theorems, maybe 3-4 examples, and a bunch of exercises on the last page. (b) each one links the pamphlets you'll need to understand it. (c) each one is tagged with the general skill it teaches like "Bio 101" or "Special Relativity"

4:27 PM

Also, @JohnRennie @ACuriousMind I passed Chemistry

@LuBu We normally derive the equations for osmotic pressure assuming an ideal solution. But real solutions have interactions and are non-ideal. This can increase or decrease the osmotic pressure.

because I feel like there's a lot of common ground here that could just be, "background: read the PHYS-2135 pamphlet. answer: because the Euler-Lagrange equations of X are Y and that means Z."

@JohnRennie Oh, ok.

@BernardoMeurer 'Grats! Is the bum better today? :-)

of course we don't like to link out our explanations, but still, it seems like there is a cut-and-paste-able prelude to help ease understanding plus a simple clarification at the end.

4:30 PM

@LuBu It may well be that the osmotic pressure of urea/water is significantly different from the ideal solution.

@JohnRennie A bt, but it's sure to get stretched open again tomorrow at Digital Systems exam :)

@JohnRennie Just due to the interaction/bonding?

And then it's like, "well I want to learn twistors, I'd better read all of the pamphlets tagged Twistor Theory first."

@LuBu Yes. As I recall urea is quite polar so it will form hydrogen bonds with water.

@JohnRennie Oh, ok. Good to know.

4:34 PM

@BernardoMeurer Digital systems actually sounds quite fun. Better than just learning integrals ...

@JohnRennie 33% fail rate, and it's a first semester class :P

It's cool, but it's hardcore

Cor! Then it's down to you to be one of the 67%!

Working on it

If I fail anything it will be analysis

At least I already passed Linear Algebra, Chemistry, and Intro to Engineering

@CRDrost I'm not sure what you mean by "we don't like to link out our explanations", but in the long run, one could consider a parallel of the SO documentations to source these "pamphlets" of yours from physics.SE.

@BernardoMeurer Is Analysis the one you've just had?

4:44 PM

@JohnRennie Yes, on the 9th, but if I fail that I have a final exam on the 30th

The name is derived from the Greek lysis meaning to split and anal meaning, erm, well let's just say the name is quite appropriate.

Q: Would Bayer demosaicing of RAW files work with perfect color filters?

-1

I have an ongoing friendly dispute with another member over on Photo Stack Exchange about the fundamentals of how RAW works, and I'm hoping you can settle it. My understanding is that Bayer demosaicing works basically entirely on the assumption that one can deduce likely color information from m...

visible-light vision camera sensor

^on-topic?

@JohnRennie Too bad that anal is not a Greek stem :P

Also, lysis is "the split", "to split" would be lysein.

Details, details :-) Actually I'm not sure if lysis is Greek but I imagine that nice Mr. Google can help ...

Aha, it means to unbind

@ACuriousMind How on earth do you know that

@BernardoMeurer Because I learned Ancient Greek in school :P

4:47 PM

@ACuriousMind Did you go to a school for geniuses?

@ACuriousMind Really? I stand in awe. No, seriously!

It's one of the subjects I would love to know more about but have never had the time.

@JohnRennie Are you excited for the 10nm die shrink coming around?

Actually, yes :-)

Me too!

@BernardoMeurer No, just a so-called "humanistic" school which has mandatory Latin and optional Greek and Hebrew classes

4:48 PM

That's probably sad but hey I'm a nerd! :-)

(I didn't take Hebrew, but only because it didn't fit into my schedule)

Actually I'd love to know more about ancient Hebrew as well.

@ACuriousMind We know you didn't take it because you don't like Israel

So many hours, so little lifetime.

@BernardoMeurer :: John shuffles nervously ::

Note no smiley.

I loved learning Latin and Greek and did consider for a while to study that instead of physics

4:50 PM

@JohnRennie I want to see what gains in efficiency will come with the die shrink, but I am most excited about the differences on GPU type chips

Isn't a 10nm die a bit small to roll and/or read? :P

@ACuriousMind I had a dream you helped me pass Mechanics and Waves next semester

@BernardoMeurer For me it's keeping the same power but at decreased heat production and increased battery life.

@ACuriousMind groan :-)

OMG

I have something I have to show you guys

Although 10nm dies might make the absurd quantities of d6 I occasionally have to roll more managable ;)

4:56 PM

^ When your girl really loves you

The close queue could use some love; I see 30 things in it

@JohnRennie "Vapor pressure or equilibrium vapor pressure is defined as the pressure exerted by a vapor in thermodynamic equilibrium with its condensed phases (solid or liquid) at a given temperature in a closed system."
There is no vapor pressure to speak of in an open system then?

@BernardoMeurer Now I'm wondering what the unexpected statement was. Naturally all sorts of indecent suggestions spring to mind :-)

@JohnRennie The notifications are backwards

The unexpected statement was saying that I'm not stupid, lol

Doh!

5:05 PM

@BernardoMeurer Yeah, i was also wondering if that is the case.

@BernardoMeurer She must really love you if she's willing to lie :-)

@JohnRennie I will nuke Chester

@LuBu The partial pressure of water vapour is equal to the vapour pressure of the liquid at equilibrium. If you have e.g. a beaker of water just sitting open in the lab it is almost certainly not at equilibrium because air currents will carry away the water vapour before it can build up to the equilibrium level.

@BernardoMeurer I can probably get plans for a nuclear shelter online :-)

I hate incompletely specified logic functions

@JohnRennie So the vapour pressure is just some value you look from a table. The water vapours partial pressure doesn't have to equal the vapour pressure for the liquid to boil

5:13 PM

You need to distinguish boiling from evaporation.

@BernardoMeurer What's a "logic function"?

@JohnRennie I think i already have. Boiling is the bulk phenomenon that happens within and evaporation happens on the surface.

A liquid will evaporate if the partial pressure of the vapour is lower than the vapour pressure. Conversely if the partial pressure of the vapour is higher than the vapour pressure then the vapour will condense back into liquid.

@ACuriousMind A function defined over a boolean algebra

i.e. a map on a boolean ring

Also, let it be known that I hate K-maps

Boiling is the special case where something constrains the partial pressure of the vapour. For example when you heat water ina pan the partial pressure cannot get higher than 1 atmosphere because it just expands into the air around it.

5:17 PM

I hate some people who did 85% downvotes and 15% upvotes :/ 😈 — Ramanujan yesterday

That pins the temperature of the water at 100C and adding more heat causes it to boil at constant temp instead of getting hotter.

I wonder who that's aimed at... :P

Everyone's a critic, and those who squeal loudest are usually those who contribute least. Our Mr. Ramanujan might be advised to concentrate on writing more than one answer and getting more than one upvote before criticising others.

@JohnRennie So we have 100C water in an open beaker in atmospheric
pressure. So the vapor pressure of the water at this
temperature is 1 atm. And this water then boils-
But the partial pressure of the water vapor cannot be
spoken of, because the vapor just disperses.
Isn't this right?

@BernardoMeurer that seems like hard core maths you're doing. I've never even heard of a K-map

5:23 PM

It's a a table-like representation of the mappings of a given function, when done right it becomes a 3-dim toroidal shape and you can simplify the logic functions this way

@LuBu The point is that the partial pressure of the water vapour cannot get higher than 1 atm. Any region of vapour at P higher than 1 atm would just expand pushing the air around it out of the way until the pressure cam back down to 1 atm.

The guy who came up with it, Karnaugh, is still alive, I tried adding him on facebook

@BernardoMeurer Like I said - hardcore :-)

@BernardoMeurer A torus is 2d.

K-map

@ACuriousMind I just said that

Wait, no I didn't

Oops

5:26 PM

A torus embedded in a 3D manifold?

@JohnRennie Meh, I don't like that attitude. One can contribute helpful and substantial criticism even if one doesn't have other contributions to show for.

@JohnRennie But how could any partial pressure build up, if the system is open and the water vapour just disperses?

K-maps are pretty easy, just a pain in the ass

> just a pain in the ass

That seems to be a feature of all your courses :-)

Yeah, I should've become a carpenter

5:29 PM

@LuBu the water vapour will drift away at a a finite rate. If you generate the vapour fast enough i.e. boild the water fast enough, you will produce water vapour faster than it can disperse. Near the surface of the water the partial pressure will be very close to 1 atm.

Also, my K-maps are a mess because I only have one colour of pen

@BernardoMeurer Carpenter? Do I want to know the significance of that?

Fun fact I'm reminded of by the torus-rectangle equivalency: An (orientable) surface of genus $g$ can be obtained by gluing the sides of a $4g$-gon in the correct fashion

@JohnRennie No significance, I'm just sulking having gone into engineering

@JohnRennie Perhaps he wants to become a modern Jesus :P

5:30 PM

Engineering is kind of a meme

@ACuriousMind I agree it's being a bit negative, but experience (30 years more experience than you :-) has told me that people who carp are usually not people I will come to admire.

@ACuriousMind Fine by me, I have some nails somewhere ... :-)

@JohnRennie So we have 100C water in an open beaker in atmospheric
pressure. So the vapor pressure of the water at this
temperature is 1 atm. And this water then boils-
As the water vapour then starts to accumulate the maximum
partial pressure near the surface of the liquid it can
exert is equal to the external pressure
(1 atm in this case) Is this right?

@LuBu Yes, exactly.

If it was ina sealed vessel with rigid walls the partial pressure could exceed 1 atm, but in the open it can't.

And that's why water can't get hotter than 100C in the open, but it can get hotter than 100C in a sealed vessel e.g. a pressure cooker.

Wow, the verb to carp is mixed Latin and old English/Norse. There can't be many words with a history like that.

5:36 PM

5-var K-maps are a mess

@JohnRennie Are you into audio?

@BernardoMeurer Kind of. I have a pretty good hi-fi but an old one. I don't keep up with the latest Linn/Naim stuff.

@JohnRennie I've been considering getting a turntable

@BernardoMeurer That kind of feels like a fashion accessory to me ...

I have a few (<10) records for recordings I absolutely love and that I found while randomly shopping

Meh, digital audio is too easy

I have a very expensive CD player, and I've compared playing CDs on it to a FLAC ripped from the CD and played on my Mac Mini. I couldn't tell the difference.

Now I no longer use the CD player and just listen to FLACs.

5:41 PM

@JohnRennie And at that point the amount of gas condensing and liquid vaporizing is in an equilibrium?

@LuBu Yes.

@JohnRennie Yeah, I used to have all my music in FLAC, but moved to ALAC a while ago for compatibility with apple devices

Apple? Apple? That's it, your soul has been sold.

2

As long as you have AccurateRip even mediocre CD drives will do the job perfectly

I use Exact Audio Copy.

5:43 PM

@JohnRennie Someone paid for that thing?

2

@JohnRennie Lol, it's an open source standard!

@ACuriousMind Yes, it's a Zoo novelty

@ACuriousMind :-))))))))))))))))))))))

@JohnRennie Ok so this might be a weird question, but: Was my water boiling when it reached 100C or only after the partial pressure accumulated to 1 atm?

@JohnRennie I used EAC at the beginning, now I just use dbPowerAmp because it encodes with multiple threads and saves me time

it's also easier to use than EAC

@BernardoMeurer I was thinking it might've been more at home in a haunted house-style thingy

"The potato horror"

5:45 PM

@ACuriousMind My soul is what causes those bugs that no one can find and that just randomly disappear

one room would just be a burning kitchen ;)

In another, giant grapes try to microwave you

@LuBu the water cannot reach 100C until the vapour partial pressure is 1 atm. If the partial pressure is below 1 atm then adding heat to the water evaporates it instead of raising its temperature.

Hahaha, I gotta microwave grapes again!

If in the afterlife things get a chance to do to you what you did to them I'm screwed

A giant grape cuts you in half so the halves are just joined by a flap of skin then microwaves you. There's a Hollywood blockbuster in there somewhere.

2

There have been sillier premises

Like the tire that murders people

5:48 PM

Oh my God it's true

@JohnRennie And so when we had reached 100C our partial vapour
pressure was already at 1 atm. And in this combination
our water is said to be boiling?

@LuBu Yes.

Because the partial pressure is now pinned at 1 atm and can't get any higher.

How do you accept taking part in a movie like that

@JohnRennie I'm somewhat insulted you doubted me ;)

"Hey do you want to get killed by a tire in my movie?"

"Yes"

wtf

5:50 PM

@JohnRennie And so in 99C our partial vapour pressure couldn't reach 1 atm?

@BernardoMeurer "Hey, do you want to get killed by a tire in my movie for money?" - "Yes" FTFY

@LuBu Yes

@JohnRennie But was close.

@JohnRennie Yeah, ok. I think i'm starting to get these concepts cleared out.

At 99C a water vapour with a partial pressure of 1 atm would condense back into liquid water until the pressure fell back to the vapour pressure of water at 1 atm.

@ACuriousMind Lol, fair enough

5:52 PM

But as you say at 99C the partial pressure will be only slightly lower than 1 atm

I would get killed in a movie by about anything if I was paid for it, I think

2

FWIW it's not even that much money

@JohnRennie Do you mean it would fall to the vapour pressure of water at 99C?

Also, am I the only one that reads FWIW as "fwywy"

La Grande Bouffe

La Grande Bouffe (Italian: La grande abbuffata, English: The Grande Bouffe and Blow-Out) is a 1973 French–Italian film directed by Marco Ferreri. It stars Marcello Mastroianni, Ugo Tognazzi, Michel Piccoli, Philippe Noiret and Andréa Ferréol. == Plot == The film tells the story of four friends who gather in a villa for the weekend with the express purpose of eating themselves to death. Bouffer is French slang for "eating" (the Italian abbuffata means "great eating"). The first protagonist, Ugo, owner and chef of a restaurant, "The Biscuit Soup", decides to commit suicide, probably because...

5:53 PM

@JohnRennie "to the vapour pressure of water at 1 atm."

@LuBu Yes

@JohnRennie But didn't you write that part wrong, shouldn't the 1 atm be corrected to 99C?

@JohnRennie Have you had Jock's itch?

@LuBu Ah, opps, yes. Sorry that was a typo.

@BernardoMeurer What kind of question is that?!

5:55 PM

@ACuriousMind A health one?

Have you?

At 99C a water vapour with a partial pressure of 1 atm would condense back into liquid water until the pressure fell back to the vapour pressure of water at 99C.

@JohnRennie Yeah, i think i might be on my way to get some concept cleared.

@BernardoMeurer Isn't that a fungal infection of the equatorial regions?

No, fungi and my gonads have never been in close proximity (to the best of my knowledge)

@JohnRennie Not necessarily the equatorial region, it's just a fungal rash affecting areas like toes, groin, armpit (IIRC), and things like that

Lovely

5:58 PM

I got this crap in Brazil over Christmas, and it's some inferno stuff

:-(

@BernardoMeurer Ah, what does "Jock" stand for ? :P

Presumably you've been prescribed some anti-fungal for it?

@anonymous I think it stands for athlete here, it's commonly associated with that

@anonymous Jock is a euphemism for penis

As in jock strap

It's because the fungal ind=fection frequently affects the groin.

6:00 PM

Jock (stereotype)

In Canada and the United States, a jock is a stereotype of an athlete, or more to the point, someone who mainly accesses sports and sports culture, and does not much access or have access to intellectual culture . It is generally attributed mostly to high school and college athletics participants who form a distinct youth subculture. As a blanket term, jock can be considered synonymous with athlete. Similar words that may mean the same as jock include meathead, musclebrain, and musclehead. These terms are based on the stereotype that a jock is muscular, but not very smart, and cannot carry...

Really? I thought it was related to the fact that it happens mostly to people who do sports and don't clean up well

@JohnRennie Now as were in this equilibrium some of the water vapour
on top of the liquid will disperse into the atmosphere, right?
And they will be replaced by water molecules that
vaporize as to keep the equilibrium going.
And this results in a rapid/bulk movement of water from
the liquid to vapour and into the atmosphere?

I see :P

Never heard of it before

@anonymous Most jocks are di ... BAN INCOMING!!

@JohnRennie yeah, I used Terbifine but it wasn't strong enough, so now I moved to Econazole in the hopes of it being faster

I wish I could get hold of Oxiconazole, but that requires a prescription

6:02 PM

I guess there's not a lot you can do about it except wait.

@JohnRennie Wikipedia to blame XD

There is a whole article on it wikihow.com/Cure-Jock-Itch

Seems like a terrible thing to be affected by :(

@LuBu yes, and that is of course what happens when you boil a pan of water. The water boils away.

@JohnRennie And this rapid movement is also known as boiling.

@anonymous Not fatal, but nasty :-(

@anonymous Are you a man?

6:05 PM

@JohnRennie Fatal when you are standing in a room full of people and you feel the sudden urge to .... XD

@LuBu Yes. Remember that the rate of boiling is determined by the rate at which you add heat (from the gas burner) because you need to supply the latent heat of vapourisation to turn water into steam.

It's like a fiery itch on your balls 24/7

in The Nineteenth Byte, 6 mins ago, by orlp

@LuisMendo so if my scrotum was a sphere I would never be able to comb it to satisfaction? noooooo!

lol

Someone flagged that! :-)

6:07 PM

@JohnRennie And so at that point all the energy goes to breaking the bonds between the water molecules?

Dangit

@JohnRennie good old hairy ball theorem

@LuBu Yes

In German, it's called der Satz vom Igel - "the hedgehog's theorem".

@BernardoMeurer For the time being you can consider me to be a third gender :). My profile name exists for a reason :)

6:08 PM

Why anyone would try to comb a hedgehog is beyond me

@ACuriousMind Ah, I didn't realise hedgehogs combed their testicles.

@ACuriousMind That's a great idea actually

Hii @JohnRennie

I wonder if I can legally buy hedgehogs

@BernardoMeurer Combing a hedgehogs testicles?

6:09 PM

Actually, scratch the legally

@JohnRennie But doesn't this thought process then
explain why the boiling point is defined as is. "The
temperature at which the vapor pressure of the liquid
is equal to the pressure exerted on the liquid".

Do hedgehogs live in Portugal?

Why it does not depend on R$_0$

I know a guy who drunkenly picked up a hedgehog and woke up the next morning in his bathtub snuggling with it.

4

(and with scratches all over him, of course :P)

@LuBu Yes. The pressure exerted on the liquid is just the atmospheric pressure.

@ACuriousMind and fleas.

6:11 PM

@ACuriousMind I want to meet this man

Hedgehogs are crawling with fleas.

@JohnRennie But earlier on when i asked why is the boiling point defined as it is, you wanted to bring about gibbs free energy. Why is that?

@JohnRennie Doesn't this thought process explain the definition?

@JohnRennie could you help me in that question

@LuBu Because understanding Gibbs free energy will tell you why the boiling point exists.

@BernardoMeurer I thought so :P

6:14 PM

@koolman I'm afraid it's too long ago that I did circuit theory. I can help you with general relativity but not circuits.

@ACuriousMind Haha. I know a family which owns a couple of "pet" tigers and sleeps with them on the same bed :D

@JohnRennie ohk no problem

The family is crazy though

Strangest thing I ever woke up with was a pink plushy slipper and some cactus needles in my hand. Took some detective work to piece together that night again :P

@anonymous that...doesn't sound particularly safe, nor particular animal-friendly for the tigers

I once woke up in bed, fully dressed and covered with mud. But that's probably fairly routine around here :-)

6:17 PM

@ACuriousMind The family is insane obviously but the laws allow it :P

@JohnRennie Sounds like every morning at Wacken to me :D

Just that there's no bed

Aha yes :-) Glastonbury too now you mention it.

@JohnRennie Well if the partial vapour pressure is equal to the
external pressure then we're at equilibrium and we see
the bulk movement. Doesn't this explain WHY?

I pity the tigers

:P

@ACuriousMind I wish Braintentacles played at Wacken :P

I want to go see Death Grips live this year

6:18 PM

That is a great star board.

and possibly break some bone in the process

@JohnRennie Indeed, one of our better arrangements :)

Lol, indeed it's a work of art

We just need one of the posts about testicles to make the star board to complete the set.

My testicles look like an apple if that works?

6:20 PM

@JohnRennie fully dressed at least means you don't had to worry where your clothes went ;)

That's it - my work is done!

@JohnRennie You're not running away from me are you.

::dust settles as @JohnRennie vanishes into the sunset::

@ACuriousMind I have this feeling that student life at Cambridge might have been on the tame side ... :-)

discogs.com/…

In case someone wants to give me a gift for no reason

6:23 PM

For posterity, because they need to know these things:

And on that note I bid you adieu

@JohnRennie Goodnight man

@JohnRennie Well if the partial vapour pressure is equal to the
external pressure then we're at equilibrium and we see
the bulk movement. Doesn't this explain WHY?

@JohnRennie Sayonara ;)

He ran on me )=.

@LuBu what's your question ?

6:29 PM

Well it was what i just asked, after John stated this: "@LuBu Because understanding Gibbs free energy will tell you why the boiling point exists."

And then i asked the above.

But is it that the GFE is used to explain the different values of the vapor pressures at different temperatures?

@LuBu No it doesn't seem that is a good explanation.

@anonymous What even is the "WHY" question?

@LuBu See socratic.org/questions/is-delta-g-zero-at-boiling-point

Gibbs free energy is the best way to describe boiling

That's actually a great description of enthalpy

where is it from @anonymous?

@anonymous Is the GFE used to explain the different values for vapor pressurest at different temperatures?

6:37 PM

Daniel V Schroeder's Thermal Physics, page:150

@BernardoMeurer

@BernardoMeurer I think i found that same description from wikipedia.

@anonymous Cool

@LuBu Yes, it could be used to explain it. But it is a lengthy explanation which I need to myself compile before I can tell it to you. I'm out of touch with thermo

@anonymous So that is prob what @JohnRennie meant with the "WHY" question.

@LuBu yes i think so

AccidentalFourierTransform

6:40 PM

@anonymous But yeah, you don't need to explain it to me. I prob wouldn't understand it yet.

dmckee

@BernardoMeurer Variations on it can be found in a number of textbooks. I've been meaning to go looking for the earliest formulation of it because I would like to cite it.

Anyone want to offer up an early version?

whats up with the starboard anyway?

@dmckee I literally just learned what enthalpy is

I knew how to calculate it, and I knew how to do all sorts of chemistry wizardry with it

but I never knew what it was

thanks image

@AccidentalFourierTransform Scrotum

AccidentalFourierTransform

@BernardoMeurer When i saw that description in wikipedia i also thought that it seemed nice, so i saved it into a notepad.

youre so wacky

6:44 PM

@BernardoMeurer And now i saved the images onto my hard drive. =)

@AccidentalFourierTransform Hm?

Mohamed Ziad

Hey guys, can someone help me in here ?
http://physics.stackexchange.com/questions/304453/second-moment-of-area

@dmckee Here I am drawing like Davinci to make a circuit that multiplies by 3 using NAND gates, when I go look the answer the prof used an 8-bit summer

Screw this lol

AccidentalFourierTransform

@anonymous In the image: "This is just the system's energy, minus the heat term that's in F" What does the F stand for?

Fourier

6:50 PM

@LuBu Probably refers to the TS term ... which is the spontaneous heat entering the system

@anonymous Oh, ok.