The Grove

17:35

@bobble You know how if you put water in a vacuum it starts to boil?

Is the water inside the vacuum hot?

Or is it still room temperature?

bobble

the temperature would be decreasing, under the assumption that "vacuum" means not enough air/media to conduct heat away. boiling is endothermic

Prince North Læraðr

Can you translate that into a way you'd describe it to I don't know, a kindergartener like me?

bobble

you didn't magically add thermal energy by moving it into the vacuum, I assume

Prince North Læraðr

This isn't a test question, it was just like "oh I saw a video where water was boiling in the vacuum and I was curious if the water is hot" -_-;

bobble

Okay, I'll list the assumptions/framework my thought experiment will operate under:

Prince North Læraðr

17:38

Okay

bobble

1) the water is magically transported into the vacuum instantaneously (because if you e.g. moved it quickly in, that movement translates to kinetic energy, some of which would transform into thermal energy and heat the water up)

2) the vacuum is a true vacuum (impossible), or at least close enough that there is functionally no air to conduct heat away

Prince North Læraðr

Okay

bobble

(conduction requires a medium to move the thermal energy through)

okay, so we got some water at room temp and we've just magically moved it into the vacuum

Prince North Læraðr

Yee

bobble

the equation q = m * c * delta-T means that to increase the temperature of this water (make delta-T positive) we would need to input energy into the system (make q positive)

Prince North Læraðr

17:41

O_O

bobble

or, intuitively, stuff can't get hot if you don't heat it up

Prince North Læraðr

Okay

bobble

so water is not hot because there is nowhere for that heat to come from

now, then, you ask "why is it boiling?"

'tis because of the low pressure, of course, but I expect you'd want more than "low pressure"

Prince North Læraðr

Nah that's good

bobble

have you ever heard the term "vapor pressure"?

Prince North Læraðr

17:42

No

Is that like

Idk nvm, continue :P

bobble

remember that temperature is a measure of average kinetic energy

Prince North Læraðr

yee

bobble

at any point in time, some of the molecules will have enough energy to vaporize

so they will, producing vapor

"vapor pressure" is a measure of how much pressure this temporary vapor exerts, at a certain temperature

as temperature increases (with all else held constant) there would be more molecules which randomly have enough energy to vaporize, thanks to probability and the law of large numbers etc.

thus temp up, vapor pressure up

anyways, the reason this matters is the temperature at which something evaporates is the temperature at which its vapor pressure equals the surrounding air pressure

before that point, the surrounding air pressure would look at the wimpy little bits of temporarily vaporized molecules and laugh, "ha ha there are so few of you, you don't get to join our club"

Prince North Læraðr

Hehehe

bobble

but now at vaporization temperature, there are so many vaporized molecules exerting so much pressure that the surrounding air is like "FINE you can come" and all of the molecules go vaporize and party

Prince North Læraðr

17:47

Lmao

bobble

this is actually the principle by which vinegar smells terrible - it's pretty volatile, fairly high vapor pressure, so when you open the bottle a lot of saved-up vaporized molecules come out and party in your nose, so you can smell it even though most of the vinegar is still liquid

Prince North Læraðr

Ahhh

bobble

the reason this matters in a vacuum is - surrounding pressure is pretty near 0, so water's vapor pressure at room temperature is greater than that

thus, boiling

Prince North Læraðr

Cool

Thank you :)

bobble

and I mentioned that boiling is endothermic, which means that it absorbs heat

because thermal energy has to go to breaking bonds between water molecules, so they can leave each other and party as separate gaseous molecules

thus while it's boiling, the water is actually cooling down, since the parts that are vaporizing pull the needed energy from the rest of the water

and this concludes bobble's science lecture for the day

Prince North Læraðr

17:51

That's wack

Water's boiling while getting "colder"

bobble

this is how sweating works!

your body secrets water onto your skin so it will evaporate, and while it does so it pulls heat energy from your skin, cooling you down

Prince North Læraðr

That I do remember from chemistry

bobble

~~please give bobble's science lectures a five-star review so we can get more customers~~

Prince North Læraðr

Hahaha

Sid

18:46

@bobble that was a beautiful explanation tbh.

I would think you would make a very good teacher/lecturer/professor.

bobble

^.^ I like tutoring

Sid

That's nice! Yeah, I thought so. That explanation was better than what I have heard from many teachers of Chemistry/Science.

bobble

I would honestly not mind tutoring for a living, except I can't probably. Teaching pays almost nothing and I would die having to memorize everyone's names.

tutoring and grading and paperwork (being a TA) is just about my favorite thing to do that's not purely lesiure.

Sid

Ah, you're a TA? I won't say "nice". I have had mixed experiences with TAs in my Uni, lol.

bobble

I TA'ed in high school so that's my reference point

my favorite class I TA'ed was the very first one. I made all the homework, quiz, and test keys, helped set up labs, graded about half of all the papers, and would walk around the class whenever needed to help

the teacher loved me

Sid

19:00

(I imagine you got paid for that much work?)

bobble

nope, other than taking one less regular class

Sid

Ah, I suppose one less class is still some compensation for that much effort.

bobble

Plus most of the set-up was just because I would arrive before school started so I wasn't doing anything anyways, and I was taking a higher chemistry class at the same time so all the helping and keys etc. was basically just practicing foundational concepts I needed for my other class

And I think the teacher gave me a $20 gift card at the end of the year as a thank-you, but that wasn't required

Sid

@bobble that's wonderful. You must have had a really good teacher.

bobble

She was :) Anyways, I'm off to lunch now.

Prince North Læraðr

22:02

Learn How to Solve a 1x1 Rubik's Cube

►

@Sid High school TAs are slightly different from college TAs

Sciborg

College TAing was a blast for me, i loved my professor a lot and we goofed around in the lab together. He was basically my bro

Prince North Læraðr

High schools TAs are as the name implies - teacher's assistant, where they assist in the small stuff like stapling, simple grading, setting up, etc. Whatever the teacher needs done that they don't want to do, boom, give it to the TA

College TA you actually teach stuff right?

Sciborg

Yup, I got to teach the class sometimes :D we would joke about him giving me the privilege of using his whiteboard to teach

It was the Whiteboard of POWERRRR

Prince North Læraðr

Also, @Sciborg also are you glad now that you can solve a 1x1x1 after that tutorial?

Sciborg

But a lot of it was still grading papers, we would vibe in the college cafe and grade papers together

@PrinceNorthLæraðr Yes, it was very helpful :p

I miss that guy so much, that job was the best job I've ever had.

Prince North Læraðr

22:07

@Sciborg I'm glad. I love being helpful

Btw, that short algorithm that jperm mentioned (RUR'U') is an actual thing known as the "Sexy Move"

Sciborg

Hehe

I never really got into Rubik's cubes, but some of my buddies were obsessed and their dorms were just full of different shaped and sized cubes. Like the big ones or the triangular ones or the polyhedrals

They're very common with ASD people because of the fidget factor and letting you hyperfixate to relax

But I was always more into stress balls and doodling

Prince North Læraðr

It comes up in a lot of different algorithms (take T-Perm, for example, which goes R U R' U' R' F R2 U' R' U' R U R' F'

@Sciborg Hehe

@Sciborg I dare you to go up to Sam and be like "You're looking quite R U R prime U prime today"

Sciborg

I have no idea what that even means, lol

How is your composition going? We have to keep up with floof :p

bobble

@PrinceNorthLæraðr I taught a few times since the teacher had a kid and the temp sub was uh not well versed in science

I gushed over the Reading Room about that series I mentioned borrowing

Prince North Læraðr

22:24

@Sciborg that’s the sexy move, or at least how you’d pronounce it :P

I just resumed on my composition but our family is leaving to watch an Anthony boirdain documentary

Sciborg

the one where they used an AI to generate deepfaked voice clips?

i heard quite a bit about that one

Prince North Læraðr

Idk

You should learn the rubik’s cubeeee

Sciborg

it's honestly not something i would probably get absorbed in, it's just not my thing.

plus i would have to buy one, i don't have one currently :/

bobble

mm, this is relevant to our California tree: someone linked me to some CA state standardized science test and the score ranges are something cde.ca.gov/ta/tg/ca/castscalescores.asp

like seriously people, don't make the range be 550-650

that's weird

Prince North Læraðr

What the

Sciborg

22:28

yeah, what the hell are these numbers

bobble

minimum could be 0 or 100 or something smaller

getting a 550/650 sounds good until you find out that's literally the LOWEST SCORE POSSIBLE

ooh, I found aggregated results by school district and eesh are some of these numbers concerning

e.g. this district had 100% fail to meet standard D:

Sciborg

o-o

bobble

sorting by "percent not met standards" on this page actually gives a surprising number of schools that had everyone fail

hehe it's fun researching this test

cde.ca.gov/ta/tg/ca/documents/castfactsheet.pdf

> The CAST measures what students know and can do using the California
Next Generation Science Standards, which focus on understanding the
scientific concepts found in the Life Sciences, Earth and Space Sciences,
and Physical Sciences. These standards integrate the Disciplinary Core
Ideas, Science and Engineering Practices, and Crosscutting Concepts to
help students understand how science works in the natural world.

that's an extremely long way to say "this is a science test"

> the CAST encourages students to build the knowledge and skills needed for college and careers.

Sciborg

"this examination tests your capacity for environmental and scientific ability -"
"yeah, it's a bloody biology test, Craig"

bobble

yeah right taking a standardized test sure gets kids excited about science

O_O I found statistics on statewide aggregate results, and less than 30% of students met or exceeded standards

if those are you standards, CA, you're uh failing

on their parent guide their diverse science students are Ron, Ginny, and Dean Thomas

sorry I'll stop doing this :)

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