Pink flowers were glowing against the gloomy sky. I saw the sakura tree bloom for the first time in all it’s glory, with petals gliding to meet the lawn. There were no words left, only a faint smile and a silent stare. It’s been a long time since that smile has visited this face. Five years ago in Barcelona I was in Sagrada Familia, and even before that in Norway fjords, and a gothic cathedral comewhere in Europe.

There is now an image of pink petals engraved in my head, along with a single line that I hope to carry through my life, unchanged: be worthy to live in the world where sakura blossoms. And if your heart is in the right place and your mind is clear, you’ll see it and remember, and carry it’s light within you.

@Pat
That’s true, it would work. But phase change actually stores more heat per volume and allows to keep the temperature at a single point for a long time. The idea is interesting though. Have you compared the heating bill or temperature log before and after?

Nerdy things I happen to know part one.

Thermoaccumulators, in particular - phase-changing materials. So imagine a house being heated in winter or late autumn. The temperature outside swings from hot to cold, back and forth, and it’s aither colder inside at night or the heating is more intense, thus spending more energy and money. Would it be cool to store the excess heat accumulated during the day and release it at night?

Guess what, we can do just that. A highly concentrated salt solution stores energy when it’s being molten and releases it when solidifying, thus cutting heating costs and reducing carbon emissions. A temperature at which this transition happens depends on the solution’s composition and can be tuned to suit the particular use case.

PCM usually come in a form of plastic capsules with solution inside. They are put into heat-insulators inside walls or in some cases into bricks themselves. It’s very useful technology that is already in use, but it requires a thorough research on the water-salt system properties. That just happens to be my job.

#thermodynamics #PCM #nerd #uni

Since I’m in a good mood today and the majority of my peers skipped one of the most interesting courses.

How to learn quantum physics (the fundamentals of it, anyway)

1) Prerequisites. Integration, derivatives and partial derivatives should have been practiced ad nauseum at this point. A good grasp on linear algebra and basics of operators will also come in handy, as well as some complex analysis.
2) Classical mechanics. Yes, you have to know it, at least remember the basics, because it makes your life easier. Ideally, learn some Lagrange mechanics, since it teaches you to think in terms of energy rather than path. You’ll also need Coulomb’s law and centripetal acceleration for deriving Bohr’s atom model.
3) The first few chapters should be taught hand-to-hand with experiment and history. If your curiculum doesn’t provide this for some reason - go to youtube or even look experiments up on wikipedia. Learning concepts is easier when they are tied to real world at least in some way. At least know that Planck’s formula basically describes an oven.
4) The more advanced stuff will feel challenging. In the first part of the curriculum the sequence is always the same: make some assumptions about the system’s structure (e.g. electron in a potential well), from them obtain a hamiltonian, use Schrodinger’s equation to build a differential equation, then solve it using some gimmicks from differential equations course. The solution’s form is usually given in advance or supposed from the equation’s type.
5) Quantum mechanics is all about approximations: the only equations you will sovle precisely are for hydrogen atom and for an electron in some electrical or magnetic field. Everything else will imply some sort of approximation; learn them first, the rest can be derived.

#quantum #physics #stem #learning #studying #uni #student

Random evening thoughts.

How to learn virtually any STEM subject.

1) Go through prerequisites and fundamentals, math being the most important one. You won’t be able to grasp important concepts the meaning of formulae is unclear. Speak Italian in Italy, speak math in physics class.
2) Fix you handwriting. Make sure it’s readable, increase the size if necessary. Every symbol is important and there is no point in writing if you can’t read it later on. Use A4 paper for complicated stuff to fit more on one page, especially if you went with “bigger is better” approach.
3) Don’t break the sequence. Most textbooks follow the same narration order for a reason, and skipping a topic is generally a bad idea. Every concept builds on top of the previous one, so do yourself a favor and don’t skip chapters.
4) Whenewer you don’t understand something from the first attempt - spend anywhere between twenty minutes and an hour pondering the concept. Then make a break and afterwards do it again for 20 minutes or so. If this didn’t help - open your browser, go to youtube and look the thing up. The thing you are struggling to understand is probably explained thoroughly multiple times, and different wordings usually solve the problem.
5) Don’t hesitate to go back in your or to make your notes look nasty. Cross things out, write on margins, just make sure it’s readable. Whenever it isn’t - cross it out and rewrite. Notebook is not a project, it is a tool that helps you to understand the subject.

@zpartacoos
That sounds like an optimal solution…

Do you like becherovka? Hope I spelled that right.

Jagermeister turned out to be surprisingly good. Who knew.

@FailForward

Yeah, you are right. I meant “worldview”, which is interchangeable with motivation in context of literature, but here it does look odd. I guess I’m still in the process of figuring things out with this language.

At some point in my life I went across one of Joe Rogan’s podcasts, and overheard a great idea there. To gain a motivation boost, imagine yourself being a hero of a documentary, with an invisible camera pointing at you. Would it be interesting to watch someone binging their netflix? Or would you rather see one of these cool guys on this “screen”, the one who overcomes obstacles and strves to reach one’s goals? This is a good change of perspective, but I recently came up with even better version.

Don’t try to be a hero in this movie, rather focus on being a villian. Don’t be a dick, I don’t mean it. A good villian is a powerful, capable entity with well-defined motivation, that is usually powerful from the very beginning, contrary to the hero who has to work their way up. Trying to adopt this attitude and behaviour is a surprisingly good tool. After all, we often like villians more than heroes, and for a good reason.

Essays are wonderful, and simultaneously very difficult to write, for the same reason: one can write about anything, but not everything. There is freedom in the abscence of plot, story or characters one has to keep track of in fictitious story, but with this freedom all the distractions and decorations are stripped off as well. The essay should explore one topic or thought to the furthest extent and stay as sharp and concise as possible.

This brings me to the point: writing a good essay is very hard and takes a crystal clear understanding of the subject along with writing skills. And reading one is a delight and an intellectual challenge. If you have any good essays on your mind, ideally on the topics of science and technology, but other domains will do as well - please tag me. In return I suggest you “Cinque scritti morali”, or “Five Moral Pieces” as an entertaining read, by Umberto Eco.

@SmilingTexan
Caffeine metabolism is a bizzare thing. I knew a person who would use energy drink, white “monster” specifically, as a sleeping aid. This is, if I recall correctly, due to genetic anomaly. There is a minority of people who react to caffeine differently, this is also connected with some circadian rhythm shenanigans. I don’t remember the specifics :p

It was a difficult day, but way easier than yesterday. Now I’d like to write something since there is like 15 minutes I have before the class starts.

Will caffeine become the next nicotine? Think about it carefully: it is a well-selling stimulant that has grown very fashionable and popular over the last few decades. It has mild effects, causes dependency and associates strongly with success and productivity, much like smoking cigarettes was advertised as something correlated with wealth.

From the physiological, or rather biochemical point of view, the effects of both coffee and smoking are mild. Nicotine constricts your blood vessels and brings blood pressure up a notch, while caffeine gives some sharpness and speeds the heart rate up. And they are both addictive: nicotine interferes with your breathing and emotion regulation systems, while caffeine screws up the circadian cycle. One could argue that caffeine withdrawal is generally less severe, but it doesn’t mean caffeine is not harmful in the long run.

It is not data but an anecdote, of course: I have recently stopped drinking coffee and noticed how it actually affects me. Spoiler alert, it’s very unpleasant, especially if I haven’t had any protein- or fat-rich food beforehand, and seeing coffee being so heavily marketed lead me to these thoughts.

@FailForward

not quite sure*

It’s evening and eyesight gets blurry, I can barely see letters sometimes.

@FailForward
Heheh, thanks for the concern. I am more or less fine, there is quite a lot going on with studying and lab work. I’m quite sure if there’ll be daily posts, not in the next month at least.

Also, I’m turning 21 today! Survived for this long somehow.

There is an itch to start a more personal blog-like record, but this feels outdated and boring, so I’m unsure.

@FailForward

1) Ha-ha, classic.
2) Ha-ha, I live here.
3) Oh fuck, I really do live here, don’t I?..

On a serious note, the propaganda around vaccines is real, there are even speaker announcements in subway along the lines of “vaccinate, help to stop the spread of the virus”.

2021-03-26, 19:05, Friday

I promised a few paragraphs about x-ray diffraction, so here it goes. This is mostly unedited because I’m tired and lazy.

Basically, light has a property to undergo what’s called diffraction: shine a laser beam on a grated piece of plastic and beam will split into an uneven number of new beams. Using this pattern and some trigonometry you can calculate the wavelength of light if you know how fine the grating is and the angle between beams. This works only when wavelength is a few times smaller than the grating size.

Now, the important bit is that atoms in crystal sort of work like grating. Light reflects from different layers of atoms differently and this forms the same diffraction pattern. Since the distance between atomic layers determines the structure of the crystal, we can now measure it using light and some math called Bragg’s law. The only thing we need is a light source with fixed, well-known and very small wavelength. Now, the “grating” in our case is approximately 2-4*10^-10 m, or 2-5 angstrem.

Conveniently, metallic anode, when put in a vacuum and under high voltage, emits high energy photones, generally of a fixed wavelength, corresponding to the valent electron’s excited state. And if we use copper, this wavelength is roughly 1.51 angstrem, which is about what we need.

Now that all elements are in place, we just need to build a complex machinery that will hold our sample, put a piece of copper under a few kilovolts, cool it down simultaneously, while also rotating a detector to capture light intensities under a range of angles. Different lattices will give different diffraction patterns, and one can be calculated from another.

And this is more or less how x-ray diffraction works.

#qotojournal #science #xrd #materialsciences

2021-03-25, 20:35, Thursday

I am slightly behind on my studying. Still managed to write a piece on XRD, I’ll proofread it and post either here or in the blog. We’ll see how it goes.

I am also kinda fascinated by the quantum physics and ab initio approach, so maybe something will come up about this. Not quite sure.

@lucifargundam

#dailylatin

Aqua regia, “royal water” - a mixture of hydrochloric and nitric acids, 3:1 by volume, which can be used to dissolve gold. The more important and common application, however, is cleaning pots for high-temperature experiments/studies.

Mix acids together in a glass beaker, better use a new one. Put small melting pots in, cover with a piece of glass leaving a small hole for fumes to come out. Now heat this sheer monstrosity up to a boil! Nitric acid gives a nice “fox tail”, dark-orange cloud of NO2, nitrogen oxide IV, when heated up. Your pots will be ready in a few hours. Remember to do it under an exhaust and rinse your pots afterwards.

2021-03-24, 15:30, Wednesday

One thousand words per day turned out to be a doable task. In two sittings, and this is a zero draft, but you have to start somewhere.

Now I need to prepare for a test on crystall chemistry. It is a surprisingly difficult subject that requires very few math and a lot of imagination and logic. I might do a short post here explaining some basic concepts once I’m done with the test.

Come to think of it, at this point most of the science I learn looks like some perverted wizardry. Let’s shine some light onto a powder, look at how it is reflected and compute it’s atomic structure from the result, huh. But the visible light’s wavelength is too big so let’s take a piece of copper and put it under a few megavolts, this should do the trick. It sounds like random bullshit but it is actually the way XRD works.