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.

Jagermeister turned out to be surprisingly good. Who knew.

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.

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.

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.

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.

2021-03-22, 19:40, Monday

Stephen King writes around two thousand “decent” words per day. I tend to land around 500 words of the first draft, and even this is a challenge. There is a long road to go down and I finally feel like having enough persistence.

2021-03-21, 19:00, Sunday

Well, I managed to write some notes on the classes I skipped this week. There is a lot more left but I’ll manage to catch up in a few days, I believe.

Quantum mechanics (and solid state physics in general) is sure fun, but I feel like our professor spends a bit too much time talking and to few time teaching. I watch recordings with doubled speed and take notes like that, without any issues.

2021-03-20, 14:35, Saturday

The “not too bad” part turned out to be false, I’m still a miserable wreck and the headache subsided only this morning. I managed to study for half an hour before it kicked in again, rendering me useless.

I’m now in my chair, drinking freshly brewed cocoa, trying to get some rest.

2021-03-18, 08:50, Thursday

So I caught a cold. It’s not too bad but I’m still out of the game for a few days. That sucks.

2021-03-17, 08:47, Wednesday

Yesterday I was on “Billie Eilish: The World’s A Little Blurry” in actual cinema and here are some thoughts on it.

A documentary film about life or rather performances of Billie Eilish. It shows the process of song writing with Billie’s brother, Finneas, and tours, and some of the struggles. There are some things that impressed me and that I’d like to mention.

• She is 19 this year and got popular 3 years ago, I couldn’t pull that off in my 16 or even now.
• Her parents are a huge part of the success and even survival. They both played music for her and her brother, they taught them and encouraged them. In a sense, I would not like to be Billie Eilish, but I would like to someday be as good as a parent.
• If you have ever seen the videos of her jumping during “bad guy” - she spained an ankle at one of them, had fairly severe complications because of it and kept going, along the lines of “the worst thing isn’t not giving the show, the worst thing is giving a crappy one”.
• Pet spider! So cute.
• She writes songs with Finneas, her brother. By the way, he has a music project of his own called “FINNEAS”, as opposed to “billie eilish”. Worth checking out.
• Popcorn in movies is sooo overpridced these days. Buying some snacks in advance was the best financial decision of the year, honestly.

2021-03-16, 12:23, Tuesday

New diary entry I decided to publish. There is no storyline, just a sketchy piece I put together in the evening and felt like sharing.

2021-03-16, 10:20, Tuesday

So I had an anxiety attack last night. Managed to get some sleep, but clearly not enough. Trying to relax and do some errands like pruning my houseplants and organizing drawers. Come to think of it, I might get a bonsai…

Anyhow, the name of the game is taking advantage of the situation. I now have a uniqye opportunity to watch all of my classes recorded from zoom, and that’s why I can relax now for a bit and catch up later. Gotta write some of that novel now.

2021-03-15, 08:00, Monday

Today I’ll need to somehow juggle tensor analysis, English classes and creative writing, along with some homework. That’s gonna be tough.

2021-03-14, 16:45, Sunday

You know what would be cool? If governments or political parties flexed not just their programs and ideologies, but their resources in terms of mathematicians and supercomputers. Hey, we can run these supercomplex simulations instead of blindly picking whatever looks like a decent option! Would save some trouble for average folk that faces the consequences of the decisions made by politics. Not a solution to all the problems, but it would be nice.