For those who've not heard of it, the scp wiki is a community-based collaborative writing effort based around "anomalous" objects/beings and the efforts of the SCP Foundation to contain them and protect the general public. Users can submit and vote on articles about SCPs, written in the style of research/containment notes. Some popular entries are SCP-173, SCP-87 and SCP-682, alongside a few more abstract and lighter entries.

Anyone want to share some SCP entries they've enjoyed reading? SCP-3515 is the most recent I've read and I'd definitely recommend it.

Last week I didn't realize I hadn't made the weekly post until it was a couple days too late, so I decided to just rollover to this week. Sorry, folks. Might have to get someone else to post sometimes.

Anyway, what have you been watching/reading this week?

Feel free to talk about something you saw that was cool, something that was bad, ask for recommendations, or anything else you can think of.

If you want to, feel free to find the thing you're talking about and link to its Anilist, MAL, or any other anime/manga database you use!

EDIT: With the help of @ducks the post now has illustrations to clear up the experimental set-up.

Introduction

I want to give an introduction on several physics topics at a level understandable to laypeople (high school level physics background). Making physics accessible to laypeople is a much discussed topic at universities. It can be very hard to translate the professional terms into a language understandable by people outside the field. So I will take this opportunity to challenge myself to (hopefully) create an understandable introduction to interesting topics in modern physics. To this end, I will take liberties in explaining things, and not always go for full scientific accuracy, while hopefully still getting the core concepts across. If a more in-depth explanation is wanted, please ask in the comments and I will do my best to answer.

Previous topics

Spintronics
Quantum Oscillations
Quantisation and spin, part 1

Today's topic

Today's topic will be a continuation of the topics discussed in my last post. So if you haven't, please read part 1 first (see link above). We will be sending particles through two Stern-Gerlach apparatuses and then we'll put the particles through three of them. We will discuss our observations and draw some very interesting conclusions from it on the quantum nature of our universe. Not bad for a single experiment that can be performed easily!

Rotating the Stern-Gerlach apparatus

We will start simple and rotate the set-up of the last post 90 degrees so that the magnets face left and right instead of up and down. Now let's think for a moment what we expect would happen if we sent silver atoms through this setup. Logically, there should not be in any difference in outcome if we rotate our experiment 90 degrees (neglecting gravity, whose strength is very low compared to the strength of the magnets). This is a core concept of physics, there are no "privileged" frames of reference in which the results would be more correct. So it is reasonable to assume that the atoms would split left and right in the same way they split up and down last time. This is indeed what happens when we perform the experiment. Great!

Two Stern-Gerlach apparatuses

Let's continue our discussion by chaining two Stern-Gerlach apparatuses together. The first apparatus will be oriented up-down, the second one left-right. We will be sending silver atoms with unknown spin through the first apparatus. As we learned in the previous post, this will cause them to separate into spin-up and spin-down states. Now we take only the spin-up silver atoms and send them into the second apparatus, which is rotated 90 degrees compared to the first one. Let's think for a moment what we expect would happen. It would be reasonable to assume that spin-left and spin-right would both appear 50% of the time, even if the silver atoms all have spin-up too. We don't really have a reason to assume a particle cannot both have spin up and spin right, or spin up and spin left. And indeed, once again we find a 50% split between spin-left and spin-right at the end of our second apparatus. Illustration here.

Three Stern-Gerlach apparatuses and a massive violation of common sense

So it would seem silver atoms have spin up or down as a property, and spin left or spin right as another property. Makes sense to me. To be sure, we take all the silver atoms that went up at the end of the first apparatus and right at the end of the second apparatus and send them through a third apparatus which is oriented up-down (so the same way as the first). Surely, all these atoms are spin-up so they will all come out up top again. We test this and find... a 50-50 split between up and down. Wait, what?

Remember that in the previous post I briefly mentioned that if you take two apparatuses who are both up-down oriented and send only the spin-up atoms through the second one they all come out up top again. So why now suddenly do they decide to split 50-50 again? We have to conclude that being forced to choose spin-left or spin-right causes the atoms to forget if they were spin-up or spin-down.

This result forces us to fundamentally reconsider how we describe the universe. We have to introduce the concepts of superposition and wave function collapse to be able to explain these results.

Superpositions, collapse and the meaning of observing in quantum physics

The way physicists make sense of the kind of behaviour described above is by saying the particles start out in a superposition; before the first experiment they are 50% in the up-state and 50% in the down-state at the same time. We can write this as 50%[spin up]+50%[spin down], and we call this a wave function. Once we send the particles through the first Stern-Gerlach apparatus each one will be forced to choose to exhibit spin-up or spin-down behaviour. At this point they are said to undergo (wave function) collapse; they are now in either the 100%[spin up] or 100%[spin down] state. This is the meaning of observing in quantum mechanics, once we interact with a property of an atom (or any particle, or even a cat) that is in a superposition this superposition is forced to collapse into a single definite state, in this case the property spin is in a superposition and upon observing is forced to collapse to spin up or spin down.

However, once we send our particles through the second apparatus, they are forced to collapse into 100%[spin left] or 100%[spin right]. As we saw above, this somehow also makes them go back into the 50%[spin up]+50%[spin down] state. The particles cannot collapse into both a definite [spin up] or [spin down] state and a definite [spin left] or [spin right] state. Knowing one precludes knowing the other. An illustration can be seen here.

This has far reaching consequences for how knowable our universe it. Even if we can perfectly describe the universe and everything in it, we still cannot know such simple things as whether a silver atom will go left or right in a magnetic field - if we know it would go up or down. It's not just that we aren't good enough at measuring, it's fundamentally unknowable. Our universe is inherently random.

Conclusion

In these two posts we have broken the laws of classical physics and were forced to create a whole new theory to describe how our universe works. We found out our universe is unknowable and inherently random. Even if we could know all the information of the state our universe is in right now, we still would not be able to track perfectly how our universe would evolve, due to the inherent chance that is baked into it.

Next time

Well that was quite mind-blowing. Next time I might discuss fermions vs bosons, two types of particles that classify all (normal) matter in the universe and that have wildly different properties. But first @ducks will take over this series for a few posts and talk about classical physics and engineering.

Feedback

As always, please feel free to ask for clarification and give me feedback on which parts of the post could me made clearer. Feel free to discuss the implications for humanity to exist in a universe that is inherently random and unknowable.

Addendum

Observant readers might argue that in this particular case we could just as well have described spin as a simple property that will align itself to the magnets. However, we find the same type of behaviour happens with angles other than 90 degrees. Say the second apparatus is at an angle phi to the first apparatus, then the chance of the particles deflecting one way is cos^2(phi/2)[up] and sin^2(phi/2)[down]. So even if there's only a 1 degree difference between the two apparatuses, there's still a chance that the spin will come out 89 degrees rotated rather than 1 degree rotated.

So I've just finished watching the new season. I had low expectations going in, given how the writers had to cut out their main character at the eleventh hour, but I still can't help but feel disappointed.

Soo many plot threads left open. No repercussions for any of the shit that went down over the last 5 years. The good journalist ends up dead, Claire Underwood commits murder literally in the oval office while secret service is right outside the door and then... nothing. That's it. That's what we get for series a finale. I mean, what?

I've also been quite pissed off how they tried to turn Claire into a feminist icon. Claire is a monster. She is at least as bad as Frank. She wanted to literally start a nuclear war to deflect attention away from herself.

Don't get me wrong, having a feminist message is ok. It's good. It's even timely. But not with Claire fucking Underwood for fucks sake! In the first episode where that female soldier asks her if she even has a plan so that more soldiers won't end up dead, Claire snarks at her with "you wouldn't ask me that if I was a man". Really? This fresh recruit, this soldier who you will be sending to her death is asking you - someone who never held any public office before - whether you have a plan and your response is fuck patriarchy?

How about that scene where she fires her entire cabinet and fills it with an all-female cast? Forget about real life, it's not even realistic in the show's world. Remember how hard Frank had to fight, how many people he had to cross, bribe and even murder just to replace a single seat in earlier seasons? Where was the senate? Did everyone else just roll over; how come nobody fought her on this? It felt like the writers really, really wanted to play out their deepest, guilty-pleasure Hillary 2016 fantasies out on the show and the script suffered for it.

If they just left things at the last season's finale where Claire looked into the camera with "my turn!" it would have been a much more powerful moment, certainly better than this disorganized, directionless mess we got.

So yeah, that's where I'm at. How about you?

It's a dry, windy day. I had my left hand stationary on my cat's back and was petting him with my right hand. I noticed when I removed my right hand from contact with his fur, I got tiny shocks in the middle finger of my left hand, but only when removing my right hand and only in my left middle finger. (He didn't seem to notice any shocks.)

Why is this very specific type of electric shock occurring?

it's here.

anthony fantano's 5th 10-star rating ("strong 9, light 10", ten-status granted)

"You Won't Get What You Want" by Daughters

the other albums rated this highly from fantano have been:

"The Money Store" - Death Grips

"Kids See Ghosts" - Kids See Ghosts (Kanye West, Kid Cudi)

"To Be Kind" - Swans

"To Pimp A Butterfly" - Kendrick Lamar

what do you think about this album? what'd you like, what'd you hate?

where would you rate it, out of 10?

how do you feel it performs compared to it's compatriot records listed above?

how would you rank those?

cheers!

I started Dear White People with a skepticism towards their intent. I thought the name of the show was an indication that it would be another example of media exploiting identity politics. I began watching with that expectation and held that perspective for quite a while afterwards.

The characters and story itself immediately engaged me. I was compelled by virtually every person and their experiences. The students of Armstrong-Parker are unique, passionate, ambitious and intelligent. As a natural result of this perspective it was easy for me to want to entertain their ideas and arguments.

This experience was at odds with another: The students extended very little thought and charity towards any opposing ideas or experiences of people outside of their ideology and social group. I felt uneasy that these characters who I liked and respected were making so many failures in upholding their intellectual integrity.

After a long period of confused enjoyment I realized that my issue was a false assumption. My initial expectation felt like it was being reinforce continuously so I never thought to reconsider the shows intent. After some reflection I think the actual intent is demonstrating the deeper problems of identity politics through the “good” characters exhibiting real human flaws. The racial issues are, of course, important and I’m glad to have engaged them but the true value is in the subtleties of how people interact with each other on these issues.

Prometheus (2012), Alien: Covenant (2017), Life (2017), The Cloverfield Paradox (2018), you name it. Why is everyone in the team is a complete incompetent buffoon? Why is the science behind the films so bad? Why do the protagonists do stupid crap? The crew from Alien IV looks like geniuses compared to these people.

Am I the only one who is seriously disturbed by this trend?

I admittedly didn't reread the docs, but a search for "self" showed no results.

EDIT
a search for "self-promotion", and not "self promotion", pointed me to this previous thread:
https://tildes.net/~tildes.official/3i5/daily_tildes_discussion_approaches_to_self_promotion

For those that don't know, NaNoWriMo (National Novel Writing Month) is an annual challenge to write a 50,000 word novel over the course of the month of November. That translates to roughly 1,600 words a day. More info on NaNoWriMo here.

I first tried it two years ago though I fizzled out at around 10,000 words and moved on to another WIP. Last year I didn't formally participate though I made an effort to write something every day. Not sure about my word count.

This year I'm doing a series of short stories in a shared setting since I've been doing more short form writing as of late and I've been mulling over the idea for a few weeks now. It's a nice way to experiment with different settings and themes within a "singular" work. I've made some notes on plot hooks, settings, characters, and ideas I wanted to explore, so it's only a matter of writing the stories now. Maybe I'll even share excerpts as I go along.

So has anyone else made plans to do it this year?

feels like we should probably have one of these in here since it doesn't appear we've had one of these as a community in ~creative in awhile--if ever.

i've spent the better portion of my day today working on a census form for the kryfona kingdom, which is one of the many countries in my fairly large worldbuilding effort. the first page actually came out really well, i think, so that was time well spent. i've considered making a post about some of its more intricate detail since i think some people on here might enjoy that, but for now i've opted to just make this general thread since i dunno how well it'd go as a discussion topic. maybe if y'all think it's worthy of one? idk.

anyways, what creative things have you been working on recently?