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14 votes
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The name ‘Mormon’: Why all the fuss, and why now?
8 votes -
Film director Mamoru Hosoda talks gender roles, parenthood, and identity in Japan
7 votes -
This week in Anime: week 44 of 2018
Technically I'm late again, but it's still Friday somewhere right? How do? Since we're currently lacking native spoiler tags, I'd ask all of you to follow this scheme: Post a top level comment...
Technically I'm late again, but it's still Friday somewhere right?
How do?
Since we're currently lacking native spoiler tags, I'd ask all of you to follow this scheme:
Post a top level comment with the title and episode number of the anime you want to talk about like this
**JoJo's Bizarre Adventure: Vento Aureo - Episode 1**
Then reply to those top level comments with your thoughts. This way people who haven't seen something yet or plan on binge watching once all the episodes are out can simply collapase the top level comment to not get spoiled ^.^What do?
Simply post, discuss or joke about any currently airing anime you want. For Anime you've been watching that aren't currently airing refer to Cleb's weekly thread.
When do?
But what if the anime I want to talk about hasn't aired yet?
No problem, just post a comment here once the episode has aired, these threads aren't meant to last one single day.
Archive
Archives of these threads can be found at the unofficial wiki
5 votes -
The news is bad in Hungary: "Viktor Orban didn’t like what the press was reporting, so he took it over."
11 votes -
Google Chrome’s users take a back seat to its bottom line
16 votes -
TikTok surpassed Facebook, Instagram, Snapchat and YouTube in downloads last month
14 votes -
CBD is everywhere. But is it a scam? The super-popular cannabis compound, explained
12 votes -
RED Hydrogen One review: I wanted this to be great! (MKBHD)
5 votes -
True Detective | Season 3 official trailer
8 votes -
Space horror: Is it dead?
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...
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?
20 votes -
Trailer for Warcraft III: Reforged
15 votes -
Triple the apparatuses, triple the weirdness: a layperson's introduction to quantisation and spin, part 2
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...
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 1Today'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.
32 votes -
Destiny 2 base game for PC is free on Battle.net through November 18
27 votes -
Ten great adventure-game puzzles
8 votes -
The Great American Read
6 votes -
Silent Planet - When the End Began (2018)
Apple Music Google Play Spotify Progressive metalcore outfit Silent Planet has finally released their third studio outing after teasing with almost half a dozen singles released. Like their...
Apple Music
Google Play
SpotifyProgressive metalcore outfit Silent Planet has finally released their third studio outing after teasing with almost half a dozen singles released. Like their previous efforts, the album is drenched pathos.
Garrett Russell's lyrics continue to impress and be the thing that truly sets Silent Planet apart from other heavy rock outfits on the scene right now. His employment of footnotes in his lyrics to help the listener know his purpose in word choice has become a hallmark of the band's output. But while Russell's lyrics have always been good, When the End Began marks a new level in his delivery. His guttural lows are booming and intense in songs like Northern Fires, while his understanding of timing and beat helps punctuate his words much better than he's ever done before, really shown off on Share the Body. Not to be content with that, he even attempts some clean vocals on the albums with a fair amount of success.
This is all complimented by guitarist Mitch Stark's djenty riffs on the guitar. While Silent Planet has been known for their emotional aesthetic, Stark sneaks in a bit of catchy riffs in tracks like Firstborn. Planet has always straddled the line between ambient and heavy, and they continue to in When the End Began, as guitars will effortlessly switch from chunky riffs to fleeting noises.
If there is a better heavy rock album coming out this year, I'd like to hear it, because I honestly want the feeling of being blown away that When the End Began gave me a second time.
4 votes -
What role should victim impact statements play in Canadian courts?
5 votes -
Most useful Chrome extensions
What are the most useful Chrome extensions that you have come across? I use this extension called Workona, which has been just amazing at dealing with my obsession with having hundreds of tabs open.
19 votes -
Palau to ban sunscreen products to protect reefs
10 votes -
Pakistan’s ultra-Islamist party blocked roads in major cities for a third day on Friday in protest against the acquittal of a Christian woman on death row for blasphemy allegations
8 votes -
Over 50 of the biggest US companies sign pledge to stand with trans people
7 votes -
what creative projects are you working on?
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...
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?
15 votes -
Daughters - You Won't Get What You Want (2018)
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:...
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!
6 votes -
Fifty Fizzbuzzes
5 votes -
Why be nonbinary?
15 votes -
Apple's New Map — by Justin O’Beirne, a follow up to "Google Maps' Moat"
21 votes -
Tab Muter: re-enables Google Chrome's "Mute Tab" feature
22 votes -
We regulate the wrong things
13 votes -
Graveyard Keeper: How the graphics effects are made
8 votes -
US Federal Communications Commission Republican claims municipal broadband is threat to First Amendment
12 votes -
~music Listening Club 20 - Washing Machine
Hey, we made it to week 20! Here we've got this week's user-voted record: Washing Machine by Sonic Youth! Washing Machine is the ninth studio album by the American experimental rock band Sonic...
Hey, we made it to week 20! Here we've got this week's user-voted record: Washing Machine by Sonic Youth!
Washing Machine is the ninth studio album by the American experimental rock band Sonic Youth, released on September 26, 1995 by DGC Records. It was recorded at Easley Studios in Memphis, Tennessee and produced by the band and John Siket, who also engineered the band's previous two albums. The album features more open-ended pieces than its predecessors and contains some of the band's longest songs, including the 20-minute ballad "The Diamond Sea", which is the lengthiest track to feature on any of Sonic Youth's studio albums.
Taken from @Cleb's pitch:
I listened to this fairly recently and after my previous experience with Sonic Youth (Daydream Nation, Sister), which I thought was mostly just okay, fine, whatever, I did not expect to get as much enjoyment out of this album as I did. Yeah, it's Sonic Youth going even less no-wave inspired than before, but I think they fit far better into that groove of noisy-ish alt rock without the no-wave coming in at times. Maybe I just think the writing is cooler. All I know is it made me finally able to say "I appreciate Sonic Youth."
Here's the place to discuss your thoughts on the record, your history with it or the artist, and basically talk about whatever you want to that goes along with Washing Machine. Remember that this is intended to be a slow moving thing, feel free to take your time and comment at any point in the week!
If you'd like to stream or buy the album, it can be found on most platforms here.
7 votes -
What are the rules on self-promotion? Can I share links to my own blog posts?
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:...
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_promotion25 votes -
Modern STEM toys don't do a good job of educating because they're just toys, not tools
11 votes -
Pete Smith - Off The Scale
3 votes -
Flickr's free accounts will be limited to 1,000 photos and videos starting January 8, 2019
30 votes -
Mixer (Microsoft's streaming service) announces upcoming changes related to viewer interaction, "progression", and supporting streamers
9 votes -
Guillermo del Toro - Monsters, makeup and movie magic
7 votes -
Ulf Kramer- frei² tribute to Chip Tronic (23.10.18)
3 votes -
iOS - are you able to highlight some text in a comment so that you can copy and paste into a quote?
I have not been paying close attention lately, but I swear that it was possible to highlight some text in my notifications and/or topic’s comment thread views, so that I can paste it into a quote...
I have not been paying close attention lately, but I swear that it was possible to highlight some text in my notifications and/or topic’s comment thread views, so that I can paste it into a quote in my reply.
Anyone else have an iOS device that they can try this on?
3 votes -
Nintendo Direct - Super Smash Bros. Ultimate
9 votes -
Annihilation and decoding metaphor
8 votes -
My grandfather thought he solved a cosmic mystery
8 votes -
Silent Planet - Visible Unseen (2018)
4 votes -
Getting into the games industry
6 votes -
Today's the first day of NaNoWriMo (National Novel Writing Month), is anyone else participating?
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...
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?
19 votes -
Brad makes black garlic | It's Alive
7 votes -
Which social media design features you find to be pet peeves?
Most social media users enjoy some design features and dislike others. However, there are often things that, while minor, significantly worsen these users' experience. What are your social media...
Most social media users enjoy some design features and dislike others. However, there are often things that, while minor, significantly worsen these users' experience.
What are your social media design pet peeves?
19 votes -
Manolis Manoussakis & Harris Panagiotakis - Kontylies + Pentozali | Sofar Heraklion (Crete)
4 votes -
A scary amount of LGBT women and non-binary folks report seeing a ghost
10 votes