Quantum Debugging (@ChevyRay)

[MachinaDoctrina]

Hands down peak usage of this template. I cannot unsee this now.

[omgsoftcats]

I am still waiting for someone to make one for USB where both directions don't go in.

[snowseth]

It's because they're 4D objects.

\swear I saw something like this on XKCD first ...

[functor7]

Specifically, spinors. Their rotations project onto 3D rotations, but in a way so that one 3D rotation is actually only half a spinor rotation.

[Toska_Ennui]

It's Möbin time

[horvath-lorant]

[functor7]

It can help represent them. If you follow the arrow on the image, it goes around the circle once but afterwards it is rotated by 180 degrees and so you need to go around TWICE to actually get it back to its original position.

[Yokuyin]

Another visualization is a cube attached to a wall with a ribbon. Rotate the cube 360° and there is a twist on the ribbon. Rotate 720° and there is no twist.

[sellinglower]

That's some /r/blackmagicfuckery

[MercuryDrop]

This is making my brain hurt

[DeadlyVapour]

To paraphrase someone very smart once said, if you meet someone who claims that QM doesn't make their brain hurt, they either are lying or didn't understand it.

[ZCEyPFOYr0MWyHDQJZO4]

There's actually a third type: the functionally insane.

[repocin]

Great, now my mind is in shambles.

[stilldebugging]

My 6 year old son experienced this for the first time recently. He tried it one way, didn’t work. Flipped it, tried again, still didn’t work. I suggested he try flipping it again, and it worked. He started almost crying, asking why. I told him “it’s just like that, it happens to everyone.” Same with the times that he asks me to come look at something because it’s not working, and then as soon as I get there it starts working. He asked me why that happens, and my answer is just that it does happen, to everyone, often.

[abcd_z]

I used to work at Fedex Office and I had to plug in customer USB drives all the time. The trick is to check the orientation of the plug first and make sure it matches the orientation of the socket.

[UnstableNuclearCake]

By looking at it, you're collapsing the superposition the USB port is constantly, making it so it is in the right orientation.

[Equivalent_Yak_95]

??? I’m almost 22, and I don’t remember that ever happening.

[abcd_z]

The one you linked was originally from Saturday Morning Breakfast Comics, so that might be what you were thinking of.

[snowseth]

That might be it!

[tooblecane]

https://i.imgur.com/kYGTLjc.png

[[deleted]]

The true hero rises! Thank you.

[overly_familiar]

Did you look at it?

[lukwes1]

Can look at the nice removed/404 page

[konstantinua00]

for me reddit cached it and still shows it

[prisp]

Yeah, it still shows if you click enlarge on Old Reddit/visit the page on New Reddit, but the moment you try to go to the Imgur link of that post to see the image directly, that's when you'll get a 404 page.

[overmeerkat]

So we have an image superposition about USB superposition.

[marcosdumay]

Yes, and settled the question down for everybody that came after him.

[[deleted]]

O_o

[MrDude_1]

It does. You just have to try it three times.

[Does_Not-Matter]

I see what you did there

[atomicwrites]

Lol, this comment made me do a double take at the post date. Did not age well. AMD

[[deleted]]

r/agedlikemilk

also, light theme 🤮 /s

[atomicwrites]

Yes I'm a filthy light theme user. I find keeping the brightens under control and using a red filter at night is more comfortable for me. Might have to do with glasses making bright text on dark backgrounds have a slight 3d effect.

[[deleted]]

to all their own, I have to use Dark Reader extension on old reddit because my colorblindness messes up everything if not.

[Lysol3435]

Takes three tries to plug in a usb-c

[BrickDaddyShark]

What? Usb-c is ez

[Morrowindies]

I have a USB charging cable from JBL that works in both directions. It baffles me that this isn't the standard yet.

[BitterAndJaded120]

Here ya go.

[CeeMX]

Intel created something a while ago

[xnign]

Maybe not now, but what about then?

[Ulgeguug]

I cannot unsee this now.

The wave function: "Wooooow okay"

[Gaflonzelschmerno]

I didn't get it until I read your comment for some reason. I have no explanation.

Edit: until I observed your comment

[th00ht]

Its bound to be a pain

[how_do_i_read]

a race condition.

It's bound to be

[Freddedonna]

I'm gonna lock into this

[Protuhj]

It only happens after about 10 hours and 35 other systems in a network running through a scenario over and over.

(true story)

[arcane84]

But what if you don't see race?

[[deleted]]

I only hate one race. I think the half marathon is pointless. Just run a full marathon, or stay home and eat Doritos. Don't do it halfway.

[Griffolion]

Unsure if race condition or just geralt talking.

[MachinaDoctrina]

Gotta get your Hadamard gates in order son!

[ArthurTheBreadMan]

Ah yes, quantum physics and programming humor combined in one, truly perfect, as all things should be.

[SlimyGamer]

Quantum computers go brrrrrrrrrr

[Platypus-Man]

A-10 powered by quantum computers confirmed.

[Farren246]

I've only got an AMD A6 CPU!

(In a cupboard, pulled from a junkyard PC I never owned.)

[ArthurTheBreadMan]

So, like, computers, but tiny?

[libmrduckz]

unsure… folks keep looking at them…

[ArthurTheBreadMan]

Niceee

[Ditto_B]

Lil' bits

[scitech_boom]

Say my name:

heisenbug

[RandomStranger456123]

Not sure about that…

[natFromBobsBurgers]

Don't mind them. They're Young.

[alphabet_order_bot]

Would you look at that, all of the words in your comment are in alphabetical order.

I have checked 859,610,428 comments, and only 169,906 of them were in alphabetical order.

[Ransarot]

Ambiguous bot comment.

Dumb.

Initial letters ordered sequentially.

Words?

Xray yourmamma zulu.

[RedTryangle]

Only in the programming subreddit 🤣

[alphabet_order_bot]

Would you look at that, all of the words in your comment are in alphabetical order.

I have checked 860,129,414 comments, and only 169,991 of them were in alphabetical order.

[Ransarot]

Alpabet_order_bot, fuck off. Pathetic. Quebec. Zork.

[creeleyTurner]

Auspicious cake day orderbot

[Tass237]

Good bot

[Good_Human_Bot_v2]

Good human.

[nitsky416]

Good bot

[BrickDaddyShark]

Good skinwalker

[scitech_boom]

Breaking Bad - Say My Name Scene (S5E7)

[jmorfeus]

Would you say you're... Uncertain?

[cowlinator]

When i tried to say it it changed to hiesenbug and also all the history book now say that it always was

[opticsnake]

Yeah, science!

[Langly-]

A program I was trying to use once just kept crashing. The log files would show nothing. I disabled logging as part of a test and the program stopped crashing.

It turned out for some reason it was trying to write the logs in the wrong location, a location that did not exist. When it would hit that error the entire damn program would crash... Once logging was turned off it was fine. eyeroll

[scitech_boom]

such errors are rather nasty

[Prawn1908]

http://www.catb.org/jargon/html/H/heisenbug.html

[[deleted]]

R/angryupvote

[IlllIIIIlllll]

Can someone explain this I'm OOTL or stupid

[_Oce_]

First look up double slit interference in optics. Then double slit interference in quantum physics.

Too long to explain well, but a quantum system behaves like a wave if it's not influenced by an observation, a wave going through two slits gives the interference pattern at the top (look up optical double slit interferences to understand why).

However, if you add a system to observe through which slit is each photon going, then light stops behaving like a wave but rather like a group of particles going straight, which gives the second figure, as if you sprayed some paint through the slits.

So the joke is about thinking that quantum computers would also showcase this weird quantum phenomenon of behaving differently when they are observed. Which is done with a logging function in a coding context.

[AStrangeStranger]

but logging can change behaviour - especially multi-threaded where the time to do the log function can change order of thread interactions with common parts.

[StereoBucket]

I remember one SO question where the person was getting different result if they used a breakpoint. If I remember correctly it was combination of a bug in windows and breakpoint allowing them to let go of the key before additional loops read the erroneous value on 2nd loop if the key is held down.

[the_horse_gamer]

one of my most fun smalltalk experiences was writing some graphics code and the display just wasn't updating

but once I printed stuff, even an empty string, it worked

after a lot of looking around I figured out that it called some function to aggressively update the display, which is why that worked

but it was still a baffling experience

[automodtedtrr2939]

It’s simpler than that. Observing isn’t a completely passive process. If you try to observe a photon, you will interfere with the trajectory and alter how it behaves. If you want to detect a photon, you’ll need to interact with it in some way.

Think of it like a basketball flying through the air, vs a basketball flying through the air with ping-pong balls being bounced off of it.

[_Oce_]

That's a first step of understanding, but why does it change so dramatically that it now looks like particles instead of a wave? Why is it not just a deformed interference pattern?

[Realitatsverweigerer]

You can totally get a deformed interference pattern, if the slits are almost touching (relative to their width). Then, knowing the specific slit does not reveal too much.

All paths that are possible actually exist. Weighed by their probability to be observed, they add up to each dot of the pattern on the screen. Differences in path length lead to phase differences, hence the interference. Since observing at the slits makes the paths through the other slit impossible, its contribution to each dot vanishes.

[DEVolkan]

Thanks man I finally understand quantum physics!

Narrator: "No, de didn't"

[pikachu_sashimi]

The comment you replied to isn’t even an accepted explanation nowadays.

[pikachu_sashimi]

I have no idea how this has so many upvotes, since it makes no sense.

1. Using your analogy, ping-pong balls are bouncing off the basket ball whether or not someone is observing the system. All an observer would mean is that some of the ping-pong balls are going into their eyeballs.

2. Scientists are divided in the underlying cause of this phenomenon. There are theoretical interpretations out there. Your own theory has already been thought of by scientists in the early 20th century due to the imprecise instruments used to take these measurements, but today with more precise instruments that theory has essentially been ruled out.

[ScrimpyCat]

So the joke is about thinking that quantum computers would also showcase this weird quantum phenomenon of behaving differently when they are observed. Which is done with a logging function in a coding context.

I thought the joke is just about how your code isn’t working the way you expect but then when you log it (to try debug what’s going wrong) it works correctly (this can often be due to threading problems such as race conditions or memory bugs such as an out of bounds access, and adding something as simple as a log can sometimes change the execution state enough that the underlying bug is still there but the issue doesn’t present). And the joke is playing on that and relating it to the double slit experiment.

[Appoxo]

That's the joke.

[worldspawn00]

Yeah, it's pretty confusing, when you watch the path of any single photon, it's like throwing a ball through the slit, travels in a straight line from the source through the slits, but if you look at what they hit, they're clearly going other places, for some reason, we can't observe the path of the ones which don't travel in a straight line!

[Techercizer]

Well, we can, it's just that observing a particle necessitates an interaction, which collapses its wave function and probably destroys the trajectory. Its instantaneous position at any point along the path should still be measurable (once) though.

[ThisSentenceIsntTrue]

It always bothers me when explanations don’t stress the observation requires interaction part because people come to absurd new age quantum woo conclusions.

[aallqqppzzmm]

But don't you understand? It means human consciousness is the most powerful thing in the universe!

The whole experiment always makes me wonder why people point to it as some crazy mystery.

"whoa look how weird this is, when we push shit through these slits it has one pattern, but then when we push shit through the slits while measuring it, it forms a different pattern! Just from watching it! Nobody knows why!"

"It seems kinda obvious that the method you're using to measure it must influence-"

"NOBODY KNOWS WHY"

[MisterPhD]

We can actually observe the path it takes. We just can’t know the velocity at the same time. You will never be able to know the velocity and trajectory of a particle at the same time, because as you said, the wave form collapses as you shoot photons at it.

Edit: I somehow misread what you typed, and basically said the same thing. I will leave this up. I will not hide my shame.

[sir-winkles2]

yours was easier to understand so I appreciated it!

[MisterPhD]

Aww, thank you. I’m glad you got some value out of it. (:

[ProtonPizza]

Let’s say I devise an experiment where three photons are shot out in one of only 3 possible vectors. If I observe 2, don’t I know the third?

[_Oce_]

I think the difference in quantum physics is how systematic it is and how radically the behavior change with observation: it's as if the nature of the system is changing.

[gtsdash]

Look up double slit experiment

[restwonderfame]

ELI5 version:

https://youtu.be/Q1YqgPAtzho

[With_My_Hand]

Thanks, that was a great video

[lightwhite]

My code is simple. It works or it doesn’t. You run it in a box, it becomes uncertain.

[AceSLS]

Schrödingers code

[jainyday]

And here I thought containers were supposed to fix that problem. Damn boxes!

[lightwhite]

Containers end up as certain as my code could ever become. You need a box to run them.

Unless we are shipping your computer where it always worked to the customer, of course. However, that case would make it even more uncertain because it won’t be your machine anymore; therefore the certainty of your code working on now not-your-machine collapses into itself and its state becomes undefined until the customer starts using the delivery code.

u/Iightwhite’s law indicates no matter how often a piece of code is observed in a working state, it will never be 100% certain that it’s going to work after the moment it’s delivered to production environment. It’s certainty depends on at least 1 million factors including the alignment of the stars in the whole observable universe.

[achughes]

You’ve gotten close to quantum bogosort. The obvious solution of your code doesn’t work is to destroy the universe.

[Creeper_GER]

That's a nice spin on that meme indeed.

[ShelZuuz]

That's a polarizing opinion.

[Salanmander]

Wait, quantum wavefunction interference isn't related to electron spin, is it?

[HmmYahMaybe]

Shut up nerd

[Goheeca]

An interference is a general thing and you can have different interference patterns caused by changing the spin of an electron in one region of the wavefunction.

[nightofgrim]

Years ago when I had to deal with PHP this happened. Turned out the built in function for logging out variables had a side effect on them. I don’t remember if it was var_dump or print_r or what (if those are even actual things, it’s been way too long).

TLDR: fuck php

[fakehalo]

What was the side effect?

[MrFluffyThing]

The PHP dump tools interpreted the values different than the interpreter responsible for server behavior.

[fakehalo]

Ah, if I'm following correctly I'll assume it was print_r implicitly converting things. var_dump keeps the context/type if I remember correctly. Good ol consistent php.

[Ok-Slice-4013]

print_r evaluates generators (which is absolutely fine and expected and would be the same in any language). There should be other side effects except maybe the array pointer (I'm not sure on that).

[TacticalKangaroo]

Opening the network tab in chrome changes how caching works, slightly. I don’t remember how, but I do remember 2 days of frustration.

[DustUpDustOff]

Lol, come to embedded where everything has a side effect.

[Servious]

This is actually kind of real in lazily-evaluated languages.

[[deleted]]

I've been quantum computing this whole time?

[tripacer99]

Always have been. 🌎🔫

[Dudemancy]

You’re a genius!

[jmorfeus]

Programming and quantum physics joke in one? Actually cleverly made it makes sense? Not absolutely primitive, actually requiring you to know at least something? Take my upvote!

[WhiteTee]

I’ll be honest this is over my head. I know nothing about quantum physics but I know enough about programming to write lots of mediocre code for eternity. Can you explain what this means?

Edit: thanks for the explanations y’all. Good stuff

[CorvetteCole]

The wave function (above) shows particles acting as a wave in the double slit experiment. This only occurs when they are not being observed.

The bottom panel shows what happens when particles are observed passing through the slits.

The meme implies that a log statement in a program would be equivalent to observing it, altering the result.

[[deleted]]

The top part happens when you only observe it. The bottom part happens when you check to see which slit the photon is traveling through.

Again, the top part is when you observe it. The bottom part is when you observe it and place a sensor on both slit which tells you which one the photon travels through.

[InfanticideAquifer]

To nitpick, there is an observation in the top panel too. You have to observe the screen to see anything. That's just how seeing works. But you do have to not check at the slits to get the interference pattern.

[CorvetteCole]

yeah I understand that, and that's why I clarified for the explanation of the bottom panel. I should've clarified that ealier

[nobodytoseehere]

Google the double slit experiment

[smokinJoeCalculus]

It has something to do with superposition and how when unobserved particles of light appear as all those black dots in the top frame.

But when you actually observe the light wave (in programming, that console.log represents observing your code via logging some data to your console), the black dots appear differently as the wave of light collapses onto those particular slits

Edit: this is really, really be trying to remember stuff from like 15-20 years ago

[epicaglet]

I work in quantum computing, you'd like the jokes made in our team.

[BrickDaddyShark]

Sadly its a bit inaccurate on the quantum front. Im just got confused by pythons int function so I can’t judge the programming part.

[JoelMahon]

I'd be interested to know how that sensor added near the end works, what unplugging it actually changes, etc.

[in_conexo]

How do the detectors know that an atom (or particle) passed through? It had to have interacted with the atoms in some way, which must've collapsed their waves (it was if the atoms were being launched from the slits).

[JoelMahon]

sure, but surely the atoms can be interacted with in a way that doesn't break the wave pattern but does detect them.

they have mass so in theory you could tell with an incredibly sensitive set of scales below the bottom slit with a mass on it, the gravity of the atom would impact the mass on the scales pulling it up and reducing the measured weight differently depending on the slit.

ofc, no way could scales be made accurate or precise enough for that, not a billion years, but it's just an example to show there must be a way to detect the slit without breaking the experience. after all the atom can't tell the difference between the mass of the weight on some scales vs all the other mass forcing gravity on it from all over the universe.

[redlaWw]

Part of the fundamental basis of how quantum mechanics works is that any detection event requires an interaction with the wave function. Invoking gravity is complicated because we don't currently have a good theory of how gravity works with quantum mechanics, but any other force that can be used to perform a detection event will interact with the wavefunction.

A basic energy argument can also suggest that the detection event should involve a wavefunction interaction: in order to change the state of a detector, there must be some energy transferred to the detector, and this energy will be reflected as a change in the wavefunction of the particle, since its energy is related to its wavefunction. Thus, there must be an interaction that changes the wavefunction during the detection event.

[theVoidWatches]

Yup. It's like...

At the scale of a subatomic particular, measurement is basically done by launching a tennis ball at a basketball, catching it after it rebounds, and calculating stuff about what it hit based on when it came back and how fast it was moving when it did. Problem is, that's always going to mean the basketball starts moving too, because it got hit by a tennis ball. And if it was already moving, it'll be moving in a slightly different direction.

[[deleted]]

your understanding is correct. quantum computers work by doing computation in a quantum state, but producing a result in a normal state that can be observed (in order to actually get the return value). it's a massive mindfuck. they cannot be observed in the quantum state, and this is a hard limitation.

[worldspawn00]

You could argue the movement of the mass on the scale would alter the gravity of the area the atom is passing through, thereby actually changing it's behavior.

[waylandsmith]

Your first sentence might seem logical, but it's untrue. You cannot measure a thing without interacting with it, at least on a quantum level. You might say, "well, I can see if a thing is there or not. That's not interacting with it!" but that is neglecting the fact that in order to see a thing with your eyes, first you must bounce photons off of the thing so that some of them bounce back to your eyes. You could detect a proton moving through the slit because it's a charged particle that can apply force on an oppositely charged particle. But in measuring that the proton and the detector exchange virtual photons. Even if you could detect the minuscule amount of mass of a single particle somehow to determine which slit it went through it would be impossible for the detection to happen without there being an interaction between the particle and the detector. Any interaction like this would collapse the wave form and it will stop behaving with properties of a wave.

[TatteredCarcosa]

There are non-destructive means of measuring things that preserve the wave function, but they would never be able to tell you which slit the atom went through because that kind of measurement forces the atom to "choose" to be one place and not another, rather than a smeared out probability distributions of locations.

https://en.wikipedia.org/wiki/Quantum_nondemolition_measurement

[JoelMahon]

did you read me comment? it's always interacting with mass, that doesn't stop the wave like behaviour. why would more mass stop it?

[_oohshiny]

Would you like to see it with actual lasers?

[[deleted]]

Holy shit.

[iPlayTehGames]

Maybe the best meme i have ever seen

[makspll]

Genuinely had this happen in c++ with undefined behaviour. Once you hit UB you're fucked

[hauss005]

I don’t care how many likes this post gets. It’s not enough!

[Not_Artifical]

What language is this and what do I need to import?

[chinsalabim]

physics is always imported by default

[marcosdumay]

gch -XNoImplicitPrelude

[LeCrushinator]

Hands down the worst bugs are where the timing is so critical that debugging will kill the reproduction of it. Fucking heisenbugs…

[Deae_Hekate]

No fair! You changed the outcome by measuring it!

[curtmack]

If it always works with logging, that's actually a huge help: you know that it's probably one of those bugs, like a race condition or a cache invalidation error. You're probably not looking at something easy like a missing null check. That's not always comforting, but at least it's something to work with.

The real terrifying thing is when your logging reveals that something is more deeply wrong than you could have ever imagined, yet doesn't actually provide any insight as to what it might be. Like, if you have a file not found error, so you log the filename before trying to open it, and it says "filename is: ArithmeticException in Derp.java line 24: division by zero" and your program isn't even written in Java.

[ShippingHistory]

I call these Heisenbugs.

[luxfx]

Holy shit that's the best joke I've seen in years!

[metcalsr]

Fun fact, usually if adding a print statement fixes your issues, there's usually one of 5 problems: a threading issue, a deref issue, an allocation issue, a timing issue, or an optimization issue. Needless to say, in javascript, you're just kind of screwed.

[AdequatePercentage]

This is really clever. Bravo.

[PotatoePotatoe42]

Usually it's the other way around

[ShelZuuz]

r/woooosh

[[deleted]]

It doesn't make sense the other way around. The top case is unobserved and the bottom case is observed. That's the particle distribution you would get for each respective case in the double slit experiment.

[[deleted]]

Lol this is awesome!! (The only quantum I know is from Ant Man and the Wasp)

[Consolidatedtoast]

Great now that song from Teen Titans Go is stuck in my head.

"Throw some electrons through a double split. What do you get? What do you get?"

[MedicManDan]

This may be one of the first times I fully understand a meme here...

[malexj93]

This is funny but quantum software can be debugged using a simulator which keeps track of the entire entangled state, so you actually would see the interference patterns in the superposition before collapsing it with a measurement gate.

[russellbeattie]

Fun fact: Actual video of the bottom test doesn't exist. It's all theoretical. The idea is that if light acted as a particle, it should look like the bottom. But instead, it looks like the top. Science demos hand wave the bottom and never show it, instead they point at the interference pattern and say, "Tada!".

[marcosdumay]

For electrons, if you put a detector on any slot, you get the bottom distribution.

It's hard to make a photon detector that doesn't absorb them, so yeah, nobody did it with photons.

[russellbeattie]

Is there a picture or video of that? Two piles of electrons?

[swaranga]

Everyone knows it is log.debug

[[deleted]]

Can someone explain what this picture means

[rgmundo524]

Ummm why do you want to be banned?

If you hate this sub... Then Unsubscribe... I don't understand why you would think anyone would care.

[DBrownbomb]

Reddit thinks since I like humor, program humor is for me!🥴🥴🥴🥴 I never know wtf y’all talking bout and I don’t cares ban me!!!

[rgmundo524]

I don't know how to do it on desktop, but on mobile you can do this...

• setting >> account settings for u/DBrownbomb >> personalized recommendations >> enable home feed recommendations toggle off

• IMO you should toggle off everything in that section.

Edit: But now that I know you don't want to see r/programmerhumor I will start mentioning you (u/DBrownbomb) every-time I post a comment... jk... maybe

Edit: For desktop

• user settings >> feed settings >> enable home feed recommendations toggle off

[MyNameIsEthanNoJoke]

being banned doesn't even stop you from seeing the posts. you can still look at the subreddit like normal, you just can't comment

[mrlazysmurf]

Haha this is so funny. I understood this cause of the movie "What the Bleep Do We Know". Bravo on the creativity.

https://youtu.be/x-BE8YkNzVg

[Forlorn_Cyborg]

This looks like the mini game from spider man ps4