Why Computers Can't Count Sometimes

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Tom Scott : This was a really difficult script to write! Folks who know 'eventual consistency' as a more formal term may be annoyed that I'm using it a bit loosely here. Hopefully this works as an explainer for folks who are new to it, though!

Tommy Callaway : A programmer is going to the grocery store and his wife tells him, "Buy a gallon of milk, and if there are eggs, buy a dozen." So the programmer goes, buys everything, and drives back to his house. Upon arrival, his wife angrily asks him, "Why did you get 12 gallons of milk?" The programmer says, "There were eggs!"

Lindsay Daly : *Tom Scott* *Tom Scott Returns* *Tom Scott Forever* *Tom Scott and Robin* *Tom Scott Begins* *The Dark Programmer* *The Dark Programmer Rises* *Tom Scott vs. VSauce: Dawn of Knowledge*

Fergus Griggs : Good ol' 301 views.

Matt Snyder : FIRST!! I actually was. My local server just held onto my comment for a while.

Skills With Phil : I've learned so many random things thanks to this channel. These are types of the channels that deserve a YouTube Premium show.

ian1231100 : Mary Poppins Mary Poppins: Revenge of Nanny McPhee Mary Poppins: Dark of the Moon Mary Poppins: Age of Extinction Mary Poppins: The Last Nanny Mary Poppins Mary Poppins: Age of McPhee Mary Poppins: Infinity War

Abbreviated Reviews : "Eventual Consistency" is the method I use for getting enough sleep. I'm sure it'll get there one day.

Fabian Huber : What counts as a youtube view? Watching 100% of the video? What if I skip 10 seconds? 🤔 What if I have the video on loop over night, does the Youtuber get all my views for his revenue?

iRacecraft : Right, did TOM SCOTT just say "Math" ?? National Treasure status revoked.

T : Q. Why did the multithreaded chicken cross the street? A. To the get other to side

Thurston Cyclist : This would be an ironic video in which to wonder why there are more likes than views.

Potato K : *_Overgrown calculators_*

T33K3SS3LCH3N : That is a great explanation, but there is one more thing at work! Many large social media sites deliberately send out slightly randomised numbers to make it impossible for clients to see if their views and votes are counted. This is to enable so-called Shadowbanning, where an account's comments and votes are no longer counted, but the user is not supposed to find out. With this method they can ban vote bot accounts without the owner noticing it (which would simply cause them to delete and replace the bot) thereby reducing the viability of vote manipulation. On some platforms it is even used to deal with generally toxic users.

Squiggs 【Glitches - ROM Hacks - Speedruns】 : Your editing is so on-point in these videos... it really helps to make what you're talking about easier to understand.

Charky : Finally, something we can link on those "omg more likes than views" comments! I could've sworn there was already a video covering that, but I've never managed to find it.

Deryck Chan : There were 48 views and 21 comments when I started watching this (3min after the video was posted). A few minutes later I refreshed the page; there were 24 comments and there were 179 likes but the number of views stayed stuck at 48 views - fewer views than likes due to sync lag - nice illustration of your point.

LapisSea : It's not the counting that is the hard part. It's the communication that is hard

Chriseurosong : MathS, Tom. MathS. You’re English.

El Queso : When I worked for Big Software, one of our products had a notoriously inaccurate progress bar. Our lead programmer explained why making the progress bar more accurate was a "bottom of the list" priority item: "The task that the computer is showing the progress bar takes up about 98% of the computer's processing power, with about half of what's left (1% of the total processing power) going to figuring out progress and animating the progress bar. If we want to make that progress bar more accurate, we have to take processor time away from the task (which is supposed to be most important,) to give it to the progress bar animation. This will make the actual task take longer, in a logarithmic curve to where the task will take forever and the progress bar will show an infinite amount of time remaining, if we let it."

Potato K : I can count: 1,2,3... *Number 15, Burger King foot lettuce* Nvm I can’t count

DynamicWorlds : Want to try explaining why US voting machines seem to be unable to count? They keep claiming it's just a software error where huge numbers of votes can be lost from a single machine with a single user at a time and that sounds like BS to me.

ano1nymus1 : There's also vote fuzzing, which intentionally give as an inaccurate number to discourage manipulation by making it harder to tell whether it actually works or not.

J.J. Shank : There are some systems that get _easier_ with scaling, not harder. For example, the behavior of a crowd is easier to predict than the behavior of an individual. The ideal gas law is awesomely simple and effective, but only works when you lump together a trillion trillion particles. Larger ecosystems are more resilient and self-sufficient than smaller ones. And so on. Fun fact of the day.

BlackBear345 : This is perfect timing because I have been binge watching your videos!!

Sir Rahmed : 0:53 Dear Tom Scott, I regret to inform you but it seems you have made a regrettable mistake of saying the illegitamate word "math" instead of "maths". I can sympathise upon your belief that it was unintentional; a simple "slip-of-the-tongue" as they call it - but please, for the sake of our children and forefunners, do not make this mistake again. Sincerely, A concerned viewer.

Simon L : Tommmm why do you say math! It’s maths you Brit!

Darius Alexander : Dude, you said "math". That's heresy 😂

The Killer Spud : This seems to be the way reporting on an election in the U.S. works.

Anton Timeboy : Did you have to adjust the camera to the screens in the background? Or did it just work

Dom Minniti : MATHS IT'S MATHS NOT MATH!

Gosforth Handyman : Aww... CPC464... getting all nostalgic there! 😢 My second computer after a Tandy TRS80. Because of this I'm now a woodworker.

TheOyvind99 : Not everyday I watch a video the second it goes up

SirBanana : i guess i'm a computer

Squiggs 【Glitches - ROM Hacks - Speedruns】 : Your video has 500 views and 250 likes and it's only two minutes old... people know before they could even possibly be done watching that they're going to like it.

Akshay Anand : Thank you for giving me a video I can link to those idiots who say things like 'X views X+Y likes good work YouTube'. I'm sick of those knobheads.

KABY : This is happening on this video right now

Skeleton Trumpet : Doot doot

HydroCannon13 : *B I G D A T A*

Moss : Huge amount of math*s* Tom, remember your heritage, remember.

KarolaTea : Machining systems also usually single--threaded. If there's more than one processor they'll use a master-slave system (the master requesting/sending information to each slave along the same single thread) or if there's more than one master via token-passing, each master being assinged a set time to send & recieve. That way you can ensure you got the numbers right, and your robot arm isn't still in the machine when it starts grinding. Thanks for the video, really great to hear an example of how counting can get messed up :D

Herleik Holtan : Who's here because of Tom Scott?

Jared McCray : This is actually legit interesting to me. As soon as you started to explain each part it made perfect sense, but I've never really thought about it.

GoldenKnight175 : Thank god, I was looking for something good to watch then you uploaded. Saved me from watching some boring video on YouTube

Timothy McLean : I think it's fair to say that counting accurately, _quickly,_ is the difficult part. If numbers are flooding in faster than your counter can count, which is certainly possible with how big the Internet can make things, you're gonna have a bad time (or some clever engineering).

Marcel Robitaille : Why wouldn't you just have a timestamp on the data from the caching server and ignore it if it's older than the data in the client's memory?

mountnstream : One thing I've seen instead of a queue, is giving a timer. For booking tickets for seats in a movie theatre for example, one is given a timer of 30 seconds picking seat. And if one picks a seat before you, or the timer runs out, it refreshes so one has to pick a different one, with said timer starting again.

Euan McDougall : Alright, everyone watch this video at 4pm Pacific Time

G-Money : 48 views. 133 likes. Ok YouTube

Aidiakapi : Two other techniques that can also change what numbers you see: - Fuzzing: Intentionally changing the data by a bit, in order to throw off bots. - Predicting: Often with unimportant "realtime" counters, they'll observe that "it's been increasing by 1000 per hour", so every few seconds it'll add a number to the count, without ever querying the server.