1053: Ten Thousand

Explain xkcd: It's 'cause you're dumb.
Jump to: navigation, search
Ten Thousand
Saying 'what kind of an idiot doesn't know about the Yellowstone supervolcano' is so much more boring than telling someone about the Yellowstone supervolcano for the first time.
Title text: Saying 'what kind of an idiot doesn't know about the Yellowstone supervolcano' is so much more boring than telling someone about the Yellowstone supervolcano for the first time.


This is certainly a great approach to take with someone that doesn't know an apparent common fact, rather than taking the "idiot" approach. For all those who haven't yet seen the Diet Coke and Mentos eruption: here is a Mythbusters video, and here is a music video (Pork and Beans by Weezer) with excessive eruptions. The Diet Coke and Mentos eruption has also been mentioned in a previous strip 346: Diet Coke+Mentos.

The approximate rate of 10,000 people per day hearing about something for the first time is estimated by the birth rate of 4,000,000 people per year divided by 365 days per year, assuming that the birth rate is constant and that indeed everyone learns or gets the fact (or that those in the US who don't are about equal in number to those in other countries who do). The target age of thirty years is irrelevant in this calculation; the 10,000 number is simply equal to the number of newborns per day, or equivalently, the number of people who reach a given age each day.

The title text provides another, perhaps more emphatic example of how explaining a fact to a person for the first time is much more entertaining than just expressing annoyance about that missing knowledge. Here is a good video about the Yellowstone supervolcano. Interestingly enough both events includes some kind (very different kind) of eruptions.

Supervolcanos are again mentioned in 1159: Countdown and in 1611: Baking Soda and Vinegar.

This comic also appears in Randall Munroe's book How To, in the introduction of the book, albeit in a modified form.


I try not to make fun of people for admitting they don't know things.
Because for each thing "everyone knows" by the time they're adults, every day there are, on average, 10,000 people in the US hearing about it for the first time.
Fraction who have heard of it at birth = 0%
Fraction who have heard of it by 30 ≈ 100%
US birth rate ≈ 4,000,000/year
Number hearing about it for the first time ≈ 10,000/day
If I make fun of people, I train them not to tell me when they have those moments. And I miss out on the fun.
Megan: "Diet Coke and Mentos thing"? What's that?
Cueball: Oh man! Come on, we're going to the grocery store.
Megan: Why?
Cueball: You're one of today's lucky 10,000.

comment.png add a comment! ⋅ comment.png add a topic (use sparingly)! ⋅ Icons-mini-action refresh blue.gif refresh comments!


Regarding: "This also assumes that 10,000 people learn of something every day from the day they are born." That's not accurate. Whatever the any distribution of "age you learn" is, the average will hold. For example, if everybody learns some particular fact on their 21st birthday, it holds simply becuase there are roughly 10,000 people having their 21st birthday each and every day.

I think it also may be referring, in a tongue-in-cheek manner, to the fact that people who call people idiots because they don't know something, and yet fail to explain it, are creating ignorance to criticise it.

Person A says, "What is x?"

Person B responds, "You're an idiot for not knowing x."

Person B is now responsible for the idiocy he claims Person A to have, thus making Person B the real idiot. In this comic, he makes this point by refusing to be Person B, while at the same time making subtle references to still having the sadistic glee person B has. 22:37, 24 June 2013 (UTC)

I think he's getting the pleasure of seeing the look on Person A's face when Person A learns/sees something incredible! I think it's more of a positive. -- Theo (talk) (please sign your comments with ~~~~)

I wonder which relative came back to life?Pennpenn (talk) 05:02, 30 January 2014 (UTC)

Would someone care to explain the math behind this comic? (talk) (please sign your comments with ~~~~)

I did a try. The age is unimportant, it's only the birth rate. I'm happy about a feedback. --Dgbrt (talk) 20:18, 13 May 2014 (UTC)

Looks like there might be a callback to this comic in the latest What-If. http://what-if.xkcd.com/135/ 10:14, 6 April 2015 (UTC)

Yesterday I did just this! My mother had mentos and I had diet coke, and asked her if we should try to mix them (so I could show it to my children). And it turned out she'd never heard about it. So after we tried it with some success, I showed her this comic as well ;-) --Kynde (talk) 13:20, 11 March 2016 (UTC)

To explain the math...In a given year the age of people under 30 is 4 million/yr * 30 yrs. Each of these people have a 1/30 chance of learning "it" in a given year: 4 000 000/yr * 30yr * 1/30yr * 1yr/365day = 4 000 000 / 365day = 10 959/day ~= 10 000 Zelcon (talk) 23:37, 7 September 2016 (UTC)

Before solving a math problem, the most important thing to do is recognize what you are trying figure out and what the variables are. So let's examine your "statistics" for learning it. I will accept your estimation of 30 years*4 million (even though the number of people being born each year grows). However, when we get to 1/30, I have a serious issue. You are saying that my chance of learning anything in a given year is 1/30. Where did you get 30 from? The years that people are under. So you are essentially saying that a person has a 1/x chance of learning something in a given year where x is the age? This makes no sense!!! There is not a 1/30 chance that I am going to learn the cure to cancer this year!! (talk) (please sign your comments with ~~~~)

The 30 comes from the assumption that roughly 100% of people learn the "something" by age 30. You do not have a 1/30 chance of learning the cure to cancer this year, because there is not 100% chance of you knowing the cure to cancer by age 30. 19:50, 2 March 2017 (UTC)

I had the chance to watch Star Wars prequel with someone who did not know who was Darth Vader, the shock was amazing in Revenge of the Sith. I wish everyone can discover that plot twist! Zyramere (talk) (please sign your comments with ~~~~)

4,000,000	People born yearly
x	30		Everyone "IT"  knows by what age (yrs)
120,000,000	EQUALS Number of people born in 30 years who will learn "IT" at some point
x	0.033333333	Odds you'll know "IT" this year (1/yrs, in this case, 1 in 30)
x	0.002739726	Odds you'll know "IT" this day (1/365 days in a year)
10,959	Segment of population who will learn "IT" today.

NOT 10k? (talk) (please sign your comments with ~~~~)

It is. You got 10,959. The comic is meant to be approximate. The result is approximately 10,000. 13:44, 17 August 2019 (UTC)

There's no precedent for the daily average. Depending on the fact, there's no reason it would be gradually learned rather than learned immediately in huge numbers upon something important bringing it to light. For rather important facts (like where your country is on a map), not knowing them would be a sign of complete obliviousness. This comic seems to only cover irrelevant facts though that would make sense to be gradually learned. There's also no precedent for spreading the learning event over a single year. Chances are some individuals wouldn't learn a fact that may be common knowledge for others of their age until much later on than the majority of people (years after others), also denoting obliviousness. For irrelevant facts, berating someone for not knowing them isn't constructive since hearing about them would be more coincidental. However, berating someone for not knowing extremely important facts only berates how oblivious they must be to not absorb such a fundamental fact. This is constructive in that the person would learn being so oblivious is not a good thing.

-- 09:17, 6 September 2020 (UTC)Can we add diet coke and methos or some other tag to quickly search this comic? It's pretty useful life advice.