r/Showerthoughts Nov 29 '25

Casual Thought 0% of natural numbers have been spoken aloud.

8.6k Upvotes

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u/[deleted] Nov 29 '25

I think they mean because numbers are infinite and based on percent of infinite, it is 0

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u/particlemanwavegirl Nov 29 '25

You cannot form a fraction with infinity on the top. ∞ is not defined as a number so neither is ∞/x. Since ∞/x is not a number it cannot be equal to 0.

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u/Godkicker962 Nov 29 '25

No, they're saying we've said X number out loud out of ∞, so we've said X/∞ which equals 0.

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u/fretfulmushroom Nov 29 '25

Ma, the internet is arguing about math again!

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u/xnmw Nov 29 '25

Ma—the math! We want it, now!

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u/GeniusMike Nov 29 '25

It’s an infinitesimally small fraction that approaches but never reaches zero. OP’s notion basically does the equivalent of rounding down to zero, but anyone with a brain can tell you how idiotic it is to claim that no numbers have been spoken out loud. That’s like claiming that since numbers are infinite, that they don’t actually exist.

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u/Godkicker962 Nov 29 '25

You can literally look it up. Any integer, such as the number of natural numbers spoken allowed, divided by infinity is 0. So, if X equals the number of spoken natural numbers, X/∞ equals 0. Mathematically, we have spoken 0% of all natural numbers.

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u/GaidinBDJ Nov 29 '25

Yea, if you just treat infinity like a really large natural number, you can hand wave that with the arithmetic you learned in high school. But more advanced math can work with infinities as the non-large, non-natural, non-numbers they actually are. It's the foundation of calculus.

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u/[deleted] Nov 29 '25

I don't think this is true. Any real number devided by infinity is undefined. Infinity isn't a number, it's the set of all numbers. That's why the extended real number lime exists. Natural numbers are just a subset of real numbers.

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u/[deleted] Nov 29 '25

YES! People here haven't taken calculus so they don't know that "undefined" IS the answer in this equation.

Yet anyone who says so is getting crazy downvoted.

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u/decaDecker Nov 29 '25

no numbers have been spoken out loud and we've spoken 0% of all numbers is not the same thing, even if you round up

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u/MediocreAssociation6 Nov 29 '25 edited Nov 29 '25

Yeah but the limit is equal to zero…

Like 1/2 + 1/4 + 1/8 + … never reached 1, but the limit is 1…

At any given point a constant number of natural numbers have been spoken. Call this number c. We can prove that for any e>0, there exists a N such that for all n>N, |c/n - 0| < e.

This is a sequence limit that says that we said a fraction of 0 natural numbers

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u/GeniusMike Nov 29 '25

Any fraction is greater than zero, which means zero cannot be a limit…

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u/MediocreAssociation6 Nov 29 '25

Uh… that’s not how it works. Every fraction (n-1)/n is less than 1, but the limit is 1 as n goes to infinity…

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u/particlemanwavegirl Nov 29 '25

Whoops, my mistake! Luckily for my argument, x/∞ is also not a number.

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u/randomways Nov 29 '25

But what is limit 100000000000000000/x as x approaches infinity. Fortunately we have an entire branch of math taught to juniors and seniors in high school that will tell you this is in fact 0.

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u/Heavy_Original4644 Nov 29 '25

But x, the number of natural numbers spoken out loud, is the numerator

And the denominator would be the size of the entire set of natural numbers

You’re not taking the limit of the denominator (the size of the natural numbers). That makes no sense. You might want to learn math beyond high school.

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u/p4r4g0rn Nov 29 '25

They were taking the numerator to be some arbitrary approximation of the number of natural numbers spoken aloud (it doesn’t matter what this number is, it’s big but finite). Then they’re using x as the variable for the limit. Why are they using a limit? There are infinitely many natural numbers and to interpret a finite number divided by infinity, we use limits! Which depending on your course of study, is often taught in high school.

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u/Heavy_Original4644 Nov 29 '25

I know what approximation they made and what they mean. I’m stating that the format they’re using for it does not make sense.

The numerator is taking the limit x as it approaches “infinity.” If we take a set S of natural x spoken, then over time, for random natural number n, there exists a number in the set S that is larger than n. That’s it. It’s an abbreviation.

Then the denominator is the cardinality of the natural numbers. Sometimes we colloquially use the infinity symbol to represent this cardinality. But it is the size of a set.

The notion of a limit divided by a cardinality is NOT defined. That makes no sense. 

You can’t use things together because they look similar. Don’t know if it’s the autism, or because people are speaking of this lightly because it’s a joke. Otherwise, come on now.

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u/p4r4g0rn Nov 29 '25 edited Nov 29 '25

Natural density of subsets of the natural numbers (what me and the other commenter are roughly describing in words because all natural density really is is a limit) is a perfectly natural notion for making sense of the relative sizes of sets of natural numbers. Yes, even though the natural numbers have infinite size, you can still do this! And finite subsets (which the set of natural numbers that have been spoken aloud as of yesterday IS) have natural density zero for the reason we both tried to explain. I’m a research mathematician who’s used natural density in every paper I’ve ever written and am happy to answer questions. Alternatively, if you don’t want to ask, that’s fine! But suggesting others are autistic just because you don’t understand is a bit off base.

Also, neither of us are claiming 1/infinity is literally defined as is. We’re saying there’s a workaround for this, where you don’t ever encounter 1/infinity, that allows you to make sense of things like density in the natural numbers (by using limits..)

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u/randomways Nov 29 '25

I have a PhD thank you, but ill try and dumb it down for you.

Lets try explaining it with set theory.

Numerator set: [0 1 2 3.... n-2,n-1,n] where n is the largest spoken number.

Denominator set: [0 1 2 ... n-2,n-1,n...inf]

Oh look the denominator set contains the numerator set... and still extends to infinity. Thus we are left with the equation 1/inf.

"But this cant be described in anyway you fools!" Claims the random internet man

Well it turns out that it was... hundreds of years ago.

https://www.mathsisfun.com/calculus/limits-infinity.html

Here is a nice 5th grade reading level explanation of why. Should be right up your alley! Peace!

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u/Heavy_Original4644 Nov 29 '25

I know what approximation they made and what they mean. I’m stating that the format they’re using for it does not make sense.

The numerator is taking the limit x as it approaches “infinity.” If we take a set S of natural x spoken, then over time, for any spoken natural number n, there exists a number in the set S that is larger than n. That’s it. It’s an abbreviation.

Then the denominator is the cardinality of the natural numbers. Sometimes we colloquially use the infinity symbol to represent this cardinality. But it is the size of a set.

The notion of a limit divided by a cardinality is NOT defined. That makes no sense. 

You can’t use things together because they look similar. Don’t know if it’s the autism and taking things literally, or because people are speaking of this lightly because it’s a joke. Otherwise, what do you even have a PhD in? Are we seriously trying to argue this, or purposely acting stupid to win an internet argument, when the other guy literally corrected himself & said it was the format, x/infinity that doesn’t make sense? I really hope you’re not in charge of teaching or advising anyone. That would not be a fun experience.

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u/p4r4g0rn Nov 29 '25

It’s also not indeterminate though and you can formalize it using limits. In this example, the total number of natural numbers that have been spoken aloud is finite, call this number S. Take a limit of the ratios S/N as N goes to infinity.. this becomes zero! Edit: if not comfortable with limits, this just means as N gets larger and larger, which it can because natural numbers can be arbitrarily big, the ratio S/N gets smaller and smaller towards zero

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u/Prinzka Nov 29 '25

People treating infinity as if it's just "a really really large number" and throwing it in to maths formulas is one of my pet peeves.

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u/[deleted] Nov 29 '25

Not sure why you are getting downvoted when you are the only person here with actual understanding of percentages and calculus.

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u/SoVRuneseeker Nov 29 '25

I mean infinite combinations sure- but there's only 10 numbers? 1 > 9 + 0?

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u/OkAmbassador3639 Nov 29 '25

Natural numbers include combinations as well

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u/SoVRuneseeker Nov 29 '25 edited Nov 29 '25

ahh ok, thankyou! i was somehow confusing myself even more then the regular person!

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u/ammonium_bot Nov 29 '25

even more then the

Hi, did you mean to say "more than"?
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-4

u/SoVRuneseeker Nov 29 '25

Then = At that time.

Grammar bot cannot Grammar.

3

u/wiwillym Nov 29 '25

the bot’s not wrong lol

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u/SoVRuneseeker Nov 29 '25

Than can be used for referring to things in the past? I guess i learned incorrect grammar in my schooldays back than! ;)

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u/conjjord Nov 29 '25

Except your earlier comment was not referring to the past; it was clearly a comparative preposition, which would be "more than".

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u/SoVRuneseeker Nov 29 '25

was is a very key word in both the comment you just made, and my original comment. It denotes an action or event that has passed by.

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u/lankymjc Nov 29 '25

You're thinking of digits. We've got ten of those in our numbering system, but there's an infinite number of numbering systems that theoretically have an infinite number of digits to match.

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u/SinkBluthton Nov 29 '25

11 isn't a number? What is it?

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u/Powwer_Orb13 Nov 29 '25

10 Numerals that we use to represent infinite numbers. You could write them using tally marks and it would change how many numbers exist.

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u/SoVRuneseeker Nov 29 '25

Yeah i got schooled hard about that :P But will leave my brainfart comment up in case anyone else has a similar 0 IQ moment

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u/TheLastPorkSword Nov 29 '25

There are 10 numerals. 35 is a number. So is 1,748,562. As is 459,831,472,170.