What is the largest real number one can write within 200 characters?

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SUMMARY

The forum discussion centers on the challenge of expressing the largest real number within a 200-character limit, utilizing mathematical notations such as Knuth's up-arrow notation and Graham's number. Participants explore various expressions, including factorials and exponential functions, while adhering to the rules that prohibit references to previous posts and attempts to replicate Berry's paradox. Notably, the discussion highlights the complexity of comparing extremely large numbers and the creative approaches taken by users to maximize their expressions.

PREREQUISITES
  • Understanding of real numbers and their properties
  • Familiarity with mathematical notations such as factorials and exponential functions
  • Knowledge of Knuth's up-arrow notation for expressing large numbers
  • Basic comprehension of Graham's number and its significance in mathematics
NEXT STEPS
  • Research Knuth's up-arrow notation and its applications in large number theory
  • Explore the properties and implications of Graham's number in combinatorial mathematics
  • Learn about Berry's paradox and its relevance to discussions of infinity and large numbers
  • Investigate advanced mathematical functions and their representations in character-limited formats
USEFUL FOR

Mathematicians, educators, students, and enthusiasts interested in large number theory, mathematical notation, and the creative expression of numerical concepts within constraints.

  • #61
micromass said:
Not a real number.

really?
 
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  • #62
ChrisVer said:
really?

What real number would be the answer?
 
  • #63
Code:
let G = graham's #
let ☺ mean G ↑'s in knuth notation
let ☻ mean G ☺'s
base G
13☻☻☻☻☻☻☻☻☻☻☻☻☻☻☻☻☻☻☻13

edit: well i guess we already kinda went there on page 1, but i'll keep my notation
 
Last edited:
  • #64
If the subscript notation used in describing Gram's number is considered standard much larger numbers then Grams should be easily constructed thus...
ggn recursive subscriptsn
Now you are left with describing the largest possible n with the remaining of the 200 characters.
This is just 1 example though of a rapidly increasing function recursed a large number of times, it may not be the best one to use.

More broadly, I think this will essentially come down to the most clever method of unambiguously describing 2 things...
1. The most rapidly increasing function
2. Vast numbers of recursions.
I'm sure someone has better ideas on how to approach both of those problems then I do, though they seem like they might be the same problem.
 
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  • #65
Time to come clean. I made this thread because I read a very interesting article about big numbers. It seems in this thread, many found their way to Graham's number and Ackermann function. But there is a function which increase even faster than those: the busy beaver function. Check it out:

http://www.scottaaronson.com/writings/bignumbers.html
 
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  • #66
micromass said:
Time to come clean. I made this thread because I read a very interesting article about big numbers. It seems in this thread, many found their way to Graham's number and Ackermann function. But there is a function which increase even faster than those: the busy beaver function. Check it out:

http://www.scottaaronson.com/writings/bignumbers.html
I really liked this part:
Could early intervention mitigate our big number phobia? What if second-grade math teachers took an hour-long hiatus from stultifying busywork to ask their students, "How do you name really, really big numbers?" And then told them about exponentials and stacked exponentials, tetration and the Ackermann sequence, maybe even Busy Beavers: a cornucopia of numbers vaster than any they’d ever conceived, and ideas stretching the bounds of their imaginations.
So it seems a very large number can use the BB function with BB(G) recursions? I know there is a more elegant and rigorous way to write it, but I don't think I'm clever enough.
 
  • #67
googol, period
 
  • #68
TheQuietOne said:
googol, period
Even a googolplex is very very very small compared to graham's number.
 
  • #69
ChrisVer said:
really?
yeah, suppose ##\lim_{x \rightarrow 0} 1/x^2=b##. A theorem says that ##\lim_{x \rightarrow a} f(x) = c## if and only if for every sequence ##x_n## which converges to ##a##, the sequence ##f(x_n)## converges to ##c##. So take the sequence ##\{1/n\}_{n \in \mathbb{N}}##, this sequence converges to 0, but ##f(1/n)=n^2## for ##f(x) = 1/x^2##. This sequence does not converge to any real number, so it won't converge to ##b##.
 
  • #70
TheQuietOne said:
googol, period

Graham's number is so much bigger than googol, that it is impossible to write down Graham's number in exponential form if you could write a trillion numbers on every atom in the universe and you had one hundred trillion universes. Meanwhile, googol is just ##10^{100}##.
 
  • #71
222222222222222222222222222222222222222

divided by .00000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000012222222222222222232
 
  • #72
OrangeDog said:
222222222222222222222222222222222222222

divided by .00000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000012222222222222222232

Not even close to Graham's number alone. If you can write it using exponents, then it's much smaller than Graham's number. Actually, unfathomably smaller than Graham's number.
 
  • #73
OrangeDog said:
222222222222222222222222222222222222222

divided by .00000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000012222222222222222232

Not only does it vastly go over the character limit, it is also vastly smaller than Graham's number. No matter how many exponents you put in, there's not enough space and time in the universe for the exponent tower to get anywhere near Graham.
 
  • #74
You can't actually read my text, so how do you know that each one of those tiny exponents isn't grahams number?
 
  • #75
OrangeDog said:
You can't actually read my text, so how do you know that each one of those tiny exponents isn't grahams number?

If you hit "QUOTE", you can see what you wrote.
 
  • #76
Lies
 
  • #77
OrangeDog said:
no you cant
...Yes... you can...
 
  • #78
more lies
 
  • #79
Code:
[QUOTE="OrangeDog, post: 5423766, member: 584341"]2[SUP]2[SUP]2[SUP]2[SUP]2[SUP]2[SUP]2[SUP]2[SUP]2[SUP]2[SUP]2[SUP]2[SUP]2[SUP]2[SUP]2[SUP]2[SUP]2[SUP]2[SUP][SUP]2[SUP]2[SUP]2[SUP]2[SUP]2[SUP]2[SUP]2[SUP]2[SUP]2[SUP]2[SUP]2[SUP]2[SUP]2[SUP]2[SUP]2[SUP]2[SUP]2[SUP]2[SUP]2[SUP]2[SUP]2[/SUP][/SUP][/SUP][/SUP][/SUP][/SUP][/SUP][/SUP][/SUP][/SUP][/SUP][/SUP][/SUP][/SUP][/SUP][/SUP][/SUP][/SUP][/SUP][/SUP][/SUP][/SUP][/SUP][/SUP][/SUP][/SUP][/SUP][/SUP][/SUP][/SUP][/SUP][/SUP][/SUP][/SUP][/SUP][/SUP][/SUP][/SUP][/SUP]

divided by .0000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000001[SUP]2[SUP]2[SUP]2[SUP]2[SUP]2[SUP]2[SUP]2[SUP]2[SUP]2[SUP]2[SUP]2[SUP]2[SUP]2[SUP]2[SUP]2[SUP]2[SUP]2[SUP]3[SUP][SUP]2[/SUP][/SUP][/SUP][/SUP][/SUP][/SUP][/SUP][/SUP][/SUP][/SUP][/SUP][/SUP][/SUP][/SUP][/SUP][/SUP][/SUP][/SUP][/SUP][/SUP][/QUOTE]
 
  • #80
In either case, if you used Graham's number, you needed to specify its usage.
 
  • #81
I guess someone doesn't like trolls.
 
  • #82
I do actually, especially when they fail.
 
  • #83
How about, a googolplex "factorialed" a googolplex number of times?

e.g., 3 "factorialed" two times would be (3!)!, or 6! or 720
 
  • #84
jfizzix said:
How about, a googolplex "factorialed" a googolplex number of times?

e.g., 3 "factorialed" two times would be (3!)!, or 6! or 720

Can't beat Graham.
 
  • #85
wouldn't it take more than 200 characters to properly explain how Graham's number works?
 
  • #86
OrangeDog said:
Micromass takes Graham very seriously.

Aren't you in awe at the hugeness of this number??
 
  • #87
jfizzix said:
wouldn't it take more than 200 characters to properly explain how Graham's number works?

I guess it would. But I allowed referencing to outside sources for explanations.
 
  • #88
micromass said:
Can't beat Graham.
GrahamGraham
 
  • #89
Graham's number is the most terrifying number I've seen, and that's why I love it. No amount of googolplexes anyone strings together will even come close to the might that is Graham's number. If ##G## is Graham's number, every number theory textbook ought to start out by saying "Let ##\infty = G##..."
 
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  • #90
Maybe we can tighten up the competition to see what's the biggest number we can write with five characters without allowing outside references

e.g.,

9^99!
 

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