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

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The discussion revolves around a playful challenge to create the largest real number within a 200-character limit, using standard mathematical functions and notations. Participants debate the effectiveness of various notations, including Knuth's up-arrow notation and factorials, to express extremely large numbers. There is a focus on Graham's number and its implications for size comparisons, with users attempting to outdo each other by proposing increasingly complex expressions. The conversation highlights the challenge of adhering to the rules while still aiming for the largest possible number. Overall, the thread showcases creativity in mathematical expression and the competitive spirit of the participants.
  • #121
micromass said:
Doesn't terminate so not a valid number.
We have defined a size of an infinite set a valid cardinal number, haven't we ? -/+infinity is an extended real number until you hit Control+C.
 
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  • #122
Pepper Mint said:
We have defined a size of an infinite set a valid cardinal number, haven't we ? -/+infinity is an extended real number until you hit Control+C.
Micromass would have to confirm, but I'm assuming that rule 1 for the contest implies extended real numbers are not permitted since it explicitly prohibits the use of infinity.
 
  • #123
Dembadon said:
Micromass would have to confirm, but I'm assuming that rule 1 for the contest implies extended real numbers are not permitted since it explicitly prohibits the use of infinity.

Indeed, only real numbers are allowed.
 
  • #124
Code:
 The number of seconds required to calculate the number of digits in every number in this thread using an abacus, an unlimited supply of paper and pencils, and a wooden spoon.
 
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  • #125
micromass said:
Doesn't terminate so not a valid number.
Still much more real than many.
 
  • #126
Drakkith said:
Code:
 The number of seconds required to calculate the number of digits in every number in this thread using an abacus, an unlimited supply of paper and pencils, and a wooden spoon.
Nice but, sadly, non-computable, owing to its self-referentiality generating an infinite regress. But if you added 'other than posts 104 and 124' it would work.
 
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  • #127
Dembadon said:
Since you initialize x to zero, the condition in the for-loop will be false and it will not run your statement.

Doesn't matter, he and everybody else who try looping/recursive code tricks, will inevitable run out of RAM before even getting close to Graham's number [or TREE(3) or SCG(13) or BIG FOOT]. It won't work even if you turn the whole observable universe into a Samsung semiconductor plant ... :smile:
 
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  • #128
andrewkirk said:
Nice but, sadly, non-computable, owing to its self-referentiality generating an infinite regress. But if you added 'other than posts 104 and 124' it would work.
That's okay. I still have my spoon.
 
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  • #129
Dembadon said:
Since you initialize x to zero, the condition in the for-loop will be false and it will not run your statement.
I'm using java and that is an endless loop. The loop will run even if x is zero, if you think otherwise I don't think you know code.
 
  • #130
DevilsAvocado said:
Doesn't matter, he and everybody else who try looping/recursive code tricks, will inevitable run out of RAM before even getting close to Graham's number [or TREE(3) or SCG(13) or BIG FOOT]. It won't work even if you turn the whole observable universe into a Samsung semiconductor plant ... :smile:
The number I'm producing is something and its called infinity. You can't show infinity on a computer, which doesn't make it false or not a concept. Just because their isn't enough ram to make my number doesn't mean it does exist.
 
  • #131
Patrick_Hutecker said:
The number I'm producing is something and its called infinity. You can't show infinity on a computer, which doesn't make it false or not a concept. Just because their isn't enough ram to make my number doesn't mean it does exist.

Infinity is not a real number.
 
  • #132
micromass said:
Infinity is not a real number.
ok its a concept you got me there
 
  • #133
Patrick_Hutecker said:
I'm using java and that is an endless loop. The loop will run even if x is zero, if you think otherwise I don't think you know code.
I think you should probably try and run your code before suggesting someone "doesn't know code". The fact that the condition in your for-loop will always be false is not the only problem with your "endless loop". Your program won't even run because you didn't define a data type for 'x' and you missed a semicolon at the end of your statement in the for-loop.
 
  • #134
Dembadon said:
I think you should probably try and run your code before suggesting someone "doesn't know code". The fact that the condition in your for-loop will always be false is not the only problem with your "endless loop". Your program won't even run because you didn't define a data type for 'x' and you missed a semicolon at the end of your statement in the for-loop.

Not to mention the fact y can't hold number larger than MAXINT (whatever it is in the particular system - assuming Java it should be +9,223,372,036,854,775,807). If memory serves me well, Java won't even tell you there was an overflow.

Not to mention the fact OP never stated it is Java and it can be C or C++ as well (not that it changes the code behavior or problems it has).
 
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  • #135
Can we use busy beaver, or do the functions have to be computable?
 
  • #136
TeethWhitener said:
Can we use busy beaver, or do the functions have to be computable?
Assuming that we can...here's a start:

Code:
Defs: [BB=busy beaver; f^n=f composed w/self n times; f→m→n=f^(m^(m…), m appears n times; g64=Graham’s #], number: (BB(g64)→BB(g64)→BB(g64))→(BB(g64)→BB(g64)→BB(g64))→(BB(g64)→BB(g64)→BB(g64))

8 characters to spare, just to leave room for someone to top it!

Edited to make BB^n definition clearer.
 
  • #137
Patrick_Hutecker said:
The number I'm producing is something and its called infinity. You can't show infinity on a computer, which doesn't make it false or not a concept. Just because their isn't enough ram to make my number doesn't mean it does exist.

You are using "int y=100000000;" and the int64 unsigned range is 0 to 18,446,744,073,709,551,615 which is quite far from both infinity and Graham's number ...

Now, it's true that you can "show" many (virtual) things on a computer (including flying dogs), and one way to handle extremely large numbers is the binary64 double-precision floating-point format, with a max exponent of 1023, however the numbers you get is rounded approximations and does not qualify as a real number.

Beyond that, there is Arbitrary-precision arithmetic, that was originally implemented in Lisp and nowadays is supported in most modern languages like Java, Ruby, C/C++, etc. Using this technique, the digits of precision are limited only by the available memory of the host system (including integer). The processing speed is naturally much slower, since fast CPU registers can not be utilized as normal.

This brings us back to the "Observable Universe Samsung Semiconductor Plant", which is the final inexorable bottleneck for digital precision computing.

Why!?

Well, let's say Samsung finds a very clever way to utilize every particle in the observable universe for storing one digital bit (1/0) — how man many bits can we store?

10^{90} bits

Normally the approximation is 10^{80} atoms in the observable universe, but Seth Lloyd (MIT) has published a paper Computational capacity of the universe where he calculate the number of bosons and fermions (particles/antiparticles) and thus get the bigger number (he also take gravitational energy into account but that's overkill = 10^{120} bits).

So, how big is the digital number Samsung/Seth Lloyd can ever store in the entire observable universe?

2^{10^{90}}

That's a very big number, and I tried the Big Online Calculator (with 2048 bits mantissa and 256 bits exponent) but it halted at 2^{10^{76}} and returned:

1.75\times 10^{301029995663981195213738894724493026768189 8814621085413104274611271081892744}

Not giving the full picture, that's a hefty number ...

But how hefty is it in comparison with the Real Monsters? Well, we can directly see that the 'tiny' (in this league) Googolplex 10^{10^{100}} is already much bigger.

Conclusion: If you use a digital computer to find the largest number — you're doomed to lose.

(And that goes for seconds and abacus as well, unless you plan to live longer than the universe! :wink:)
 
Last edited:
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  • #138
Code:
Defs: [BB=busy beaver; f^n=f composed w/self n times; f→m→n=f^(m^(m…), m appears n times; gr=Graham’s #], number: (BB(gr)→BB(gr)→BB(gr))→(BB(gr)→BB(gr)→BB(gr))→(BB(gr)→BB(gr)→BB(gr))
Code:
11 in base^

(changed g64 to gr to save a few characters)

can we use BIG FOOT or TREE(3) without links? (don't really understand either but pretty sure they're exact finite numbers)
 
  • #139
DevilsAvocado said:
(And that goes for seconds and abacus as well, unless you plan to live longer than the universe! :wink:)
Darn, I was going to use my abacus :oldlaugh:
 
  • #140
:biggrin:
 
  • #141
0.3(3)
 
  • #142
DevilsAvocado said:
(And that goes for seconds and abacus as well, unless you plan to live longer than the universe! :wink:)

I don't know about you, but I plan to live forever.
 
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  • #143
Drakkith said:
I don't know about you, but I plan to live forever.
Hoping is different from planning. And I'm pretty sure you only hope to live forever!
 
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  • #144
Shyan said:
Hoping is different from planning. And I'm pretty sure you only hope to live forever!
And planning is different from knowing :biggrin:

Drakkith knows that he's not going to live forever (I hope)
 
  • #145
ProfuselyQuarky said:
Drakkith knows that he's not going to live forever (I hope)

Way to dash my hopes and dreams... :cry:
 
  • #146
Drakkith said:
Way to dash my hopes and dreams... :cry:
There, there. My dream was to prove that narwhals are really unicorns undercover, but I soon got over it
 
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  • #147
ProfuselyQuarky said:
There, there. My dream was to prove that narwhals are really unicorns undercover, but I soon got over it
Who says they're not?:wink::wink:
 
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  • #148
Isaac0427 said:
Who says they're not?:wink::wink:
Aha! A believer! Try telling that to a biology teacher :woot:

**I, for one, have done just that and do NOT recommend it**
 
  • #149
Drakkith said:
but I plan to live forever

Or die trying?
 
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  • #150
Drakkith said:
I don't know about you, but I plan to live forever.

No worries, mate. I'm almost a little bit jealous ... imagine 4-8 billion* years from now, when the Milky Way and Andromeda merge into one ... man, talk about fireworks.

800px-Andromeda_Collides_Milky_Way.jpg


On the other hand, the Dark Era in 10^{100} years, doesn't look that tasty ... photons, neutrinos, electrons, and positrons flying from place to place, hardly ever encountering each other, and on top of that; a terribly unstable abacus and wooden spoon + the knowledge that you have only come halfway in this hair-raising PF Contest ... :rolleyes:

*Of course, that little hiccup of the Sun turning into a red giant, can easily be fixed with a wooden spoon and some perkiness.
 
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