Is Pi divided by E rational, and what other irrational numbers exist?

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Discussion Overview

The discussion revolves around the rationality of mathematical operations involving the irrational numbers pi (π) and e, as well as the exploration of other irrational numbers. Participants inquire about the proofs related to combinations of these numbers and the nature of irrationality and randomness in numbers.

Discussion Character

  • Exploratory
  • Debate/contested
  • Conceptual clarification

Main Points Raised

  • Some participants question whether π divided by e, added to e, or other operations combining these two numbers can yield a rational result, noting that it remains an open question.
  • One participant suggests that it seems unlikely for any combination of π and e to result in a rational number unless it simplifies to a trivial case.
  • Another participant mentions the existence of various irrational numbers, including specific sequences like 0.123456789101112... and 0.10010001000010000010000001..., and discusses the nature of randomness in number generation.
  • There is a discussion about the definition of randomness, with some participants asserting that truly random numbers are difficult to generate and may require physical processes for generation.
  • Some participants express interest in the origins of randomness and the challenges in defining it, suggesting that a clear definition is necessary for meaningful discussion.

Areas of Agreement / Disagreement

Participants generally express uncertainty regarding the rationality of combinations of π and e, with no consensus on whether any such combinations can be rational. There are multiple competing views on the nature of irrational numbers and randomness.

Contextual Notes

Participants note the complexity of defining randomness and the challenges in discussing irrational numbers without a clear framework. There are references to various mathematical concepts and theorems, but no resolutions to the questions posed.

Jedi_Sawyer
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Does anyone know if it has ever been proved that pi divided e, added to e, or any other mathematical operation combining these two irrational numbers is rational. Another thing does anybody know of any other irrational numbers that is not some derivative of pi and e.
 
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e^{i\pi} = -1
 
jedi_sawyer said:
another thing does anybody know of any other irrational numbers that is not some derivative of pi and e.

0.123456789101112...
 
Yeah I understood that Euler's idenity combined e, i, and pi and you can find a good write up of why that is in Penrose's book "The Road to Reality". I guess I should have specified I was not interested in polar coordinate solutions where pi is integral to the coordinate system.
 
well the fraction 0.1234... seems to be a well have a predictable pattern for what any arbirary next digit should be, so induction would solve what the next digit should be. I guess it could be an irrational number if we give up on randomness.
 
Jedi_Sawyer said:
well the fraction 0.1234... seems to be a well have a predictable pattern for what any arbirary next digit should be, so induction would solve what the next digit should be. I guess it could be an irrational number if we give up on randomness.

There is an algorithm for working out, in order, the digits of sqrt(2) and sqrt(2) is certainly not rational.
I'm not sure what you mean by randomness though..
Give me an example of a number with 'randomness' please.
 
Jedi_Sawyer said:
Does anyone know if it has ever been proved that pi divided e, added to e, or any other mathematical operation combining these two irrational numbers is rational. Another thing does anybody know of any other irrational numbers that is not some derivative of pi and e.

It's an open question. Nobody knows whether or not some rational linear combination of e and pi is rational or not.
 
I can't imagine that there is any way using only multiplication and addition of \pi and e that would give a rational number unless it simplified to something trivial like
\frac{e}{\pi}-\frac{e}{\pi}
I bet this can be proven for all transcendental numbers if it is true, but as it is, there is not a well defined question. Since euler's equation wasn't what you were looking for, you should be more precise about what you mean by "mathematical operation"
 
There are a lot of numbers that are irrational. Your'e all right about that. I'm actually looking into the origin of randomness, how could a truly random number ever be generated, and I have to do more thinking on it before I can phrase the question rignt.

Thank you over and out.
 
  • #10
There is also the famous 0.10010001000010000010000001... and variations on that.
 
  • #11
Jedi_Sawyer said:
There are a lot of numbers that are irrational. Your'e all right about that. I'm actually looking into the origin of randomness, how could a truly random number ever be generated, and I have to do more thinking on it before I can phrase the question rignt.

Thank you over and out.

There are lots of numbers that can not be described by any finite-length algorithm or formula. These are the non-computable numbers. Any number, even an irrational, that can be computed to any desired precision by an algorithm, can't reasonably be called random.

http://en.wikipedia.org/wiki/Computable_number
 
  • #13
You might also want to look at the discussion on Wu's riddle forum

http://www.ocf.berkeley.edu/~wwu/cgi-bin/yabb/YaBB.cgiPost name: Combinations of Pi and Sqrt(2)

The problem:

"Say I am given a number X = A*[sqrt]2 + B*[pi], where A and B are integers.
Given X, how can you find A and B, without using brute force?"
 
  • #15
Jedi_Sawyer said:
There are a lot of numbers that are irrational. Your'e all right about that. I'm actually looking into the origin of randomness, how could a truly random number ever be generated, and I have to do more thinking on it before I can phrase the question rignt.

Thank you over and out.

It is deceptively difficult to actually come up with a completely random set of numbers. The best way to do it is via physics systems. For example, nuclear decay is totally random, and by listing of numbers you get out of a geiger counter, you'd have a truly random list of integers, however, you'd be limiting your integers to a preferred range. Certain numbers would be more likely than others.
 
  • #16
soothsayer said:
It is deceptively difficult to actually come up with a completely random set of numbers.

This might be true, but you are first going to have to actually define what you mean by random. Without a working definition, a discussion about it is meaningless.
 

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