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The Man Who Invented Modern Probability

nautil.us

11–20 of 73 posts

Re: The Man Who Invented Modern Probability

#11
post #8
post #6

>For example, irrational numbers—those that cannot be written as fractions— almost surely have no pattern in the numbers that appear after the decimal point. Therefore, most irrational numbers are complex objects, because they can be reproduced only by writing out the actual sequence. That's false. Pi is irrational, but there's many short algorithms to calculate it's digits.

The key phrases there are "almost surely" and "most irrational numbers." There are irrational numbers like pi which can be defined algorithmically, but taken together as a set they have zero Lebesgue measure. (In fact, they're countable.)

I didn't know that. Any link to a proof?

Re: The Man Who Invented Modern Probability

#12
post #9
post #4

> Kolmogorov armed a group of researchers with electromechanical calculators and charged them with the task of calculating the rhythmical structures of Russian poetry And this is what "big data" and NLP were like before computers :). One can only imagine what he could have done with a modern computer. (Which is particular hard to imagine because he's responsible for advances which ultimately led to these same modern…

>And this is what "big data" and NLP were like before computers :) aside, I recently interviewed a candidate for a "Big Data" position. He got quite chatty about Kolmogorov & Measure Theory, so I quickly cooked up an interesting problem to relax his nerves. I opened the interview with "If the side of a cube comes from a uniform distribution between 1 and 5 inches, what's the expected volume of the cube ?" I thought h…

What's the answer?

Re: The Man Who Invented Modern Probability

#13
post #9
post #4

> Kolmogorov armed a group of researchers with electromechanical calculators and charged them with the task of calculating the rhythmical structures of Russian poetry And this is what "big data" and NLP were like before computers :). One can only imagine what he could have done with a modern computer. (Which is particular hard to imagine because he's responsible for advances which ultimately led to these same modern…

>And this is what "big data" and NLP were like before computers :) aside, I recently interviewed a candidate for a "Big Data" position. He got quite chatty about Kolmogorov & Measure Theory, so I quickly cooked up an interesting problem to relax his nerves. I opened the interview with "If the side of a cube comes from a uniform distribution between 1 and 5 inches, what's the expected volume of the cube ?" I thought h…

27?

Re: The Man Who Invented Modern Probability

#14
post #11
post #8

Earlier quoted context omitted.

The key phrases there are "almost surely" and "most irrational numbers." There are irrational numbers like pi which can be defined algorithmically, but taken together as a set they have zero Lebesgue measure. (In fact, they're countable.)

I didn't know that. Any link to a proof?

Consider the set P of programs that take no input and generate an infinite stream of digits. Each program in P has a finite length and is written out of a finite set of symbols, so there must only be a finite number of programs of any given length. That makes P countable. Let Q be the set of numbers described by programs in P. Each program from P describes exactly one number, so Q must also be countable. The set of irrational numbers is uncountable, so there must be an uncountable set of "complex" irrational numbers remaining after you take away all the "non complex" ones in Q.

Re: The Man Who Invented Modern Probability

#15
post #13
post #9

Earlier quoted context omitted.

>And this is what "big data" and NLP were like before computers :) aside, I recently interviewed a candidate for a "Big Data" position. He got quite chatty about Kolmogorov & Measure Theory, so I quickly cooked up an interesting problem to relax his nerves. I opened the interview with "If the side of a cube comes from a uniform distribution between 1 and 5 inches, what's the expected volume of the cube ?" I thought h…

27?

39

Re: The Man Who Invented Modern Probability

#16
post #11
post #8

Earlier quoted context omitted.

The key phrases there are "almost surely" and "most irrational numbers." There are irrational numbers like pi which can be defined algorithmically, but taken together as a set they have zero Lebesgue measure. (In fact, they're countable.)

I didn't know that. Any link to a proof?

There's only a countable number of formulas of ZFC. Therefore, there's only a countable number ways of writing out a formula of ZFC that uniquely specifies a real number. Therefore, only countably many real numbers exist that have such definitions. And all countable sets of reals have zero Lebesgue measure.

Re: The Man Who Invented Modern Probability

#17
post #9
post #4

> Kolmogorov armed a group of researchers with electromechanical calculators and charged them with the task of calculating the rhythmical structures of Russian poetry And this is what "big data" and NLP were like before computers :). One can only imagine what he could have done with a modern computer. (Which is particular hard to imagine because he's responsible for advances which ultimately led to these same modern…

>And this is what "big data" and NLP were like before computers :) aside, I recently interviewed a candidate for a "Big Data" position. He got quite chatty about Kolmogorov & Measure Theory, so I quickly cooked up an interesting problem to relax his nerves. I opened the interview with "If the side of a cube comes from a uniform distribution between 1 and 5 inches, what's the expected volume of the cube ?" I thought h…

[deleted]

Re: The Man Who Invented Modern Probability

#19
post #13
post #9

Earlier quoted context omitted.

>And this is what "big data" and NLP were like before computers :) aside, I recently interviewed a candidate for a "Big Data" position. He got quite chatty about Kolmogorov & Measure Theory, so I quickly cooked up an interesting problem to relax his nerves. I opened the interview with "If the side of a cube comes from a uniform distribution between 1 and 5 inches, what's the expected volume of the cube ?" I thought h…

27?

I'd say 45, assuming the side length is an integer.

Re: The Man Who Invented Modern Probability

#20
post #11

Earlier quoted context omitted.

I didn't know that. Any link to a proof?

Consider the set P of programs that take no input and generate an infinite stream of digits. Each program in P has a finite length and is written out of a finite set of symbols, so there must only be a finite number of programs of any given length. That makes P countable. Let Q be the set of numbers described by programs in P. Each program from P describes exactly one number, so Q must also be countable. The set of i…

Your proof seems to only prove that a finite number of programs (described by you) which can produce a finite number of irrational numbers, while there are infinite number of irrational numbers.

But we're surely not talking about a finite number of programs.

I'm not even sure what the Kolmogorov complexity of a "complex irrational number" means. If you need the sequence of digits and you cannot use an algorithm to produce the digits, then the complexity is infinite?

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