Moderators: Darkchilde, Calilasseia
Dason@Talkstats wrote:.......[snip]
Take for example coin flipping. If we flip a perfectly fair coin we would expect that after an infinite number of flips the number of heads and the number of tails should be equal. Now listen closely.... In that infinite sequence it is almost sure that you will see a sequence of heads as long as K. What is K you ask? Who cares, it can be any natural number. Let's say K is 8 for the time being. If we randomly group the infinite sequence into blocks of 8 then each block of 8 has probability 1/2^8 of being all heads. Now if we use the naive approach and only look at the successive blocks of 8 you can ask what the probability is that you won't have one of those blocks be a complete run of heads. The probability that any block won't be a run of 8 heads is 1-(1/2^8). So the probability that the neither of the first two blocks is the a sequence of heads is (1 - (1/2^8)^2. The probability that none of the first m blocks contains that sequence of heads is (1-(1/2^8)^M. You can see that 1-1/2^8 < 1 so if we take it to higher and higher powers it becomes smaller and smaller. (Note that I'm being really conservative in that the sequence of 8 heads could have been somewhere that didn't fit perfectly into one of our blocks but this route makes the calculation easier and gets the point across just as well). So taking M to infinity means that the probability that we don't see this sequence goes to 0. But my block size of 8 was completely arbitrary. This works for any block size. So if we have an infinite sequence the probability that there isn't a sequence of heads at least 23423136572352352345 long goes to 0. I hope you can see how this directly relates back to the problem you "disproved".




HughMcB wrote:How can he be so specific that a "23423136572352352345 long goes to 0"?


Take for example coin flipping. If we flip a perfectly fair coin we would expect that after an infinite number of flips the number of heads and the number of tails should be equal.

HAJiME wrote:
Can someone explain how it is possible to flip a coin 'an infinite number of times', and what exactly half of infinite is? If these questions cannot be answered, how do we know probability works...? Has anyone actually even proven that it works in the real world? If it's not possible in the real world, what is it's purpose? What's the point?
I always used to hate maths (and still do) because I fail to see it's working in the real world. I've never, ever, ever had to use anything bar very basic maths in my daily life... And even use of very basic maths is done on the calculator on my phone. I didn't want to do anything with maths for a career, so why on earth was I being taught all this useless bullshit?

Eduard wrote:HAJiME wrote:
Can someone explain how it is possible to flip a coin 'an infinite number of times', and what exactly half of infinite is? If these questions cannot be answered, how do we know probability works...? Has anyone actually even proven that it works in the real world? If it's not possible in the real world, what is it's purpose? What's the point?
I always used to hate maths (and still do) because I fail to see it's working in the real world. I've never, ever, ever had to use anything bar very basic maths in my daily life... And even use of very basic maths is done on the calculator on my phone. I didn't want to do anything with maths for a career, so why on earth was I being taught all this useless bullshit?
NNOOOOOO!![]()
I can understand your dislike for maths, but its practical implications in the real world are abundant! Complicated math (I'm assuming anything more complicated than basic arithmetic) is everywhere: your cellphone, your computer, car, tv everywhere.
Math is not useless, it's helped in defining gravity, sending people to the moon. It's allowed us to formulate and solve incredibly complex or computive intensive problems we can't solve with simple arithmetic.
As for probability, well I only had calculus and stats to my third year in university, but to put it in basic terms (I might be wrong): if we can prove a mathematical theorem on paper it's true. In real life, at best we can do experiments to replicate and test these theorems, but they're always true. I'm talking about how probability theory shows that a coin toss gives use a 50/50 chance for heads or tails. Similarly, we can test all sorts of other math theories and find it to be true, like pi = 3.14... and Pythagoras' theorem with triangles. Without a lot of these things big industries we have today won't exist as they do.
Btw, if you divide infinity by 2 you still have infinity. I'll leave it to guys who are way more clued up to inform us on how infinity works in comparison to really really unimaginaly big numbers.

Lazar wrote:*Silly me Roger Cook already posted this. Consider this an expansion for simple folk like me.![]()
Good overview of the probability behind this question at talk stats (post four) here by on of the mods.Dason@Talkstats wrote:.......[snip]
Take for example coin flipping. If we flip a perfectly fair coin we would expect that after an infinite number of flips the number of heads and the number of tails should be equal. Now listen closely.... In that infinite sequence it is almost sure that you will see a sequence of heads as long as K. What is K you ask? Who cares, it can be any natural number. Let's say K is 8 for the time being. If we randomly group the infinite sequence into blocks of 8 then each block of 8 has probability 1/2^8 of being all heads. Now if we use the naive approach and only look at the successive blocks of 8 you can ask what the probability is that you won't have one of those blocks be a complete run of heads. The probability that any block won't be a run of 8 heads is 1-(1/2^8). So the probability that the neither of the first two blocks is the a sequence of heads is (1 - (1/2^8)^2. The probability that none of the first m blocks contains that sequence of heads is (1-(1/2^8)^M. You can see that 1-1/2^8 < 1 so if we take it to higher and higher powers it becomes smaller and smaller. (Note that I'm being really conservative in that the sequence of 8 heads could have been somewhere that didn't fit perfectly into one of our blocks but this route makes the calculation easier and gets the point across just as well). So taking M to infinity means that the probability that we don't see this sequence goes to 0. But my block size of 8 was completely arbitrary. This works for any block size. So if we have an infinite sequence the probability that there isn't a sequence of heads at least 23423136572352352345 long goes to 0. I hope you can see how this directly relates back to the problem you "disproved".




cavarka9 wrote:lets just add something to this infinite monkey guesses.
consider that there are infinite monkeys typing infinitely,randomly, will they get the value of say pi.They only have ten symbols and the dot symbol.
Then, will any of those monkeys keep typing the value of pi?. If it does, then we might as well say that the function of the monkey over those keys results in pi.?
I am not sure, does randomness mean nothing or does it mean everything that there is?.

Depends on what do you mean by "infinity". If you mean countable infinity (=the same as natural numbers), then the anwser is: probability that one of the monkeys will get the value of Pi is 0, but this doesn't mean that it can't happen. But if you mean continuum infinite number of monkeys (the same as real numbers), then the anwser is: probability that some monkey will get number Pi is equal to 1, but that doesn't mean that it will surely happen.cavarka9 wrote:consider that there are infinite monkeys typing infinitely,randomly, will they get the value of say pi.They only have ten symbols and the dot symbol.
There are different distributions of randomness.. But what you are asking is not distrubution function, but what kind of events can occur. The anwser is: any kind of events that are contained in your probability space.cavarka9 wrote:I am not sure, does randomness mean nothing or does it mean everything that there is?.

home_ wrote:Depends on what do you mean by "infinity". If you mean countable infinity (=the same as natural numbers), then the anwser is: probability that one of the monkeys will get the value of Pi is 0, but this doesn't mean that it can't happen. But if you mean continuum infinite number of monkeys (the same as real numbers), then the anwser is: probability that some monkey will get number Pi is equal to 1, but that doesn't mean that it will surely happen.cavarka9 wrote:consider that there are infinite monkeys typing infinitely,randomly, will they get the value of say pi.They only have ten symbols and the dot symbol.There are different distributions of randomness.. But what you are asking is not distrubution function, but what kind of events can occur. The anwser is: any kind of events that are contained in your probability space.cavarka9 wrote:I am not sure, does randomness mean nothing or does it mean everything that there is?.
For example (this is very informal): you can define your probability space in a way that an event is "when monkey successfully hits a button", and then you can try to find out what's the proportion of the events, that contain some specific sequence of characters. Anwser to your question of randomness in this particular case is: it means all possible sequences of characters.

I'm not sure if I understand your question. Monkey typing Pi is an event in probability space, but real function is a function to real numbers. You can't say these two are the same, that's like comparing apples and pears.cavarka9 wrote:Now how can one claim this monkey to be different from a real function meant to give the exact value of pi?
I don't know what you're talking about. Distribution is distribution, and random variable is random variable... but what is non-random distribution, that's a mystery to me.cavarka9 wrote:Take this argument further, we then have within infinite, every conceivable non-random distributions too. That is, the value for e, and with slight modification, every conceivable non random series which converge to something say e or pi on infinite summation gives rise to this.
You know the anwser, but I don't even understand the question.cavarka9 wrote:How do we differentiate a function with a purpose to a non-random distribution in some monkeys among the infinite monkeys.
(i know the answer).


This is philosophical question (i.e. "what Pi really is?"), sorry, I don't have anything to say about this one.cavarka9 wrote:it really isnt pi, its just the symbols arranging themselves in a way that to us it appears as pi as we use the same symbols



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