David said:
^^ I love you soo much, you still keep using that word "define" improperly. Give me your address I'll send you a good book on defining things, and the tricks of language.
Give me
your address and I'll send you a dictionary with the correct definition of "perfect", because your black hole description certainly wasn't.
sexyanon2 said:
So then, 1/3 is equally an idea as the number 5 is?
Excluding a typo I said "If it is consistent". You are free to define something in mathematics, provided that you can show it can then not be used to contradict something from previous work. Going about proving a new idea or method is consistant with other areas of mathematics is probably one of the most maticulous, painstaking things mathematicians do.
Every possible use is considered and examined. Often a new idea can take a few years before its announced because they must make sure its consistent.
sexyanon2 said:
What about quantum physics?
Thats part of the "experimental error". If your quantum fluctuations change the values of a result in say the 9th decimal place onwards, you are going to have to take Pi to more than 9 places to make sure that almost all the error lies in the quantum fluctuations. If you take Pi to 15 decimal places, you've got errors 1 millionth the size of the quantum fluctuations. If you're really bothered, go to 20 places, and thats 100 billion times smaller. The slight discrepency of your taken value of Pi and the actual value means nothing, the quantum fluctuations of a system make it irrelevant.
But then that is physics, and has no bearing on wether Pi exists or not in mathematics.
sexyanon2 said:
First, I don't understand the base 12 example.
Binary is Base 2. That means you count 1, 10, 11, 100 etc. Since you can't have "2", you have to use 1's and 0's to count. In base 3 (perhaps called "Trinary") you count 1, 2, 10, 11, 21, 22, 100 etc
Work your way up to base 12 and you have (I'm going to use "A" to represnet the number ten and "B" to represent eleven)
1,2,3,4,5,6,7,8,9,A,B,10,11,12,......,19,1A,1B,20 etc
Rather than having our "digits" as 0,1,2,3,4,5,6,7,8,9, we have 0,1,2,3,4,5,6,7,8,9,A,B. This alters our digits expansions too, because I can have use A and B after the decimal point. Like 0.A.
To convert this to "normal" base 10, you'd do as Cex demonstrated. In Base 10 0.34 = 3/10 + 4/100. In base 12 0.A = A/12. This means in Base 12 0.4 = 4/12 = 1/3.
Therefore, just be introducing new symbols for eleven and twelve (nothing wrong with that is there?) I've subtely altered my way of representing numbers. The numbers themselves have not changed, just how I represent them (like a fraction and a decimal are 2 ways of representing a number), and it seems 1/3 can have a terminating digit expansion.
Can you now see why this shows the flaw in thinking "It must have a terminating expansion to exist"?
sexyanon2 said:
I'm confused then. Is this some form of relativity? Some numbers in some bases, or "realities" of math, are ending, but can go on forever in other bases? Is there one base that has all numbers ending?
Its to do with prime factors of both a Base you are working in, and the number in your fraction.
10 = 2*5, so Base 10 will only have terminating digit expansions for numbers whose ONLY factors are 2 and 5, like 8 =2*2*2, or 25 = 5*5.
If I have a Base 7 system, because 7 is prime, only numbers which are a power of 7 will have terminating decimals, so 1/7 = 0.1 and 1/49 = 1/(7*7) = 0.01, but anything which has another prime factor other than 7 will be non-terminating. 1/2 cannot be expressed as a terminating decimal!!
Better Base systems include Base 8, since its a power of 2 and Base 60. 60 = 2*2*3*5, so you'd get terminating decimals for 1/2, 1/3, 1/4, 1/5, 1/6, 1/12, 1/15, 1/20, 1/30, and all numbers which have prime factors 2, 3 or 5, like 1/9.
The ancient Babylonians used to work in Base 60, and I think its where we get out "minutes, seconds" from.
Base 10 is actually a very clumsy and bad base to use. People do not realise it because they automatically think in Base 10 and often cannot see how another system would work. As I said before, if we had evolved with 12 fingers, 1/3 would have a terminating decimal. Infact you'd probably be arguing the "non-existance" of 1/5 because in base 12 1/5 is an infinite digit expansion.
sexyanon2 said:
Now if fractions are ideas, what seperates them from ending decimals or whole numbers? You can get a third of a ruler, or a half of a ruler, no problem. You just have to measure it first, thus you'd bring in real numbers, not ideas.
You keep bringing up measuring a ruler, as if a mathematician needs to do that when he divides something by 5 or multiplies by 2/7. These are
thought experiments where physical constraints don't apply.
Fractions are an extension of integers. They take the definition of integers and develop it further. Some fractions have terminating decimals, some do not. ALL have a terminating decimal in some Base system or other (though not at the same time).
sexyanon2 said:
Apples, fingers, its all good

I just think apples are the traditional way of describing these things. That or oranges :D
sexyanon2 said:
Yes. The method involves doing a mathematical operation which is easy to do one way, but hard to do the other. It wasn't thought one such thing existed that would be practical for computers, but then someone realised about primes. If you take 2 huge primes (100+ digits each) and multipply them together you get another huge number with only 2 factors. This can then be used to encode your data, and send it over distance. Should anyone intercept it, they can only read your data by "unlocking it" by knowing the prime factors of your "key". It takes a hell of a lot of trial and error to find these 2 primes. Its not unbreakable, but sufficently hard to put off people scamming for credit card numbers. Banks use numbers thousands of digits long!
Thats the vague idea, the specifics are a little more complicated, but I'll be happy to elaborate if you want
