i can goto 5 sites and pull a different definition of real numbers, irrational numbers, and infinity.
I wouldn't doubt it. There are often many
equivalent ways of defining something.
For instance, (IIRC) the first rigorous definition of the real numbers was that a real number is an equivalence class of cauchy sequences of rational numbers. (In laymen's terms, any real number is identified with the sequences of fractions that approach it)
The usual modern definition preferred would be to define the real numbers as a complete ordered field. (In laymen's terms, +, -, *, /, and < all work "properly", and there are no "holes")
And it can be proved that the first definition satisfies the requirements of the second definition. Conversely, anything that satisfies the second definition is isomorphic (in laymen's terms, the same) to the first definition.
(Incidentally, 5? Really? I can only think of 3 definitions of real numbers you could be reasonably expected to find online, and only one definition of irrational. Different definitions of infinity wouldn't surprise me, because there are a lot of different concepts that are (sloppily) called "infinity")
the point of the matter is, you say the number line is infinitely divisible but then you say when you divide it by infinity "it can't be determined" or "is close enough to zero we'll just call it zero"
Actually, we say "Please be more specific".
"Infinitely divisible", taken entirely literally, means that it can be divided into an infinite number of terms. (Notice I did
not say "an infinity of terms") In particular, the real line can be divided into
c (= |
R|) terms.
c is a thing called a
cardinal number. It is not a finite cardinal, so it must be an infinite cardinal. (Some call it a transfinite cardinal, simply because so many laymen get confused when things are called infinite)
Division is not well-defined on cardinals, because multiplication is not very nice. For example, 1 * c = 2 * c. If you could divide by
c, you would get 1 = 2, which is bad.
i'm trying to establish a notational system that allows for infinite division AND allows for division beyond that.
Learning math might be helpful to see how to do this.
Here's a simple approach to defining such a system:
Consider all (real) rational functions in x. E.G. things like 6, 7 + x^2, and (1 + 3x + 4x^5)/(4x + 3x^7)
+, -, *, and / can all be defined and function "properly" in this field. You can order this field by decreeing that x is bigger than any real number, and then extending the definition of < to accommodate this decree. So, for example, 7 + x^2 is infinite, because it is bigger than any real number. Proof:
Let r be any real number.
r < x
1 < x
r = 1 * r < 1 * x < x * x < x * x + 7
Thus r < x^2 + 7
Similarly, (1 + 3x + 4x^5)/(4x + 3x^7) is an infinitessimal.
If you don't like x, maybe you could use w (omega), a common symbol for transfinite numbers.
There's another number system (whose technical details are
very difficult to follow) called the hyperreals which have transfinites and infinitessimals, but, for the most part, behave exactly like the real numbers. You might find information on this by searching for "non-standard analysis". Last time I went looking, there was actually an undergraduate calculus text in PDF format somewhere on the web that develops calculus using nonstandard analysis (i.e. with infinitessimals and transfinite integers, etc) instead of the usual way.
you guys say the current system works, why mess with it, but totally balk at the idea of replacing it with something that works BETTER.
We're "balking" because you are claiming the current system
doesn't work.
of course i meant last term. Integral has me talking about digits and then you jump on me when i get a word wrong. okay okay spanish inquisition over here..
Or, maybe I'm just making sure I knew what you meant.
