Free Republic
Browse · Search
General/Chat
Topics · Post Article

To: who_would_fardels_bear
It has no meaning.

If you know L'Hospital's Rule, you can easily construct limits which superficially appear to be indeterminate forms like ±∞/±∞, 0/0, 1, ∞0 which can be constructed from actual limits which are +∞, -∞, 0, 1, or any real number.

For example:

limx→∞ (1+x)α/x. Superficially, this looks like 1. But, for every N, no matter how large it may be 1N = 1. This is pretty much a textbook definition that the idea of 1 = 1. However [you can verify this very quickly with a calculator or by plugging numbers into the google web page search] You can make the above limit any positive real number by choosing α correctly. For example, if α = 1, then limx→∞ (1+x)1/x = e. If α = 0, that limit = 1, If α = -1, it's 1/e. If α = ln(π) limx→∞ (1+x)α/x = π.

You can do the same thing with any indeterminate form that looks like ∞/∞. Just tune the limit properly and it can be 0, ∞, or any other number you like, including the OP's "1." That's why indeterminate forms are symbols, which have no meaning.

The number of reals is infinite. The number of integers is infinite. The statement [number of reals]/[number of integers] has no meaning. The cardinality of the reals is greater than that of the integers. There is no bijective function [1-1 and onto] that maps the integers to the reals. There is a "sense" in which there are more reals than integers, but that "sense" is not translatable in terms of "the number of objects in the sets," because both are infinite.

Infinities are to mathematicians as high current live wires are to electricians: There are tools for handling them, and they won't harm you as long as you're careful. Rigor is the key.

This physicist may want to get rid of the concept of infinity in physics, but he can't. The reason he can't is that he cannot get away from the concept of zero. And as long as you are talking about zero, infinity is always on the other side of that coin.

73 posted on 02/20/2015 9:07:59 PM PST by FredZarguna (Mit der Dummheit kämpfen Götter selbst vergebens.)
[ Post Reply | Private Reply | To 65 | View Replies ]


To: FredZarguna
limx→∞ should be limx→0 throughout that post.
75 posted on 02/20/2015 9:19:08 PM PST by FredZarguna (Mit der Dummheit kämpfen Götter selbst vergebens.)
[ Post Reply | Private Reply | To 73 | View Replies ]

To: FredZarguna

Can you tell me more about bijective functions, please?

Also, the fact that Zero leads to infinity, can be seen with Obama and our national debt...

Cheers!


83 posted on 02/20/2015 10:49:11 PM PST by grey_whiskers (The opinions are solely those of the author and are subject to change without notice.)
[ Post Reply | Private Reply | To 73 | View Replies ]

To: FredZarguna

If there is a smallest unit of space and time and matter and energy then there is no divide by zero problem and therefore no infinity problem.


93 posted on 02/21/2015 10:21:59 AM PST by who_would_fardels_bear
[ Post Reply | Private Reply | To 73 | View Replies ]

Free Republic
Browse · Search
General/Chat
Topics · Post Article


FreeRepublic, LLC, PO BOX 9771, FRESNO, CA 93794
FreeRepublic.com is powered by software copyright 2000-2008 John Robinson