## A Friendly Chat About Whether 0.999… = 1

Via reddit I stumbled upon this site which talks about something called hyperreal numbers and claims that in this theory, the equation 0.999… = 1 is false.

For those who follow the internet, the question of whether 0.999…=1 has come up a quadbrazillion times on practically every math related forum and even the non-math ones. And every single time it turns into this huge argument with

non-mathematicans vs frustrated-mathematicians

and neither of them winning. Some mathie forums even have strict rules banning users against posting topics that deal with 0.999….=1.

But the site mentioned above actually gives some decent points to support why 0.999…=1 isn’t necessarily true., but you have to change some of the concepts that we take for granted.

In my opinion, 0.999… and 1 are as equal as can be.

(No Ratings Yet)

## Mathematical modelling: online guilds vs street gangs

As pointed out in this boing boing post, the paper titled “Human group formation in online guilds and offline gangs driven by a common team dynamic” discusses how the structure of online guilds can be modeled using the same mathematical models as street gangs.

Massively multiplayer online games typically allow individuals
to spontaneously form, join, or leave a formal group
called a guild. [...] Millions
of people worldwide log on to the world’s largest online
game World of Warcraft (WoW) for the equivalent of
several days every week. Indeed, online games are one of the
largest collective human activities on the planet [...]

A seemingly unrelated
social phenomenon that is also of great concern is urban
gangs. Urban gangs have been gaining in popularity
among young people both nationally and internationally.
There are obvious differences in the settings and
history of online guilds and offline gangs, however, the empirical
data sets that we have compiled enable us to perform
a unique comparative study of their respective grouping dynamics.

and the authors analyze the data that they have collected over the last
few years to show evidence of a quantitative link between the
collective dynamics of the two systems above.

The
authors of the paper are: Neil F. Johnson, Chen Xu, Zhenyuan Zhao,
Nicolas Ducheneaut, Nicholas Yee, George Tita, and Pak Ming Hui.

doi: 10.1103/PhysRevE.79.066117

(No Ratings Yet)

## A review of online whiteboard ScribLink

Ever had to tutor someone in mathematics ONLINE!!? It can be difficult, especially if you’re just using an IM like MSN / AOL / ICQ / QQ / AIM / that google one / whatever else I’m missing

I decided to try out a few different online sites to make the process easier. In this blog entry I’ll be reviewing my experience with ScribLink. I also checked out a couple of others and may talk about them later ^_^.

I
played around on it for like 30 minutes drawing silly graphs and such.
I loved using it, but here are some pros/cons in my opinion

Pros:

• No advertisements! Definite pro. If you like the site and use it a lot, I suggest donating towards it.
• Can easily add formulas using LaTeX.
• Easy to use, simple interface, attractive looking.
• Can easily choose colors of the board and the pencil thingy.
• Very easy to invite others to the session. Just click on Get URL.
• Has the option to save the image and email it.
• VOIP and chat options.
• Scriblink team seems to be very open to suggestions about improving the service.

Cons:

• Hard to erase. I would recommend the site make it so that “right click” on the mouse
button acts as an eraser, and make the eraser a bit more powerful.
• I
can’t find any option to graph functions. There was another whiteboard
website with this option (but I didn’t like their interface). But
inserting functions of lines, parabolas, trig, etc would be highly
useful.
• It won’t let me move formulas around after it’s been
placed on the screen. Ideally, I’d like to move “objects” around on the
board.

Overall, my experience was great. I drew up a
short lecture about area between two curves with graphs and colors and
formulas! It turned out pretty awesome. All in all, check out the site!
And if there is anything you don’t like about the site, bugs, etc, let

Edit (Nov 30th, 2009): I love the color palette the site uses. You can also insert nicely written formulas and equations, which I didn’t do above (see the x=x^2 stuff on the left panel which can be added and moved around as pointed out by Jordan – the double clicking did work, not sure how I missed that ^_^).

(No Ratings Yet)

## Are the reals countable?

John Gabriel (a non-mathematician) claims in his blog that the real numbers are countable. The author tries to enumerate the real numbers in the interval [0, 1) by writing out all those whose decimal representation has one digit after the dot (0.1, 0.2, …, 0.9), followed by those with two digits after the dot, then those with three digits, and so on.

He goes on further to say that this establishes a procedure for writing
down an ordered sequence of numbers in which every real number of the
source interval will appear eventually (although, it should be clear
that any number with an infinite decimal representation will never
occur in his sequence of numbers).

This argument shows that the subset of real numbers between 0
and 1 that have a finite decimal representation is countable. Although,
it fails to work for the interval [0, 1).

It’s rather entertaining to watch fellow mathematicians humor him. Either way, things like this happen all the time .

## Sine Flu

Two excellent “Sine Flu” comics!! See below.

The first comes from LukeSurl.com. His comics are very good. I haven’t read all of them yet, but it’s one of the things on my to do list

The second is the popular Brown Sharpie. I love the Seinfeld twist! errr Sinefeld

(No Ratings Yet)

## BrownSharpie – Knitting Circle

This Brown Sharpie comic is great

Just the other day, there was some math profs in the department talking about crafts and knitting. Apparently, they have their own little club and are meeting for craft night!! :-\

(No Ratings Yet)

## new xkcd and abstruse goose

For some reason, both xkcd and Abstruse Goose comics today were very entertaining to me!! Yay!

By the way, today’s Abstruse Goose comic references one of my favorite movies (and I don’t mean star wars! arrg). Check it out, hilarious! Here is a hint.

(No Ratings Yet)

## MathFail.com Stats

Are people actually subscribed to my silly blog?

The majority of traffic comes from google. The keywords “math fail” takes the lead followed by key phrases that have both “math” and “sex”. According to my search, some other site has the top position for math sex on google (without quotes)!! GRRRRrrrrrrrrrr…… I strive to be #1 for math sex!!! Perhaps if I make more math sex pages on my site hmm….

## On a curious property of 3435

This is a neat little paper regarding the number 3435. Basically it has the following property:

3435 = 3^3 + 4^4 + 3^3 + 5^5

More interesting is that the only other number with this ‘property’ is the number 1. The property is what he calls a “Munchausen Number“. The preprint was written by Daan van Berkel and can be found on the arxiv.