Pablo G. and Leonardo C. were kind enough to create a

**Spiked Math app**for the iPhone/iPad. For those who use those devices, go to (http://bit.ly/spikedmathhd) to get the free app. Any reviews/feedback for the developers can be left at that link and is greatly appreciated!

benzocyclobutadiene has double bonds which are pi (electron) bonds not sigma

And to be fair there are sigma bonds as well, He's just ignoring the pi bonds nothing wrong with that.

Yup. It all depends which model you are looking at. In some representations you ignore the Hydrogen atoms and double bonds and only focus on the Carbon-Carbon bonds. This specific graph model that only looks at sigma-electron bonds can be helpful when analyzing the stability of the molecule. For example, if the take the adjacency matrix of the graph of an alternant hydrocarbon (essentially, alternant = bipartite) and look at the eigenvalues, then it turns out that the molecule is instable iff 0 is an eigenvalue. For non-alternant hydrocarbons there are related results but they aren't as pretty.

You could encode the type of the bond in the weight of the edge, and still be able to model more complex representations.

Mike, you are this matrixmaster ..Here comes the query:

Are results from graph theory really applicable in cutting-edge science as for example PPI or research of complex biomolecules in general? I know that basics of graph theory are in courses often showing by examples in other fields, but I've never seen application that had revealed something new (obviously, because I know absolute zero about chemistry, sociology, economics, ..) Could someone say that molecular biology(or something else) wouldnt be so far without graph theory?

As a pure mathematician I don't keep that up-to-date with other fields. I think people view graph theory as being this magnificent tool that can be used to their advantage. In particular, the centrality of a vertex is used quite a bit. For example, in ecology, "betweeness centrality" is used to determine species (vertices) in a food web (graph) that play important roles in the spread of epidemics and parasitism rates. In cancer research, digraphs corresponding to molecular wiring diagrams of interaction between genes/proteins/etc are analyzed. By computing the betweenness centrality of each node in a particular digraph, the proteins of highest importance can be determined and be chosen as potential targets (in order to slow/stop the cancer from spreading).

Saying a certain field wouldn't be as far if it weren't for graph theory can definitely be true for some fields. I know of some examples where people in the sciences start coming up with "new ideas" in their own field (with their own terminology) but it turns out it's already quite well known in mathematics. Sometimes when this happens you don't realize it until 30 years later.

I would graph theory could help researches in biology or make researches have a different view: how? mining graphs and there are tons of examples on how it was applied to biology. check out pattern recognition journal from Elsevier for papers about it. I know because I am writing a paper reviewing this subject for various areas.

of course, I am writing it with no silly English mistakes >

Hey! Mike is a mathematician, He gives same names to many different things

This reminds me of something Mike Phirman (you probably know of him from Hard 'n Phirm) said while introducing himself on stage a couple of weeks ago. "Like most people, my name is Mike"

Maybe Mike's parents' generation were mathematicians too, giving the name Mike to many different things.

Don't even get him started about things being

normalWhere's the droid app???

As soon as one is made I'll let you know. I don't have that skill set though to do it myself.

… or regular, for that matter.

You missed the State Machine Diagrams and Markov Process Diagrams. Both are Digraphs.

Unfortunately, I missed an infinite number of applications of graphs and digraphs and trigraphs and hypergraphs and...

First of all, I think the punchline is great. I enjoy this comic so much!

Just a thought: especially on the Social Networks graph, you could've been way funkier in the representation of it, further absurdifying the idea that they are the same.

Watch out, Mike!

Get Fuzzyis horning in on your territory! (Feb 4, 2011)Whenever I see this quote, I can never help but add as corrollary that statistics is the art of giving different names to the same thing...

>Pablo G. and Leonardo C. were kind enough to create a Spiked Math app for the iPhone/iPad.

Whereas everyone NOT using iJunk already had that app. It's called Firefox.

I love this version.

In logic class, I always found it odd that "if and only if" was never really used as much as Mathematicians do. Even the chain rule was only defined for "if...then". But iff is an equivalence relation--and much more powerful.

Just shows that Mathematicians are better at isomorphisms than Philosophers are.

LOL nice a graph :)

Sigh, it appears to me that I think like a mathematician. Everything looks the same to me, or many stuff can be grouped in the same category. But really, I don't see why people out there giving so many names to what appears to be the same thing.

Because they don't identify the similarities at first--and often are in very different fields (as this cartoon suggests: Chemists, Sociologists, Biologists, and we could add a dozen other fields) so they come up with the different terms first, and only later do they get shown to be essentially the same.

That compund can be named as follows.....Bicyclo [4,2,0] Octane..

Why all so dislike math person? They just do all simpler.

what is science?

The observation, identification, description, experimental investigation, and theoretical explanation of phenomena.

Such activities restricted to a class of natural phenomena.

Such activities applied to an object of inquiry or study.

Methodological activity, discipline, or study: I've got packing a suitcase down to a science.

An activity that appears to require study and method: the science of purchasing.

Knowledge, especially that gained through experience.

Science Christian Science

i love math in our school if ders not math we canott count time money cm meters wid and others?