Friday, March 31, 2006

For name's sake!

A very recent blog at Samudrikaon how nomenclature is fixed in science, (in particular in physics) provoked me to share this fantastic historical note (put in my own words, of course) at the beginning of a paper, I recently read.

For me the most interesting and thrilling part of a theoretical physicist's career is calculating feynman diagrams.For a mathematician, they are just graphs. connected graphs, disconnected graphs, simple graphs, euler graphs...and that's all....how boring! But, for a physicist they are his life...his bread & butter. And you care for whatever you do, for you truely love your creations. So, for a physicist, there is a ritual set for treating these diagrams. Put down a proper lagrangian, find out interaction terms...check renormalizability...... represent them with feynman rules..... start building diagrams... first order ones,tree level... higher order, loop insertions... and then calculate!

Simple, no? NO! I told you, you care for what you do....so in between you name it! Naming a diagram??.... true.. and hence, there are many interesting names. Tadpole diagram, fish diagram, bubble diagram, sunset diagram. And there is Penguin diagram. Interesting thing is, a tadpole diagram looks like a tadpole, a sunset has a sun setting on the horizon. But why a penguin diagram? believe me, there is no penguin in it. It is just a simple (one of the) loop diagrams.
Puzzled, like me?
Let's start with a story. It starts in a pub in Geneva at a game of dart. Four world renowned physicists, with one of their students were at the game, when one of them shared a joke on a penguin, which bursted into a great laughter for some time. Somehow, this evolved into a resolution, that the loser of the dart game would use the word penguin in his/her next work. And, hence the name penguin for his seminal paper on this loop diagrams in 1977.

Want to know the name of the loser: none other than Prof. john Ellis (the same from Ellis-howking, I suppose). So, aren't physicists interesting/funny personalities?

6 comments:

Basudeb Dasgupta said...

also note that none of the feynman diagrams look like feynman either...i know! i know! I can be really dismal.

Nikhil Joshi said...

vw :

point noted....but, think seriously, if one decides to draw feynman's outline solely with feynman diagrams?...you are good at drawing, sometime try it...it will be fun!

the mathematician :

one of my friend from maths, dept had a strong objection on the line saying

For a mathematician, they are just graphs. connected graphs,
disconnected graphs, simple graphs, euler graphs...and that's all....
how boring!


To him:
I don't mean that graphs are boring to a mathematician, as you interpreted...the boring there refers to their approach...as a matter of fact, mathematicians do only "kaam ki cheejhe, no bukwaas"...naming a graph, door ki baat hain...please, don't feel offended :O

Anonymous said...

This is in fact a stronger statement than the earlier one.

the boring there refers to their approach...

Besides, to make Physics sound interesting, you do not have to make some other subjects, and their approaches, boring. :-).

Nikhil Joshi said...

the mathematician:

I am extremely sorry, if I have hurt you. But believe me, I didn't mean that.

And, I still prefer you went through the blog once again, to find what I wanted to say: It is just, that we keep doing things which are totally uncorrelated stuff with the same seriousness as the regular bread-butter stuff. Mathematicians that way are much more "precise" about their work. And this demarkation between physics and maths was totally of secondary importance in the whole blog.

If you think there was any other offensive statement there, I hereby cordially withdraw any such thing and assure you that there was none!

Shashikant Kore said...

Hey, you deleted a post called missing link?

Nikhil Joshi said...

shashi:

I will put it later...un-modified...only date will change...this for no reason, but to confirm with the data mentioned in it...