Ok, so here goes. A bit of physics linked to this all so significant date. There’s this term that people in string theory were using a lot in the middle to late 90’s, called the “9/11 flip”. I think maybe the Verlinde brothers, Erik and Herman, possibly in conjunction with Robbert Dijkgraaf, made the term popular but I am not sure about that and I welcome a correction. [Update, since there is some confusion: I’m talking about the term here, not the technique itself, which is older.]
(On right (click for larger) is a snapshot of one of the figures from their influential 1997 “Matrix String Theory” paper. You can see the use the term there, and it is in the paper’s text too, and soon everyone was using it in seminars and other papers to follow.)
The flip became particularly useful when people were discovering the wonders of “M-theory”, which is the catch-all term for whatever is the parent theory of string theory, something we are still trying to formulate. There are a number of narrower uses of the term, however – some more justified than others. For a while, everyone was thinking about the five ten-dimensional supersymmetric string theories (“type IIA”, “type IIB”, “type I”, and two types of “heterotic” theory) which, prior to the middle of 1995 (actually as early as late 1994 or early 1995) all seemed like totally distinct theories, and in the post middle-1995 era (after Witten’s remarkable talk at strings 1995 here at USC: paper here) were recognized to be all part of the same theory. The universe (at least the continually expanding string theory one) changed radically overnight.
(One of my preferred ways of presenting the puzzle that is M-theory, and how the ten dimensional string theories fit in the puzzle. This is a slide from one of my general talks on the subject.)
The 9/11 flip is really simple, although when a setting is complicated enough, it can […] Click to continue reading this post →
So what were some of the big ticket items, at least in terms of where all the regular press were? Well, the biggest was of course the X-prize. There was a long movie with lots of stuff about space, and dreams about our future in space, and animations and things of roving robots on planetary surfaces, and all that good stuff…. very nice, I thought, and began to wander off…. and then there was a round of applause from everyone and I came back as a voice announced “The Google Lunar X-Prize”, and various other people showed up on the stage (like one of the founders of Google – forgot his name, and later, good ol’ Buzz Aldrin, who seems to be required at these sorts of events). The Google co-founder guy began his speech by acknowledging all the Google engineers… and announcing that they’d just launched a new version of the moon. Applause. (I’m pretty sure that they mean Google Moon, by the way.)
Drat.
