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Comment Re:Hold up. (Score 1) 600

I think long-term the really interesting outcome of this work would be if it could inspire more accurate metaphors for describing the basic particle interactions. As other posts have mentioned, the Feynman diagrams are quite Newtonian in that they adhere to a strict particle based view of events, such that any process is described as a sequence of interactions between point-like particles (even light gets broken up into particles, photons). But this means that wave-like properties of particles may be poorly represented, and it is possible that the twistor method strikes a better balance between particles and waves. The question is, how can we who are not high-energy physicists get a picture of what these objects are, and how they interact, in terms of more intuitive concepts?

Comment Re:hmmm.... (Score 1) 600

I don't know the details, but I've seen from other work that what tends to happen in scattering probability calculations (the physical quantity observed in experiments, essentially the square absolute value of the amplitude) is that the contributions from many Feyman diagrams tend to (almost) cancel out. The true answer is a small difference between large numbers, and many high-order Feynman diagrams contribute to these (e.g. containing virtual particles); this is why they are so inefficient for calculating complex interactions. The Twistor approach more recently developed is so much more efficient because it provides the right elements as basic building blocks -- no need to do a lot of calculations to cancel out the terms you already have.

Comment Sleep among the stars (Score 1) 141

With his Culture novels, Iain M Banks is unparalleled in sheer mind-blowing scope and depth. Many of the stories have a strong bitter-sweet quality (such as Consider Phlebas, the first one I read and still one of my favourites), the exception is possibly Player of Games which is a lot more cheerful. Excession is one of very few stories that extrapolate technology in a significant way. Use of Weapons is one of the most horrible stories I've ever read, with it's masterful exploration of the depths of the human psyche. Thank you Iain for the many wonderful, sad, funny, mind-boggling moments I've had reading your books, and may generations of people enjoy the same experience!

Comment A better diff is the solution (Score 1) 328

I prefer to use a different diff program, wdiff, that can identify differences word-by-word (and also allows for ignoring changes in white space, which are usually irrelevant for latex).

I use a shell script where i type

tex_diff.sh <old file> <new file> > result.html

to create an html page where the differences are marked (blue for new words, strike over red for deleted words). The file result.html can be viewed in a standard html browser (e.g. then one you are using right now :)). the tex_diff.sh contain (on a single line)

wdiff --start-delete='<font color=red>' --end-delete='</font>' --start-insert='<font color=blue>' --end-insert='</font>' $1 $2 | sed -e '1,2 d;s/$/<br>/'

change the font commands using basic html if you prefer a different style. it is also possible to use wdiff to show only new text.

Comment Re:The standard? (Score 1) 328

Three solutions to this problem:
1. Use a latex editor that allows for clicking on the pdf to find the corresponding position in the source file and the converse (Texshop does this on the mac).

2. Use LyX, and export to latex if you have to.

3. Writing in latex for a while you will quickly be able to read the code without looking at the compiled pdf :)

Comment Svn has track changes (Score 1) 328

Lyx has a track changes function, very similar to that of Word. Personally, I find that tracking changes quickly results in a very cluttered document. I prefer to use svn in combination with a different diff program, wdiff, that can identify differences word-by-word (and also allows for ignoring changes in white space, which are usually irrelevant for latex).

I use a shell script where i type

tex_diff.sh <old file> <new file> > result.html

to create an html page where the differences are marked (blue for new words, strike over red for deleted words). The file result.html can be viewed in a standard html browser (e.g. then one you are using right now :)). the tex_diff.sh contain (on a single line)

wdiff --start-delete='<font color=red>' --end-delete='</font>' --start-insert='<font color=blue>' --end-insert='</font>' $1 $2 | sed -e '1,2 d;s/$/<br>/'

change the font commands using basic html if you prefer a different style. it is also possible to use wdiff to show only new text.

Comment Re:Not much of a problem (Score 1) 264

I agree. I did a project for a company some ten years back, a small database app integrated in a barcode printer. They used a standard barcode scanner, it sent the scanned code as a standard ascii string on a serial port. Just read from the serial port where you attach the scanner, using your standard stdio routines, and you're all set in that part of your solution.

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