Monthly Archives: August 2011

Handbook Extract, 1

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Not long ago I was in Leadville, a mining town you get to from Aspen by going over Independence pass and then down into the valley. (It is apparently North America’s highest -in elevation- incorporated town, being at over 10K feet… Its roots are in gold and silver mining, starting back in the mid 19th Century.) I love visiting the big store that sells all sorts of curiosities and antiques there, and then after wading through lots of bits and pieces, going to the saloon bar for Irish coffees.

This time I actually bought something. Two things in fact – Some old handbooks for mine crew personnel of the Climax Molybdenum Company, from 1978. They are quite small, about 5 by 4 inches, but they are packed with delightfully presented dos and don’ts about how to do the job, including safety practices, and warnings about what might go wrong if you do things the wrong way. I particularly love the fact that the pages are […] Click to continue reading this post →

Peak

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After just having walked down a few minutes from Electric Pass Peak back towards the Pass (the peak is a fun 13635 ft / 4156 m elevation), I remembered to take this short panorama to show the surroundings. You can see the peak just descended in the middle of the film, and just before you’ll see Cathedral Lake in the distance, along with the meadow of wild flowers through which the hike to the peak takes you.

The 15 seconds of film is after the fold: […] Click to continue reading this post →

Heretic…?

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We had a really interesting discussion of the quantum physics of de Sitter spacetime yesterday here in Aspen, starting with a review of the behaviour of scalar fields in such a background, led by Don Marolf, and then, after lunch, an open-ended discussion led by Steve Shenker. This is all quite difficult, and is of course quite relevant, since a piece of de Sitter is relevant to discussions of inflation, which seems (from cosmological observations) to have been a dominant phase of the very early universe. As the most symmetric space with positive cosmological constant, de Sitter may also be relevant to the universe today, since dark energy (first recognized after 1998’s observations of the universe’s accelerating expansion) may well accounted for by a positive cosmological constant.

So we need to understand this type of spacetime really well… and it seems that we don’t. Now there’ve been a lot of people looking at all this and doing really excellent work, and they understand various issues really well – I am not one of them, as I’ve not worked on this in any detail as yet. Do look at the papers of Marolf, and of Shenker, and collaborators, and references therein, and catch up with what’s been going on in your own way. For what it is worth, the sense that I get is that we’re trying to solve very difficult issues of how to interpret various quantum features of the spacetime and getting a lot of puzzles by trying to make it look a lot like things we’ve done before.

Now, we may solve all these puzzles…. but my current take on this all is that we’re […] Click to continue reading this post →