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Archive for June, 2008

Green astronomy

In matters relating to the Mother Star, Core77 point out a company claiming to build higher-efficiency solar collectors: instead of a flat photo-voltaic cell across the entire collection area, a small-but-more-apparently-more-efficient cell is placed at the focus of a curved mirror:we reflect, you decide.

Now wait just a minute, there. Photons, check. Primary and secondary mirrors, check. CCD-analogue, check. Yes, it’s the world’s smallest, single-band, optical telescope. I for one welcome the prospect of roofs lined with arrays of Solar observatories.

Not to step lightly over the glorious history of start-ups in Mountain View, CA, I am sure that SolFocus have the semi-conductor physics well in hand, though their website contains jargon commensurate with the field of solid-state physics an ambitious new-energy company, and I am not able to understand properly how the cell in the middle is different from regular photo-voltaic cells. Upon reflection, I think we are supposed to conclude that it is exactly the same, but because the cells are the expensive part of the collector and mirrors are cheap, the design provides the same energy as a larger collector at a smaller cost.

In any event, it’s interesting and exciting, like spintronics, about which more needs to be written, and with more clarity.

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Another item in the pantheon of amusing tweaked Google results:

Fourty-one days is, however, ambitious.

(ht: Andrew Sullivan)

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It seems that the International Astronomical Union’s decision to re-classify the Planet Pluto has reached the ears of T-Shirt makers. Here’s a funny design from Snorg Tees:

It\'s OK, Pluto.

That’s probably the funniest astronomy-related-T-shirt I’ve seen, but it doesn’t have much competition.

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A Calendar Puzzle

Here’s a nice, neat puzzle for those with a spare minute.

I was at a mate’s house and saw that he had a desk calendar that worked as follows. The day of the month was displayed using two cubes, which had one number on each face. A quick calculation would suggest that the first cube (the tens column) needs the numbers 0,1,2,3. But the second cube (the ones column) needs the ten numbers 0-9. Each cube only has six faces, so it looks like we’re 4 + 10 – 12 = 2 faces short. So how does it work?

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Recently, I was watching my cousin Ben play Tetris on his home computer. Being related to the Brewers, Ben has a somewhat obsessive personality, and playing Tetris had become a habit, something to do when there’s nothing else to do. One day, while discussing Tetris, Ben mentioned that all of the high scores on their computer (shared between Ben and his brother Andrew) were between 18,000 and 21,000. “Wow”, I said, “you guys must play tetris a lot”.

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We saw from one of my previous posts that we can’t choose the notes of the musical scale such that, from every note, an interval of a perfect octave (ratio of 2:1) and a fifth (ratio of 3:2) is available. In this post, I will explain how this problem is fixed in the modern musical scale.

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A while ago I posted on Joy Christian’s supposed disproof of Bell’s theorem, under the title “Did the universe just get less weird?” I was just looking through the statistics of how people find our blog. At some point today, someone stumbled onto my post by typing the following search into Google:

How to be less weird

I doubt that he or she learned anything useful about social normalcy from 4 astronomers …

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