2 May 2007

Years ago I researched and presented a lecture for the AAA on terrestrial impact craters. It was prompted when I got into GIS and wanted to geospatially understand their presence. Now I am copying some old Zip disks to my hard drive and have come across the data again and decided to try to depict some of it in Excel. This is my first cut at displaying size vs location. I think the location of the points relative to each other is fairly good, but they don't match up with the longitude scale very well. I see this mostly in the west where I am familiar with the location of some of the craters and the longitude values for the US. The same might be true for Europe, Asia and Africa but I don't see it because I am not as familiar with those areas. I would like to underlay this data over an outline map of the world. The thing that struck me seeing the data displayed this way was the stripes of craters across the northern US/southern Canada, through southern Europe/Asia and Africa. My studies back then indicated that we knew the most about impact structures over North America and Europe because these were the areas that where most of the population has lived for the longest period of time. Satellites are changing that now.

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I was checking for broken links and found that I have a new birthday star:

Your birthday star is in the constellation Gemini. It has the name ξ (Xi) Geminorum in Johann Bayer's Uranometria star catalog. It is also called 31 Geminorum in the Historia Cœlestis Britannica of John Flamsteed and Edmund Halley. It is called NS 0645+1253 in the NStars database.

It has visual magnitude 3.35 meaning that you could see this star with the naked eye in good viewing conditions. It is marked in the center of this star chart, at celestial coordinates (J2000 equinox):
Right ascension 6:45:17.4
Declination 12:53:44.1

This star is 57.2 light years away, which means that the light we see from it today set off on its journey at about the same time that you were born. Come back in a month or two and your birthday star may change, as the light from more distant stars reaches Earth.

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Here is a picture of the mySky unit. I found a web page that says selected dealers should have a small quantity of units by not but no word when the product will ship in earnest.

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Tonight I attended a Science & the Arts program at The Graduate Center of the City University of New York. It was titled Geometry and Art: From Escher to Animation.

It started out with a reading from the biography of Donald Coxeter, who is credited with saving geometry from the dustbin, by author Siobhan Roberts. The reading was well done and had a flow to it, almost like it was an abridged version of the book.

Next George Hart, researcher from SUNY, Stony Brook, presented some of his geometric sculptures.

The last presenter was an animation professor from and NYU who tried to show us how geometry is used in animation. It was OK for a while but he got too deep into the details and jargon and people started walking out before he was finished.

At the end the author came back to show a fly through universe that we had to wear 3D glasses to see. It wasn’t much of a universe and didn’t do much, but the 3D effect was good.