The Magic numbers

"The magic numbers, as we know them now are :
2, 8, 20, 28, 50, 82, 126
and most importantly, they are the same for neutrons and protons."

Maria Goeppert-Mayer, The Nobel Lecture

The last female Nobel Laureate in Physics, 1963.

fluorescent light runs at 25kHz

The newish fluorescent light (well, added in 1999 to make up for a lost skylight) fixture in the RAS office must have an electronic ballast that runs at 25kHz, as that is a strong signal that pops up on the oscilloscope & antenna when that light circuit is running. The older fluorescent lights are probably ancient magnetic ballasts.

...I'm sure y'all care.

Pits on the Moon

Phil Plait points out pits on the Moon!



Click to enlarge. Images via NASA/GSFC/Arizona State University/LROC

Notable: the size of the standard AC outlet

Did you know the distance between the center of the slots in the 120V standard AC outlet is exactly 1/2 inch? And so is the distance between the center of those and the center of the ground pin. 0.5". All of this only came out after I bought an inexpensive digital caliper and started measuring everything I could get my hands on.

Today's sunny and windy weather

Click to enlarge to medium size. The link below goes to the really big image.
Today's weather in Chicago as seen from above via the MODIS imager on the Terra satellite. It was sunny and very windy with winds out of the southwest. It looks like you can see some dust streamers coming out off the lakeshore. Click on the link below for the huge 5200x6000 image with 250m resolution.

http://ge.ssec.wisc.edu/modis-today/index.php?satellite=t1&product=true_color&date=2010_09_07_250&overlay_sector=false&overlay_state=false&overlay_coastline=true§or=USA3&resolution=250m

Credits: http://ge.ssec.wisc.edu/modis-today/credits.html

"The SDSS and e-science archiving at the University of Chicago Library"

The SDSS and e-science archiving at the University of Chicago Library

Barbara Kern, University of Chicago
Dean Armstrong, University of Chicago
Charles Blair, University of Chicago
David Farley, University of Chicago
Kathleen Feeney, University of Chicago
Eileen Ielmini, University of Chicago
Elisabeth Long, University of Chicago
Daniel Meyer, University of Chicago
Peggy Wilkins, University of Chicago



The Sloan Digital Sky Survey (SDSS) is a co-operative scientific project involving over 25 institutions worldwide and managed by the Astrophysical Research Consortium (ARC) to map one- quarter of the entire sky in detail, determining the positions and absolute brightness of hundreds of millions of celestial objects. The project was completed in October 2008 and produced over 100 terabytes of data comprised of object catalogs, images, and spectra. While the project remained active, SDSS data was housed at Fermilab. As the project neared completion the SDSS project director (and University of Chicago faculty member) Richard Kron considered options for long term storage and preservation of the data turning to the University of Chicago Library for assistance. In 2007-2008 the University of Chicago Library undertook a pilot project to investigate the feasibility of long term storage and archiving of the project data and providing ongoing access by scientists and educators to the data through the SkyServer user interface. In late 2008 the University of Chicago Library entered into a formal agreement with ARC agreeing to assume responsibility for:

• Archiving of the survey data (long-term scientific data archiving)

• Serving up survey data to the public

• Managing the HelpDesk

• Preserving the SDSS Administrative Record

This paper outlines the various aspects of the project as well as implementation.

Kepler starts releasing smaller planet data: 1.5 Earth Mass transit exoplanet found

http://www.nytimes.com/2010/08/27/science/space/27planet.html?hp

2009 US Energy use

https://publicaffairs.llnl.gov/news/news_releases/2010/images/energy-flow-annotated.pdf

The latest energy generation/use chart for the US is out. Sinks and source, plus general field of use--it's a fascinating chart, and I hope it gives you a sense of where real solutions to the energy issue lie. Let's work on the efficiency issue.

Via Treehugger

Another impact on Jupiter

http://www.skyandtelescope.com/observing/home/101264994.html

My first thought once it was confirmed was "What is the real rate of visible Jovian impacts versus our sampling rate of looking for them?".

Haze and smoke from western Canada

Haze and smoke visible in on the visible satellite image for this afternoon might give the less humid weather the next few days in Chicago a tinge of non-clarity.

http://www.osdpd.noaa.gov/ml/land/hms.html

Saturn visible behind Lutetia during flyby

Hey, this is pretty cool; I'm always a fan of planetary conjunctions.

Saturn was visible in a few of the images of Lutetia taken by Rosetta as it passed by!

Fly-by of Lutetia is a success

Another successful asteroid fly-by!
http://www.planetary.org/blog/article/00002577/

Old Mars photos from 2003: No, it's not going to be big in August.

Inspired by a query regarding the false meme going around about Mars, I took a look at some images I took of Mars during it's big opposition in 2003. That was a great opposition. Here's a couple of those images. The first one is a single image without manipulation, the second and third are Registax processed images from videos, and the last is one of those videos.
Mars at the moment is not approaching one of those awesome 17 year oppositions like 2003 or 1988. It's just fading away from its January opposition and currently visible in Leo in the evening.

nose grease

In my high school days I had a part-time job at a professional photo lab / studio called "Phillips' Photo Lab". I was hired as the black and white darkroom guy--I manually processed film, printed custom prints, shot copy negatives, and cleaned the color film and print processors. Later I branched into running the shop on Saturdays and once, just once, did a color print job.

I learned a lot from the pros whose lifeblood was photography: the tips and techniques that make life easier.

One of the things that I would not had believed unless I had personally experienced it was the magic of nose grease. The skin on the nose and to a lesser extent the neck near the back of the ears produces a hydrocarbon of about C30H50 called squalene. The only reason this is important was squalene had the same index of refraction as the gelatin used in photographic processes and hence could be used to fill in scratches on negatives and slides. You would acquire some nose grease, rub it gently into the scratch, and rewash the negative. Nearly as good as new, and it allowed prints and reproductions from otherwise damaged negatives.

This particular example is this blog's first mention of a principle I like to call "matching impedances". In the world there are a lot of interesting issues that in the end are solved or mitigated by taking two different systems and making them the same at the point they meet. In electronics, to maximize power transfer between two parts of a circuit, you match their electrical impedances (which is a function of their resistance at all frequencies).

You have encountered this when setting up a TV or stereo system; the speakers have an impedance rating on them, usually 8ohms for a home stereo and 4 for car audio. Your amplifier speaker outputs need to be designed to deal with a particular impedance; stick a 4ohm speaker on an amp designed for 8 and you might mess things up. On your TVs there used to be two terminals for antennas--one was coaxial and had an impedance of 75ohms and is now the de facto standard, and the other was two screws that had an impedance of 300ohms. To get the most signal you'd want all the impedances to match up: the TV, the cable, and the antenna. If they didn't, part of the precious signal would be reflected back towards the antenna and lost. For converting the impedances to match a little transformer was used, of which there may be a hundred million hiding behind the TVs of the world. Again, here the principle of matching the impedances came into play.

In the optical world reflections occur at surfaces that have differing indexes of refraction. The bigger the difference the higher the reflection ( I think it's a square of (n-n2/n+n2). For solar panels, for instance, the high index of refraction of silicon (4) compared to air (1) makes something like 50% of the incident light reflect off unless you use anti-reflective coatings to improve it. So even for something like a renewable energy resource you have to consider such details.

I use nose grease (n=1.45) to also try to fill in scratches in CDs/DVDs (made of polycarbonate, n=1.58). It's not perfect, but sometimes it makes it playable.

So, in the end: Match your impedances!

Hayabusa coming home

An amazing comeback for the little falcon that could--


Credit: ISAS / JAXA / Øyvind Guldbrandsen / Planetary Society Blog

The Japanese spacecraft Hayabusa will be returning to Earth with perhaps a sample of the asteroid Itokawa in just four days. This spacecraft has had as many setbacks in the seven years it's been running as you can have without losing the craft completely. When they released the data archive in 2007 I made a color image of Earth made by Hayabusa during a flyby and some more surface close-ups here.