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.

Winter Solstice 2009

Happy Winter Solstice.

From http://buscam.uchicago.edu/ taken on 11:54AM (a few minutes past the solstice time) (on campus only)

Chicago is looking as good as 2006!

Enjoy this graph of the date and time of the solstice over the years.

400 Years of the Telescope: Friday on PBS

This such an auspicious year. I watched an interview on Chicago Tonight with one of the creators of "400 Years of the Telescope", to be broadcast on PBS this Friday. Immediately a shot of the Yerkes 40-inch refractor passed by in glorious HD, a scope I am intimately familiar with, and now I am compelled to watch. Friday at 8PM on WTTW. Of course, I am very happy when E.E. Barnard pops up on the schedule page on the site--Barnard's experimentation with astrophotography has a tie to the RAS observatory: our 1895 Warner and Swasey mount was first lent to Yerkes Observatory so Barnard could test camera lenses.

Adventures in large format digital photography: part 5

I got the camera working again, kinda of. It doesn't work with TWAIN enabled stuff. It will work just fine using Vuescan on Windows and XSane on Ubuntu. Exposures are weird with Vuescan--I seemingly lost 3 stops of speed with it.

I also dremeled open the highly vignetting slot that previously limited the images to that narrow vertical view. I can now scan 7x11 inches. (Somehow I lost an inch and a half--the sensor is dead below 7 inches). There is also a band of vignetting and/or low sensitivity right across the central-top of the frame.

Rockefeller Chapel, Reynolds Club, and Flowers

The light was rapidly falling last evening and this was my last image, with a full open aperture, but it was still underexposed by about a stop. Expressed in other terms, a film camera with 100ASA film would expose for this for about one second at f/8. Autoleveled and hue adjusted in photoshop. See the original here. This also was the first outing of the camera with a coat of black paint in the interior, an additional baffle on the top to handle light when doing macro work, and I added a shoulder strap with some eyelets (one broke on the trip). Remind me to stick some teflon strips or wax the bottom of the inner box--it's getting too hard to move to focus.


A color image, underexposed. The lightest of breezes moved the daffodils a touch between exposures. The flowers were just over 4 feet away.

Adventures in Large Format Digital Photography: part 4

Today I mounted an inexpensive IR blocking filter in front of the lens using a cardboard mount. It's ugly, but gets the job done. I did this because after a second outing with the camera the odd tones on vegetation and clothing were getting tiring. It also allows me to make real color images with three separate red green blue scans.


Three separate scans using a 25A red, 47 blue, and a combo X1+Y2 greenish filters. Added together in photoshop and auto-leveled, plus some addition saturation, and some highlight/shadow work.
The green is not a true tricolor green, it's more yellowish. I need to buy the 61 green to get better matching.

Adventures in Large Format Digital Scanning: Part 3

Click to enlarge any of these to the original size (the first image is actually only 50%).


An early image with the prototype cardboard camera. This image was auto-leveled, sharpened, and hue altered to attempt to match the original color out of the camera.


When outdoors with a small aperture all the dust on the scanner glass becomes visible, as seen in this and all further images in this post. I ended up cleaning it after this first trip outdoors.


You can heavily sharpen the images out of the camera: this one is at 169%. I am still experimenting with basic things like focusing and apertures, so final sharpening levels are way in the future.


I made a second scan of Lui at 1200dpi, cropped, and cropped some more in post-processing. It looks soft on the original and I think 1200dpi might be interpolated (although Canon says 1200x2400dpi). It's also possible the focus was off.

Ryerson Physical Laboratory: "Ghostly"

I originally passed over this image while taking a bunch of near infrared photos on campus. The underexposure from looking into the partially overcast sun killed all the shadow detail and the flare was a distraction; essentially I was looking at the image in the context of the shoot that day, which was finding scenes that exemplified some IR photographic ideal.

Back to the present day where I am reading up on William Henry Fox Talbot, one of the inventors of photography. His early images of Lacock Abbey are ghostly and fuzzy as he made his negatives on coated paper and made contact prints with the same process that made the positives even more dreamy and indistinct.

This makes this previous rejected image more desirable.


Taken on May 4th, 2005 with a Canon A95 and several layers of fully exposed color negative film as an IR filter. 10 second exposure.

Original size here.

near infrared lights

When I need good near-infrared lighting, I turn to the broadband sources called the Sun and incandescents. They are the closest thing to a blackbody we see on a regular basis.



I presumed on this post that I was seeing an intense sodium line from high-pressure sodium lighting while taking daytime near-IR images. What I didn't realize while speculating at that point was that every high-intensity discharge light has a very hot envelope--for high-pressure sodium, a bulb of aluminum oxide (all jokes about transparent aluminum aside, of course). For metal halide and mercury vapor it's usually fused quartz, but sometimes it's the above alumina or sapphire. The tough requirements of dealing with a circa 3500K corrosive plasma dictate the choice of material. Have you ever seen a cycling HPS streetlight? As soon as the arc extinguishes you can see the pure blackbody glow of the very hot bulb window which is at or just below 1200K. That's what I'm detecting in the infrared shots--any HID light that is on is a great IR source. See this shot of the Chicago Theological Union / Oriental Institute or this one on the central quad of the University of Chicago -- the metal halide lights are on in the early evening with sunlight still streaming in. (Don't get me started on energy decisions here). Or here.


Or this HPS streetlight here at Hull Gate.

Compare that with fluorescents: they on the other hand are very poor in near-IR light, as expected from an efficiency standpoint--visible light is what you want in an efficient system. (The HID lights are highly efficient despite emitting copious near-IR light because the arc is incredibly bright and efficient in the visible. But you can't get such efficiencies in a low wattage bulb).
You can see fluorescents glowing a bit in this test focus shot of the first floor of the Reg:


Around the edges of the room are fluorescents, dimly adding some near-IR that is red or very near red. Notice that the ends of the fluorescent tubes are purple: this is further into the IR, and what you're seeing is the thermal glow of the little filaments that heat up and emit electrons. When I need near-IR indoors, I use old-fashioned tungsten: a single 60W incandescent bulb will outlight a room of fluorescents.

Watch the clouds go by

See the clouds go by at night at http://skycam.uchicago.edu/. It's a field of view 30x50 degrees pointed south at about 50 degrees up.

Match your local light pollution by seeing what you can see in Orion. Ryerson is somewhere in magnitude 3.

Maroon article on campus lights

New lights dim club's stargazing

The new lights have created extensive light pollution in the local sky, a phenomenon that occurs when light scatters off air molecules. As a result, distant stars and galaxies disappear in the uniform glow of the overlit sky. Dean Armstrong, a longtime RAS member and University staff member, recalls a time when the stars were more easily visible from Ryerson.

“We used to show galaxies as part of a standard observation,” he said. “We don’t do it anymore. Either people can’t see them, or they’re just unimpressive.”

Located immediately below the Ryerson telescope, the new lights have brought the hurt home. A new light installed last week shines directly on the dome topping the telescope, and many others shine directly into the sky surrounding it.

Claims that these lights are shielded and only hit the first 25 feet of the facade are false. Here's a few images:


Do these lights only hit the first floor? No. View from the six-story roof.


The inverse view, lighting up the turret.

Blinding glare around the corner of Ryerson

Coverage of "shielded" light extends to nearly the zenith.

This light directly hits the dome and is much brighter in person.

Additional images at http://www.lib.uchicago.edu/~dean/lights/

Astronomy communities

The media has globbed onto the existence of planned astronomical communities where bad lighting design is not allowed by rules and housing covenants. These are new places, places only needed in the recent past, because of the horrendous growth of light pollution. Continued light pollution increases of 5-10% per year mean the end of the visibility of the stars in just a few decades. Already 2/3rds of Americans haven't seen the Milky Way. By 2025 there will simply be no more dark sky in the United States. Simply no place. Current arguments about "why don't you move your scopes to a dark place" are ignorant by this measure and besides, are the people who created the light pollution paying for relocation? Destruction of useful observatories like Mt. Wilson and the current degradation of Palomar by misinformed politicians who'd rather be concerned about aesthetics than efficiency and science:

(Mayor Dick Murphy) said he also supports the change for aesthetic reasons: "People think they're ugly."

Astronomers also are concerned about a plan before the council to replace some hooded streetlights with decorative acorn-shaped lamps in various historic districts. The acorn lamps allow most of their light to shine upward, to the sky.

"They are blantantly inefficient," said Paul B. Etzel, director of the nearby Mount Laguna Observatory. "It's a 19th century solution to a 21st century problem."

Critics also point to higher costs. Getting rid of the low-sodium lights would cost nearly $2.8 million and raise the city's power bill by a half-million dollars a year, according to a city report.

This alley has 4 250W lights plus a 150W streetlight within a thirty foot radius. A resident of this building can't get the city to remove or shield any of the lights.

Which constellation lost will make people realize the sky is gone? Orion? The asterism of the Big Dipper? Already seeing the Pleiades is tough in Chicago, and the faintest star of the Big Dipper is getting difficult to see.

I've seen it first hand in a place that doesn't need anymore light, yet we in Chicago increase the energy use in lighting by leaps and bounds whenever the mayor needs re-election or a University president feels to rule by fiat. I can only hope people will eventually realize spending tens of thousands of dollars for just the light that goes up into the sky (yes, really) is not smart for a campus nor the millions of dollars per year for a city like Chicago. The nation as a whole wastes--not uses, but wastes--$5 billion a year or more in outdoor lighting that doesn't hit its target.


Would you want to live with this light outside your bedroom, giving you breast cancer?

People think that brighter lighting decrease crime--but it doesn't, period, and in fact, I was shocked to discover someone actually checked: Brighter alley lights in Chicago increased crime in the alleys by 21% percent: Each of the three crime categories experienced an increase in the number of
reported incidents between the pre and post- installation period. Violent Index offenses
increased 14 percent (119 to 136), property Index offenses increased 20 percent (30 to
36) and non-Index offenses increased 24 percent (279 to 347). All this, using 160W more per fixture (there's 175,000 of them in the city), adding 28 Megawatts to the "Greenest" city.

A Trip Back in Time and Space -- Harvard's Cosmos

The New York Times has a good article on a dedicated effort to digitize the Harvard Observatory plate archive.

I hope Chicago eventually does the same with the Yerkes collection. With the closing of the Yerkes Library, much of the plate collection is coming down to campus, although I don't know how much of the telescopic plate collection is coming. Yerkes has a fantastic historical photo collection of observatories, instruments, and astronomers.

Online Geiger counter: off

The online Geiger counter is temporarily off while I deal with power issues in my office. I've also been thinking of taking it and a GPS on a tour around campus--there are a few places with exotic granites/other intrusives (like the Henry Moore sculpture not a few hundred feet away from my very desk) that have decent Uranium/Thorium concentrations.

Description of the counter

Happy 300th Birthday Linnaeus

Today marks the 300th anniversary of Carl Linnaeus aka Linné's birth.



These two images are identical--open them up in two browser windows and switch between them to see the difference between near-IR and visible light.

A link to another infrared image of the Linné statue

Carl Sagan

Carl Sagan died ten years ago today. Has it really been ten years? I guess I can say it has: new visitors to Ryerson Observatory often do not know who he was and miss some of the symbology of the one-hundred-and-six-year-old refractor they are peering through. What they don't realize is how important he was not to the advancement of science, but to public science education.

He was a student here at Chicago; he was, as the picture indicates, president of the University of Chicago Astronomical Society (now known as the Ryerson Astronomical Society). After his short stay in the college he went to the Astronomy department and left a Ph.D. I quote a visit from John Musgrave, a member of the Society, to Yerkes during Sagan's period there:

I remember the one Yerkes night we had that fall (1958): it was cloudy; 
but if it had been clear we could have used any of the telescopes as no
one was using them for research - no one on staff greeted us - just some
"lowly grad students".  Rather than observe we heard a lively spur of
the moment lecture by a post-doc introduced to us in somewhat apologetic
tones -  "we don't know if he is for real or not" - unusual even by U of
C standards. It was Carl Sagan and he spoke about the possibility of
extraterrestrial  life (maybe other things as well - but with Carl I
remember the performance more than the content - including waving
arms).  I guess the "we aren't really sure about this guy" label haunted
him through to the end.

I often wonder what the dismal atmosphere of a coal-smoked Chicago was like for astronomy in the early fifties--and whether the old cranky telescope (fifty-two years old then, in 1952) did anything to inspire future thoughts. His logs are short, and there never seemed to be much observing or possibility of observing. See here for a scan of a sample logbook page. Or here for the entire text of the 1952-1964 logbook.



A member of the club in the seventies, when Sagan was back on campus showing off images of the new Viking landers on Mars, got him to sign the logbook yet again. I never met him, but a fellow RAS member at the time, Chris Conselice, was in attendance when they created a graduate student award in the astronomy and astrophysics department. He said he looked quite frail--this would have been 1995 or 96.

Keay Davidson in his biography, "Carl Sagan: A Life", writes:

And atop Ryerson Hall, he and a band of future astonomers learned (with the guidance of the astronomy club advisor, Guy C. Omer Jr.), how to operate equipment in the campus observatory. Other club members included Tobias Owen, who, like Sagan, would go on to a distinguished astronomical career. Sagan ran the astronomy club's "theoretical" section, and arranged speeches by famous professors such as Subrahmanyan Chandrasekhar.

Omer "taught me how to make the right ascension and declination drives go, and gave me a key to the observatory... and so there I was: I could go and look at the stars if ever there was a clear night in Chicago," Sagan later recalled. Yet he wasn't much of a stargazer. The club's logbooks show that Owen and several other members showed up night after night, for years, to meticulously record their observations. But Sagan observed only seven nights between October 1952 and November 1953; and when he observed, he left only terse notes. One searches the logbooks in vain for early fragments of Saganish eloquence. His most vivid entry dates from 2:15 to 3 AM on November 25, 1952, during his sophomore year: "Some [cloud] openings; then clouded over. Also COLD."

...

"Much more important" than stargazing, he later joked, was that at Ryerson Observatory, "I could bring young women to a place where could be undisturbed--which was far and away more important than being able to look through the six-inch telescope!"

In that spirit I leave you with this cartoon from the 1957 Cap and Gown. (My notes have it mislabeled as 1953--it could be 53 or 57, it matters not):

Rockefeller Chapel and the Moon, 2001 July 3rd

.
The Gibbous Moon rising over Rockefeller Chapel, taken over 4 years ago from Ryerson.
I took this image with an Olympus E-10. It was a humid but nice evening. What can't be seen are the hordes of gnats flying around nor the thunderstorm to the west. I also took an image of the Sears Tower with a tall thunderstorm behind it, with the idea to use the known distance and height of the tower to determine something about the cloud behind it (although you need one more bit of information about the cloud to figure it out).

live radiation reports from my office

http://www.lib.uchicago.edu/~dean/float.htm

It's completely temporary, and could go down at any time, but the average radiation rate for the last minute in my basement office is available at the link. The long term average for the geiger counter is about 7.6 microrads / hour. If the rate goes up to 30 or so, it's likely I put a small dixie cup of western Michigan beach sand on it (the sand is enriched in monzanite which has a small amount of thorium in it).

UPDATE: Back up and running: http://dwarmstr.blogspot.com/2011/03/geiger-counter-back-up.html

Radioactive Krypton in the atmosphere

The radioactivity of atmospheric krypton in 1949–1950
Anthony Turkevich, Lester Winsberg, Howard Flotow, and Richard M. Adams
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=33711

Highlights:

"The work reported here was carried out in the old ruling engine room for grating production in the basement of the Ryerson Physics Laboratory of the University of Chicago."

"As mentioned earlier, atmospheric krypton in the 1990s has a radioactivity of tens of thousands of disintegrations per minute per liter. It is now about a hundred times more radioactive than the samples reported on here."

"The largest current producer of radioactive krypton is the French reprocessing plant at Cap-de-la-Hague, which released 1.8 × 10¹⁷ Bq of krypton radioactivity in 1994. If diluted by the whole world's atmosphere, this would produce a radioactivity of krypton of 2,400 dpm per liter (STP). Cap-de-la-Hague's output may represent about half of the present input into the atmosphere of this radioactive nuclide."