Mirror, Mirror, on the Wall…

In the film “Milk”, the murder of San Francisco mayor George Moscone was filmed from the reflection off a curved mirror hanging on the wall of the mayor’s office. This type of mirror, convex in shape, is seen often in stores or airports or wherever for surveillance. An early appearance of this type of mirror in Art is one depicted in the Early Netherlandish artist Johannes Van Eyck’s painting of a couple, “The Arnolfini Marriage”. The mirror itself occupies just a small portion of the painting, but is used in a clever way. There’s a good Wikipedia article

 

about it.

This article includes a 6 megapixel capture of the painting, which you can download and inspect in any image viewing software, perhaps zooming in on the mirror and the inscription on the wall above the mirror. To grab the image off the Wikipedia page, with Windows, right-click on the image and choose “Save Picture As…”. I don’t know Macs – maybe you just Will It To Happen with those.

 

Convex mirrors like these always give an upright image. Concave mirrors, as are found commonly in astronomical telescopes like the Hubble or an amateur’s Newtonian Reflector, are trickier. In telescopes, there is always a second optical element, usually a glass lens. Women’s makeup mirrors are also concave. The image one gets from these depends on the ratio of the distance of the object (say a woman’s face) from the mirror, divided by the radius of curvature of the mirror. If this ratio is less than 0.5, the image will be upright. If the ratio is greater than 0.5, the image is inverted. There are of course formulas for the magnification, again as a function of this ratio.

 

Simple astronomical telescopes, using just two optical elements, have a concave mirror with parabolic shape, in fact this is very important. When the Hubble telescope first went up in the early 1990s, after the Space Shuttle had placed it into orbit and returned to Earth, NASA opened the front flap of the telescope and took a picture and it was very blurry. The specifications for the mirror had been hand-copied, erroneously, by someone, and the company which manufactured the mirror, Perkin-Elmer, had decided to save a million dollars and not build a test rig for it. So, a few years later, NASA sent up another shuttle with a very nicely figured special lens to insert in the optical path of the telescope to correct the aberration and got fantastic images afterwards. In the intervening years, decent but not exceptional images were obtained by using mathematical algorithms (Deconvolution) on the images sent down from Hubble.

 

In maybe 5 years, mathematical algorithms like Deconvolution, but fancier, will be paired with multiple image sensing pixel arrays in digital cameras for the consumer, to allow taking a picture without worrying much about focusing the picture at all, or worrying about a background object being out of focus while a foreground object is in focus. The file from the camera will go into special software, like Photoshop, where the user can turn a software knob or slide a slider, and bring any desired part of the image into focus. The main company developing this technology is Refocus Imaging, which has a nice demo of this capability on their web site;  

 

http://www.refocusimaging.com/about/

 

This same technology will greatly lessen the demands on the optical quality of the optical elements in the camera, namely the lenses, so great photographs, with perfect focus, will come from perhaps cheaper cameras. 

 

Katrina Uncovers Structural Failure

When something is stressed beyond its limit in engineering, it experiences structural failure. Featuring footage shot by lower Ninth Ward New Orleans residents Kimberly Roberts and her husband Scott before, during and after Hurricane Katrina hit in 2005, directors Tia Lessen and Carl Deal’s documentary “Trouble the Water” suggests another gathering storm in New Orleans and urban America with dangerous repercussions: the cycle of poverty.

As Katrina’s clouds began to darken the sky and cars sped out of town, Kimberly admits, “If I had wheels, I’d be gone too.”

Kimberly and Scott did not have a car or the means to leave New Orleans as Katrina approached, so they waited out the storm.

Eventually the levee failed, flooding the lower Ninth Ward and forcing residents left behind to seek shelter. As local, state and federal government failed to respond effectively to Katrina, those who remained behind had to fend for themselves. The experience left many disappointed with authorities.

“If you don’t have money, if you don’t have status — you don’t have a government,” says one of Kimberly’s relatives, bitter about the bungled response to Katrina. She vows to do whatever it takes to make sure that her son is able to get an education. Some are not so lucky.

“Trouble the Water” highlights how large-scale poverty and lack of education contribute to a downward spiral of a lack of opportunities and crime. Kimberly has struggled to survive since her mother died of AIDS, and a brother waited out Katrina in prison.

Kimberly’s husband Scott talks with amazement of how enemies — rival gang members one might assume from an image shown of him proudly brandishing a gun — helped each other out during Katrina as they worked to rescue victims of the flooding.

Shocked and distrustful of authorities, some lower Ninth Ward residents left New Orleans for good. Yet a number of those residents returned after finding it difficult to make a new start elsewhere. Luckily, Scott found a job in construction back in New Orleans after offering to watch over a foreman’s construction supplies. He was happy just to have work. Not everyone was as lucky as Scott, however, and eventually reconstruction will cease. What then?

The role of poverty and lack of education in urban America was examined by the 1968 Kerner Commission Report, known fully as the “National Advisory Commission on Civil Disorders.” Illinois Governor Otto Kerner, Jr., chaired the commission, whose mission from President Lyndon B. Johnson was to examine civil disorders that were happening in the late-1960s and ask what happened, why it happened and what can be done to prevent it from happening again. Johnson thought that the rioting was some sort of conspiracy, but the commission found that the conditions in inner-city America were so severe that almost anything could provoke people to riot. Among the conditions observed: low income, high unemployment, poor education and poor transportation.

Former Oklahoma Senator Fred R. Harris, who worked on the commission, spoke with Bill Moyers on the March 28, 2008 edition of the PBS television show the “Bill Moyers Journal” about the commission’s work.

“Crime, narcotics and so forth — these are the handmaidens of poverty,” said Harris. “There are a lot of people who want to punish people for being poor,” he added. “What you need to do is give people a hand up.”

Today Harris teaches political science at the University of New Mexico and works with the Eisenhower Foundation, an international nonprofit organization whose mission is to continue the work of the Kerner Commission.

Allowing poverty and lack of education to continue only leads to difficulties, not only for the poor, but for society as a whole. America will be a better place when more people can afford to survive and provide for themselves and their families. Otherwise, the structural failure witnessed in New Orleans because of Hurricane Katrina will happen again and again — in New Orleans and in other urban centers.