Science: Plasticity, DNA, Universe Theory

Attending: Barbara, Howard, Gretchen, Bruce, Dave, Bob

We had a pleasant meeting, better than the last one in spite of my wi-fi problems. Everybody brought an item and had many comments. After the meeting, I complained about my problems with the building wi-fi and was given my own personal router and modem. Things should be better in August.

Barbara led off with an article from the Wall Street Journal about brain plasticity in the setting of albinism and severe visual problems. Albinism is a heterogenous condition; all affected have some degree of visual handicap. The single most important factor in the visual handicap is abnormal crossing of visual fibers at the optic chiasm. Retinal pigmentary abnormalities and nystagmus, an involuntary movement of the eyes, are usually less significant. Most children with nystagmus see a stable visual image but may have to get very close to a book or other visual target. With both central and peripheral components of visual impairment, it is still possible to improve, as the brain adapts or learns how to deal with degraded information. Barbara also gave us a brief report about ‘dragon man’ a recent fossil at the bottom of a well in Harbin, China with a very large skull, speculated as a possible Denisovan, a new species in the hominid tree of life or perhaps a mosaic due to interbreeding. We’ll need more data to clarify these issues.

Howard reported about a new twist in crime scene DNA analysis, DNA analysis of trees. Here, DNA analysis was used to convict two men of stealing valuable trees from public land (in the Olympic National Forest) and selling them to sawmills. The case turned on the DNA analysis which showed that the wood sold must have come from the Olympic National Forest with a probability of a chance finding being one to the 10th followed by 36 zeroes.

Gretchen continued the same thread reporting that spectroscopy was being used more and more to detect fake paintings. Various early 18th century scientists described the light and dark lines in the prismatic spectrum from sunlight and various terrestrial light sources William Fox Talbot first suggested, in 1826, that the distinctive line patterns could be used in chemical analysis. Talbot was a giant in the history of photography who developed what he called the calotype process, the precursor of negative-positive photography. There are many different forms of spectroscopy – I used atomic absorption spectroscopy in the early 1970s. Raman spectroscopy, named after its inventor, became the principal method of chemical analysis in the 1940s. A tiny piece of pigment can be removed from the painting, combusted and its spectrum analyzed. Each kind of spectroscopy has advantages and disadvantages. Spectroscopy is very important in astronomy and astrophysics..

Bruce brought many comments and brief reports. He was especially interested in flying cars and a flying Renault. The first roadable fixed wing aircraft actually to fly was built by Waldo Waterman, associated with Curtiss Aircraft. On March 21, 1937, Waterman's Arrowbile first flew. The Arrowbile was modified from Waterman's tailless aircraft, the WhatsitThe Arrowbile had a wingspan of 38 feet and a length of 20 feet 6 inches. It was powered by a Studebaker engine and could fly at 112 mph (180 km/h) and drive at 56 mph (90 km/h). Only five were built. In 2009 the U.S., the Defense Advanced Research Projects Agency (DARPA) initiated the $65 million Transformer program to develop a four-person roadable aircraft by 2015. The vehicle was to have had VTOL capability and a 280-mile (450 km) range. AAI Corporation and Lockheed Martin were awarded contracts. The program was cancelled in 2013. Small numbers of flyable cars have been built since 2010. Wikipedia has list of flying cars, which it says is incomplete. There is also https://www.hotcars.com/flying-cars-that-actually-took-to-the-sky/.

I reported on iconoclastic cosmologists pursuing a cyclical theory of the universe. I believe that the most significant is Steinhardt’s theory, proposed initially by Steinhardt and Turok in 2001. It has gone through several modifications; but its basic premises are that two parallel planes or M-branes collide periodically in a higher-dimensional space. Our visible four-dimensional universe lies on one of these branes. The collisions correspond to a reversal from contraction to expansion, or a Big Crunch followed by a Big Bang. The matter and radiation we see today were generated during the most recent collision in a pattern dictated by quantum fluctuations created before the branes. After billions of years the universe reached the state we observe today; after billions more years it will ultimately begin to contract again. Dark energy corresponds to a force between the branes, and serves the obviates the monopole, horizon, and flatness problems, which bedeviled earlier cyclic models of the universe. You may associate branes with string theory, where a brane is a physical object that generalizes the notion of a point particle to higher dimensions

Astrophysicist Katie Mack has written a recent book, clear and intelligible and now in paperback: The End of Everything (Astrophysically Speaking) published by Scribners and aimed at intelligent lay people. It attempts to balance out the many books on the Big Bang. “in about five billion years, the sun will swell to its red giant phase, engulf the orbit of Mercury and perhaps Venus, and leave the Earth a charred, lifeless, magma-covered rock.”

She covers five current theories. There’s the Big Crunch, when the current expansion reverses and the Universe condenses into a tiny very hot dot. The most widely accepted explanation is Heat death, when everything gets too far apart and the Universe becomes dark and desolate. The Big Rip is a model in which the matter of the universe, from stars and galaxies to atoms and subatomic particles, and even spacetime itself, is progressively torn apart by the expansion of the universe until distances between particles will become infinite. Vacuum Decay is equally counterintuitive and seems not very likely. An explosion or something dramatic is proposed to create a bubble, a true vacuum which would gobble up or erase the universe which has no areas of true vacuum (we think). Finally we get to the alternating cyclic universe theories.

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