Photograph by Lesley Smith.

Rainbow Photograph by Lesley Smith, used with permission.

Lesley Smith posted this picture on Facebook. I had never seen a rainbow in which the colors were so bright and, in particular, well differentiated. In most rainbows, the colors sort of blur into one another. I suspected that the colors were so sharp because the raindrops were comparatively large; exceptionally large droplets would give rise to minimal diffraction and thus blur the colors less than in more prosaic rainbows. Small droplets give rise to a large diffraction angle and can blur the colors to the point where the rainbow appears white (alas, I have never seen a white rainbow, but I have read about them). The sky was also very clear, so there was minimal scattering by particulates in the air.

I took to the Web, and NCAR came to the rescue. Buried, I am afraid, under a heading about supernumerary arcs, they note, without explanation,

The "purity" of the colors of the rainbow depends on the size of the raindrops. Large drops (diameters of a few millimeters) give bright rainbows with well defined colors; small droplets (diameters of about 0.01 mm) produce rainbows of overlapping colors that appear nearly white.

This photograph also shows, incidentally, that the sky is very much brighter inside the arc than outside, because the sky outside the arc lies beyond the critical angle.

Earth is young, but not flat

Book cover
Book cover.

The ad for the book, Falling Flat, A Refutation of Flat Earth Claims, by Danny Faulkner, says somewhat breathlessly,

There are people in the world today who believe the world is flat. And they are working very hard to convince everyone else that it’s flat – even if it means distorting the truth to do it. Read this book and get the facts regarding the flat earth fallacy.

I have not read the book, but I have read the article, “Reflections on the flat-earth movement,” by the same author, and I can tell you with a fair degree of certainty, just replace “flat” with “young” wherever you see it, and you will get a pretty good refutation of the young-earth movement. If you do not believe me, try it with the quotation:

There are people in the world today who believe the world is flat young. And they are working very hard to convince everyone else that it’s flat young – even if it means distorting the truth to do it. Read this book and get the facts regarding the flat young earth fallacy.

If you have $15 to burn, you may preorder the book here, but frankly I would rather you gave your money to the National Center for Science Education.

Ken Ham attacks new USPS dinosaur stamps

A screenshot of a tweet by Ken Ham

We received an e-mail from Dan Phelps today, regarding what he calls “The latest inanity from Ken Ham.” We had to look carefully to realize that the word was “inanity.” Here is Mr. Phelps’s e-mail, lightly edited for HTML. The photographs may be found in Wikipedia. We could not track down their origins, so we assume they are subject to the same copyright as Wikipedia, specifically, CC BY-SA. — Matt Young

Herewith, Mr. Phelps’s e-mail:

The evidence for feathers in Tyrannosaurus rex is weak, but there is abundant evidence for feathers in its relatives and ancestors.

For some of the evidence for feathers in Tyrannosaurus relatives, see: T. rex like you haven’t seen him: with feathers, Basal tyrannosauroids from China and evidence for protofeathers in tyrannosauroids (abstract only), and A gigantic feathered dinosaur from the Lower Cretaceous of China (abstract only).

Finally, Mr. Phelps provided these photographs, taken from Wikipedia, in which you can see evidence of feathers:

Hughes Mountain Columns


Photograph by James Kocher.

Photography contest, Honorable Mention.

Hughes Mountain columns
Hughes Mountain Natural Area, Irondale, Missouri.

Mr. Kocher writes: “This mountain is composed of columnar-jointed rhyolitic ash-flow tuff-ignimbrite. The single column in the foreground is broken, and shows a plane of deposition with several crushed/flattened pumice fragments. These fragments are the lighter-colored blotches in the darker ash matrix. Age = ~1.4 Ga; Neoproterozoic. U.S. quarter for scale.”

Grant County loses again


Head writers have to save space. In plain English, this headline from the Grant County News says, “The Grant County Board of Education is appealing the assessed valuation of the Ark Park by the County’s Property Value Administration,” which I take to be the assessor’s office. According to the article, which was not on the Web when we received it from Dan Phelps, the Board of Education had appealed the PVA’s valuation, lost, and is now suing.

The Board of Education claims that the 2017 assessed value of the property was $46 million, but they estimated that the fair value of the “Ark” is more like $130 million. According to the article, they note that the capital investment in the “Ark” was $90 million, and they estimate the gross income for 2017 to have been $30-$40 million. They further estimate that the value of the land was $10 million, so the total assessment, they claim, should have been $130 million. As a result of the undervaluation, the school board alleges a loss of approximately $470,000 in property tax revenue.

Thus does the “Ark” benefit Grant County.

The Kentucky Claims Commission Tax Appeals (is a preposition or something missing?) ruled that the Board of Education is not a taxpayer and so cannot challenge the assessment. The Board of Education then filed suit. You might want to make book on the likelihood that the court will deny them standing, but as a nonlawyer I would not take that bet.

Acknowledgment. Thanks once again to Dan Phelps for the tip and the photographs of the article.