Cluster Map

Saturday, October 1, 2011

Pollyanna says Shana Tova and Best Wishes


 took Rosh Hashana off and is thus a day late. 

She wishes all a Shana Tova and a G'mar Chatima Tova that is roughly translatable as "may you be inscribed for good in the Book of Life."  Pollyanna is not extremely religious, but we did go to synagogue these last few days and will go on Yom Kippur that is coming up in a week.  It does no harm to take a moment and think about our lives, our actions and as The Hitchhiker's Guide to the Galaxy put it, Life, the Universe and Everything.   If religion helps people be better and more moral, enhances social justice and contributes to peace and well being, we are all for it.  Alas, historically, it has often done the opposite.  We refer you to some insight on the God/god question from  Wes Nisker in the Huffington Post.  It smacks of satire, but there is some substance as well.
This week we look at Tethys, the satellite of Saturn, and its coorbitals Telesto and Calypso.
Meet Tethys battered and bruised, credit Cassini Imaging Team
 Like Mimas, Tethys has an enormous impact crater on one side, named Odysseus. But Odysseus is a very different crater from Herschel (the big crater on Mimas). While Herschel has very steep scarps, the floor of Odysseus is quite smooth in its topographic profile; the surface of Tethys has "relaxed" so that the crater floor follows the shape of the moon. All of the features on Tethys draw their names from Homer's Odyssey. Curling across Tethys' surface is a gigantic canyon system called Ithaca Chasma. Views of Ithaca Chasma during a close flyby by Cassini show that it has been battered with impact craters, indicating that it is extremely old.
Size: 1,072 x 1,056 x 1,052 kilometers - 5th largest moon of Saturn
Orbital radius: 294,660 kilometers - 4.88 Saturn radii
Orbital period: 1.888 days - about 1/8 of Titan’s
Discovery: 1684 by Giovanni Domenico Cassini
It shares its orbit with Telesto which is a tiny moon that orbits in Tethys' leading  Lagrange point  (L4). That is, Telesto orbits Saturn on the same circular path that Tethys does, but ahead of Tethys, and the centers of   Tethys, Saturn, and Telesto form an equilateral triangle.    
Saturn's moon Telesto
This raw image was captured by Cassini during its closest planned encounter with Telesto, on October 11, 2005. Credit: NASA / JPL / Space Science Institute

Size: Irregular, 34 x 28 x 36 kilometers
Orbital radius: 294,660 kilometers - 4.89 Saturn radii - within the E ring - at Tethys’ leading Lagrange point (L4) - co-orbital with Tethys and Calypso
Orbital period: 1.8878 days - about 1/8 of Titan’s
Discovery: 1980 by Brad Smith, Harold Reitsema, Stephen Larson, John Fountain                                           

Tethys also has a follower, Calypso a tiny moon that orbits in Tethys' trailing Lagrange point (L5). That is, Calypso orbits Saturn on the same circular path that Tethys does, but behind Tethys, and the centers of Tethys, Saturn, and Calypso form an equilateral triangle.  
Size: Irregular, 34 x 22 x 22 kilometers 
Orbital radius: 294,660 kilometers - 4.89 Saturn radii - within the E ring - at Tethys’ leading Lagrange point (L4) - co-orbital with Tethys and Telesto 
Orbital period: 1.8878 days - about 1/8 of Titan’s 
Discovery: 1980 by Dan Pascu, P. Seidelmann, William Baum, D. Currie
Saturn's moon Calypso
This is the best view that Cassini will likely ever produce of Calypso. It was captured on September 23, 2005 from a distance of 101,000 kilometers. It is shown here magnified by a factor of three. Source: NASA / JPL / Space Science Institute
In mythology TETHYS was the Titan goddess of the sources of  fresh water which nourished the earth. She was the wife of Okeanos, the earth-encircling, fresh-water stream, and the mother of the Potamoi (Rivers), Okeanides (Springs, Streams and  Fountains) and Nephelai (Clouds). Tethys was imagined feeding her children's streams by drawing water from Okeanos through subterranean aquifers. Her name was derived from the Greek word têthê, "the nurse" or "grandmother."  TELESTO was one of the daughters of Oceanus and Tethys  while CALYPSO was a nymph, who lived on the island of Ogygia, where she detained Odysseus for a number of years.   She is generally said to be the daughter of the Titan Atlas.                            
Usually Pollyanna does not get into politics etc. which she leaves to her ranting brother Titan.  She does, however, have strong feelings about ecological issues and would like to ask you to help stop the paving of a highway in the Amazon regions of Bolivia.  Avaaz asks you to sign the petition and Pollyanna supports it.

WOMEN'S RIGHTS She goes orbital about abuse of women, such as seen in  Saudi Arabia that has long been a country about which she has never been glad.  It is therefore good news that women there have been given the right to vote for the first time in history.   It would be even nicer if they could drive to the polls.                                                                                                                  
Pollyanna is very glad about advances in the early detection and treatment of cervical cancer that are saving lives, especially in Thailand.   Thanks to Yosefa for pointing this story out to us.  This killer disease can be fought if efforts are made.

Anuree Talasart, a nurse provider in Roi Et Province, Thailand, teaches a group of women about the female reproductive system. Credit New York Times
Pollyanna also says cheers for the people at the Hebrew University, Jerusalem who have come up with a cheap and effective way of fighting deadly mosquitoes by means of poison nectars that can be placed as bait and serve to eliminate them. This is a major contribution to the fight against malaria.
“You can’t move flowering trees around,” said Yosef Schlein, a parasitologist at the university’s medical school. “So you have to use movable bait. That’s how we came up with fruit juice.”  Supported by a grant from the Bill and Melinda Gates Foundation, Dr. Schlein and his research partner Günter C. Müller concocted an array of nectar poisons known as Attractive Toxic Sugar Baits that are easy to make, environmentally friendly and inexpensive.
MALARIA VECTOR Anopheles sergenti sips the nectar of the Nile tamarisk. Credit Josef Shlein
Pollyanna was quite concerned about the report of neutrinos making the trip from CERN to the OPERA detector in the Gran Sasso Laboratory faster than light. The group reports that the travel time of the ultrarelativistic neutrinos is about 60 ns less than expected as described last week by Titan.. 
We are grateful to Bob Park in his What's New blog for pointing us at the paper by  Cohen and Glashow that shows that the neutrinos could not have done what was attributed to them because of Cherenkov energy loss via electron-positron pair production.  Physics can relax and go on.

We think it is cool that very ancient  feathers have been found from 79 million years ago that offer an unusually wide-ranging view of what late dinosaurs and early birds were wearing.
A cluster of small barbs (shown), which once branched off a main feather upright, show remains of pigment but not interlocking hooks. The barbs might have come from the ends of the outermost layer of body feathers. Science/AAAS
Here are a few goodies from  Science News magazine.  I recommend subscribing to it.  You get the latest gossip of what is going on in science around the world, especially from fields outside your own.   You  will probably find this article interesting as well.

This weeks book review is of Pathfinders: The Golden Age of Arabic Science by Jim al-Khalili reviewed  in the Guardian by Tim Bradford..
llustration by Clifford Harper/
 It deals with a period of total intellectual darkness in Europe.  During these times the  Muslim world had discovered the works of the Greeks and Byzantines and was busy expanding upon them.  Of course, Jews and Christians in these countries participated, vid. Maimonides and many others.  If the subject interests you, you can sign up for a Webinar involving the author.  Registration is required.From the blurb of the Webinar.

We learn at school that Newton is the father of modern optics, Copernicus heralded the birth of astronomy, and Snell deduced the law of refraction. But what debt do these men owe to the physicists and astronomers of the medieval Islamic Empire? What about Ibn al-Haytham, the greatest physicist in the 2000-year span between Archimedes and Newton, whose Book of Optics was just as influential as Newton’s seven centuries later? Or Ibn Sahl, who came up with the correct law of refraction many centuries before Snell? What of the astronomers al-Tusi and Ibn al-Shatir, without whom Copernicus would not have been able to formulate his heliocentric model of the solar system? In this lecture, Jim Al-Khalili recounts the stories of these characters and more from his new book Pathfinders: The Golden Age of Arabic Science.

From the review we have a quote from an 11th century Persian polymath  Al-Biruni, who measured the height of a mountain and the angle of dip of the horizon to calculate the circumference of the planet  to within an accuracy of 1%.   He warned that the extremist "would stamp the sciences as atheistic and would proclaim that they led people astray, in order to make ignoramuses of them, and to hate the sciences. For this will help him conceal his own ignorance, and to open the door to the complete destruction of the sciences and the scientists." He might have been talking about the mullahs of modern Tehran, or the ranters of the US religious right.

Since Titan, Pollyanna and I belong to the rocket science community, we keep a close watch on what our competitors the brain surgeons are up to.  Before giving you the Andy Borowitz take on this, let us tell you a true story from San Francisco passed on to us by Ray Goldstein and his spouse Jane. They were on their way to have dinner with us in SFO but were held up by a police cordon protecting the King of Jordan.  While waiting, they got into a conversation with a policeman who, when hearing that they were in town for the American Geophysical Union meeting, told them the following tale:  In the pre-computer era when they would scoop up the comatose drunks off the street, they had to fill out a form which included the occupation of the scoopee.  Since these characters were beyond speech and the police were required to complete the booking form, they would write in either rocket scientist or brain surgeon.   With that in mind, we pass on to you the latest communique.                                                               

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