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.
A FAMILY OF MOONS
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
SAVE THE AMAZON
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|
“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|
TOO FAST NEUTRINOS
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.
OUR BOOK REVIEW
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/agraphia.co.uk|
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.
BRAIN SURGEONS VS ROCKET SCIENTISTS
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.