Leap Seconds
20 Jan 2012 Leave a Comment
in Science Tags: Coordinated Universal Time, Leap second
The rotation of the earth is slowing down and so we add a second to our clocks every once in a while. The last time this happened was in 2008. Another will be added this June 30.
A leap second is time added or subtracted to the atomic clock.
A leap second is a second, as measured by an atomic clock, added to or subtracted from Coordinated Universal Time (UTC) to make it agree with astronomical time to within 0.9 second. It compensates for the slowing in the Earth’s rotation and is added during the end of June or December. It is important to look at how seconds are used in relation to modern time keeping to gain an understanding of the concept of the leap second and why it is used.
The International Earth Rotation and Reference System Service (IERS) observes the Earth’s rotation and nearly six months in advance (January and July) a “Bulletin C” message is sent out, which reports whether or not to add a leap second in the end of June and December.
IERS schedules a leap second as needed to keep the time difference between atomic clocks and Earth’s rotation to below 0.9 seconds.
Seems pretty simple. But somehow it has become controversial. According to the New York Times
Opponents of leap seconds, led by the United States, say the sporadic addition of these timekeeping hiccups is a potential nightmare for computer networks that depend on precise time to coordinate communications.
But nations like Britain that wish to keep the current system say that eliminating leap seconds might create bigger problems.
They also oppose the uncoupling of time from the notion that the length of a day is tied to the motion of Earth and Sun. Because Earth’s rotation is gradually slowing, days are lengthening. Without leap seconds, noon on the clock would slide earlier and earlier in the morning.
This is a fight between nature and technology. The decision about adding another leap second has been put off for three years but the leap second will be still be added in June. This is how this will happen.
| UTC Date | UTC Time | Local time world-wide |
|---|---|---|
| 2012-06-30 | 23:59:57 | Corresponding times |
| 2012-06-30 | 23:59:58 | Corresponding times |
| 2012-06-30 | 23:59:59 | Corresponding times |
| 2012-06-30 | 23:59:60 | Leap second added |
| 2012-07-01 | 00:00:00 | Corresponding times |
| 2012-07-01 | 00:00:01 | Corresponding times |
| 2012-07-01 | 00:00:02 | Corresponding times |
How cats drink
15 Nov 2010 Leave a Comment
in Cats, Science Tags: Cats, Physics, Water
This was supposed to be the only post (before I heard Dave Barry, that is) for today because with four cats anything and everything about them is fascinating. We have one cat who plays with water and will drink from any place. Mr. Bunter, like a dog, has been known to try to drink out of the toilet. He also drinks out of the fish tank. He used to drag the water bowl (a large heavy bowl glued to an old dinner plate) around the pantry. Then we got a fancy waterfall drinking fountain and he tries to move that also. The other three are more normal.
But now we have the physics of how cats drink. Delicately without wetting the whiskers. I went to get my glasses adjusted today at lunch and the optician, who also has cats, asked me if I had seen the story. So cat lovers everywhere are talking about this discovery. I always assumed it had something to do with the roughness of the tongue, but that would be wrong.
Cats, both big and little, are so much classier, according to new research by Pedro M. Reis and Roman Stocker of the Massachusetts Institute of Technology, joined by Sunghwan Jung of the Virginia Polytechnic Institute and Jeffrey M. Aristoff of Princeton.
Writing in the Thursday issue of Science, the four engineers report that the cat’s lapping method depends on its instinctive ability to calculate the point at which gravitational force would overcome inertia and cause the water to fall.
What happens is that the cat darts its tongue, curving the upper side downward so that the tip lightly touches the surface of the water.
The tongue is then pulled upward at high speed, drawing a column of water behind it.
Just at the moment that gravity finally overcomes the rush of the water and starts to pull the column down — snap! The cat’s jaws have closed over the jet of water and swallowed it.
The best part of the story is how they calculated the lapping speed based on cat size. Who knew? But then, who knew anything about how cats drink before this week?
Stem cell research and Muslims
26 Aug 2010 Leave a Comment
in Civil Rights, Culture, Politics, Science Tags: Dan Wasserman, Islam, stem cell research
Dan Wasserman combines two leading stories of the week into one cartoon.
Need one say more?
Contemplating trees and allergy season
12 Apr 2010 Leave a Comment
in Science Tags: Allergies, Olivia Judson, Trees
I have a terrible tree pollen allergy so I was amused to see that Olivia Judson picked the tree for her Life-form of the month for April.
Trees figure in our mythologies and metaphors — the tree of life, the tree of knowledge — and we often imagine them to harbor spirits and sprites. They also figure in a big way in our reality: forests (still) cover about 30 percent of the planet’s land, and may make up as much as 80 percent of Earth’s biomass. That is, if you were to put all the organisms on the planet on a giant set of scales, trees would account for 80 percent of the total.
Better yet, trees harbor plenty of non-imaginary beings. Birds like starlings or blue tits nest in tree holes; others, like magpies and crows, build their nests high in the branches. Chimpanzees sleep in trees. A number of fungi — truffles, anyone? — associate with tree roots. Insects like wasps make houses (galls) in the leaves. And so on.
Until last November, we had a huge Norway maple tree which covered the entire front of the house and reached to the 4th floor. Over a hundred years old, it as beginning to learn away from the house and over the street. It was also rotting from an old wound. It had to come down. I was wondering if taking it down would lessen my allergies, but so far it doesn’t seem to have made a difference.
Olivia Judson again
Yet although trees are familiar to all of us, many aspects of their biology remain enigmatic: because they grow slowly and live for so long, they’ve been hard for us to study in the laboratory. Which is why they are my nomination for Life-form of the Month: April.
…
What, then, is a tree? Precise definitions vary, but most of them mention the words “tall” and “woody,” and add that a tree has a single self-supporting stem (i.e., a trunk) that branches well above the ground.
The first trees appeared more than 375 million years ago, in several different plant lineages, in a burst of evolution that some authors have termed “the scramble for the sky.” If you’d been walking through the Earth’s early forests, you might have seen club mosses that were 40 meters (131 feet) tall, as well as giant horsetails. Both types of tree are now extinct. But what’s interesting about them is that they made wood differently from, say, pine trees. Pine trees grow outwards, forming a solid woody cylinder. In contrast, the trunks of tree-horsetails were hollow tubes, like bamboo. Tree-club mosses produced trunks with a hard outer casing, and a softer interior. Meanwhile, tree-ferns evolved a fourth type of woody structure: they grow several stems that are bound together by other tissues.
However you define a tree, they are beautiful, provide shelter, and are a renewable resource if harvested carefully. I find looking at them restful – even if they make me miserable for a couple of months a year.
Understanding Particle Physics
07 Apr 2010 2 Comments
in Science Tags: CERN, Dennis Overbye, Large Hadron Collider, Physics
The Large Haldron Collider (CERN) is now operating. The day of the first collision, Bob was wearing his CERN sweatshirt. We have a relative by marriage who retired from CERN. Dennis Overbye wrote on March 30 in the New York Times
The soundless blooming of proton explosions was accompanied by the hoots and applause of scientists crowded into control rooms at CERN, the European Organization for Nuclear Research, which built the collider. The relief spread to bleary-eyed gatherings of particle physicists around the world, who have collectively staked the future of their profession on the idea that the collider will eventually reveal new secrets of the universe.
Among their top goals are finding the identity of the dark matter that shapes the visible cosmos and the strange particle known as the Higgs boson, which is thought to imbue other particles with mass. Until now, these have been tantalizingly out of reach.
I was amused by this second article by Dennis Overbye in the New York Times last Sunday
For those whose physics knowledge was a bit rusty, the news about the Large Hadron Collider, the world’s biggest physics machine, might have been puzzling.
Yes, the collider finally crashed subatomic particles into one another last week, but why, exactly, is that important? Here is a primer on the collider – with just enough information, hopefully, to impress guests at your next cocktail party.
Let’s be basic. What does a particle physicist do?
Particle physicists have one trick that they do over and over again, which is to smash things together and watch what comes tumbling out.
Here is a particle physicist.
The collider, which is outside Geneva, is 17 miles around. Why is it so big?
Einstein taught us that energy and mass are equivalent. So, the more energy packed into a fireball, the more massive it becomes. The collider has to be big and powerful enough to pack tremendous amounts of energy into a proton.
Moreover, the faster the particles travel, the harder it is to bend their paths in a circle, so that they come back around and bang into each other. The collider is designed so that protons travel down the centers of powerful electromagnets that are the size of redwood trunks, which bend the particles’ paths into circles, creating a collision. Although the electromagnets are among the strongest ever built, they still can’t achieve a turning radius for the protons of less than 2.7 miles.
All in all, the bigger the accelerator, the bigger the crash, and the better chance of seeing what is on nature’s menu.
What are physicists hoping to see?
According to some theories, a whole list of items that haven’t been seen yet — with names like gluinos, photinos, squarks and winos — because we haven’t had enough energy to create a big enough collision.
Any one of these particles, if they exist, could constitute the clouds of dark matter, which, astronomers tell us, produce the gravity that holds galaxies and other cosmic structures together.
Another missing link of physics is a particle known as the Higgs boson, after Peter Higgs of the University of Edinburgh, which imbues other particles with mass by creating a cosmic molasses that sticks to them and bulks them up as they travel along, not unlike the way an entourage forms around a rock star when they walk into a club.
Will physicists see these gluinos, photinos, squarks and winos?
There is no guarantee that any will be discovered, which is what makes science fun, as well as nerve-racking.
When protons collide, is there a big bang?
There is no sound. It’s not like a bomb exploding.
I’m excited by what we might discover, but I don’t think the pictures will be anything like what the Hubble telescope has sent back.
The Woman Who Named Pluto
10 May 2009 2 Comments
in Culture, Science Tags: Planets, Pluto, Venetia Phair
The English woman who in 1930 suggested the newly discovered planet be named Pluto died on April 30. [Regardless of what it is considered now, I still think of Pluto as a planet. ] The eleven year old Venetia Phair suggested the name to her grandfather at the breakfast table.
“My grandfather, as usual, opened the paper, The Times, and in it he read that a new planet had been discovered,” she recalled in a short film, “Naming Pluto,” released earlier this year. “He wondered what it should be called. We all wondered.
“And then I said, ‘Why not call it Pluto?’ And the whole thing stemmed from that.”
Her grandfather told a friend who told the discoverer, Clyde W. Tombaugh.
When the name was publicly announced on May 1, 1930, Mrs. Phair said her grandfather rewarded her with a five-pound note. (The same purchasing power today would be about 230 pounds, or $350.)
According to the London Telegraph, Ms. Phair is the only woman to have named a planet. The photograph of Ms. Phair at 11 is from the Telegraph obituary.
She was fascinated with astronomy, and recalled playing a game at school using clay lumps to mark out the relative positions of the planets.
She was also a keen student of mythology, and knew about Pluto, the Roman name for the Greek god of the underworld, Hades.
“There were practically no names left from classical mythology,” she told the BBC. “Whether I thought about the dark and gloomy Hades, I’m not sure.”
She tartly rejected any suggestion that the planet was named for the Disney dog, instead of the other way around.
…
She studied mathematics at Cambridge University and taught economics and math until retiring in the 1980s.
Coming full circle in a way, my husband read me her obituary from the Boston Globe this morning at breakfast – the print edition, of course.
Wash your hands
29 Apr 2009 Leave a Comment
in Culture, Science, Uncategorized Tags: Allison Aubrey, Hand Washing, NPR, Swine Flu
The CDC says the best way to prevent swine flu is to wash your hands. Here is a great story from NPR on washing effectively.
Grandma was right: If you want to prevent the spread of viruses, wash your hands.
But how long do we need to scrub? Preschoolers know the answer, and they sing a silly song or two to help them while away the 20 seconds that experts recommend.
Turns out that the “ABC” song is about right. So pre-schoolers can practice hand washing and the alphabet at the same time. But, as one of my co-workers said today, he’d get hauled away singing the alphabet song in the men’s room. Allison Aubrey at NPR has a solution.
NPR’s reporters were quick to offer their suggestions: The chorus of Neil Diamond’s “Sweet Caroline” is about the right length. Maybe the guitar riff from “Layla” by Eric Clapton, or how about that famous bridge in Queen’s “Bohemian Rhapsody” about how “we will not let you go”?
For those more inclined to the theater, the first six lines of Lady MacBeth’s “Out, Damned Spot, Out” soliloquy clocks in at 22 seconds.
Also mentioned was “My Country ‘Tis of Thee” which is my choice only because I know all the words. What ever you pick be sure to actually scrub and get the nails, the backs of your hands and between your fingers while you sing.
Two Birthdays
13 Feb 2009 Leave a Comment
in Civil Rights, Politics, Science Tags: Darwin, Eric Foner, Lincoln, Olivia Judson
Two hundred years ago on February 12, two extraordinary men were born. One on the American frontier and the other in England. Besides their day of birth, what do Abraham Lincoln and Charles Darwin have in common? Quite a bit it seems.
Both men were family men who loved and cared for their childen. Olivia Judson writes about Darwin
At the same time, he was a humane, gentle, decent man, a loving husband and father, and a loyal friend. Judging by his letters, he was also sometimes quite funny. He was, in other words, one of those rare beings, as likeable as he was impressive.
For example, after his marriage, Darwin worked at home, and his children (of the 10 he fathered, seven survived to adulthood) remembered playing in his study. Later, one of his sons recounted how, after an argument, his father came up to his room, sat on his bed, and apologized for losing his temper. And although often painted as a recluse, Darwin served as a local magistrate, meting out justice in his dining room.
Darwin is best known for the theory of evolution while Lincoln is known for his own political evolution. Again, Judson on Darwin
The “Origin,” of course, is what he is best known for. This volume, colossal in scope yet minutely detailed, laid the foundations of modern biology. Here, Darwin presented extensive and compelling evidence that all living beings — including humans — have evolved from a common ancestor, and that natural selection is the chief force driving evolutionary change.
Eric Foner writes this about Lincoln in The Nation
Until well into the Civil War, Lincoln was not an advocate of immediate abolition. But he was well aware of the abolitionists’ significance in creating public sentiment hostile to slavery. Every schoolboy, Lincoln noted in 1858, recognized the names of William Wilberforce and Granville Sharpe, leaders of the earlier struggle to outlaw the Atlantic slave trade, “but who can now name a single man who labored to retard it?” On issue after issue–abolition in the nation’s capital, wartime emancipation, enlisting black soldiers, amending the Constitution to abolish slavery, allowing some blacks to vote–Lincoln came to occupy positions the abolitionists had first staked out. The destruction of slavery during the war offers an example, as relevant today as in Lincoln’s time, of how the combination of an engaged social movement and an enlightened leader can produce progressive social change.
Finally, both Darwin and Lincoln opposed slavery. First, Judson on Darwin
Moreover, while many of his contemporaries approved of slavery, Darwin did not. He came from a family of ardent abolitionists, and he was revolted by what he saw in slave countries: “Near Rio de Janeiro I lived opposite to an old lady, who kept screws to crush the fingers of her female slaves. I have stayed in a house where a young household mulatto, daily and hourly, was reviled, beaten and persecuted enough to break the spirit of the lowest animal …. It makes one’s blood boil, yet heart tremble, to think that we Englishmen and our American descendants, with their boastful cry of liberty, have been and are so guilty.”
And Lincoln, while not initally supporting immediate abolition did oppose slavery
“I have always hated slavery,” Lincoln once declared, “I think as much as any abolitionist.” He spoke of slavery as a “monstrous injustice,” a cancer that threatened the lifeblood of the American nation.
So let’s wish them both a very happy birthday!
Issac Newton and Sandy Koufax
31 Dec 2008 1 Comment
in Science, Sports Tags: baseball, Issac Newton, Sandy Koufax, Science
Sir Issac Newton was born on Christmas Day 1642 according to the Julian Calendar. Or January 4, 1643 if you use the Gregorian one that we use today. Olivia Judson proposes to resolve this difficulty by celebrating for 10 days – the Ten Days of Newton or the Newton Birthday Festival. She has even written the words to a song celebrating his life and achievements. The tune is, of course, the Twelve Days of Christmas.
On the tenth day of Newton,
My true love gave to me,
Ten drops of genius,
Nine silver co-oins,
Eight circling planets,
Seven shades of li-ight,
Six counterfeiters,
Cal-Cu-Lus!
Four telescopes,
Three Laws of Motion,
Two awful feuds,
And the discovery of gravity!
Sandy Koufax was born on December 30, 1935, He was my first sports hero. I began following him when the Dodgers were in Brooklyn and continued after the move to LA. I had an old console radio on which I could, at night, get AM stations from New Jersey (where I grew up) to St. Louis and New Orleans. So in the summertime, I could get the Dodgers playing most of the National League. Looking back, I think I admired him because he seems to have a life outside of baseball and to be secure in his own person – not that I could have articulated that as a teenagers.
Koufax was a great pitcher and I’m sure many batters thought he defied the Newtonion Laws of Motion. It is only right that his birthday comes in the middle of the Newton Festival.
