by Kim Malville
April 1: Venus dominates the western sky in the evening throughout the month. Perhaps you have been watching Jupiter and Venus, which have been flirting with each other during March. Jupiter will be dropping closer to the horizon and become hard to see at the end of April.
April 2-3: Venus passes through the Pleiades. Binoculars will enhance the view. The moon passes Regulus, the brightest star of Leo, and then grazes ruddy Mars.
April 6: The moon passes Spica, the brightest star of Virgo. Just to the left of Spica you can spot Saturn.
April 10: Sinking of the Titanic 100 years ago.
April 15: Saturn reaches opposition with the sun, rising at sunset and setting at sunrise. You can breathe easier: Mars stops its retrograde motion and starts moving eastward away from Regulus.
April 21-22: Lyrid meteor shower. It’s going to be modest this year, with a dozen meteors per hour before sunrise. It you are out and about before sunrise, the meteors should be coming out of the constellation of Lyra, near its bright star, Vega.
April 24: Venus will be glowing to the upper right of the slender crescent moon. It should be a great sight
Next month’s solar eclipse
Get ready for Sunday afternoon May 20, at which time we will have a partial solar eclipse, one of the best in decades for us living in the Southwest. The eclipse will be annular, which means the moon will be too far away from the earth and therefore too small to cover the sun entirely. This will be the first annular eclipse in the US in 18 years. The path of the eclipse will be some 300 km wide and thousands of km long, starting in China and ending in Lubbock, Texas. In Arizona and New Mexico, the center line passes from Canyon De Chelly, Chinle, Farmington, and Albuquerque. One of the very best places to observe it is Chaco Canyon, where the park rangers are planning a special eclipse party. If you ever were planning a visit to Chaco Canyon, this would be a splendid opportunity.
Einstein’s theory survives another test
“I suspect. . . that both Einstein’s theory and my boxer shorts are safe.” —Physicist Jim Al-Khalili at the University of Surry who had promised to eat his boxer shorts on TV if neutrinos were confirmed to travel faster than light.
A second team of Italian physicists announced last month they had measured the speed of neutrinos and found no evidence that they travelled faster than light, preserving the status of the Special Theory of Relativity as one of our most remarkable successful ideas of the 20th century. The team, called Icarus, led by the Nobel Prize-winning physicist Carlo Rubbia, measured the speed of neutrinos fired from CERN, the European Organization for Nuclear Research, in Switzerland, to a detector 453 miles away in Italy. “The results are very convincing,” Mr. Rubbia said, “and they tell us essentially that there was something not quite right with the results of Opera.” Opera was the team that reported in September that its tests appeared to show neutrinos speeding faster than light, prompting widespread disbelief among scientists, as well as loud guffaws from science deniers, who relished the idea that if Einstein is wrong, then all those who scientists who predict climate change must also be wrong.
Einstein’s Special Theory of Relativity, a pillar of modern physics, predicts that nothing in our universe can be measured to travel faster than the speed of light in a vacuum, 186,282 miles per second. Doubts about the earlier Opera results were heightened last month when researchers reported that they had found a loose plug, which might have distorted the experiment’s results. Antonio Ereditato, a member of the Opera team, said he welcomed the latest results. “These results are in line with our recent findings about the possible malfunctioning of some of the components of our experimental setup,” he said. Asked whether he was disappointed, he said: “This is the way science goes. What matters is the global progress of scientific knowledge.”
“Oh, they built the ship Titanic to sail the ocean blue/and they thought they had a ship that the water would never get through./But God’s almighty hand knew the ship would never land, /It was sad when that great ship went down…”
One hundred years ago on April 10 at 11:40pm the Titanic struck an iceberg and in less than 3 hours the great ship had gone down to the bottom of the sea, carrying with it some 1500 passengers. Recent analysis of extremely high tides that occurred in the preceding three months suggests that they may have been responsible for bringing an unusually large number of ice bergs into the shipping lanes of the North Atlantic in the spring of 1912.
These high tides were the result of a combination of a spring tide and a so-called Perigean tide. The moon distorts the earth’s oceans into a bean, with high tides both underneath the moon and on the opposite side of the earth. When we have a new or full moon the sun and the earth are in a line, and the combined influence causes the highest high tides, known as spring tides. In addition, if the moon is closest to the earth in its elliptical orbit (at its perigee) the tide-raising forces will be even greater. Such a rare condition occurred on December 6, 1911, January 4, 1912, and February 2, 1912. On January 4 when the moon was 221,441 miles from the earth, the combined tide raising force due to the sun and moon was 74% greater than normal. The last time the moon had been closer to the earth was the year AD 796. The Titanic iceberg may have broken off the Jakobsavn Glacier of Greenland a year earlier and slowly worked its way southward along the coasts of Labrador and Newfoundland. Many of the ice bergs that follow this path run aground in the shallow waters of coves and eventually melt their lives away. The extreme high tides preceding the sinking of the Titanic may have refloated many of those grounded bergs and allowed them to travel into the shipping lanes of 1912.