From: Kathleen M. Wong, California Academy of Sciences
Published January 17, 2005 12:00 AM

The Sound of the Big Bang, and Other Stories

The Sound Of The Big Bang


After analyzing the locations of thousands of modern galaxies, astronomers say they've found strong evidence of the sound waves that crashed through the universe during the Big Bang. Two teams of researchers have found that most galaxies in the modern universe tend to be separated by a distance of about 500 million light-years. The remarkable regularity of this pattern hearkens back to when matter and energy first began to cluster together from the uniform fabric leftover from the Big Bang. Ripples in the Big Bang's sound waves created areas where matter was slightly denser than in other areas. The stronger pull of gravity around these ripples drew ever more matter and energy toward them, and over the next 13.7 billion years, formed into galaxies. As scientists examine the spacing of ripples farther away in space, which therefore formed even earlier in time, they should be able to determine whether the universe has expanded steadily or in several spurts. Because the universe's expansions are thought to be powered by dark energy, this work could help scientists characterize this mysterious force. The findings were announced at a meeting of the American Astronomical Society in San Diego.


Temples Confirm Hawaiian Histories


New dates from ancient Hawaiian temples suggest a building boom hit the islands more than 400 years ago. Traditional Hawaiian genealogies claimed that two warring chiefdoms on the island of Maui were joined by the ruler Pi'ilani around 1600 A.D. Seeking to verify the dates of those histories, Patrick Kirch and Warren Sharp of the University of California, Berkeley, employed new methods to date the island's many ancient temples. The temples were built with live corals plucked fresh from the sea. By measuring the amount of thorium-230 isotope in the tips of those corals, the researchers were able to determine when they died--and thus pinpoint the dates of temple construction. The researchers report in the journal Science that most of the temples went up between 1608 and 1638 A.D. Their discovery shows a powerful religious state emerged on Maui within just 30 years and at the same time helps confirm the accuracy of Hawaiian oral histories..


Spiders Seek Balanced Diets


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Spiders are surprisingly picky eaters. Instead of devouring any food they can catch, these tiny predators choose diets that round out their nutritional intake. David Mayntz of the University of Oxford, United Kingdom, and colleagues studied food cravings of spiders and a predatory ground beetle. Each carnivore received either a fatty or high-protein diet--fruit flies fed on either carbohydrate or protein. When finally given a choice of prey, beetles on the high-carb diet opted for high-protein flies, and vice versa. Wolf spiders with given food options tasted each fly and ate more of the prey that would bring balance to their diet. Web spiders received one fat-rich and one protein-rich fly in succession. Those on a high-fat diet were able to use their digestive enzymes to extract more of the protein from each fly, while those on high-protein diets sucked out more fats from their meals. The findings reported in the journal Science.


Sleuthing Uncovers Historic Ant Plague Culprit


Nearly 500 years ago, a scourge of ants descended on the island of Hispaniola. Spanish colonists recorded how in 1518, ants with a painful sting suddenly decimated entire plantations of sugar cane and other crops. Now ant expert E.O. Wilson of Harvard University reports in the journal Nature that he's solved this ecological mystery. He found that native tropical fire ants (Solenopsis geminata) were species whose characteristics best matched historical accounts. These ants both deliver stinging bites that bother humans and live among plant roots. However, fire ants don't eat plants. Instead, they tend to lick up the sugar and protein-rich liquid secreted by sap-sucking creatures such as scale insects and mealybugs. In return, the ants protect the sap-suckers from would-be predators. Putting two and two together, Wilson suspected the invasion was the result of a team effort. Searching shipping records, he found that plantains from the Canary Islands first arrived on Hispaniola in 1516. The plantains may have harbored sap-sucking insects that escaped into the countryside. With the fire ants protecting their numbers, populations of the sapsuckers could have exploded and ultimately caused the destruction of the island's crops.


Swordfish Heat Their Eyes To Hunt


Swordfish stay in tip top hunting form by heating their eyes and brain, according to new research. Kerstin Fritsches of the University of Queensland, Australia, and colleagues have demonstrated in the journal Nature that toasty retinas give swordfish a keen edge over their cold-blooded prey. Scientists have known for some time that one of the muscles typically used to move the eye has been converted by swordfish into a heat generating organ. To investigate the purpose of this strange mechanism, the researchers dissected the retinas of freshly caught swordfish and connected them to electrodes. They then measured the electrical responses of the retinas to flashes of light. The scientists found that retinas warmed to about 20 degrees Celsius, normal in living swordfish, were able to distinguish between light flashing at ten times the speed recognized by eyes kept at ocean water temperatures. Faster visual processing rates would help swordfish spot speedy prey such as squid in dim ocean waters.


Salt No Barrier To Hardy Microbes


Proving that microbes can survive just about anywhere, scientists have discovered bacteria that live in brine twice as salty as soy sauce. These pockets of salt water exist up to 500 meters down in the Mediterranean Sea. Called salt basins, they are leftovers from 6 million years ago, when the Mediterranean dried up and left mineral deposits behind. Sediments covered the salt before the rising sea levels resubmerged them. Today, the salt basins contain a whopping 476 grams of magnesium chloride per liter of water. Paul van der Wielen of the Kiwa Water Research Institute in the Netherlands and colleagues took water from four of the Mediterranean's saltiest basins and fished for DNA in each sample. To their surprise, they discovered about 50 new species of bacteria as well as 20 known species of primitive archean microbes. The findings, reported in the journal Science, suggest those looking for life on other planets can include even salty planets in their search areas.


Related Links:


The Sound Of The Big Bang: New York Times
Temples Confirm Hawaiian Histories: Scientific American
Spiders Seek Balanced Diets: CBS News (Reuters) / National Geographic
Sleuthing Uncovers Historic Ant Plague Culprit: New York Times
Swordfish Heat Their Eyes To Hunt: New Scientist / news@nature.com
Salt No Barrier To Hardy Microbes: CNN (Reuters) / news@nature.com


Source: California Academy of Sciences


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