Stephen Moss: Islands formed from volcanic eruptions, such as the recent one off the coast of Japan, are harsh environments. But as the 50-year-old island of Surtsey near Iceland shows, nature will take hold anywhere
Scientists in Japan use ancient trees to look back on the history of our local cosmos, and discover a mystery.
Since the invention of the telescope in the year 1608, mankind has collected information about our local cosmos. As it turns out, we’re not the only ones. Trees have been doing the same for millennia.
A group of physicists led by Nagoya University graduate student Fusa Miyake has begun using information stored in ancient Japanese cedars to gain the oldest firsthand accounts of the local universe. They have discovered, hidden within tree rings, clear evidence of some surprisingly high-energy events—possibly supernovae or solar flares—that occurred more than 1200 years ago.
On Japan’s Yakushima island, trees regularly live at least a thousand years, thriving under the tree equivalent of a low-carb diet in the form of a low-nutrition granite bedrock that encourages a slower pace of growth. Miyake and her team examined core samples from two trees on this small island. Back at Nagoya University, they studied the number and thickness of the tree’s rings not just to determine the age of the trees but also to gather information about the atmosphere they breathed.
When high-energy radiation from space enters Earth’s upper atmosphere, it interacts with naturally occurring atmospheric molecules to produce the isotope carbon-14. As trees are firmly plugged into the earth’s carbon cycle by photosynthesis, the carbon-14 ends up in each tree ring, creating an annual record etched into the flesh of the tree of the average carbon-14 level in Earth’s atmosphere.
Miyake and her colleagues had good reason to focus on the rings corresponding to 775 AD. A previous project called IntCal, which uses tree records of carbon-14 levels to calibrate carbon-14 dating, had seen a noticeable rise in carbon-14 levels toward the end of the 8th century.
The signal Miyake’s team found was far above anything seen in recent times, indicating that Earth had been bombarded by an extremely intense burst of radiation. The rings revealed that, over the course of one year, the atmospheric level of carbon-14 rose 1.2 percent: nearly 20 times the normal variation.
This massive flash of radiation could have been caused by a supernova; a gamma ray burst from a supremely rare galactic event such as a collision of two neutron stars; or a super solar flare at least 10 times the size of the largest observed flare.
Using their knowledge of earth sciences, biology and astronomy, Miyake’s team uncovered a smoking gun in a cosmological whodunit. Now all that remains is to identify who fired that gun.
Venture into the micro world of human anatomy and animals with teeth reinforced with iron, scales that reflect light and velvet 'fingers' on their skin captured by scientists from the Australian Microscopy and Microanalysis Research Facility.
A new, superconducting oxide system multiplies the electron mobility in electronic oxide transistors. Benefits include superconducting nanotransistors, self-charging electronic devices and a new type of RAM.
A quick glance at a world precipitation map shows that most tropical rain falls in the Northern Hemisphere. The Palmyra Atoll, at 6 degrees north, gets 175 inches of rain a year, while an equal distance on the opposite side of the equator gets only 45 inches.
Scientists long believed that this was a quirk of the Earth’s geometry – that the ocean basins tilting diagonally while the planet spins pushed tropical rain bands north of the equator. But a new University of Washington study shows that the pattern arises from ocean currents originating from the poles, thousands of miles away.
The findings, published Oct. 20 in Nature Geoscience, explain a fundamental feature of the planet’s climate, and show that icy waters affect seasonal rains that are crucial for growing crops in such places as Africa’s Sahel region and southern India.
Come on, admit it, you've had this question. 'Since astronomers know that the Universe is expanding, what's it expanding into? What's outside of the Universe?' Ask any astronomer and you'll get an unsatisfying answer.
Endangered North Atlantic right whales are disappearing from customary feeding grounds off the U.S. and Canadian coasts and appearing in large numbers in other locations, leaving scientists to wonder if shifts in climate may be behind the changes.
Comet ISON is just days away from its first close encounter with the sun. Hopefully, it will survive to put on a nice show during the first week of December 2013. We will be watching, and if new NASA pictures become available, we’ll post them here.
Comet ISON began its trip from the Oort cloud region of our solar system about 10,000 years ago, and it is now travelling toward the sun.
The comet will reach its closest approach to the sun on 28 November 2013, skimming just 730,000 miles above the sun’s surface. If it comes around the sun without breaking up, the comet will be visible in the Northern Hemisphere with the naked eye, and according to NASA, ISON is predicted to be a particularly bright and beautiful comet.