Why do hurricanes and typhoons harbor such destructive winds? Add sea spray to the list of causes.
As winds ramp up, they generate increasing amounts of spray, which can act as a lubricant and reduce the turbulence where moving air meets mountainous seas, say a research team from the University of California at Berkeley and the Russian Academy of Sciences. Spray has long been suspected as aiding and abetting the strongest storms. But scientists have focused mostly on its tendency to cool the air just above the sea surface. The cool layer smooths the path for winds at higher levels, compared with the rougher surface presented by the waves themselves.
Using a model simulating the action of winds, waves, and droplets without this cooling effect, the team found that collectively, the droplets form a third fluid in the system, in addition to the air and sea, across which the winds can flow. This lubricating influence alone is significant, the team says.
Noting that ancient mariners poured oil around their ships to blunt the effects of passing squalls, the team hints that the work could help build a case for dumping spray-retarding chemicals in the path of hurricanes to weaken the winds.
For the first time, researchers have detected subatomic particles that open a window on the furnace at Earth's core. This internal heat source melts rock and drives plate tectonics.
Physicists at Japan's KamLAND neutrino detector deep beneath the Japanese Alps report the first detection of antineutrinos from Earth's core. Antineutrinos are the mirror opposite of neutrinos, subatomic particles so small and light that they rarely interact with matter. Neutrinos and their antineutrino counterparts emerge from nuclear reactions in the hearts of stars and nuclear-power plants. Scientists have long held that the core's heat comes from this decay, as well as residual heat trapped in the center since the planet's formation. By analyzing what scientists are now calling "geoneutrinos," they not only expect to get a better handle on the sources of heat, but also the types and relative abundance of the radioactive material decaying deep inside Earth. The results appear in Thursday's issue of Nature.
One can only wonder what a pair of University College of London professors did to create their new mathematical model on the cost-effectiveness of spending big money on dates.
The two wanted to know what function gifts serve and what works best. The answer: Gifts are the human equivalent of a bird flaunting its gaudiest feathers. Expensive but "worthless" gifts such as a nice dinner or theater tickets can signal interest in a long-term commitment. But gifts that have potential resale value, such as jewelry, do little to screen out gold-diggers. Big-ticket gifts with no resale value, on the other hand, send gold-diggers packing but tend to keep more-serious potential partners interested. "Our results show there is an evolutionary logic in men 'burning money' to impress the girl," says Robert Seymour, a professor in the university's math department. The results of their efforts appear in the journal Proceedings of the Royal Society B of London.