menno_h (2670089) writes "Archer fish are able to hit aerial preys with a powerful jet of water in a fraction of a second. Their muscles, however, are not strong enough to produce such strong jets. Researchers have filmed archer fish with a high speed camera and have found that the jets increase in power after leaving the fish. The head of the jet moves slower than the tail, which catches up with the head and enlarges it, which increases the force of the jet. This is similar to the way ink drops in drop-on-demand printers are deposited onto the paper." Link to Original Source top
menno_h (2670089) writes "Although dolphins (Tursiops truncatus) have been trained to match numbers and durations of human vocal bursts and reported to spontaneously match computer-generated whistles, spontaneous human voice mimicry has not previously been demonstrated. However, after seven years in captivity, a white whale has begun to make sounds reminiscent of the human voice. We should keep in mind that the human brain is quick to recognize words. Even partial or garbled words are identified. Reports of animal mimicry based solely on hearing vocalizations must therefore be viewed skeptically." Link to Original Source top
17th century microscope book is now freely readable
menno_h (2670089) writes "In January 1665, Samuel Pepys wrote in his diary that he stayed up till two in the morning reading a best-selling page-turner, a work that he called "the most ingenious book I read in my life." It was not a rousing history of English battles or a proto-bodice ripper. It was filled with images: of fleas, of bark, of the edges of razors.
The book was called Micrographia. It provided the reading public with its first look at the world beyond the naked eye. Its author, Robert Hooke, belonged to a brilliant circle of natural philosophers who--among many other things--were the first in England to make serious use of microscopes as scientific instruments. They were great believers in looking at the natural world for themselves rather than relying on what ancient Greek scholars had claimed. Looking under a microscope at the thousands of facets on an insect's compound eye, they saw things at the nanoscale that Aristotle could not have dreamed of. A razor's edge became a mountain range. In the chambers of a piece of bark, Hooke saw the first evidence of cells. Micrographia is is available on Google Books now." Link to Original Source top
menno_h (2670089) writes "Silvery fish such as sardines and herring don't polarize light in the way that most relective surfaces do, possibly to help them avoid predators. Previously, it was thought that the fish's skin – which contains multilayer arrangements of reflective guanine crystals – would fully polarize light, and therefore become less reflective. But University of Bristol researchers have found (paywalled) that the skin of these fish contain not one but two types of guanine crystal – each with different optical properties. By mixing these two types, the fish's skin doesn't polarize the reflected light and maintains its high reflectivity. "Many modern day optical devices such as LED lights and low loss optical fibres use these non-polarizing types of reflectors to improve efficiency. However, these man-made reflectors currently require the use of materials with specific optical properties that are not always ideal," says PhD stident Tom Jordan. The fish can help." Link to Original Source top
menno_h (2670089) writes "Scientists using the Lyman Alpha Mapping Project (LAMP) spectrometer aboard NASA's Lunar Reconnaissance Orbiter (LRO) have made the first spectroscopic observations of the noble gas helium in the tenuous atmosphere surrounding the moon." Link to Original Source