Applied Physics
By way of the classical photoeffect, Einstein proved in 1905 that light also has particle character. However, with extremely high light intensities, remarkable things happen in the process, say scientists of the Physikalisch-Technische Bundesanstalt (PTB) and colleagues at FLASH in Hamburg, the first free-electron laser (FEL) for soft X-rays worldwide.
The current models based on Einstein's idea are simply: A photon knocks an external electron out of an atom, provided that the photon energy is high enough. However, with wavelengths of only 13 nanometers and high radiation intensities of…
To ring traditional church bells, a team of human operators pulls ropes that spin the giant bells (some in the multiple tons) and the mechanics of the system impose strict rules on what can be played. Gone entirely is melody, replaced by the idiomatically frenetic and somewhat cacophonous sound of cascading tones played for maximum note density.
Within the two seconds it takes a bell to rotate, the tones are slightly offset so that each rings before any bell sounds twice.
So instead of playing melodies, church bells are rung in rows—patterns that describe the order of bells. The pattern of…
Scientists at Cambridge University have discovered that freshwater algae can form stable groupings in which they dance around each other, miraculously held together only by the fluid flows they create. Their research was published today in Physical Review Letters.
The researchers studied the multicellular organism Volvox carteri, which consists of approximately 1,000 cells arranged on the surface of a spherical matrix about half a millimetre in diameter. Each of the surface cells has two hair-like appendages known as flagella, whose beating propels the colony through the fluid and…
The ferroelectric materials found in today's "smart cards" used in subway, ATM and fuel cards soon may eliminate the time-consuming booting and rebooting of computer operating systems by providing an "instant-on" capability as well as preventing losses from power outages.
Researchers supported by a National Science Foundation (NSF) nanoscale interdisciplinary research team award and three Materials Research Science and Engineering Centers at Cornell University, Penn State University and Northwestern University recently added ferroelectric capability to material used in common computer…
Our modern age has become accustomed to regular improvements in information technology, says Slava Rotkin, but these advances do not come without a cost. Take the laptop, for example. Its components, especially its billions of semiconductor electronic circuits, are growing ever tinier while the instrument's power and capacity increase. But heat generated by electric current can cause the circuits to melt and the laptop hardware to fail.
Indeed, says Rotkin, an assistant professor of physics, a laptop in use can generate heat faster than an everyday hotplate and almost as fast as a small…
Researchers at the University of Arkansas have shown that changing the chirality, or direction of spin, of a nanoscale magnetic vortex creates an electric pulse, suggesting that such a pulse might be of use in creating computer memory and writing information.
Physicists Sergey Prosandeev and Laurent Bellaiche reported their findings in Physical Review Letters.
“This is new physics,” Prosandeev said. “There are many possibilities that can follow from this.”
The researchers looked at ferromagnets, a class of materials with novel properties at the nanoscale that have the potential to…
The National Physical Laboratory (NPL) has developed the first sensor capable of measuring localized ultrasonic cavitation – the implosion of bubbles in a liquid when a high frequency sound wave is applied. The sensor will help hospitals ensure that their instruments are properly disinfected before they are used on patients. The device recently won the annual Outstanding Ultrasonics Product award from the Ultrasonic Industry Association. Cavitation is used throughout the NHS by doctors and dentists to clean and disinfect surgical instruments. A high frequency sound wave is passed through a…
Combine an elementary physics formula, f=m*a, with a hunk of wood or composite material and you get hockey's most powerful shot - the slapshot.
Every year before the NHL All-Star game, players compete for the title of fastest slapshot in the league. This year's winner: Boston Bruins' mammoth defenseman, Zdeno Chara, with a 105.4 mph shot, a skills competition all-time record. (However, hockey great Bobby Hull's slapshot was once recorded at 118.3 mph - and Hull is almost a foot shorter than Chara.)
The power of the slapshot comes from the weight transfer from the back legs through his…
Some of the brightest colors in nature are created by tiny nanostructures with a structure similar to beer foam or a sponge, according to Yale University researchers. Most colors in nature—from the color of our skin to the green of trees—are produced by pigments. But the bright blue feathers found in many birds, such as Bluebirds and Blue Jays, are instead produced by nanostructures. Under an electron microscope, these structures look like sponges with air bubbles. Now an interdisciplinary team of Yale engineers, physicists and evolutionary biologists has taken a step toward…
Hank |
As I briefly laid out in The Science Of Baseball: Coefficients And Happy Haitians, people like home runs though baseball purists don't necessarily think much of them - unless their team gets one. Example: I was at yesterday's Pirates-Phillies game and the wind was blowing out about 30 MPH toward left center. When spindly Pirates center fielder Andrew McCutchen came up in the 5th inning and hit what would have been a long out in most Little League parks, my brother John, a Phillies fan, insisted I put an asterisk next to it on my scorecard (1) to represent the shamefulness of…