Magnetic moment
Using data on solar magnetism from the ESA-NASA spacecraft Ulysses, scientists at Rutherford Appleton Laboratory have calculated that the Sun's coronal magnetic field has doubled in the past 100 years, which could have a bearing on observed climate change on Earth.
Ulysses found that the coronal magnetic field is actually unexpectedly uniform. Then the RAL team was able to use data measured at a single point in space (the Earth) to deduce the recent history of the magnetic field for the Sun.
Records of magnetic storms on Earth date back to 1868 and show cycles of intensity matching those of sunspot activity. The rate of magnetic storms has also been steadily increasing though the 20th century pointing to an increasing solar magnetic field.
Since the solar wind is linked to the Sun's magnetic field and itself affects the amount of cosmic radiation hitting the Earth's atmosphere and seeding cloud cover, an increasing solar magnetic field may have an impact on the Earth's average temperature (which has risen by 0.6° in the last 100 years).
However, other scientists believe that man-made "greenhouse" effects due to aerosols and the burning of fossil fuels and forests must still not be ignored.
Computing takes a quantum leap
Scientists from MIT, Los Alamos and Harvard have produced the first simulation of quantum mechanical processes using a quantum computer, which, as Richard Feynman suggested, such computers are ideally suited to.
The researchers chose a familiar undergraduate physics problem a "truncated harmonic oscillator", in this case the series of energy levels available to a quantum particle bound to another object (e.g. an electron bound to a proton), with a finite number of energy levels.
The computer is liquid 2,3-dibromothiopene, programmed by NMR techniques: an external magnetic field forces the nuclei in the liquid to align with their spin either "up" or "down" matching the "1" and "0" of binary code. Manipulating the spins of two nuclei within each molecule reveals the possible energy states for this two-spin system and exactly simulates the possible energy states for the quantum particle. The next challenge is the extension of the simulation to the real-life model of a hydrogen atom.
AIP
Clean quackers
Researchers in Melbourne have found a novel and effective way to clean birds caught in oil spills. Oil-soaked duck feathers were coated with iron powder and then combed with a magnet, drawing out the iron powder and 97% of the oil contaminants. Moreover, the feathers retained their structure and waterproof quality unlike after cleaning with detergents. The process is also quick and less stressful for the birds. A portable field unit is currently being developed.
New Scientist
Turn down the noise
Turning up the volume of a weak radio signal amid noise increases both the signal and the noise. Sometimes actively increasing the noise can enhance the signal-to-noise ratio, in a process known as stochastic resonance.
Scientists from Italy, Germany and the US have demonstrated how to control stochastic resonance by varying the phase of an external modulation applied to a stochastic resonator. Results show that the output signal can be enhanced or suppressed and can be applied in communications, for vibration control in mechanical devices and also in biology to understand how sensory systems can pick out faint signals and perhaps to suppress unwanted interactions between electromagnetic radiation and biological tissue.
AIP