Tunable antilaser good for a switch – Photonics | In science (as in life) it’s sometimes useful to go against the flow, to experiment with the reverse. Take lasers, for example. Excite some atoms into making a beam of photons and you’ve got a laser. Now go the other way: Start with a laser beam; split it into two beams and tune the beams so they interfere with each other. Direct the beams into a chamber lined with a specific silicon that absorbs photons – all of the photons. What is it? According to the research team at Yale University (USA), it’s an antilaser. Better still, they can tune the amount of photons removed from the beam from 1 to 99 percent. That’s called a switch (like a rheostat) and has possible applications in various electronic circuits. The researchers think it might be part of a killer app, but they don’t know what just yet.
[Science, 18 February 2011, Time-Reversed Lasing and Interferometric Control of Absorption]
Nosing around quantum vibrations – Quantum Physics | Should we be surprised that quantum effects are showing up in the most unlikely places? After all, quantum mechanics underlies the entire physical world. Nevertheless, the nose of a fruit fly would not be a likely place to look. Except for Luca Turin (Massachusetts Institute of Technology, USA) who suspected for some time that the incredible sensitivity of smell might be more than the usual explanation – molecules of a certain shape fitting receptors of the same shape in the nose. He reached that insight when he noticed that fruit flies could distinguish between two forms of molecules that had identical shape but one contained normal hydrogen and the other contained the deuterium isotope of hydrogen. Through many experiments the research team came to believe that fruit flies (and by extension other animals) can make these fine distinctions because of what is called the quantum tunneling effect, where the different rate of vibration in the normal or deuterium bond is transmitted to a receptor. The notion is controversial and verification by other research groups is in order.
[PNAS, 14 February 2011, Molecular vibration-sensing component in Drosophila melanogaster olfaction]
Easing post traumatic stress with Virtual Reality – Virtual /Augmented Reality | One of the reasons people go to a shrink (psychiatrist) is to have them probe traumas that occurred long ago, usually in childhood, and by bringing them to consciousness help to remove their effect. This is also a helpful approach for soldiers returning from war, but often the mental traumas are so fresh and painful that verbal probing is unsuccessful. A new approach, called virtual reality exposure therapy uses the patient’s own memories of traumatic events to slowly and carefully construct a virtual reality of sights, sounds, and sensations related to the event. This ‘recreation’ can then be replayed, varied, and modulated so that the patient can, in effect, safely relive the trauma until it becomes less emotionally destructive. The results, so far, have been encouraging with significant reduction in PTSD (post traumatic stress disorder) symptoms and 62% of the patients reporting meaningful change in their condition.
[Journal of Traumatic Stress, 3 February 2011, Effectiveness of virtual reality exposure therapy for active duty soldiers in a military mental health clinic]
Brain Computer Interface goes to clinical trial – Body Implants | Experiments in controlling computers and other devices with thought have been in progress for over two decades, so that even though there’s a kind of science fiction flavor to this research, it’s significant when BCI (brain computer interface) technology moves from the lab to clinical trials (that is, to trials involving several or many real patients). In this case, researchers at the University of Pittsburgh (Pennsylvania, USA) will be installing electronics in the brains of people with spinal cord injuries who are unable to use their arms or hands. The trials have two components: One will test an electrocortigraph placed on the motor cortex to help patients learn how to control prosthetics, computer cursors and the like; the other uses an electronic array on the surface of the brain to read individual neurons that activate a highly sophisticated prosthetic arm. Human trials are the first (slow) step toward making BCI practical for real-world cases.
[EurekAlert, 17 February 2011, New Pitt projects will test brain computer interfaces for people with spinal cord injury]
Data Factoids – Online Information | Thanks to an ambitious study of the world’s total technology capacity by a large consortium of research teams, we have some delightfully big numbers to contemplate:
You gotta like these numbers: How much is a zettabyte? That’s 10 to the 21st power, or 1 followed by 21 zeroes (1,000,000,000,000,000,000,000). If you started counting at the Big Bang, you’d still be counting. In just the year 2007 about 1.9 zettabytes of information was distributed (broadcast) around the world. That’s like every person on Earth reading 174 newspapers every day.
In case you hadn’t noticed, the shift from analog to digital storage has been rapid. 2002 was the first year in which more information was stored in digital format than analog forms. By 2007 almost 94% was stored digitally.
Here’s a favorite: At the moment, in all of humanity’s digital storage capacity there is about 295 exabytes of information (that’s 295,000,000,000,000,000,000 bytes). That’s about 315 times the number of grains of sand in the world. Yes, it’s an impressive number, but let’s stay humble: It’s less than 1% of the information stored in the DNA molecules of a single human being.
If you can remember them (doubtful), factoids like these can be used at dull cocktail parties. Mostly though, people google them when they’re writing a paper or trying to impress someone. Otherwise, the safest thing is to say – “Man, do we have a lot of information at our fingertips or what? If I just knew what to do with it.”
[Science Express, 10 February 2011, The World's Technological Capacity to Store, Communicate, and Compute Information]