Applied Physics

Scientists have achieved an unprecedented level of control over defects in liquid crystals that can be engineered for applications in liquid matter photonics. They can lasso an intangible ring created out of liquid crystal defects - attaching a microsphere to a long thin fiber using optical tweezers. 

Liquid crystals are familiar to us from their application in LCD screens. What makes them so interesting is that they are rich in defects. Thanks to advances in manipulation tools such as optical tweezers, the authors were able to create an arbitrary number of defect pairs on a long thin fibre plunged into a nematic liquid crystal - an ordered fluid with long organic molecules all pointing in the same direction like sardines in a tin.
In 2005, scientists studying tiny sac-like creatures called sea squirts found bacteria containing two types of chlorophyll (a and b) in cavities inside the squirts' tissues.

Those two pigments were soaking up most of the sunlight - the violets, indigos, blues, green, yellows and oranges - and all that filtered through the squirts was deep red light. On the underside of the squirts  was a film of photosynthesizing microbes and they turned out to be full of chlorophyll d, a rare variant of the chlorophyll molecule that absorbs near-infrared light.
The Nobel Prize-winning Higgs boson – the “God particle” - believed to be vital for understanding all of the mass in the universe, was found in 2012 at CERN’s Large Hadron Collider, but that's not where the search began.

Instead, the first hint of the boson was inspired by studies of superconductors – a special class of metals that, when cooled to very low temperatures, allow electrons to move without resistance. The discovery of the Higgs boson verified the Standard Model, which predicted that particles gain mass by passing through a field that slows down their movement through the vacuum of space. Now a team of physicists has brought that work full circle, by reporting the first-ever observations of the Higgs mode in superconducting materials. 
Milk has a long been a nutritional and economic staple in western countries but it is quickly susceptible to pathogens quite easily, which is why pasteurization, which kills harmful microbes, is the norm for all but the food fad fringes. Due to harmful microbes, raw milk is 150X as likely as pasteurized milk to result in illness.

Refrigeration and chemicals can manage pathogen growth but Listeria monocytogenes are less sensitive to low temperature; therefore, they can proliferate at refrigeration during transportation and storage.  And not everyone has access to the infrastructure needed for a permanent electricity supply needed to drive refrigeration.

Perhaps if electricity were just needed in bursts.
Latency is so ingrained into modern communication we almost forget about it but in live or recorded events, like performances or rehearsals over a long distance, it is crippling.

 When recording a soundtrack over a pre-recorded base, the latency is perceptible to the human ear if a delay of 15-20 milliseconds occurs - the track seems displaced from the rest, giving the sense of being poorly played. To resolve displacement over long distances, elements such as sound capture, sound coding and decoding servers, intermediate network elements, lines of communication and the software used all must be factored in.
Researchers have discovered proof that acoustic phonons, the elemental particles that transmit both heat and sound, have magnetic properties. 

In a new paper, the authors describe how a magnetic field roughly the size of a medical MRI reduced the amount of heat flowing through a semiconductor by 12 percent. But because the phonons reacted to the magnetic field, the particles must be sensitive to magnetism.  
My wife and I were in an airport newsstand. I was looking through the magazines to find something to read on the flight when I saw something that didn't make sense. Quite confused, I had to blink a few times to make sure I was seeing what I was seeing. My wife was a few yards away in the store looking at some knickknacks, so I had to say this loud enough for her to hear: "Tabby, I think I've accidentally stumbled into an alternate universe because Paris Hilton is on the cover of National Geographic:




Mar 17 2015 | 2 comment(s)

Build a laser oscilloscope using Lego, littleBits, Erector set, and the Kano Computer. In honor of The International Year of Light I’ll demonstrate how use the Kano computer to drive a littleBits motor with an optical coupler, or optocoupler. An optocoupler, according to Wikipedia, "is a component that transfers electrical signals between two isolated circuits by using light." The Kano Computer is one isolated circuit and the littleBits Light Sensor/Motor is the second isolated circuit.

In a previous blog post, I demonstrated how to build a magnetic optical mount for a laser using Erector set parts. Here's another method of attaching a chip clip to the Erector set stand.

Parts Needed

Erector set right angle bracket 3-hole (mine is a bit more than 90°)
Erector set nut
Computer case thumbscrew
Chip Clip

I used a knife to cut a slit in the rubber grip of the chip clip just wide enough for the Erector set angle bracket to fit tightly once inserted in the grip.

Red lead is familiar to us due to rustproof paint but artists have treasured the brilliant color for its durability since ancient times.

Yet it has limits and now scientists are learning more about why.  A combination of X-ray diffraction mapping and tomography experiments at the DESY synchrotron light source PETRA III has shown an additional step in the light-induced degradation of lead red. Key was identification of the very rare lead carbonate mineral plumbonacrite in a painting by Van Gogh.