Musings on optics, physics, astronomy, technology and life

Archive for July, 2015

The centennial of Charles Townes

Today, July 28, would have been the 100th birthday of Charles H. Townes. Of course, he’s not here to enjoy it, because he passed away six months ago.

Optics & Photonics News marked the centennial by tweeting a link to the feature article I wrote about Dr. Townes for the May 2015 issue. The Charles Townes Center, a program for gifted students in his hometown of Greenville, S.C., posted a birthday remembrance on its Facebook page. A German website posted this message (in German) about Dr. Townes’ contributions to astronomy. And tonight the South Carolina State Museum will have special programs in honor of the state’s native son. From the museum’s website:

DID YOU KNOW? July 28th would have been the 100th birthday of laser pioneer and Nobel Prize winner Charles Townes. Townes, who passed away in January of this year, was a South Carolina native who won the Nobel Prize for his inventions of the laser and maser and helped build the foundation of laser technology.  Museum educators will be discussing his revolutionary work from 6 – 8 p.m. in front of the Townes exhibit, which houses his Nobel Prize among other laser-related artifacts.  At 7 p.m., experience the technology that Townes developed in Laser Fun, a 40-minute planetarium laser light show set to an assortment of family-friendly songs. In addition, from 7 – 8 p.m., author Rachel Haynie will be signing copies of her children’s book, “First, You Explore: The Story of the Young Charles Townes.” Activities are included with general admission, however there is an additional fee to see the planetarium laser light show.

Could your light bulb talk to you? (Update on Li-Fi)

A “talking light bulb” isn’t the product of some tin-hatted paranoiac — not if the light bulb in question is an LED model, and not if you’re using a Li-Fi signal in place of Wi-Fi.

What is Li-Fi, you may ask? Basically, it’s a type of optical wireless communications (OWC) in which a LED, not a radio-frequency router, gives off the signal that talks to your device. I wrote about it in this 2014 article for Optics & Photonics News. If you’d rather get your information by listening to it, researcher Harald Haas, who coined the term “Li-Fi,” gave a TED talk and demonstration about it in 2011.

Although that speech is four years old now, Li-Fi hasn’t made much of a dent in the marketplace … yet. Every wirelessly connected device you already own — smartphone, tablet, laptop, Fitbit, whatever — would need to have a second set of receivers and transmitters to communicate with Li-Fi as well as Wi-Fi “hot spots.” Still, it’s hard to imagine how the so-called “Internet of Things” will develop if we don’t increase the amount of electromagnetic bandwidth we use for communications — and Li-Fi would open up a lot of bandwidth for sure. Perhaps, in the not-so-distant future, flight attendants will hand out Li-Fi converters to airline passengers so that they can use their devices to communicate while traveling, the way they now hand out headphones (or used to hand out headphones, depending on your flight) and beverages.

Recently, Haas’ group, based out of the University of Edinburgh in Scotland, has figured out how to make organic solar cells into Li-Fi receivers as well as power sources. That’s cool, because in our quest to endlessly miniaturize our devices, we don’t leave a lot of real estate open for transmitters and receivers — or for additional battery packs, for that matter. If you’re truly interested in the technical details, you can find the original article here.

A slightly different, more marketing-oriented twist on Li-Fi technology is offered by a Boston-based company called ByteLight, which was recently acquired by another company called Acuity Brands. We shall see how that shakes out and how OWC will evolve over the next few years.

(P.S. Please, can we come up with a better phrase than “Internet of Things”? That sounds way too much like the “information superhighway” you might have heard about back in 1990 or thereabouts.)