It’s that time of year again! The leaves are changing color, the air is getting nippy (Not valid in the state of Florida), and the 2014 Nobel Prizes have been announced!
The big prize in Physics last year went (with little surprise) to Peter Higgs for his Boson. This time around, the winners achieved something that sounds much more prosaic, but a great deal of potential to make big impacts in future applications.
Blue LEDs are the missing piece to super cheep, energy efficient lighting of any color. Along with Green and Red, Blue LEDs make affordable flat screen TVs and pleasing white LED lighting a part of everyday life. Incandescent lighting, which requires electrical resistance to heat a metal wire to white-hot temperatures, is notoriously inefficient. Older TVs requires electron guns or backlighting, which were also energy hogs. LEDs turn electricity directly into light (like reverse solar cells!) and are therefore very efficent.
There is a joke I remember from long ago that goes like this: A boy is watching TV at home and a documentary on Tomas Edison comes on. The boy turns to his mother and says “I’m so glad the light bulb was invented, otherwise we’d have to watch TV in the dark!”
There is a grain of truth to this story, because improvements in LED technology lead to energy savings, that make possible portable devices like smart phones and laptops that last all day without needed to be recharged. And since about 1/4 of energy goes towards lighting, replacing all those energy-draining incandescent light-bulbs with LEDs will help ease our dependence on fossil fuels.
On the chemistry side, the big discovery also deals with light, but in a very different way. This advance was getting around the fundamental limit on the size of particles distinguishable by a microscope. This diffraction limit basically says that you can’t see anything smaller than the wavelength of light you are using to see it with. This is a big problem, so to speak, since visible (blue) light is around 400 nm, and alot of interesting things, like viruses or proteins, are smaller than that.
The winners of the prize figured out a way around this seemingly insurmountable limit: They used florescent microscopy, in which laser light excites the target molecules to fluoresce.
But the trick was, in addition to this excitation laser, to add a second, de-excitation (quenching) laser beam in a donut shape around the first. This “turned off” the florescence of the surronding so that only the molecules in the “donut hole” would give off light, and could be seen separate from everything else. It is very similar to Dr. Seuss’s “flashdark.”