Salk it to Me

Jonas Salk was (and remains) a childhood hero of mine.

Today would have been his 100th Birthday. To celebrate the occasion, the Google Doodle in his honor is an earnest “Thank you Dr. Salk”


Before 1954, polio was a terror that preyed upon children. The introduction of the Salk vaccine was startling and swift:

In the two years before his vaccine was made widely available, the average number of polio cases in the US was more than 45,000. By 1962, that number had dropped to 910.

Sadly, in an age of anti-vaxx politics, such a simple “thank you” message is still needed and somewhat unfamiliar. There is a cognitive blind spot for recognizing the value of the ounce of prevention that eliminates the need for the pound of cure. According to a biography, even during the era when the polio virus was killing and crippling children, fear-mongers were present.


So let’s reflect on the incredible human achievement that is modern vaccines. In an development that would defy the belief of our ancestors, communicable diseases that were a tragic part of life, like polio and smallpox, have been tamed, so much so that we hardly give them a second thought – but we should.

Steven Johnson, one of my favorite science authors, just published a new book:

It’s about what he calls “hummingbird effects” in the history of technology. He coined this term as a play on the “butterfly effect,” in which very small events can lead to totally unpredictable, chaotic effects in ways that are virtually impossible to trace back to their source. In contrast, a “hummingbird” is a historical connection between completely different domains that is easy to see in retrospect, but is not expected by anyone. The name comes from the evolution of hummingbirds, which came about only when plants began producing nectar to attract pollinating insects. Without this development, it is very unlikely that an avian species would evolve the special characteristic abilties of what he know as hummingbirds.


Some other examples:

*Chlorination of water leads to swimming as a hobby leads to changes in women’s fashion.
*Accurate clocks are developed to calculate the longitude of ships, which leads to the synchronized factories of the industrial revolution
*Microphones lead to organized political rallies which allows for the possibility of fascism
*The invention of the laser creates bar code scanners which allows for the dominance of big box retail stores
*And last, my favorite, the invention of air conditioning leads to the settling of the “sun belt” states of Florida, Texas, and Arizona, vastly influencing American politics.

PBS has a six-part miniseries going on now.

Nobel Season – 2014 Edition

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.”