211026 Sentinel, Atomic

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The seed for this post was sowed 10 months ago.

My daughter gave me a clock last Christmas that has the day of the week, the month, the date and current temperature. She knew that Joyce and I being retired were often not sure of the day of the week and the time. I found the clock to be a fascinating piece, because the clock is synchronized with the atomic clock in Boulder, Colorado via radio signals.

The word atomic comes from the word atom which is from the Greek word atomos. Its origin came from the Greek philosopher Democritus who surmised that if one continuously cut or divided a material into ever smaller bits at some point he would find it could not be divided any further and that would be atomos.

The atomic bomb was developed in World War Two when scientists found a way to split the atom and subsequently used the bomb to force Japan into surrendering and ending the war. Russia soon developed its atomic bomb and then the world began a massive transformation. Joyce remembered being in grade school during the fifties and practicing duck and cover drills in case the Russians dropped an atomic bomb on top of the school. The drill consisted of getting out of one’s desk seat and getting under the desk for protection. Since those first two bombs over Japan there have been 2,056 nuclear devices exploded around the Earth. Astounding, is it not?

Back to my clock, my curiosity got the better of me this morning and I decided to see how Atomic clocks worked. Currently atomic clocks are accurate to within one second every 100 million years. My nice little clock available at Walmart is pretty accurate. Here below is a picture of an atomic clock in Germany (there are several around the world).

The operation is fascinating and I will attempt to give you the basics that I learned this morning. Below is a simplistic diagram of the clock.

The atoms that are at state B are removed by the first magnet, leaving the state A atoms going into the resonator where they are mixed with the high frequency oscillations which cause some of them to change to state B atoms, then the state A atoms are removed by the second magnet, the detector then counts the state B atoms and comes up with a number representing time. I realize this is oversimplified for folks like me, but I find it quite interesting none the less.

The clock uses a quartz crystal oscillator operating at 9 billion, 192 million, 631 thousand, 770 oscillations per second. Those oscillations are of a caesium-133 atom going from one hyperfine oscillation state of the caesium-133 atom to the opposite state at zero degrees Kelvin.

Here is a final note, that accuracy is just not good enough for scientists, so they are working on optical clocks that operate 50,000 times faster than atomic clocks bringing accuracy down to within one second every 15 billion years. Really folks, is that necessary? I cannot imagine, but scientists can.