I really enjoyed this piece by Tom Vanderbilt on how time is kept, coordinated, calculated, and forecast. It's full of interested tidbits throughout, like:
Care to gawk at one of the world's last surviving original radium standards, a glass ampoule filled with 20.28 milligrams of radium chloride prepared by Marie Curie in 1913? NIST has it in the basement, encased in a steel bathtub, buried under lead bricks.
And:
For GPS to work, it needs ultra-exact timing: accuracy within fifteen meters requires precision on the order of fifty nanoseconds. The 5G networks powering our mobile phones demand ever more precise levels of cell-tower synchronization or calls get dropped.
And:
And as Mumford could have predicted, nowhere has time become so fetishized as in the financial sector, with the emergence over the past decade of algorithmic high-frequency trading. Donald MacKenzie, the author of Trading at the Speed of Light, estimated in 2019 that a trading program could receive market data and trigger an order in eighty-four nanoseconds, or eighty-four billionths of a second.
And:
All this makes F1 staggeringly accurate: it will gain or shed only one second every 100,000,000 years. Since the days when time was defined astronomically, the accuracy of the second is estimated to have increased by a magnitude of eight.
And:
"A clock accurate to a second over the age of the cosmos," Patrick Gill, a physicist at the U.K.'s National Physical Laboratory, is quoted as saying in New Scientist, "would allow tests of whether physical laws and constants have varied over the universe's history."
And:
"If you were to lift this clock up a centimeter of elevation," Hume told me, "you would be able to discern a difference in the ticking rate." The reason is Einstein's theory of relativity: Time differs depending on where you are experiencing it.
And I could go on and on. If any or all of those tidbits is interesting to you, you should go ahead and read the whole thing.
Tags: physics · science · time · Tom Vanderbiltfrom kottke.org https://ift.tt/PF3hDJY
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