By Scott Sullivan
“Physics Made Easy” is back despite popular demand. How long has it been? A new optical lattice clock based on ytterbium atom oscillations can tell to within one second spread over 14 billion years.
You know ytterbium. Scarcely a day goes by I don’t pick up a pack at the Quik Mart. For do-it-yourselfers, an ion-exchange process using monazite sand mined in China, Brazil or India will do the trick.
Ytterbium’s uses until now were limited to a dopant of stainless steel or laser media. Handy, but not like duct tape.
We now know clocks based on its oscillations are faster, hence more accurate, than atomic clocks based on cesium oscillations since the 1960s.
Think of the latter as a watch with a hand that ticks 9 billion times per second. Ytterbium ticks you off 10,000 times faster, almost the speed of Trump.
Andrew Ludlow led a physicists’ team that achieved the breakthrough, creating a shield which protects ytterbium from the effects of heat and electric fields. So you can count on its atoms to oscillate 500 trillion times per second. Why didn’t I think of a shield like that?
In addition to telling within nanoseconds the time since my last PME column, the new clocks can help us solve lesser mysteries like the origin of the cosmos. The device is so exact “it can give you a microscope onto our very universe,” says Ludlow.
Maybe it can even detect dark matter, which physicists think makes up 85 percent of the cosmos’ content. Trouble is they can’t see it. That’s an issue when your discipline is defined as “the study of matter, its motion and behavior through space and time.”
“How can a science be based upon speculation?” you ask. Every science is.
Scientists have faith that, based on ytterbium’s oscillations, they can measure shifts in the Earth’s gravitational field so precisely they can “see” — or infer — dark matter, therefore refine Einstein’s Theory of Relativity. “Proving” won’t be as easy, which gives rise to other questions.
- How reliable are any means by which we perceive things? How do we know ytterbium clocks, Hubble telescopes or FOX News aren’t like opaque glasses or funhouse mirrors?
- Since observing can affect what we are observing, how can we get a clean read on anything?
- What our eyes see runs through our brains. But that’s a whole different problem.
There’s another dark matter I’d like to see these clocks fathom: politics. President Trump’s “fake news” and advisor Rudy Giuliani’s “truth isn’t truth” point out what we know: True, there’s fiction.
Which is which matters — darkly — because erase standards and there’s no baseline. When words obfuscate at least as much as they clarify, why communicate at all?
Here’s why: for entertainment value. Corollary: lies sell and the truth goes begging. Trump is transparent making these points clear.
Luckily, National Hugging Day will be Jan. 21. Also Martin Luther King Jr. Day. Hug your public employee taking the day off on taxpayers’ dime to honor the late civil rights leader jailed by the government while still living. S/he may need it.
Kevin Zaborney started National Hugging Day in Clio 33 years ago to help people express their feelings. “Ask before you hug,” he advised, lest indiscriminate Clioans gave Mike Tyson a smack on the lips the next time he came to town.
Physicists need affirmation too. Ludlow says his team hasn’t reached the limits of probing the new clock’s capabilities.
“The performance is nothing like we have seen before,” he says. Similar to dark matter. “But we already have ideas on how we want to rebuild things that could lead to even more significant improvements.” Keep those grants and stipends coming.
Physicists think the cosmos is 14 billion years old, give or take a ytterbium tick or two. Demand for new PME columns suggests I can wait at least that long till the next.
Science marches on.