08.29.06
A word on watches
This is my watch: the Casio Model GW700A-1V. Not exactly a Patek Phillipe, but OTOH it’s a hell of a lot more accurate, plus I don’t have to wind it. It picks up the signal NIST broadcasts and synchs itself with the atomic clock each night (actually, hourly each night from midnight through 5:00 a.m.). Moreover, the face is a solar cell that recharges the battery, so no battery replacement needed. I really like it.
In fact, not only the watch but also all my clocks are radio-controlled. I love it when the time changes and they all reset themselves—twice a year I get to feel smug until I go out to the car and have to reset that clock by hand.
The NIST-F1 is accurate to within a second every 20 million years. Eat your heart out, Patek. But that’s nothing: recent advances have promised a clock accurate to within a second every 70 million years.
With that degree of accuracy, though, effects on time due to motion and gravity (special and general relativistic effects) become noticeable. Indeed, on the trip I read Brian Greene’s fascinating and entertaining book The Fabric of the Cosmos, and he points out:
Although they are effective at giving a feel for Einstein’s discovery, another limitation of the standard images of warped space is that they don’t illustrate the warping of time. This is important because general relativity shows that for an ordinary object like the sun, as opposed to something extreme like a black hole, the warping of time (the closer you are to the sun, the slower your clocks will run [from the point of view of someone farther away---and it's not just that the clock runs slower, it's that time itself has slowed down - LG]) is far more pronounced than the warping of space. It’s subtler to depict the warping of time graphically and it’s harder to convey how warped time contributes to curved spatial trajectories such as the earth’s elliptical orbit around the sun, and that’s why figure 3.10 [in the book - LG] (and just about every attempt to visualize general relativity I’ve ever seen) focuses solely on warped space. But it’s good to bear in mind that in many common astrophysical environments, it’s the warping of time that is dominant.
Clive Merrick Morel said,
31 August 2006 at 10:48 pm
Hi, Michael…
I see we share similar interests, aside from wetshaving!
You made an outstanding purchase with your Casio Atomic G-Shock. Wished I would have elected to buy the resin band when selecting my G-Shock, rather than the ‘decorative’ brushed stainless steel, for every darned scratch manages to rear its ugly head (not too unlike the results from a ‘bad’ shave, eh?).
Here’s a couple of links to my Casio Model MTG900DA-VCR: Here and here.
I recently purchased (4) atomic wall clocks for use around the house — to complement the existing umpteen other various atomic gadgets:
I’d like to find an ‘atomic’ wristwatch that makes *HOURLY* time synchronization updates (which would necessitate a built-in receiver that can utilize not only WWVB’s VLF frequencies, but also WWV’s signals on 2.5 MHz, 5.0 MHz, 10.0 MHz & 15 MHz — for daytime & evening reception).
Yeah — I’m an ‘exact-time nut’ (some just say NUT), and the likelihood of finding such a remarkable gadget is highly unlikely.
Take care, Michael. Love the interesting topics on your wonderful ((( Later On ))) Blog!
Cheers.
-Clive