fast flop NB7V52

The Global Positioning System is rather more extensive than that. How do you think that they do it?

I wish I were. Marketing generally works hard to make their own job as easy as possible, and happily passes on nonsensical requests to engineering.

They don't.

John Larkin Highland Tech Glen Canyon Design Center Lunatic Fringe Electronics

They use timing information to located positions on the earth surface with an accuracy of better than a metre.

You may not know how they do it, nor be able to do anything that works quite as well, but while "They don't" may be kind of answer you can understand it's not one that suggests that you know what you are talking about.

such nonsensical requests as a device having to interact with the outside world, yeh that is really annoying

do you really think that all gps devices and satellites run on the same clock and all the edges are always and forever aligned?

The discussion was about using a single clock and aligning clock edges. GPS can't align clock edges, for many reasons.

Having a common zero-skew clock for all D-flops on Earth would be an interesting concept.

I know people who are committed to single-point grounding too. We could pick a common point and ground everything to that. I suggest 0/0 latitide and longitude, or maybe a copper rod in the courtyard of the Royal Observatory in Greenwich.

Visit the Royal if you can. It's cool.

John Larkin Highland Tech Glen Canyon Design Center Lunatic Fringe Electronics

Why have oscilloscopes that use external triggers? That's some idiotic marketing thing again.

John Larkin Highland Tech Glen Canyon Design Center Lunatic Fringe Electronics

On 7/14/26 19:25, john larkin wrote: [...]

Did you see Harrison's clocks? Amazing pieces of work, these clocks, and accurate to about 1e-7, better than most quartz oscillators and roughly on a par with modern OCXOs. Quite amazing for an 18th century mechanical contraption.

Jeroen Belleman

That made me think of a pianist or organist (using an electronic instrument) being told that all key presses must be synchronised to the device's internal clock.

It also makes me wonder whether there are good reasons why Bill's initials are BS.

Light doesn't move fast enough. Bummer.

John Larkin Highland Tech Glen Canyon Design Center Lunatic Fringe Electronics

Which is why electrooptic sampling with modelocked lasers is such a mainstream thing. ;)

Cheers

Phil Hobbs

Modelocked lasers are such pigheaded things. They go their own way and don't care. The best you can do is pick out a pulse or two when you think they're not looking.

We did this for one

Pity. From a theoretical standpoint, it takes zero energy to charge and then discharge a capacitor.

Yes, we saw the clocks and old telescopes and stuff. There's a line in the courtyard where you can stand in both hemispheres at once. And then walk back to London in a tunnel under the river.

Of course I don't. For one thing the oscillators in the satellites run slow due to relativistic effects and the system corrects for them.

The end effect is still that the system works as if they were, which takes a quite a lot of engineering of the kind that John Larkin doesn't seem to be aware of.

But it does move predictably. The speed of light in air is less that it is in space, to a degree that depends on atmospheric pressure, also in a predictable way.

That's clearly not a nonsensical request. It's more that the nature of the interaction with the outside world that marketing is willing to contemplate is confined entirely to passive responses.

Handshaking is out of the question.

Curiously, piano key actions are remarkably complicated - about 12 to 14 components per key - and deliver tactile feedback when the key loses contact with the hammer after launching it at the string to be stuck.

Caroline Palmer's Ph.D. thesis is all about the accuracy of the timing of the impact on the string (to about 10 msec) that skilled pianists achieve

Pianists are well aware of the feel of a piano key, and know a good action when they play it. I was never all that skilled, but even I could manage that.

Edward Rawde isn't all that clever.

And that is an idiotic observation.