@sil best guess: same as originally happened. Possible alternative: powerful long wave transmissions from shore(s) counting pips on each GMT hour, radio receivers on ships.
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@sil Ah, the lemon, nature's battery.
But really, just take a sundial and a compass and mash them together. Now you have a sundial that keeps to North so you can tell the time, since you're already floating on a giant sundial which does not.
Or better yet, why would anyone want to keep time. You're on a boat with air you can breathe. Enjoy it, and maybe grill up a sailfish or something.
@sil While a clever start, I gather that the slowest resonance that you can get is still in the kilohertz range, so the problem becomes what can count thousands of pulses per second.
You COULD build a simple generator (spin a magnet perpendicular to a wire coil), but if you can do that smoothly enough over time to count the smaller number of pulses, then it's simpler to ditch the magnet and wire to count revolutions directly...
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@jcolag well, my thought for stepping down the pulse count was flipflops made from relays, but now that I've put nine seconds of thought into this I don't think you can get the first relay to run that fast
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@sil Some quick research on generating clock signals turned this up.
It does need a handful of transistors, which would take work to replace/develop, but a hand-wire-able 1Hz clock signal at least seems plausible.
@sil best guess: same as originally happened. Possible alternative: powerful long wave transmissions from shore(s) counting pips on each GMT hour, radio receivers on ships.
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@alex huh, longwave radio. Can you do that with 1700s tech, even if you know how? I know there were crystal spark radios that kids could make in the 1930s out of stuff they had, so it feels possible, but I don't know what you need to have decent broadcast power and whether you can do that with batteries you make out of clay jars and lemon juice
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@sil low confidence, but not zero. Shore based power feels feasible - spin copper windings for 10s maybe 100s kW AC. Maybe a mercury arc rectifier https://en.wikipedia.org/wiki/Mercury-arc_valve for DC, other glassware valves for oscillators, etc. Erecting 100m+ vertical antennas feels tricky, maybe something horizontal can work. Making ship board batteries & electronics work once is maybe feasible, mass producing reliable ones feels very infeasible.
@sil I was listening to the In Our Time about this last week and the prize wasn’t just for making the clock, it was for making something that could be mass produced in contemporary factories for all the ships. Get to it!
@sil Nope you'd still need the REST of the electronics and to invent a reliabe electrochemical battery etc..etc...Really the best in 1700 would be a 'Harrison-light' clock like he buit; His was overly cautious - he was after the prize, it was TOO precise (and we know how to make it simpler now) . Contemporary clockmakers COULD make an accurate enough clock (2 seconds a day) but the innovation was the temperature & motion driven innacuracies through his sprung system.
We have better ways to do THAT now (and we know how to use materials better)
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@scottgal the rest of the electronics aren't _too_ hard, though, are they? I mean, making a relay isn't that difficult and you need, what, two to make a flipflop, and even if you're stepping down from kilohertz ranges you only need ten flipflops or so. That feels doable to me? maybe?
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@sil They're PRETTY HARD to get 2s a day accuracy with temparature invariance plus *how do you tune it*, you have nothing accurate enough.
It's WAY easier to use existing clockmakers with a good plan to build a mechanical one than to invent the whole field of electronics, component manufacture, materials science - wires? good luck, at the tiny voltages in microelectronics 'good enough' isn't.
WE didn't invent electronic timing until the mid 20th century; and quartz timing until the mid-20th; despire know about piezoelectrics for 100 years; for good reason!
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@scottgal huh really? I didn't know we knew about piezoelectricity that much earlier. Also it has belatedly occurred to me that flipflops from relays are all well and good but the first one in the chain is going to be flipping at kilohertz frequencies which is obviously not gonna happen :)
bit disappointed that the last three hundred years of tech hasn't actually come up with anything at all better than Harrison (or at least, nothing better that Halley could have done even if he knew about it!)
@sil Hmm wouldn't you need a switch of some type - transistor/valve? to drive that quarts? I don't know if you could make yourself a point contact transistor.