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Pendulum Clock with Atomic Precision
u19925 writes "Now you can get atomic clock precision out of your grandma pendulum clocks. Here is how it works: There is a camcorder fitted inside the clock which monitors the pendulum swing. It has an atomic clock signal receiver. It compares the pendulum swings with the atomic signal hearbeat. The camcorder also has an arm. If the pendulum clock drifts, then it uses its arm to push or pull the pendulum to make correction." It's not an April Fool's joke, but it is rather impractical.
Now if we could just invent something that would push or pull Grandma when she's not regular enough...
Why not just control the swing with a couple of magnets mounted at the ends of the pendulum's arc? It would surely be cheaper and easier to maintain than a camera and mechanical arm ;-)
Code, Hardware, stuff like that.
heres a revised version of the article:
Now you can get atomic clock precision out of your grandma pendulum clocks. Here is how it works: There is a camcorder fitted inside the clock which monitors the pendulum swing. It has an atomic clock signal receiver. It compares the pendulum swings with the atomic signal hearbeat. The camcorder also has an arm. If the pendulum clock drifts, then it uses its arm to push or pull the pendulum to make correction. " It's not an April Fool's joke, but it is rather impractical.
"Now you can get A HREF="http://www.newscientist.com/news/news.jsp?id =ns99993549">atomic clock precision out of your grandma pendulum clocks.
Sigh. I'd love to get a href, but where would I put it?
Is this real science, or the results of this year's Rube Goldberg contest?
My plan was to put a magnet on the pendulum and then put the regulation mechanism on the reverse. This would measure each swing of the pendulum from the emf induced in a coil on the back of the clock. This would also be used to advance or retard the pendulum if necessary.
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Wouldn't the latency of the net connection/camera/lever defeat the whole purpose of atomic precision? I mean, anyone can just reset thier clock once and a while to the "technical" standard time. Is this really accurate?
We're only gonna die from our own arrogance, that's why we might as well take our time...
It's 1/10 second precision that get synced daily to an atomic clock - a pendulum clock with "atomic precision" doesn't even pass the sniff test
You never even thought of it until just now.
C'mon, admit it.
I don't need no instructions to know how to rock!!!!
About 20 years ago - only they used the mechanism from a quartz clock.
It's Christmas everyday with BitTorrent.
Well, it may not be what they meant, but a pendulum atomic clock is impractical simply because many of the experiments that require atomic precision, would have an adverse effect on a pendulum...
. ht ml
Here is a good link with examples of why pendulum (gravity) based systems wouldn't be too practical.
http://media4.physics.indiana.edu/~kostelec/mov
Doesn't anyone read the friggin articles?
Nowhere in the article are the words 'camcorder', 'grandma', 'arm', etc.
It wasn't designed to fit into a grandmother clock and it certainly doesn't use a camcorder. It uses an infared sensor to sense pendulum location and a 'piston' to modify pendulum swing, and it is being used to automate maintenance on large clocks in churches, etc. It can also set the clock ahead and back an hour for daylight savings time.
Gotta be the worst case of can't be bothered to RTFA I've ever seen.
Now, anyone who thinks it would be better to replace the clocks in Big Ben with some modern electronic thing... well... probably ought to be shot. This doesn't seem like a bad way to get those big clocks to operate a good long time without human intervention.
Sweet! Now the 'tick-tock-tick' my grandma hears every day of her life ominously counting down to her impending death can be atomically accurate! Thanks Slashdot!
Our clocks are perfection... Resistance is futile.
Karma: The shiznight, mostly because I am the Drizzle.
I feel that some informed comments are required for this topic. I am a clockmaker, yes I work on 200 year old clocks all the time; and I have to say that this is a really neat merging of modern and antique technology.
The clocks that are being regulated are tower clocks, they are observed by hundreds if not thousands of people a day. It would be nice to know that they are on time. It would also be a crime to rip out the old pendulum movement and replace them with an electric movement. Another feature is that the old antique system can run for several days in the event of a power failure, it just won't be quite as accurate.
The movements in these clocks are heavy cast iron units with large gears and very heavy pendulums. Using a magnet system to attempt to influence the timing rate would probably prove ineffective. However using some sort of system to raise or lower the pendulum by just a couple of millimeters will affect the timing rate by several seconds a day.
These clocks used to be wound once a week by hand and the time would have been reset at that time. These days most of these clocks have been converted to an automatic winding system, thus they see much less hands on maintenance, automatic systems for regulating the clock become much more attractive.
As a side note, the tower clock in London, commonly known as "Big Ben" ("Big Ben" is really the name of the bell that is used to count the hours) is regulated by adding or removing one or two old English Pennies, the one that were about the size of an old American Silver Dollar. The clock is regulated to be as on time as possible on the Queens Birthday and on New Years Eve.
Going even further afield some of you might get a kick out of the elaborate astronomical clocks that were designed in the 1800's. These were astonishing pieces of engineering that have been known to take an astronomer to figure out all of the settings required to set the clock.
I guess my passion for my vocation is showing, I hope that I was able to add something of interest.
Chronos
Uhh, it may just be me, but isn't the atomic receiver the one doing the time telling? I mean, you're using a clock to run the pendulum, whereas the order used to be reversed. (Pendulum ran the clock)
Does that seem really frivilous to you too? This barely fits under "Stuff that matters"
From the article:
The piston will gradually stop the pendulum over 20 swings or so, avoiding any sudden forces. Then, 11 hours later, when it will be 1 pm British Summer Time, the piston will gently set it ticking again
So if lightning strikes the clock at 8:00 am, it will be stopped at 1:00, and no one will be able get their time machine back to the future...
I know lots of things. Most of them are wrong.
Nor is it impractical. As the article points out, it is intended for very old clocks that can have very delicate mechanisms. By automating tasks like daylight savings, they can make sure changes are made gently over a longer period and that there's less opportunity for ham-fists to break things.
TFA also states that because we're talking about historic clocks, they can't go drilling holes into them and bolting stuff on. Hence the Rube Goldberg nature of these non-invasive mods.
Xix.
"Everything is adjustable, provided you have the right tools"
Danny Hillis designed the Clock of the Long Now to keep time accurate to the second for 10,000 years, and it's completely mechanical.
Camcorder - where on earth did he get that from?! Did the guy that submitted that actaully read the article he was submitting?! It doesn't mention that in the article - mainly because it would be a stupid idea. That's maxiumum overkill if I've ever heard of it. That would be like using a camcorder to 'look' and see if the fridge door is shut!
And why use a piston to change the swing? What's wrong with an electromagnet which wouldn't need to actually touch the pendlum?
Nick...
Consider where I work - we have a very accurate 10 MHz reference to sync all our RF gear to. We need that ref to be tracable to the National Bureau of Standards. Now, it would be somewhat impractical to check with the Bureau 10 million times a second (anybody want to run a fiber from Boulder to Wichita just for the time sync?).
Before I go on, let me point out the difference between precision, accuracy, and repeatability.
From a metrological standpoint, having more accuracy than repeatability is useless. Having more precision than accuracy is also useless. (Ignoring tricks like averaging for the moment.)
Back to the example. What we do is to have a very high precision and stable oscillator (we used to use a rubidium standard). It has a long term stability of about 10E-9 and a short term stability of 10E-12. In other words, over a short period of time the thing will drift not more than one part per trillion, and over the long term (days) it will drift about one part per billion.
Now, that is running next to a GPS receiver that gives us a time tick synced to the Bureau. Every second the GPS time is compared to the local time standard, and an error value is computed. That error value is averaged over a long period of time, and used to gently tweak the rubidium standard. Thus, over the long run the drift is reduced to level of the cesium clocks, about 10E-13.
So we have atomic clock accuracy but rubidium clock precision and repeatability.
Now, if you used the same sort of technique on a pendulum clock - measure the error between the clock and the GPS, average, filter, and apply - you would have atomic clock accuracy with pendulum clock precision. Granted, I would not want to use the clock's time for reporting astronomic phenomena where the precision must be very high, but for normal use this would be quite good enough.
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It's not an April Fool's joke, but it is rather impractical.
Well, that's the point, isn't it? I mean, what's the point of being a geek if you can't do geeky, pointless things?
Ed Wedig
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That's not having an atomically precise clock; that's using an atomically precise clock to automatically adjust your not-so-precise clock.
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The camcorder seems a little extravagant. Why not just use an induction loop (a la EZ-Pass or bicycle spedometers) to sync the pendulum with the atomic clock?
Statistically speaking, there's a 99.998% chance that my IQ is higher than yours. Get over it.
I'd like to point out for those moderators out there who may not be familiar with the Slashdot code of community conduct, parent was jokingly playing the role of karma whore police, because grandparent was jokingly playing the role of slashdotted story reposter while actually playing the role of that-guy-who-points-out-the-slashdot-summary-has-n othing-to-do-with-the-story. Grandparent was "Funny," but absolutely not "Insightful," unless one means insightful into the shortcomings of slashdot which are traditionally modded either "Funny" or "Offtopic." Parent is not a troll, but a prankster playing along with grandparent posing as a troll, and doing so just a little too subtly it would seem. Grandparent should be Score 3 or 4:Funny, and parent should be score 1:Funny.
Thank you for your attention. You may now return to modding down RIAA appologists.
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