Huygens' Clock Puzzle Solved 191
PhotoGuy writes "Okay, I haven't heard of this puzzle either until now, but it sounds like a fascinating phenomenon. According to this article:Huygens had two clocks side by side and he found that even when they began out of sync, they soon got into a rhythm where the pendulum on one moved as if it were a mirror image of the other.The article is pretty light on the explanation, noting only the conditions required (small relative mass of the pendulums [pendula?], relatively close speed of the clocks), and not really addressing the physics behind it.
" There's a great site at Georgia Tech that explains the puzzle in more detail.
odds (Score:3, Interesting)
the article from wired about it (Score:5, Informative)
A better article... (Score:5, Informative)
Antiphase (Score:3, Interesting)
Strangely enough, it didn't occur to them to test what happens if they put three clocks side by side... Antiphase synchronization seems somewhat hard with an odd number of clocks...
Re:Antiphase (Score:5, Insightful)
Just like three phase power... three sine waves 120 degrees apart. Sum them and you have a constant 0.
I've no idea if that would actually happen in that setup, but my guess would be that yes, they would cancel each other out in total antiphase this way.
Re:Antiphase (Score:3, Interesting)
There are two key principles at work here: Newton's laws (every action has an equal and opposite reaction), and equilibrium (if you disturb one of the pendulums it will tend to act in such a way as to restore the equilibrium).
If we look at the 2 pendulum example, when the pendulums are swinging 180 degs out of phase, there is 0 net force on the system. Let's say you apply an impulse which brakes pendulum A while it is on the upswing. This will momentarily slow down pendulum A and cause it to lead pendulum B. When pendulum A reaches its would-be apex, pendulum B will exert a force on it, causing A to go higher and simultaneously lag slightly. Thus, equilibrium is restored.
In the 3 pendulum situation, the momentums again cancel each other out. At one point, pendulum A is at the bottom going right, pendulum B is near the top right going down (left), and pendulum C is near the top left going up (left). Pendulums B & C exert equal and opposite forces at this point, so the net force on A is 0. Say we brake B slightly here. Normally, when B reaches its apex, the forces due to A and C cancel each other out. But B will reach its apex earlier; therefore, A-C will exert a force on it, causing it to go higher as before.
This suggests to me that equilibrium will also be restored in the 3 pendulum case. Of course, I am not a qualified physisist, so I might just be ranting here...
-a
Hoax (Score:1, Interesting)
You have two masses moving, in essence, side to side (horizontally).
X
The masses are equal, but not perfectly in sync. It's pretty impossible to get anything perfectly in sync. So basically, sooner or later, they will both reach the center point X at the same time. When they do, the gravitational attraction between the two masses is at it's highest. When the pendulums begin to move apart again, they are affected by an equal force resisting them moving apart. Regardless of their acceleration away from each other, they will from this point forward always come to the center point at the same time, because that is where they "want" to be.
If you want to wax intellectually on the subject, we can take a look at the clocks themselves.
As each pendulum swings, it imparts a torque on each clock. When the pendulums meet in the middle as I've described above, the torque on each clock is exactly equal and opposite also. Assuming the clocks are equal in mass they will fall back like little pendulums themselves, but at the same rate.
So what we have, basically, is gravity multiplying itself harmonically. Fascinating.
Bah.
Re:Hoax (Score:2, Funny)
Re:Hoax (Score:4, Insightful)
Mainly luck? (Score:3, Interesting)
Re:Mainly luck? (Score:4, Interesting)
Perhaps there's a physics major out there who could explain better...
Re:Mainly luck? (Score:5, Interesting)
The coupled oscillators are difficult enough to model by themselves. I wrote a paper once on coupled physical pendulums. After quite a bit of very complicated physics involving Hamiltonians and Lagrangians and other silly names, I managed to derive an equation that describes the motion of the two pendulums in terms of the 'normal modes' of oscillation (these are closely related to the 'in phase' and 'out of phase' vibrations). Needless to say, the equation took up a good 3 lines in the report. I should have just put it in an appendix.
Now if you add a coupling mass between them, you're talking about an even MORE complicated problem, because the inertia of the coupling platform affects the resonance of the pendulums. It's very much like an inductor in electronics. It doesn't allow energy transfer to happen directly through the two pendulums, because a pendulum has to push the whole mass in order to get energy over to the other pendulum. I would imagine, just through experience in nonlinear systems, that increasing and decreasing this mass will have yet more nonlinear effects on the system (such as the complete stopping of one pendulum, although the article was unclear as to whether this was a complete halt, or just momentary).
You'll find very little chaos in this system, unless the pendulums are started at a very large height. Also, like most undergraduate physics, this analysis completely ignores the effects of friction, which is where the only true energy 'loss' would happen.
Mod this down for overkill,
~Loren
Re:Mainly luck? (Score:1, Flamebait)
I'm not familiar with this particular system, but are you sure you need to consider nonlinearities to obtain the synchronization? Isn't some k(x1-x2) enough to deal with it?
I don't have the time now to hack together a perl script to simulate the system, I'll try later...
No nonlinear behaviour out of a linear System (Score:5, Interesting)
In a purely linear system all these modes of oscillation are independent of each other. But the clocks manage to get from one mode of oscillation into another. This can only happen, if energy is somehow transferred between the modes, and to get that you need a (nonlinear, or you get just another linear system with slightly different modes) coupling between the modes.
Linear Systems are, in a sense, boring, once you have worked out all the coupling constants, put them in a matrix and found it's eigenvalues you know all about it (for large enough systems, say a crystall with 10^23 Atoms that can be quite a feat and can get you some interesting results nevertheless) and can predict it into all eternity. The interesting stuff happens when nonlinearities creep in.
You could describe our solar system in a linear manner, and you will learn much about it by that, mainly that the planets orbit about the sun and are themselves orbited by moons. But if you want to know why some orbits more stable than others, for example why there are gaps in the saturn rings for orbits in sync (with w being a multiple of the W of the moon) with the moons, you have to look into the nonlinearities.
--
Re:Mainly luck? (Score:2)
The way this all makes sense to me is to consider that any movement besides antiphase vibration causes the common support to move very slightly, which damps that vibration. Thus, all vibration besides antiphase is damped, and after a long time, all that "remains" is the antiphase vibration.
The continual amplification caused by the clock spring "normalizes" whatever tiny antiphase component existed originally or develops later, until finally the pendulums (pendula?) are swinging in antiphase at full amplitude.
Re:Mainly luck? (Score:2, Informative)
That's basically it. The proper term is mode-locking. It's also the reason why one side of the moon always faces the earth and why there's a 3/2 ratio in the time of the orbits of Uranus to Neptune. You can also make some really cool high-power lasers if you mode-lock the period to the cavity length (Ti:Sapphires are the most common).
-JS
Re:Mainly luck? (Score:1)
If we think of dynamic systems in terms of energy states, more energy is bad less energy is good. For example, a ball rolls to the bottom of a hill and stays there. The solution to the clock riddle falls out of this simple principle. When the clocks are any state but anti-resonance the frame that connects them would be caused to move and thus damp the clocks into the direction of anti-resonance (the ball rolls down the hill). When the clocks are in anti-resonance the motion of the pendulums cancel the motion in the connecting frame and thus the damping stops (the ball is at the bottom of the hill)
In a similar vein, my wife and I have the same problem. When we lie in bed at night, I have to wiggle my feet to get to sleep (commonly known as restless leg syndrome). If I keep my feet in anti-resonance, the bed moves very little and my wife can sleep, however, if my feet wiggle in phase (resonance) then my wife wakes up and does mean things to me (think of this as a damping force that causes the system to move into anti-resonance). I am sure if we spend enough time thinking about this solution we can base a whole philosophy (and maybe a new wave religion on it) but I will leave that to someone else and get back to work.
Re:Mainly luck? (Score:2)
Instead, they just tell us this puzzle has been unsolved since C17, and now it's solved.
Would someone mind telling us, now that it's solved, WHY it happens?
It's like the editor forgot to publish page 2.
Ok. Now what? (Score:4, Insightful)
We've got buildings that can withstand strong quakes -- but not necessarily those of long duration. I'll bet a shiny new penny that this reseach may be insightful in this field.
-jhon
Re:Ok. Now what? (Score:1)
I should hope so... (Score:1)
Did anyone think otherwise?
Re:I should hope so... (Score:2)
I forget who I'm misquoting here, but someone said "talking about non-linear dynamics is like talking about non-elephant biology".
Periods (Score:2, Troll)
Re:Periods (Score:4, Informative)
Harem, because a man could impregnate his entire Harem in a single day since they all became fertile on the same day.
Re:Periods (Score:1)
Depending on the number of women of course, but if you did try it, I wonder if those kids will ever meet their father alive, or in a wheelchair.
Dave
Re:Periods (Score:1)
Reminds me of something by Wes Borg [deadtroll.com]..
"How come condoms only come in packs of 5 or 6, but women only come in packs of 2 or 3?"
"I saw a pack of 24 condoms the other day! I personally think that a pack of 24 condoms should come with free Gatoraid and crutches."
Re:Periods (Score:5, Funny)
More likely because a harem would be an environment in which many women lived together without much contact with the outside world.
I mean, some of these sheiks were reputed to have dozens of women in their harems. No way he could impregate them all on the same day , at least not with the technology that existed at the time.
Nowadays, for that sort of thing, we have Cowboy Neal...
Re:Periods (Score:2)
=)
Re:Periods (Score:1)
Of course he could send in a substitute impregnator (they did have that technology back then) but that kinda defeats the purpose of having a harem.
Re:Periods (Score:2)
Re:Periods (Score:4, Funny)
Sounds like a great premise for a Fox reality game show.
Re:Periods (Score:2)
Re:Periods (Score:1)
The logical solution to this is to either mutilate yourself or mutilate every single woman,
we all know which one that's commonly used.
Re:Periods (Score:2, Informative)
...Later research has suggested that synchrony is caused by some sort of scent cue, or pheromone.
Scientists at the Sonoma State Hospital Brain Behavior Research Center in California identified several women who were believed to be menstrual pacesetters--they made other women conform to their cycles.
The scientists placed cotton pads under the dominant women's arms for a day, and then wiped the pads on the upper lips of five female subjects three times a week. (One wonders how much the subjects got paid for this.)
Within five months, four of the recipients were menstruating at the same time as their donors.
Interestingly, men also have an effect on women's menstrual cycles--and not just because they make women pregnant. Women who associate with males frequently find that their periods become shorter and more regular....
Possible explanation (Score:2)
It MAY be related to the fact that roughly half the estrogen in the body is produced by cells in the lungs. (It's the particular cell type that sometimes becomes cancerous, which is why lung cancers often have effects on secondary sexual characteristics, such as breast enlargement.)
Now I don't KNOW of any proven causual relationship. But the location of these cells in the lungs makes me wonder if they might be acting as chemosensors, with their estrogen output modulated by some airborne signaling chemical. This in turn could be responsible for all sorts of interesting and advantageous effects (both in humans and other animals), such as ovulation and/or coming into heat in response to proximity to a fertile male.
One such effect might be synchronization of periods of women in long-term proximity, via estrogen release by these cells in response to a signaling pheromone emitted by the other women. Synchronized periods would help maintain pair bonding by reducing the temptation for a man to mate with other women when his usual mate was having a period and the other women were not.
Re:Periods (Score:2, Informative)
Unless someone discovers clocks with pheremones these things aren't related.
No similarity (Score:2, Informative)
That has nothing to do with pendulums. The key point of the phenomenon is that the two clocks must be on a base which is wobbly enough to transmit the "equal and opposite reaction" of the pendulum from one clock to the other while being strong enough to prevent the pendulum from swinging the clock.
Re:No similarity (Score:3, Insightful)
It seems to me that it's very much the same thing. In both cases you have oscillators with periods very similar to each other linked by very weak coupling.
The interesting things are that this coupling, even if it's very weak, can influence the system and bring up synchronization and that depending on what's up you can have locking on an in-phase state or an anti-phase state.
The same kind of things happens in a lot of other systems, like for example the coupled lasers I have here.... (in-phase and anti-phase in this case appear depending on the sign of the coupling coefficient).
Re:Periods (Score:1)
Re:Periods (Score:1)
Dave
They NURSE?!?!?! (Score:1, Funny)
Somehow, I doubt that the women there actually nurse the apes. Even if human milk was actually good for apes, I'd think they would use breast pumps, wouldn't they?
Of course, if I'm wrong, I'm sure the videos would sell well on those bestiality porno web sites
Re:Periods (Score:1, Funny)
The McClintock Effect (Score:1)
Re:Periods (Score:1)
Awhile ago... (Score:2)
Now, then, we see why the two pendula come into synch: except for the points where the pendula are momentarily 'at rest', there is always a slight random noise they're giving out. This noise is greatest when their momentum is greatest, and, by coincidence, a pendulum is least able to be disturbed when its momentum is greatest.
(Okay, old physics puzzle: disregarding air resistance, how will two pennies behave with respect to each other if you throw down one, and then the second a tenth of a second later? Answer: they will grow farther and farther apart, and the speed of the first will at one point be more than a million miles per second faster than the speed of the second!)
So, to recap:
If a and b are in synch, then when b is moving fastest it's producing the most disturbance, but this disturbs a the least because its large momentum means that this change is minor for it. (And vice versa). At every other point, however, the disturbance tends to disturb a
Hope this helps.
Anonymous J. Coward.
Professor of Entymology,
University of Timbuktoo.
Re:Awhile ago... (Score:1)
I'm not gonna say that it's wrong (ahem...), but without examining resonance and vibrational coupling, you have no way to explain your 'noise'. Energy will be transferred whether something is at rest or not... You can't stop it.
~Loren
Re:Awhile ago...does not explain why ANTI-phase (Score:1)
Stick to the Etymology/Entomology, whichever it is.
Re:Awhile ago... (Score:1)
A million miles per second? That's some gravity well. What are we dropping these into, a neutron star?
Or are these pennies of the Elbonian currency, the tachyon?
Re:Awhile ago... (Score:2)
trivial? (Score:3, Interesting)
>
As Huygens surmised, the platform motion is the culprit: if we prevent the platform from moving, there is no synchronization at all
Can you believe it took this long to solve this problem? I admit I'm sceptical. Am I missing something?
Here's how I interpret the phenomenon:
Imagine two pendulums hanging side by side (on a rocking boat (I tried to make ASCii art, but the lameness filters don't like whitespace) Align the pendulums so that they swing in the direction of the boat rocking side to side.
Pull the pendulums apart and release simultaneously (assume they don't collide).
Initially they are 180 degrees out of phase, but as the boat starts rocking, its like giving one an extra push (in phase), while the other (out of phase) pendulum a tug to shift its sinewave in the opposite direction. Eventually both pendulums will have the same phase shift and will be affected by the rocking boat equally.
A slightly more complicated example could include two children on a swingset put into phase by giving each a strategically timed push or by loosely comparing it to the harmonics that caused the destruction of the Tacoma Narrows Bridge in those old film clips.
Sounds more like vibes 101 problem than a 336 year old unsolved problem.
Am I overlooking something?
Re:trivial? (Score:2, Informative)
Re:trivial? (Score:2)
Mickey Hart called it "Entrainment" (Score:3, Interesting)
He was discussing the pervasiveness of rhythm, and used this as an example.
Of course, he didn't try to explain the science, and I wondered why at the time.
Re:Mickey Hart called it "Entrainment" (Score:1)
Mickey Hart and Jay Stevens. I saw Stevens speak at the Starwood festival last summer and he mentioned this phenomenon.
Everything was already discovered... (Score:3, Funny)
Re:Everything was already discovered... (Score:1)
grenwich, in london (Score:5, Interesting)
Get to know about John Harrison, who made the first 'accurate' timekeeper, for use at sea to measure longitude. See Harrisons first accurate time peices of the world, H1 thru H4, where H1-H3 still ticks today.
A must is to stand on the prime meridian of the world, which represents 0 degree longitude, also located there. At night, a green laser can be seen streaking across the sky marking the zero parallel.
Check out the Royal Observatory [nmm.ac.uk], you won't regret it!
Re:grenwich, in london (Score:1)
or...a Royal Observatory (Score:1)
Re:grenwich, in london (Score:1)
Longitude, a movie about Harrison and his
clocks, tonight, I believe. I saw part 1 last
week and it was quite good. Probably they'll
rerun it in the middle of the night sometime
soon.
Re:grenwich, in london (Score:1)
> timekeeper, for use at sea to measure longitude.
Nova [pbs.org] has a great show about John Harrison and the creation of his timekeeper, called Longitude [pbs.org].
Re:grenwich, in london (Score:3, Interesting)
It was strange to read in the linked article (Georgia) that Huygens' clocks "contained heavy lead weights in order to keep them upright in stormy seas" - this muct be a mistake. Clocks with pendulums are absolutely useless in any kind of sea, even a calm one, hence Harrison's search for the chronometer resistant to motion and to changes in temperature and humiduty.
One part I really liked is that after Greenwich was declared the Prime Meridian in 1884 the French, for 27 years, referred to GMT as "Paris Mean Time, retarded by nine minutes twenty-one seconds".
Re:grenwich, in london (Score:2)
Re:grenwich, in london (Score:1)
See tourism value trump science (Score:3, Interesting)
The most obvious to most people is the fact that a GPS shows that the PM is marked by an unlabeled garbage can (read: ignored) while the PM marker is a substantial distance off - as much as 100m?.
There's actually an easy and fascinating explanation. Geographical positions were originally determined by astronomy, and this implicitly took into account the actual complex shape of the earth. Most slashdot readers know about the equatorial bulge, but there are other bumps and valleys as well. But modern positioning uses GPS and a simplified model of the earth's shape, and the coordinates do not match exactly. Minimizing the differences worldwide required a sizeable jump in the London area.
This then brings up the difference between astronomical time and atomic time, how GMT tracks the former and UTC tracks the latter, and the need for leap seasons.
I think it's reasonable to expect anyone who knows enough science to visit the RO would find this interesting, but the RO apparently doesn't. Most people think the positioning of a garbage can on the true PM was an accident, I'm not so sure.
Even more bizarre was their behavior around January 1st, 2000. It wasn't Y2K until it was Y2K in London. Except it was. Except it wasn't. I don't think anyone ever figured out what their position was, except that all celebrations should somehow refer to them. (It got so bad I half expected to see a claim that the RO patented Y2K.)
Ironically, I never heard of any reference to the reason why this time zone was first among equals - the fact that UTC is widely used in computers, telecommunications, etc. Half of the world (by definitition!) may have been in 2000 by the time it hit midnight in London, but much of the technology of the world would turn over at that time. That's why I was glued to the TV at 5 pm local time, with CNN on one TV and BBC America on another.
If you have a chance to visit the RO, take it. But think of it as "Royal Observatory World," the theme park.
Re:grenwich, in london (Score:2)
Leave me out of this!
vibration transmission (Score:1, Insightful)
uh news?
i noticed that shit when i was like 4.
from the tick-tock-tick-tick-tock dept. (Score:2, Funny)
"solved" long ago (Score:2)
another example is a pendulum with one or more hinges in the middle of a stiff rod.
and observed much longer ago -- human arms! (Score:1)
Each of your arms strongly tends to swing out of sync with the other. If your arms were very tiny, this wouldn't happen and if they were gigantic, it wouldn't happen either. This was observed and no doubt pondered thousands of years before Huygens' did the same thing with clocks.
Phenomonon observed directly (Score:2, Informative)
BugBear
Piano tuners knew this long ago (Score:2, Interesting)
Massive Huygens entrainment. (Score:5, Informative)
You get it with piano strings too. Where two or more are tuned to the same note. The delta in tuning has an important on the sustain-decay profile of the notes.
Huygens figured out the general principle. If you have two things that are matched in frequency, and capable of influencing each other, then any influence, however tiny, will eventually drag them into some preferred phase relationship. If there is some difference in frequency, then this may destroy the coupling effect, if it is too small. You get it with piano strings too. Where two or more are tuned to the same note. The delta in tuning has an important on the sustain-decay profile of the notes. Arguing that entrainment must exist to some degree between two clocks is easy. Showing exactly what causes it is a lot harder. That is what the recent paper was about.
Re:Massive Huygens entrainment. (Score:1)
Re:Massive Huygens entrainment. (Score:5, Informative)
I one had a posting from an old steam train worker on Africa somwhere. They used to have pairs of back-to-back steam engines for pulling heavy trains. The drive wheels used to have a random scatter in the diameter, and people in the engine shed used to try and match up sets of driving wheels with the same diameter, because that made the enginges 'run more smoothly'. From his account, it seems that on long, straight sections of track, the two engines would lock into step, but only if the wheels were a near match on both engines.
This is a relatively well-known phenomenon on steam railways. A good example if the Ffestiniog Railway [festrail.co.uk] in Wales which runs the (now) unique Fairlie double engines [festrail.co.uk]. These locomotives have two boilers and two mechanically separate engine units that swively independently on pivots under the main frames. You can see this on the photograph here [festrail.co.uk]. Effectively these are two back-to-back locomotives joined together.
The two engine units will synchronize when the locomotives run on relatively straight sections of track. Again the prevailing theory is that the synchronization occurs because of vibrations transmitted through the main frame.
The Ffestiniog also has a pair [festrail.co.uk] of near-identical Hunslet [festrail.co.uk] locomotives that are sometimes run double-headed. These will also synchronize to each other, again presumably synching through the vibrations transmitted between them. Its interesting that the locos have to be of similar types for the synchronization to occur: it doesn't happen when dissimilar locos double-head. Going back to clocks, I would guess that the phenomenon does not happen when the pendulum lengths or other characteristics of the clocks are different.
Magnetic? (Score:2, Interesting)
Conspiracy (Score:1)
Unreasonable analogy (Score:3, Funny)
Stalking the Wild Pendulum (Score:2)
This phenomenon is known as rythym entrainment, and a few of us 'Old Ones' Grok it in fullness.
"As Huygens surmised, the platform motion is the culprit: if we prevent the platform from moving, there is no synchronization at all."
This statement is, of course, patently absurd. There simply does not appear to be any sync because of limited tools for observation. If one had patience one could wait for fullness and observe the effect.
And as far as claiming that they stopped the platform from moving goes, did someone achieve the temperature my name describes and forget to tell me???
Those who want a better understanding of this, and many other secrets of the universe may want to read
Re:Stalking the Wild Pendulum (Score:1)
Presumably he meant periodic motion and not thermal energy within the platform itself.
Those who want a better understanding of this, and many other secrets of the universe may want to read
Or on the other hand, you may not. A quick look at the reviews and the sampler on Amazon showed me it's a crank's book. Read only if you want pseudoscience and sinister conspiracy theories.
But then... I could be one of the Illuminati trying to DEFLECT YOU FROM THE TRUTH!!!!!!!!!!!!
Re:Stalking the Wild Pendulum (Score:2)
Of course, you should absolutely judge it with a quick look at reviews from people whose qualifications you know nothing of, rather than actually reading and judging it. Who was the crank again ???? And who was talking about thermal energy??? just because I mentioned absolute zero??? On second thought, don't read the book
Re:Stalking the Wild Pendulum (Score:2)
"Looks like a crank's book to me. I just went by the excerpts on the Amazon site. "
Since you didn't read the book before judging it, you missed the part where the author doesn't claim everything he writes is true and accurate. It is meant as food for thought. Much of it is right on (e.g. the Universe is holographic.)
"And yes, you were talking about thermal energy. Degrees kelvin refers to temperature. I wouldn't think that the random motions of the molecules would synchronize pendulums in any way, if that were the only "motion" in the platform. "
First of all, you could have stopped at 'I wouldn't think' since you clearly haven't. Your conditional (if that were the only "motion" in the platform) would cause a 'code never reached' warning if it was run through a compiler, which was my whole point (that you clearly missed.) Secondly, if you think the only thing that happens at Zero Kelvin is that thermal energy is zero, then you have no understanding of quantum mechanics. Third, who said anything about random motion? Each atom is coupled to the other which gives it that solid appearance, so a force on one side of a solid necessarily applies a force on the other side, albeit an infintesimal one, but I suspect I'm trying to teach a pig to sing now 8^}
Re:Stalking the Wild Pendulum (Score:2)
"...but since I have a doctorate in astronomy, I think I *can* make that judgement call. Especially when the book is in the "New Age" section of Amazon."
The fact that you have a doctorate in anything, but still can't write a proper sentence, says much about the value of college degrees these days. The fact that you think possessing a doctorate in astronomy makes you qualified to judge a book dealing with physics - and without first gathering pertinent information at that - says a great deal about you. I might point out that Dr. Bentov didn't choose the category Amazon puts his book in, but I would clearly be trying to teach a pig to sing in this case.
Summary of findings (Score:2, Funny)
[snip]
"As Huygens surmised, the platform motion is the culprit"
Summary:
Huygens, 1657: "I think the frame is wiggling."
GATech, 1995: "Yes, the frame is wiggling."
What an amazing scientific mystery that was...
=)
Christmas lights do it too... (Score:1)
I have tried to repeat this each Christmas since and have yet to see it again.
Any explanations anyone?
Perhaps this doesn't really belong in here, but... (Score:1)
My grandfather's clock was alone on the shelf... (Score:2)
An obvious interaction:
The grandfater clock stops when grandfather dies because grandfather is the fellow who WOUND the darned thing.
So it's not unreasonable for it to stop at roughly the time grandfather does. And if he's dying in the house with the clock, the family is likely to be around the bed when he goes or otherwise distracted.
When they start paying attention to anything but granddad it's likely that they'll notice the stopped clock. They won't KNOW if it stopped EXACTLY when grandpa's heart did. But since it stopped roughly at that time, to the limits of their measurement (running when grandpa cried out, stopped next time we wanted to know the time), it's easy to believe it stopped right when grandpa did.
You fools! (Score:1)
water molecule (Score:1)
moog
This was a puzzle? (Score:1)
Very common phenomenon (Score:2)
I used to demonstrate this with a pair of 555 timer chips on a solderless breadboard. If set up to oscillate at the same frequency, they would phase-lock, because when the output transistor switched, it would cause a power dip. These things would lock up even at different frequencies; I was able to obtain locking at ratios like 6:7.
This also occurs with periodic polling programs, like mailers. Programs that poll, then wait for a fixed time will, if polling the same server, lock into synchronization. Then they all poll at about the same time. This phenomenon was discovered in Sendmail in the early 1980s, by someone at Lawrence Livermore Labs.
In other news... (Score:4, Funny)
http://articles.thetechmag.com/articles/?0,0372,0
Also a press release here: http://www.fluent.com/about/news/pr/pr5.htm [fluent.com]
Re:Interesting. (Score:3, Funny)
We really have no clue how any action at a distance works. There's plenty of hypotheses out there, but nothing with a shred of proof.
Doesn't mean they're wrong though... Who knows, the explanation with the most truth could involve tiny little quantum midgets on horseback sending messages between particles...
But what are the quantum midgets made out of?!?!?
Oh dear, the search never ends,
~Loren
Re:Interesting. (Score:2)
Re:This is News? (Score:1)
Re:This is News? (Score:2)
Re:Same type of thing with fireflies (Score:1)
Firefies do, however, behave like phase-locked loops, and probably syncronous networks. I say this without much of a clue how eg. SDH works...
Re:Same type of thing with fireflies (Score:1)
Build a bunch of them and set them going. After a period of blinking at different times, they gradually get into step.
Googling with appropriate keywords ought to bring up more details.
Re:Same type of thing with fireflies (Score:1)
stipe42
Re:This fucking sucks (Score:1)
Ah, but according to Lovecraft:
So, you see, the problem is self-correcting. We'll go mad, or go back to the dark ages. Either way, this knowledge will be lost and everything's taken care of. So there's nothing to worry about.