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Playing With Atomic Clocks At Home
Wired is running a profile of the Time Nuts, a small group of people who buy surplus precision time equipment — cesium clocks for example — on eBay and keep really accurate time, because they can. The article quotes Tom Van Baak, who has outfitted a time lab superior to those of many small countries: "If you have one clock... you are peaceful and have no worries. If you have two clocks... you start asking, 'What time is it, really?'"
...Some people have too much time on their hands.
=Smidge=
I like to be REALLY just on time for my meetings...
Every experiment which ends in a big bang is a good experiment.
Real men just run ntpd and let the whole world keep time for them.
I'd be too scared what his answer would be if I asked Tom Van Baak what time it is.
Hammer time.
use www.time.gov
- Demosthenes
cynicsreport.com
...who can have two or more clocks and not constantly ask myself "what time is it?... really?"
Keeping accurate clocks synchronized is great and all..that is until accidental light-speed travel makes the whole thing pointless.
an article came up about atomic clocks and perfect time and I said...
Does anybody really know what time it is?
Does anybody really care?
If so I can't imagine why
We've all got enough time to troll....
My apologies to Chicago.
I read Slashdot for the headlines, because the headlines, unlike the articles, are usually original and never duplicated
Anyone can make the world keep time for them. Only real men can make the sun keep it for them.
I think we can keep recursing like this until someone returns 1
If you really, really know what time it is. You will find yourself quite lost. Darn that Heisenberg!
Break the sound barrier - bring the noise.
... to my watch I do have time to respond.
However, according to my computer I don't.
Interestingly, my boss concurs with my computer.
chris at darkrock dot co dot uk
http colon slash slash www dot darkrock dot co dot uk
Maybe they drive the clock around the block for a while trying to see if they relativistic time effects like Hafele and Keating http://www.teslaphysics.com/Chapters/Chapter030-H-K.htm
Summary of article: Synchronize two atomic clocks and fly one clock around world in jet and see if it differs from a clock at "rest" on the ground.
They did see if they could alter the clocks by gravity, motion is another way.
until they are thrown in prison for being terrorists because they have these clocks and are accused of trying to make dirty bombs from them?
I always said it was fun to throw a clock out a high window so you could see time fly!
One must much more careful with these new atomic clocks. After time flies, they explode and destroy whole cities!
I only look human.
My mother is a halfling and my dad is an ogre, so that makes me an Ogreling
This is really the first post; your clocks just don't agree with mine.
"Quoting famous computer scientists out of context is the root of all evil (or at least most of it) in programming." - K
>>>> If you have two clocks... you start asking, 'What time is it, really?'"
:)
Time to buy a 3rd clock?
Radio controlled clocks are sometimes called atomic clocks because their underlying time resides in a Colorado atomic clock.
These clocks give accuracy within a second as does the ntpd daemon on Unix computers.
The world seems in balance when you set 3 radio controlled clocks in front of your computer,
then watch all four with the same hour, the same minute, count the same seconds.
You shouldn't tell your clock the time -- your clock should tell you the time,
which radio controlled clocks and computers running ntp do tell.
Frustrated by clocks throughout my home with different times,
advanced by my wife to advance me, one clock advanced by 3 hours;
I got 7 radio controlled clocks which she cannot set because they set themselves.
Additionally, they give the day of week (Wednesday) and the date (December 11).
I first saw a radio controlled clock in 1992 while in Germany -- a $200 clock made by Jungans.
Several internet companies which mainly sell weather equipment also sell radio controlled clocks.
I purchased 7 of these made by Lacrosse, which can have a big LCD and can cost as little as $10 (US).
Your missing out if you only skimmed the article. Make sure you find this gem:
When the family returned to the suburbs two days later, the cesium clocks were off by the precise amount relativity predicted. He and his family had lived just a little more life than the neighbors.
An amazing PROOF that time is actually affected by gravity. We still know so little (ahem) relatively about time in physics, that seeing evidence of it being manipulated in this manner is awesome. will there be giant contained gravity wells in ambulances to slow time while patients are rushed to the hospital? Will I be slowing down time so I can get First Post AND spell check? The possibilities are endless!
Nothing great was ever achieved without enthusiasm
What's the fascination with uber-accuracy at home? Hell, I'm perfectly content with "about" accurate stuff. Kinda reminds me of weather forecasts. I remember when the weather forecast was "High in the upper 60's". If it was 46 or 70, no one complained. Now, it's "High today is 72" and people bitch when it reaches a sweltering 73.
For many services and uses, highly-accurate clocks have their place, but for every-day home use?
My mom always said, "Jim, you're 1 in a million." Given the current population, there are 7000 of me. God help us all!
I would also venture to guess that he has no girlfriend.
SJW: Someone who has run out of real oppression, and has to fake it.
Today, major swiss watch manufacturers declared they will be out of business in another decade as the atomic clocks will become the mainstream user friendly wrist watches.... ohh wait... aren't we too late to issue this news.. hold on..
you can hear NIST's WWV transmitters on 2.5, 5, 10, 15 & 20 megahertz AM (amplitude modulation), i set the clocks with my shortwave radio...
Politics is Treachery, Religion is Brainwashing
/me Looks at TFA then looks at Jameson Burts post full of quotes
Dude, are you a bot ?
You sure have a weird posting history of "poetic" quotes from the articles.
Confucius says.....
"man with one watch always know exactly what time it is....man with two watches never quite sure."
NTPD isn't good enough for me -- bad weather on the Internet has caused my server to loose synchronization one too many times, which can be mighty irritating when comparing your log files with those of other systems. On the other hand, acquiring an atomic clock seems a bit over the top to me. So, I figured a good compromise solution would be to connect a GPS receiver to my serial port and synchronize NTPD to that. I've ordered a Garmin GPS 18 OEM LVC that I will receive later this month (hopefully). According to these instructions it's not that difficult to set up, while the result is microsecond precision on Linux 2.6 and nanosecond precision on BSD -- good enough for me. All you need to do is to make sure that your GPS device has a reasonable view of the sky.
Sure, he's got all those fancy clocks in his "Time Lab", but they only go forward!
- RG>
Hey pal, this isn't a pleasantforest, so don't waste my time with pleasantries!
Clearly, the time of our lives.
Does anybody really care? If so I can't imagine why, We've all got time enough to cry . . . . (For all the oldsters out there)
It's only funny until someone gets hurt. Then, it's hilarious.
If you have one clock... you are peaceful and have no worries. If you have two clocks... you start asking, 'What time is it, really?'"
What kind of blather is that? Did he read that from a fortune cookie or something? I could almost hear the sound of a gong somewhere.
If you have one clock, you can't be sure what time it is. If you have two clocks, and they are both within a minute of each other, you can be fairly sure what time it is.
Mod down people who tell people how to mod in their sigs
Isn't it obvious? It wasn't relativity, the family lived an extra 22 milliseconds because they drove up a mountain and were closer to God. That's the only logical solution, I can't see this "gravity" you speak of. Every time someone has a problem with time physicists think they can solve it just by throwing a few nanoseconds at it. Ridiculous...
They got the saying all wrong. It goes "A man who wears one watch always knows what time it is; a man who wears two watches is never sure."
Those who fail to understand communication protocols, are doomed to repeat them over port 80.
For extra fun, tell him that they are all twenty minutes slow, making him late for school.
to know I'm not the only one who obsesses about this sort of thing. Makes me feel fairly normal for being upset when my watch gains a second every other week and I worry about not being on time.
In Soviet Russia jokes are formulaic and decidedly non-humorous.
Does anybody really care?
I found a great alternative to ntpd: I just use my $20 Casio digital watch to set time on all my servers once in a while. Why cares about time anyway? Is it December yet?
Despite the amount of confusing clocks you might have, a benevolent dictator of time becomes handy: Temps Atomique International (french) abbreviated: TAI. For us mere mortals who use time for civil needs, another timescale is dissiminated, Coordinated Universal Time (UTC). UTC is derived from TAI, but synchronized using leap seconds to UT1, which is based on actual rotations of the earth with respect to the mean sun.
International Atomic Time (TAI, from the French name ) is a high-precision atomic time standard that tracks proper time on Earth's geoid. It is the principal realisation of Terrestrial Time. As of 2007 TAI is exactly 33 seconds ahead of UTC: 10 seconds' initial difference at the start of 1972, plus 23 leap seconds in UTC since 1972. TAI in this form was synchronised with Universal Time at the beginning of 1958, and the two have drifted apart ever since.
Accurate time is very important for computer systems/networks. The best way to keep track of time is to install a local timeserver which synchronizes against a reliable public timeserver like pool.ntp.org. The local time server can be used to synchronize other computers you might have.
Just buy a clock and don't put any batteries in it - It's guaranteed to be 100% accurate two times a day.
OK, as much fun as it would be to have my own stratum-1 NTP server, how do you (read: some ordinary joe, not a university researcher) synchronize these things to TAI in the first place?
...lunch-time doubly so.'
Ford Prefect. Which is very apt, because today is Mos Def's birthday.
Shiny. Let's be bad guys...
What is with radio controlled clocks? They seem worthless to me. I have an Oregon Scientific one sitting on my desk here that has never seen a time signal. Not here at my desk at the very south tip of the SF Bay, not at my old house 5 miles away, not sitting outside in the driveway or by the window. I've had it in the Seattle area as well, and it has never received a signal there, either.
Is this whole thing a joke, or do these clocks actually work for some people? I had another one several years ago that also did not work.
Now I have to wear lead pajamas.
Latency really doesn't matter as long as you have a good understanding of the sources of delay and can statistically even out variations. NTP is the proof of that. A calibration of the USB solution (or whatever the communication path was) could probably help estimating the delay. The real sources of errors are aging hardware and/or long-term variations in hardware timings due to e.g., surrounding temperature changes.
Confucius say, "Find worm in apple - bad. Find half a worm - worse."
The next generation of geeks comes! The first guy from Washington took atomic clocks on his family camping trip and showed his children direct evidence of Einsteins Theory of Relativity. If I were growing up and my father showed me this, not to mention other cool time/electronics like this guy has, you can guarantee that I'd be hooked. Not that I'm already hooked by other things, but you get my point.
'nuff said.
Write your own Choose Your Own Adventure. http://www.freegameengines.org/gamebook-engine/
Some (most?) may want to ridicule this person for what they
see as a meaningless waste of time and resources.
Actually, this man deserves much applause for he is truly living
life to the fullest. Our modern age has experienced revolutionary
scientific developments and only a select few can even comprehend
let alone participate. This gentleman, in a feat that can be classed
only as superhuman, is extending his personal horizons well beyond
the ordinary. The pleasures from such a transcendent vantage can
only be perpetually edifying and inspiring.
All of his critics can only slip back into the inane mediocrity of
television and the movies, for they will know -- and live -- little
else.
Whew, there's IS an "L" in that word.... was worrying... for a second, or two... tick tock, tick tok...
Previously: "Linux... Toward the Sunrise..." Now: "Linux... Toward the-- No, now, part of Every Sunrise"
"...Telling the time, steadily, sensibly; telling the time for Trumpton" or if you prefer you might want to ask your girlfriend - What Time Is Love?!?
You can buy a cheapo GPS module from Garmin or somebody and then plug into the serial port of your computer. With NTP, presto! Instant GPS time reference anywhere in the world.
Give a man a fish and you have fed him for today. Teach a man to fish, and he'll say "WHERE'S MY FISH, YOU IDIOT?"
Shouldn't atoms be regulated or something?
I have two and they work fine for me both in my old house in Mountain View an my new house in Contra Costa.
They are not totally immune to interference, if all your lights are on dimmers, or they sit right on top of your PC with an open case. But I get a "lock" about 4 out of 5 days.
Give a man a fish and you have fed him for today. Teach a man to fish, and he'll say "WHERE'S MY FISH, YOU IDIOT?"
LOOSE is the opposite of TIGHT
LOSE is the opposite of FIND (or of WIN)
Why is this so difficult to get right?
I have a master clock system at home comprised of a collection of classroom clocks made by the Standard Electric Time Company from before 1950. These clocks are controlled by an electronic master clock from 1989. I couldn't take the drift of the master clock and now have it synchronized with ntpd. So my old classroom clocks are now synchronized to the second, though they only display to the nearest minute (and make a loud audible clunk when they advance to the next minute). I obsess over clocks not on the system (alarm clocks, microwave etc) and make a point of making sure that they advance when the clock system does.
I have a clock that I know is absolutely accurate twice a day. Snag is, if I don't put a new battery in it I don't actually know even approximately what the time is!
Why they built it this way, I don't know,
It's cos running the radio recever uses lots of battery power compared to running the clock alone.
If the clock has its own quartz crystal for local timekeeping, then a 'lock' and resync to the radio time signal twice a day is *more* than enough for a very accurate household clock....
Anyone quoted by a reporter knows how little they understand
Don't believe what you read is the truth.
Some guy playing with clocks making sure everyone else gets a correct time via ntp.
:-)
Some people playing with code making sure everyone has access to good quality free software. I can't code worth sh.., but have been a very grateful (bug reports) and happy Debian user for almost ten years now.
Just great
TAI itself isn't known until after the fact, since it is an average of multiple national time standards. Even those standards aren't synchronized to within their inherent precision. Different clocks which contribute to TAI can differ from each other in the microsecond range.
Timing GPS receivers can sync to well under that. NIST has some information on tracability.
The short answer is that your question was in regard to NTP, and a time server locked to GPS time is considered to be Stratum 1.
"National Security is the chief cause of national insecurity." - Celine's First Law