New atomic clock claims title of world's most accurate
By Donald Melanson 
posted April 16th 2009 10:26PM
posted April 16th 2009 10:26PM
You may have thought that the previous world's most accurate clock was good at keeping time, but it's apparently nothing compared to this new strontium atomic clock developed by scientists at the University of Colorado, which is supposedly more than twice as accurate and just as atomic. To achieve that impressive feat, the scientists made use of the same so-called "pendulum effect" of atoms as before, but took things one step further by holding the atoms in a laser beam and freezing them to almost -273 degrees Celsius, or the temperature at which all matter stops resonating. In clock terms, that translates to about one second lost every 300 million years. Of course, that's still one second too many for the researchers, and they say they "dream of getting an atomic clock with perfect precision." You just know you never want to be late for a meeting with these guys.
...what?
Minutes/Seconds/etc. in terms of positioning don't really refer to time. Those are measurements dealing with geometry, specifically, circles and spheres. As best I recall, they're either based on degrees or radians.
CU represent!
W00t w00t! Go Boulder!
haha, finally my school is in the news for reasons other than rape and alcohol poisoning!
Now I'll always be late....-sigh-
wouldn't they need a better clock to actually time this one?
I think that these are calculated to be the most precise, therefore they are.
Their timing is based on atomic movement and therefore calculations. At least that is how I understand it, could be wrong. though...
Waste of time. Where's free energy?
right...BEHIND YOU!!!
thats what she said!
waste of 3.333333 * 10^-9 seconds/year to be more precise.
(more precise, not precise, oh and btw OP, -273 degrees Celsius is NOT the temperature at which all matter stops resonating . Close though ... or not, depends on your point of reference .... , anyway ... ooh look at the time ...)
Even if they had this clock, the Chicago CTA still wouldn't manage to be on time.
@Matt
LOLOLOLOL
What I was thinking.
Can't count how accurate time is, unless you got a more accurate besides it (read: one that is only off 0.5 seconds every 300 million years)
Drool I am so into Atomic time. I have a LaCrosse for indoors and haven't found an atomic watch light enough for a gal to wear, that actually keeps accurate time where I live.
I live in a dead zone so I can not depend on my cell phone nor my gsp for accurate time. Thank goodness the LaCrosse passes over my house once a day lol.
Went into a store right after daylight savings time and NONE of the watches had the right time, the right day, the right anything. The counter person didn't even understand what I was talking about.
And while we are talking about time. What's with the watches suddenly using a shortened abrv for the days of the week???
"If you have one clock you know what time it is, if you have two, you don't"
What exactly do they use to determine how accurate they are. I mean, if this thing is inaccurate after 300 Million years, then the one they're comparing it to has to be more accurate and why aren't we using that for the "atomic clock?"
They don't compare the time of this clock directly to that of another clock.
Atomic clocks work based on the half-life of the atom they are running on. One of the most popular forms of atomic clocks which places like NIST use are a cesium atomic clock. Instruments are used to measure the rate at which the cesium atom resonates. The data is thus translated to give an output of conventional time.
The reason they are still inaccurate are due to anomalies in quantum physics. For example, the way the cesium atom resonates begins to alter as the atom ages (half-life). Because of this, it creates errors in the patterns for measuring the oscillations of the atom. This is further compounded by environmental changes such as temperature. That's why this new clock attempts to "freeze" the atom at ~absolute zero, in order to counteract some of the environmental bi-products.
As it was mentioned, accuracy in time is relevant in A LOT of fields. Such conventional things as GPS or even the little clock in on your computer are synchronized with atomic clocks in order to maintain accuracy.
As far as wristwatches are concerned however, there are several more things that keep watches from being accurate. The effects of gravity on the movement of a watch is one of them (wiki about tourbillon for more info on the subject). Although there are a lot of accurate watches out there for conventional use nowadays, such as the Citizen Skyhawk A-T which is radio controlled.
What a waste of money. I can't wait for stimulus money to kick in so we can get daily updates of stupid things that don't matter.
Spoken like a caricature of an ignorant republican, pretty well done if it was intentional.
Wouldn't a "perfect" clock violate the law of perpetual motion?
I fail to see how you manage to link the two.
Dare I ask what you mean?
I think the question here is "what is time" and how can you measure it and it's precision? They are simply measuring light and atomic movement. Time doesn't exist, and is only a measurement for past, present, and future, which doesn't exactly exist but only to the human and mammal mind. :)
Atomic clocks measure "time" in the sense that .. The second is the duration of 9 192 631 770 periods of the radiation corresponding to the transition between the two hyperfine levels of the ground state of the cesium 133 atom.
Time is just another dimension, but we are unable to see forward or backwards beyond it (just as something in the second dimension cannot see above or below it, something in the third dimension cannot see beyond or behind itself in the fourth).
@Taylor
Time is not a dimension. Time is a measurement. There is no such thing as "TIME". We are able to see forwards and backwards, physics say's we can. There is the same probability that the measurement increment "time" can move forward as it does backwards.
When you talk about dimensions what are you talking about? Do you know what dimensions are? Obviously not. Dimensions are perceptions, and measurements of units.
"something in the third dimension cannot see beyond or behind itself in the fourth)." Stop watching Starwars and read a physics book.
@taylor
Pay attention, the new standard is strontium not cesium (or not caesium if you will), that's the message of the article right?
mtjl79
It's all in perception. What you're saying is akin to saying that the only wavelengths of light that exist are in the visible spectrum; if we can't see the others, they don't exist.
We perceive movement in three axes through space, one axis in time, and who knows how many in probability.
@Wwhat: The SI definition of the second is still based on cesium, not strontium.
That said, the definition may be changed to use strontium instead...
A couple things to note:
It's accuracy is calculated based on the uncertainty of the atom's movement under these conditions; there is no "more accurate" clock which they use to compare.
This is relevant for a number of things, as mentioned previously, one example is deep space travel. More importantly, in my opinion, is the general improvement of science. Whether or not you are aware, the definition for a meter (and as a result the definition for all reasonable units of length [sorry to the fans of the archaic and horrendous US... I hate going through extra conversions for all courses in engineering just because we are trying to simulate the likely situation that we will be forced to use some American, and other obsolete units... like BTUs]). A meter is defined as as the distance that light can travel in a vacuum in 1â„299,792,458 of a second. So a more accurate definition of a second results in a more accurate definition of a meter.
This relevance continues and compounds... Volumetric units (again in the metric system) are defined in terms of cubic measures of length. A liter, for example, is 1/1000 cubic meters (1 cubic decimeter) ... a more accurate meter makes a more accurate liter, and all volumes are based on this in a logarithmic scale.
I must admit that at this point my argument starts to wear thin.... ORIGINALLY the kilogram was defined as the mass of a liter of water, or more precisely the gram was defined as the mass of a cubic centimeter, or milliliter of water. This would be relevant to the definition of (the obsolete unit) a calorie, the amount of energy required to raise the temperature of 1 g (ml) of water by 1 degree Celsius... The unit of kilogram is not defined as a specific hunk of platinum-iridium (platinum being extremely resistant to oxidization and iridium similarly being resistant to corrosion), milled to be almost the exact weight of 1 liter of water, but is now the standard itself.
However, the SI unit for speed m/s, acceleration m/s^2, force N or kgm/s^2, energy J or kgm^2/s^2, power W or kgm^2/s^3 and so on... Lets not forget in electricity a volt is defined as Watts/amperage, a farad is defined as amperage*s/voltage, a coulomb is defined as an ampsecond, resistance is measured in ohms or V/A... As such error in time causes error in all other measurements, introducing error into all results, which compounds upon itself...
These are not clocks used to check what time it is... nor are they just a show of physics, they are the basis for all standards!
Oh that and just showing off =P
oh yah, I meant to list some others, without any real explanation haha:
viscosity in pascal seconds kg·m−1·s−1 or in poise g·cm−1·s−1
kinematic viscosity in stokes cm2·s−1
pressure in pascals 1 kg/(m·s2)
frequency in hertz 1/s
density
etc.
a few proper units are defined with a less direct reference to time:
kelvin (based on absolute zero and on the 100 degrees from melting to boiling of water... that is at a defined pressure...)
and as a result all thermochemical relations and units, such as specific heat.
candela (based on the radiation at a specific frequency/the wavelength of about 555 nanometers)
mole (defined as the number of atoms of Carbon 12 to have a mass of 12g)
only a few standard units come to mind that are still largely arbitrary (other than the current definition of a kilogram):
amp
decibel
neper
These are all the (SI and similar) units that come to mind... but then again I tried to dump a lot of that info out of my head after my last two exams... so I wouldnt be surprised if I missed a unit/combination that is pretty common...
Oh, I did want to mention though (after a semester of physical chemistry excitement) that increased accuracy means a lot... Femto-chemistry really relies on it, so does any for of quantum calculation based on real world measurements...
Cheers
Wow.
I didn't think about that usage actually. Hot damn you're right.
Internetz for yous.
Even with basically all the units being based on time, directly or indirectly, the accuracy of the clock doesn't really help making a meter more accurate.
As the spacetime is relativistic, all you need to do is move the clock to higher potential in Earth's gravitational field, and the clock is already moving faster compared to another clock at lower potential.
As there is no "universal second" that everything could be based on, the second used in defining other SI units has to be standardized by other means.
The value of the clock's accuracy is not in it's precision to measure the duration of one second accurately. It is in measuring time without significant drift. This allows physicists to make more accurate measurements on the effects of relativity by comparing times between clocks.
Bit silly to bitch to the US when you mention the meter because for the longest time the meter was defined as "the length of a metal bar held in a vault in france", which isn't that scientific really, I'm glad they could improved on that standard though, and glad that they could without some idiot preventing it because it would offend his god ;)
I agree that the meter, like the current definition for the kilogram, and the definition for amp, is a pretty arbitrary unit. It was originally supposed to be 1/10 000 000 of the distance from the equator to the north pole, when measured through Paris... But that isnt entirely my point. I don't mind too much what the base of the unit is, more that the system is in base 10. When I'm doing calculations it is easy to shift the decimal place around. If I'm given a wavelength in nm, a wavenumber in inverse centimeters, a bond length in Angstroms (although the term isnt appreciated by SI, it is simply 10^-10 m), a volume in L or m^3, pipe diameter in mm but length in m etc etc.... I can instantly tell what the equivalent measurements are in units that are relevant to my calculation for finding things like the rotational constant, volumetric flow rate etc.
However, when I'm given the effectiveness of a heat exchanger in BTU's, the diameter of a pipe in inches, the length of the pipe in yards... I have to convert everything to metric OR use fractional factors which are so numerous and difficult to remember, that it makes more sense to convert. The worst thing is that when a question is posed in US units, we are generally required to report our answer in the same units, so we have to convert back at the end.
I admit that it is bitching, since the conversions are simple, and I have come to memorize a lot of them, just as I have come to memorize Avogadro's number, the boltzmann constant, the stefan-boltzmann constant, the equation for Reynolds number, Grashoff number and Rayleigh number and a hundred other equations and constants....
Despite that it seems like such a silly thing to me, like the Rankine temperature scale (absolute F), they are usable but only obtusely, and it is not as immediately apparent to make comparisons or conversions, ie. 7.4 miles or 468865 inches, which is larger? I'm sure some people know that it is 5280 feet to the mile, and 12 inches to the foot, but the math has to be done, where a comparison in cm's and km's can be done in seconds by moving the decimal; and new units can be constructed using a standardized system of scale 10 prefixes.
To be honest I could rant forever, chemical engineering is something I enjoy, but all of the remnants of days gone past bother the little bit of OCD that I have. Even thinking about it now is getting me bothered haha, especially thinking about foot-pounds, psi, fl oz and oz haha
I completely agree that base 10 is best in many cases (although that's based on our fingers and causes computers to be ever so slightly off when dealing with it due to conversion, but one day non-binary computers will be the norm so that's fixable.)
And what annoys me most is that time is not decimal yet, even in science, 12 hours, 60 minutes 60 seconds, what is that silly nonsense, sigh.
I now read that they started with decimal time very long ago already, I quote wikipedia (be careful though because this kind of thing needs external confirmation)
"In more modern times, decimal time was introduced during the French Revolution in the decree of 5 October 1793"
10 hours 100 minutes 100 seconds.
http://en.wikipedia.org/wiki/Decimal_time
That clock will be broken before it reaches 300 million years!
As long as clocks don't really measure anything but themselves I can really care less ;)
Cool, now we can say "it was exactly time for the people to stand up and not take it any more 283824000.8768638562835234 seconds ago"
NO TELL ME ONE THING.....HOW CAN THEY KNOW EXACTLY WHAT TIME IS RIGHT NOW???????????
By looking at the sun.
This is silly because we do not need such accuracy. We will never leave this planet. We will all die of starvation while trying to beat our 5 yr old nephew in Wii who is kicking our ass in some computer game despite the fact that he cannot even read yet and we all know that the games are made by the Communist Chinese aided in their plans by a race of aliens called Schroederians who seem to smell faintly of cats. The Chinese Communists don't mind because they had no plans of leaving Earth and are happy to have watches whose accuracy is less than 1 second per 3,000,000 million years, since Sun Ra will still be playing his great jazz music when he and Kilgore Trout return from Saturn. When they have staff meetings, do you think the chief engineer for this project ever says, "Sorry I'm late"?
When they return they will smile benevolently once we present the nice clock we made for them! It'll show we care.
Nitpick: China isn't communist, it's most definitely capitalist.
"...the temperature at which all matter stops resonating." Whatever happened to zero-point vibrations?!
I went to school at the University of Colorado-Boulder. Why is that these guys can build the most accurate atomic clock but no clock at the University actually is set to the correct time?
Who has the time to adjust all those clocks? Also, why didn't you? Surely you can get a GPS unit and sync them to atomic time, extra credit one assumes.
I'm impressed incidentally since they did manage to make you spell correctly and use capital letters, not many schools produce such results from students any more, I'm serious too.
I'm betting these guys are late to every meeting given the amount they are over compensating with this.
Do they actually believe the earth will maintain a constanst rotation and not cause this thing to get off just in the amount of space debris causing the orbit to change.
It''s meant to keep seconds accurate, the days and years and hours and if it's night or day or summer or winter and what not they don't give a damn about, that's more for other people to worry about, civil servants and such.
I have to wonder if this clock will address the concept of 'leap seconds'
http://en.wikipedia.org/wiki/Leap_second
The most precise form of time standard is the advantage of [url=http://www.clockdesk.com/atomic-clock-radio/]atomic radio clocks[/url]. Global Positioning System and communication companies usually use atomic clocks because of their high accuracy. High quality atomic derived time is used by most of the modern day radio clocks. The most precise is the highlight of the atomic radio clock. From true atomic clocks, most of these clocks receive their radio signals.
Haha I wish I had that clock!!!