In the beginning, time was a relatively abstract concept that was simply measured by the position of the sun and/or stars. It wasn’t very accurate, but it served a purpose.
Over a thousand years ago, the clock was no more than a dripping water vessel that improved timekeeping accuracy by a few hours. By 1300, the first mechanical timekeeping device was developed, improving accuracy to the hour (within 15 minutes or so). The 1600’s saw the introduction of the pendulum and spring driven movements, and minute hand, which improved timekeeping accuracy to mere minutes per day.
The late 1920’s gave way to the quartz movement, improving accuracy to one half a second per day. A little over 20 years later, the development of the atomic clock improved accuracy to 1 second in about 138 million years (give or take a day). This led to atomic clock movements for retail purchase, which automatically receive radio signals from Fort Collins, Colorado to keep precise time.
Can we get more accurate than atomic timekeeping? The answer is yes, although the means by which might surprise you. The year 2011 could well be marked as another significant year in the timeline of precision timekeeping with the development of the pulsar clock in Poland.
The pulsar clock is the first clock to measure time using a signal source from outside the Earth. It consists of a radio telescope that receives signals from selected pulsars, which are the remnant stars left-over from giant super-star explosions that took place long ago.
As any star continues to burn its fuel, it converts lighter elements (such as hydrogen and helium) to heavier and heavier elements. Eventually, stars reach a breaking point where they cannot convert the heavier elements (typically iron). Larger stars, much larger than our own sun, become increasingly unstable.
These massive stars basically collapse under the weight of their own gravity, as nuclear fusion is unable to sustain the core running out of fuel. The result is a massive explosion of the outer layers of the star, while the inner layers collapse into either a black hole or a neutron star under intense gravity.
If the core should happen to collapse into a neutron star, the remnant neutron star generally has a very high speed of rotation. For some, a beam of radiation is emitted along the magnetic axis of the star, yet the beam spins along with the rotation of the star. Since magnetic axis will generally differ from actual rotational axis, the stars can appear to flash, or “pulse”, which is how pulsars get their name.
In a sense, they are a cosmic lighthouse of sorts, continually rotating (pulsing) at accurately measurable intervals. For some “millisecond” pulsars, pulsars which basically rotate extremely fast, the regularity of pulsation proves to be more accurate than that of the atomic clock (about 5 times more accurate, improving precision to +/- 1 second in over half a billion years).
Are Pulsars the Future?
Could this become a regularity for timekeeping in the future, where radio receiver clocks latch onto the signal of a pulsar clock for accurate time? Pulsars will continue to rotate at regular intervals for millions and millions of years, and there is certainly no shortage of them as we continue to probe into the cosmos beyond our solar system.
It seems only fitting… And yet, it would also be a cosmic irony in a sense, considering the fact that our timekeeping endeavors first began with the stars so long ago.
Written By: Chris Akright
Chris is responsible for the kit, plan, and finishing technical support, which he has provided to Klockit customers for over 14 years. Chris also contributes new product designs, composes written/illustrated assembly manuals, and works to develop new kit and plan products for the Klockit catalog. Chris’s experience is the culmination of years of training under his mentor, and Klockit Designer, John Cooper.