A clock is a useful tool for keeping track of time. The problem is, there are so many different kinds of clocks out there that it's tough to tell what makes the clock to be most accurate.
Quartz-Strontium Atomic Timepiece
The strontium atomic clock, created by a physicist at NIST, is now the most accurate clock in the world. Over the course of its predicted lifespan in the Universe, its clocks maintain accuracy to within a hundred microseconds. Compared to caesium-based atomic clocks of the past, this is a huge upgrade. Still, its accuracy lags behind that of quartz clocks, here's how they test clock's accuracy.
For the strontium clock, thousands of atoms are trapped in a "lattice" of lasers using an intricate method. The electrons around the nucleus of a strontium atom are excited by a pair of lasers, leading to a transition between orbits. Laser light, or "maser," is produced as a byproduct, and it is used as a flywheel to replicate the strontium clock's frequency.
For this purpose, scientists at JILA employed a very steady laser to control light-trapped strontium atoms. Ten seconds of coherence time in the laser makes it possible to make connections between thousands of strontium atoms in an optical lattice. Through its interference, the laser seals off zones of high and low potential energy. This allows the clock to keep its precision timing.
Lattice-Based Optical Clock
Precision clocks based on optical lattices are the latest and greatest in the field. They make use of compact ensembles comprising thousands or even millions of atoms. Because of their close quarters, they are protected from atom collisions that would otherwise disrupt the clock frequency.
The laser in an optical lattice clock creates tiny traps. Atoms can be contained in high voltage electrodes with the help of these traps. They can modify their behavior even more by using magnetic fields.
Quantum fluctuations may now be resolved for atoms in optical lattices. However, these clocks do not have optimal stability. There's something called the Dick effect that can affect them, too. Due to aliased noise, the optical clock's readings are inaccurate.
NIST physicist Ana Maria Rey has been developing models to describe the interactions between numerous particles in optical lattices. These clocks' performance has been boosted in part because of this.
Fractional frequency instability is commonly achieved in optical lattice clocks in a matter of seconds. This increases the clock's stability, allowing for a more rapid assessment of additional systematic uncertainty.
Convection Oven Timer
Most people agree that optical clocks are more precise than microwave clocks. Precision of up to 18 digits per hour is possible with the optical clocks in under an hour, and they can even be used to monitor gravitational potential. They can also communicate with one another via optical fiber connections.
The use of a lower light frequency distinguishes an optical clock from a microwave clock. In contrast to a microwave, which operates between around ten gigahertz and over one hundred gigahertz, the optical clock may work at frequencies spanning hundreds of terahertz to the gigahertz region.
The method to synchronize optical clocks with microwave signals was developed by the National Institute of Standards and Technology (NIST). This paves the way for a plethora of potential scientific and technical developments. The study's authors detail the technology's inner workings in a Science publication scheduled for release on May 22, 2020. Moreover, the ramifications for engineering are discussed.
High-performance timekeeping is only one of the hoped-for benefits of the new microwave timekeeping system. Many advanced technologies, like multi-static synthetic aperture radar and pulse-position-modulated communication, will likely become possible because to its predicted facilitation of distributed coherent systems.
Radioactive Cesium Atomic Fountain Timepiece
The Cesium-based atomic fountain clock, commonly known as NIST F2, is one of two the most precise clocks of the several varieties of atomic clocks that have been constructed over the years. In 2014, a clock was unveiled as a result of a collaboration between the National Institute of Standards and Technology (NIST) and the Joint Institute for Laboratory Astrophysics (JILA). The atoms of the NIST F2 clock are chilled to absolute zero, allowing for an accuracy of one second per five billion years. The microwave radiations are then used to determine the atomic frequency.
The relative speeds of atomic clocks are just one of several elements that influence the time dilation effect. As a result of this, the NIST F2 is trusted as a reliable standard. By using a laser, the atoms in the clock may be cooled to absolute zero, making them stable enough to be employed in a timekeeping device.
