forestfert.blogg.se - Atomic clock

Syncing two atomic clocks is difficult because even just measuring them can alter them and introduce errors. However, these approaches require comparisons between different clocks, and the precision of these measurements, for independent devices, will be dependent on the standard quantum limit. These optical clocks are so precise that they allow for testing small changes of gravity, both to test theories such as relativity as well as to study what’s actually below our feet. Especially when multiple clocks are needed. So precise, that they may soon be used to redefine the second. They are 100 times more precise than the traditional cesium atomic clock. Atomic clocks are therefore shielded at great expense, and special pairs of electrical configurations are selected that are as insensitive as possible to external interference.Optical atomic clocks have recently been employed to make impressive strides in precision timekeeping. External influences, such as electromagnetic fields, can influence the energy levels of the states and thus also the transition frequency.

Strictly speaking, the energy difference between the ground state and excited state is constant only for individual, completely isolated atoms.

The atoms thus constantly “watch” over the frequency of the light source, which in turn can be counted and used to measure the duration of an event.

The efficiency of exciting the atom is constantly monitored and the frequency of the light is constantly corrected to yield the highest efficiency.

In an atomic clock, this process is repeated repeatedly. If the frequency of the light is just right (the energy of its photons is exactly equal to the energy difference between two states) the atom absorbs a photon and changes into an excited state.

In an atomic clock, light (or generally electromagnetic radiation) of a certain frequency is shone on an atom (or more commonly a cooling cloud of atoms).

planets in a solar system which in principle can rotate around the central star at any distance. In the simple Bohr model, you can imagine that electrons can only move in a small number of trajectories around the nucleus, unlike e.g.

Electrons moving around an atomic nucleus can only occupy a small number of well-defined ‘states’ which have well-defined energies – one of the key discoveries that led to the formulation of quantum mechanics.

Here is how an atomic clock works in principle: We cannot measure anything more precisely than time. Today’s best atomic clocks are so accurate that they would go wrong less than a second if they were turned on at the birth of the universe 13.8 billion years ago. For this reason, the second is actually defined as exactly 9 192 631 770 cycles of a Caesium atomic clock.

different mechanical clocks which each deploy a slightly different pendulum (due to inaccuracies in the manufacturing process). Different atomic clocks using the same element thus use the same ‘pendulum’, unlike e.g. Caesium and Rubidium) have the same electron configuration. They take advantage of the fact that all atoms of a particular element (e.g. Atomic clocks use atoms, more precisely the electronic transition from one state to another as their ‘pendulum’. in a mechanical clock, a pendulum might swing once every second and by counting the number of swings, one knows how many seconds have passed. A clock is simply an apparatus that counts a repetitive event, e.g.