The nucleus of thorium-229 possesses a property that is unique among all known nuclides: It should be possible to excite it with ultraviolet light. To date, little has been known about the low-energy state of the Th-229 nucleus ...
General Physics
Apr 18, 2018
0
193
A European collaboration involving clock experts from the National Physical Laboratory (NPL), the Physikalisch-Technische Bundesanstalt (PTB) and the Istituto Nazionale di Ricerca Metrologica (INRIM) has used a transportable ...
Optics & Photonics
Feb 13, 2018
0
60
Atomic clocks are no longer based on a microwave transition in cesium, instead operating with other atoms that are excited using optical frequencies. Some of these new clocks are portable. At its QUEST Institute, PTB is currently ...
Optics & Photonics
Jan 23, 2018
0
25
The Planck scale works according to the principle of electromagnetic force compensation: A weight force on one side of the scale is balanced by an electromagnetic force on the other side. This means that weights (so-called ...
General Physics
Jul 14, 2017
0
12
In physics, it is useful to know as precisely as possible how friction phenomena arise—and not only on the macroscopic scale, as in mechanical engineering, but also on the microscopic scale, in areas such as biology and ...
Materials Science
Jul 14, 2017
0
10
No one had ever come so close to the ideal laser before: theoretically, laser light has only one single color (also frequency or wavelength). In reality, however, there is always a certain linewidth. With a linewidth of only ...
Optics & Photonics
Jun 29, 2017
2
13
At present, the kelvin is literally based on no more than water—on the triple point of water, to be more precise. The base unit of temperature is therefore dependent on a material whose properties may vary. But this is ...
General Physics
Apr 5, 2017
0
21
By 2018, scientists want all physical base units to be based on solid, unchangeable fundamental constants. The units "meter" and "second" are well ahead of schedule; the kelvin, the kilogram, the mole and the ampere are next ...
General Physics
Nov 29, 2016
0
7
In the past few years, optical atomic clocks have made spectacular progress, becoming 100 times more precise than the best caesium clocks. So far, their precision has been available only locally, since frequency transfer ...
General Physics
Aug 9, 2016
2
42
Atomic clock experts from the Physikalisch-Technische Bundesanstalt (PTB) are the first research group in the world to have built an optical single-ion clock which attains an accuracy which had only been predicted theoretically ...
General Physics
Feb 10, 2016
0
19
