The wave–particle dualism is a fundamental aspect of quantum mechanics. But, in order to explore this dualism properly and what it means for our image of atoms, it is necessary to review some ideas of probability. In some situations, no single event can be predicted with certainty. But it may still be possible to predict […]
Condensed matter • Physics • Quantum physics • Theoretical physics
You may have read somewhere that atoms are actually made up mostly of empty space. The usual description goes more or less as follows. At the centre of each atom there is a very tiny nucleus, which carries all of the positive charge and nearly all of the mass of the atom. Surrounding the nucleus […]
In the previous post, Family unification 1, we reviewed the historical development of Grand Unified Theories (GUT) of force and matter, i.e. Comprehensive Unification. We saw how the SO(18) spinor, 256, is able to accomodate the Standard Model (SM) family structure, however it contains too many families and, also, phenomenologically dangerous mirror families. During the […]
How long does it take a photon to split a molecule? It is apparent that the answer must be well bellow a second, but, how much bellow? Attoscience focuses on these kind of phenomena that occur at the attosecond time-scale using pulses of electrons or photons. The prefix ‘atto-‘, symbol a, means 10-18, hence an […]
Chemistry • Condensed matter • Energy • Materials • Physics • Quantum physics
Following the need for new and renewable sources of energy worldwide, fuel cells using electrocatalysts can be thought of as viable options. Catalyst materials modify and increase the rate of chemical reactions without itself undergoing any permanent change. An electrocatalyst is a catalyst that participates in electrochemical reactions and that functions at electrode surfaces or […]
When I first started writing about condensed matter science I found some difficulties with a few purely physical concepts, being myself a chemist by education. One of those was ‘polariton’. After some years of reading solid state physics papers and writing about them on a weekly basis, now is a familiar term, but I still […]
We tacitly assume that perfect order exists throughout crystalline materials on an atomic scale when we discuss crystals in general. However, such an idealized solid does not exist at all in nature. All of them contain large numbers of various defects or imperfections. As a matter of fact, many of the properties of materials are […]
Our core theory of fundamental physics, the Standard Model (SM), describes a vast range of phenomena precisely and very accurately. In that sense it is close to Nature’s last word. It presents, however, some shortcomings. For example, the SM contains three different forces and many independent fields. It is attractive to imagine that a deeper […]
Condensed matter • Materials • Nanotechnology • Physics • Theoretical physics
For centuries, metals were employed in optical applications only as mirrors and gratings. New vistas opened up in the late 1970s and early 1980s with the discovery of surface-enhanced Raman scattering and the use of surface plasmon (collective electronic oscillations at the surface of metals) resonances for sensing. However, it was not until the 1990s […]
A dielectric is a nonconductor of electric charge in which an applied electric field causes a displacement of charge but not a flow of charge. Light propagation through a dielectric medium is determined by the spatial distribution of the material. Photons scatter at local variations of the refractive index. Therefore, how ordered the medium is […]