165 results found for physics

Conservation laws are very important in quantum physics. Two examples of applications will be given. First, optical pumping which uses transfer of angular momentum from polarized photons to atoms to produce highly polarized atomic gases. Then, laser ....

Metrology - the science of measurements - is responsible for the international uniformity and precision in standards. Today, the seven units for meter, kilogram, second, ampere, kelvin, mole, and candela of our international system of units (SI units....

Several laser-based Atomic Clocks now have an accuracy potential of ~2 x10-18, a hundred-fold better than the best achieved after more than 60 years' experience with rf resonances in Cs atoms. Still, this long attention span documents that the Cs Fou....

Elementary Particle Physics seeks to discover the basic constituents of matter and understand the fundamental forces that act on them. In this lecture I shall review the current state of particle physics, the grand success of the ñstandard modelî, ....

Recently the Higgs particle has been discovered at CERN. This particle was theoretically predicted. The historical development of field theory, leading to this prediction will be discussed.

One of the most remarkable results of astro-particle Physics has been the success of the Standard Model, recently culminated in the discovery of the Higgs particle (Ho). However, the Ho is observable only in few channels at the LHC, in the presence o....

The year 2015 has been named the International Year of Light, to mark milestones in the science of light which occurred 1000, 200, 150, 100 and 50 years go. I was a young student in physics in 1965, when the cosmic radiation background was discovered....

Maxwell's electromagnetic theory (now 150 years old) seemed in its comprehensive way to be capable of answering all of the questions one might ever pose about the theory of light. But that spell was broken in 1900 by Planck's discovery that light bea....

Two of the great scientific and technical revolutions of the 20th century were the discovery of the quantum nature of the submicroscopic world, and the advent of information science and engineering. Both of these have had a profound effect not only o....

The spectrum of a frequency comb, commonly generated by a mode-locked femtosecond laser, consists of several hundred thousand precisely evenly spaced spectral lines. Such laser frequency combs have revolutionized the art of measuring the frequency of....

In the beginning of the 60s, the laws of classical general relativity, Einstein's generalisation of Newtonian gravity, and of quantum electrodynamics, the quantum version of Maxwell's electromagnetic theory, were known. These laws describe long range....

Throughout the 20th century it was widely accepted that a light microscope relying on conventional optical lenses cannot discern details that are much finer than about half the wavelength of light (200-400 nm), due to diffraction. However, in the 199....

The discovery of the Higgs boson at CERN’s LHC accelerator in 2012 by the ATLAS and CMS collaborations was the culmination of a decades-long search that had started in 1964 with the proposal of this unique particle, a signature of the origin of the....

What do six brides have to do with Density-Functional Theory? Discover it in this lecture, in which the essential ideas behind DFT are explained in three different non-technical ways. After this practical lecture, you will be able to understand the m....

30-minute lecture about the physics of hyperfine interactions, and about how to calculate hyperfine interactions by the WIEN2k DFT code

Most of the data we generate and receive (whether emails, tweets, videos or mobile calls) are now carried by optical fibres, which use light to transmit vast quantities of information over trans-oceanic distances. The use of hundreds of wavelengths ....

A historical overview is presented of the experimental development of ever shorter laser pulses from 1960 to the present. Already in the early sixties nanosecond pulses were achieved and the entry into the picosecond domain was reached in the late s....

Our brains are always generating electrical signals, even if we close our eyes, plug our ears, and lie in a warm bath. These signals are called cortical noise because they don't correlate with any sensation or thought of which we are aware. I will ....

Light quanta are the fundamental units of radiant energy. When propagating freely they travel at the fastest attainable speed and live forever. These properties recommend them as the ideal messengers for communication of all sorts. Ordinary light ....

This talk describes a new approach to the problem of characterising physical reality, one with the potential to fill in gaps in the conventional understanding of nature. It is based on a different view from the usual one of structure at the finest l....

We are using the planet's fossil fuel resources in a time which is very short compared to that of human evolution. In the same process we are changing the planet's climate and sea level, threatening the future of large segments of the global populat....

Particle physics mainly developed after World War II. It has its roots in the first half of the previous century, when it became clear that all matter is made up from atoms, and the atoms in turn were found to contain a nucleus surrounded by electro....

I had the great fortune to receive a Nobel Prize in Physics for using electron tunneling to measure the energy gap in superconductors. In this talk I will recollect some of the events that led to this discovery and hopefully I will be able to convey....

The Optical Frequency Comb concept and technology exploded in 1999-2000 from the synthesis of advances in independent fields of Laser Stabilization, UltraFast Lasers, and NonLinear Optical Fibers. The Comb was developed first as a method for optical....