Table of contents

The current status of the search for glueballs is surveyed.

A review of modern concepts of photon noise (PN), which is observed even in the case of an ideal laser, is presented. Methods of transformation, squeezing, and nondemolition observation of PN, are described. The optical nondemolition methods seem to be very important for the interpretation of PN. The experiments with PN suppression by negative electron feedback are analysed in detail within two alternative approaches, which could be called the a priori and a posteriori concepts. According to the first approach, PN exists in the laser beam from the beginning, while according to the second it appears only in the detectors. The theory based on the a priori concept predicts the squeezing of the in-loop field — in contrast to the a posteriori one. Several possible crucial experiments using the nondemolition methods are discussed.

A theory is proposed of the mechanism of the excitation of free thermal convection, which is activated by an electric force and creates an electric instability. This thermoelectric mechanism can account for the excitation of cellular motion when a medium is heated from above by, for example, laser radiation.

Physical phenomena arising in the photoionisation of an atom in a laser radiation field are considered. Theoretical studies conducted by means of various methods are reviewed, predicting the existence of the atomic stabilisation effect — the reduction in photoionisation probability with increasing field strength in a fixed radiation field. Various experiments designed to observe the effect are discussed.

A review is given of the experimental investigations of the detection of radiation based on electron drift and multiplication in porous dielectrics subjected to an external electric field.

The phenomenon of superfluidity (as well as the related phenomenon of superconductivity) is of quantum nature and as such looks paradoxical from the standpoint of both classical physics and common sense. Suffice it to say that these phenomena imply the ability to flow without exhibiting viscosity or resistance (for this reason, for example, the circulation of a superconducting current within a closed circuit in the absence of external sources would last without damping for a period much in excess of the age of the Universe). At the same time, a number of unusual and quite unexpected features appear to be intrinsic to specific events of superfluid physics. Some of them will be considered in the present study.