Recent content by UltrafastPED

Electrical feedthroughs use ceramics bonded to a metal surface which is then welded into the chamber using vacuum compatible techniques. The ceramic-metal bonding is similar to glass-metal bonding. Obtaining materials with similar coefficients of thermal expansion is mandatory, or else the...

If the UV is in the correct energy range you can use BBO to down-convert ... but this is generally a very inefficient process. It does preserve total energy and momentum. Modern engineered materials with certain defect structures can enhance the efficiency; this topic was being researched in...

Brush discharge from an insulator increases with angularity ... a sharp tip (eg, a crack or edge) will generate a discharge long before a nice smooth surface. You can see this in action if you have a Van de Graaff generator handy.

Sure ... I do this all the time. For example, you can generate electrons via thermal emission (boil them off of a point), field emission (apply a high voltage to a point), or photo emission (strike the metal cathode with an energy above the work function, eg, UV for many metals); there are also...

The largest field concentration occurs at the pointy end ... and is minimized by flat or spherical surfaces. Thus inside any high voltage device a very sharp tip is used for emission, and mirror polished smooth surfaces are used wherever emission is not desired. Knowing the answer, you can now...

You can start by reading some of the many physico-philosophical essays about time written physicists; here is a random sampling: [PLAIN]http://users.wfu.edu/brehme/time.htm[/URL] http://en.wikipedia.org/wiki/Philosophy_of_space_and_time...

I learned the principles of quantum physics and the basic mathematical techniques quite some time ago. The only discussion of quantum entanglement concerned the EPR paper. There have been many advances in the field since that time, including the somewhat mysterious phenomenon of quantum...

On leave ...

The Gaussian decay is symmetric about the axis of propagation ... the further from the axis, the weaker the Gaussian beam. Thus r is the radial distance from the axis of propagation. Cylindrical coordinates, with z the axis of propagation, is a convenient coordinate system.

Quantum physics, or quantum mechanics? For an introduction to quantum physics I recommend: Quantum Physics (Berkeley Physics Course, Volume 4), by Eyvind H. Wichmann.

Try Kittel's "Introduction to Solid State Physics"; it is an introductory text, though it does assume some familiarity with physics. It is a widely available classic.

Conduction electrons adjust in femtoseconds or less; I suspect that dielectrics respond slightly slower. You cannot detect the difference by electronic means; it would require optical experiments.

Yes, that statement is correct ... that is why the divergence of the magnetic field is always zero. It means that for every field line going out, there is an equivalent one coming in. Just look at iron filings about a magnet: the field lines are always closed.

Moment refers to moment arm ... the lever arm times the mass. See https://en.wikipedia.org/wiki/Moment_(physics ) If the sum of the forces is zero, and the sum of the moments is zero, then there will be no net force on the system.

Yes. This is done in various types of plating systems. The conditions must be carefully controlled.