With classical ray optics, yes. For example, it is possible to trap a ray between two reflecting spheres. Here are two pictures I created with one of my old computer programs (actually this was a teamwork project).




On these two pictures, the incident ray was directed at slightly different angles. It is quite clear, that there exists some limiting case between these two angles, in which the light will not escape either downwards nor upwards. Obviously, we could also use such a system in a bottle.

However, it should be noted that the path of the ray is unstable. If we had taken account also wave-optics, the wave would have "leaked" away very fast from he unstable equilibrium. It turns out, that taking into account quantum mechanics, such a system could be used to heat a hotter body (inside to bottle) with a colder body (outside), which is a contradiction. Thus in real life, this is impossible.

Capturing a light beam
I see that many of my WordPress installs are being hit with 1000+ failed login attempts using non-existing 'admin' account name. The requests come from different IP's every time, and I see IP's such as 8.8.8.8 (google's public dns) as the origin of some of the login attempts.

I use WordFence to detect and block these attempts, but the block is based on IP, so it's not so efficient.

My question is:


Is it 'normal' for low profile WordPress sites to get these 'attacks'? I've notices an increase in the logs during the first days of 2013.
Is it something to worry about, and is it possible to detect/verify if a login request is coming from a spoofed IP?

