Recent content by Orthoceras

About the reflective strips: "IPS" (In Plane Switching) liquid crystal displays have "interdigital electrodes" within each pixel. That is, multiple electrode strips, and neighbouring strips are connected to opposite poles. As a result the electric field is approximately parallel to the surface...

Some tv-screens, such as LG, have multiple reflective strips (electrodes?) within a pixel. The groove period of these strips is 0.03 mm, so the angle between red maxima is 1° (λ = 600 nm). In some situations that produces a rainbow effect. However you need a bright point source, such as a lamp...

A formula for the frequencies of partially filled wineglasses was derived by A.P. French in 'In vino veritas, a study of wineglass acoustics' (1983). This derivation is sometimes referred to in high school lab reports. You may find it here.

Sorry, I did not really understand your test descriptions. What do you mean by "coil" (in "attaching a coil to the electroscope", "inside the jars are some copper coils" and "coil-activated containers"), by "waving" (in "waving the polystyrene on the coil") and by "it works"? Anyways, your...

Test the insulation. Disconnect the wires. Charge a balloon by rubbing it against hair or wool. Connect the electroscope to inductor 1, and try to charge the inductor with the charged balloon. If the electroscope leafs do not rise, the inductor is not properly insulated. Do the same insulation...

That unit name is unknown in the English wikipedia. I am not sure I would trust the statement in the German wikipedia. It does not seem likely that the British Association in 1888 was unaware of a unit name conflict. In contrast, they said the uncouthness of some of these terms was put forward...

In 1888, a committee of the British Association proposed "bole" as the name for the unit of momentum. (link)

It is a shadow image. In my experience the easiest way to view floaters is looking through a pinhole at a bright surface. The smaller the pinhole the better, but not too small. I got the sharpest view of my floaters with a 0.2 mm pinhole, made by poking a very tiny hole in a piece of aluminium...

Sorry, my mistake was already discussed and solved some time ago, here.

I would think the double slit interference pattern is a standing wave as well, because the nodal lines are stationary. In that case, reflection is not a requirement.

Many sunglasses have polycarbonate lenses. Polycarbonate inherently blocks UVA and UVB (cutoff at 400 nm). The unrelated phenomenon of photochromism occurs in a specific lens coating. It can be induced by visible violet and by ultraviolet. (Fun experiment: a photochromic polycarbonate lens does...

"Photochemical change" and "darkening under UVA light" is typical for photochromic sunglasses. Are you perhaps using the word "quality" as a synonym for "photochromic"?

Nice observation! On the other hand, an argument against that explanation is that an ordinary camera is able to capture the same ring phenomenon, in the absence of human anatomy, retroreflectors, holograms, illuminated inner eyes, and fair complexions, as shown by photos in previous posts.

Another way to look at that question is these two graphs. The first one shows the radius of the secondary rainbow is zero (which corresponds to the center of the rainbow) for an index of refraction of about 1.17; the radius of the primary rainbow does not tend to zero for any n. The second graph...

The metric prefix "tera" comes from the Greek word teras or teratos, meaning "marvel, monster", whereas "tyra" in tyrannosaur is derived from tyrant. Tera and tyra seem to have a somewhat similar original meaning, are they perhaps essentially the same?