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7

Surface coating of an integrating sphere is optimized for low losses. This white coating (barium sulfate or PTFE) acts like an ideal lambertian scatterer. all light is scattered (Ok, not 100%, but a very high percentage like 99,5%. See ressources) it is emitted in the hemisphere following the cosine law: perpendicular to the surface it's highest. ...


6

EM radiation, including light, is a spectrum of different wavelengths. Spectroscopy is the detailed analysis of a light signal by wavelength. Ordinary color images break up light into 3 channels (red, green, and blue), but spectroscopy is generally concerned with breaking up light into a higher number of bands (e.g. 10, 100, or more), and a spectrometer is ...


6

It depends what you mean by "without an instrument". You need something to measure pressure with - your own senses won't be able to measure everyday pressure changes (though they could measure the change if for example you were thrown out of an airlock into space without a space suit). You can easily build a diy barometer. Just take a glass bottle turn it ...


5

A spectrometer does something similar to what a prism does: light goes in, and gets split up into a spectrum. If you shine white light through a prism, a rainbow comes out the other side. But not all things give off white light. In fact, each element, when excited gives off a unique set of wavelengths that act like its signature: these are called emission ...


4

An HBTI works in a very similar manner to a Fizeau / Michelson stellar interferometer. But in an HBTI, a correlation is made between fluctuations of amplitude (intensity) at points across a surface, unlike a Fizeau/Michelson which correlates fluctuations in phase. The timing of these fluctuations is much longer and this leads to a much larger tolerance in ...


3

The electrons need to get from the top to the bottom without any interference from any gas molecules that might be in the channels. If nothing else, collisions with gas molecules will degrade performance. At atmospheric pressure, I don't think the device would work at all. You can blow a hole through an MCP with over-voltage, but I'm not sure how this ...


3

The numbers on the dial generally represent either The largest value that can be read on that setting (from which you deduce the multiplier). or The multiplier. I believe almost all the digital examples I have seen lately are of the first type.


3

In a sphere, any light emitted from the center will reflect off the sides at normal incidence come back to the center. In a cube, some rays never return to the center, so you aren't measuring all of the light emitted, which defeats the purpose of the device.


2

Application: A strain gauge is a device used to measured the strain (change in length as a proportion of the original length) in an object as a result of an applied load. Most strain gauges are designed to measure strains in only one direction. How it works: A common type of strain gauge consists of thin metallic foil cut into a pattern such that most of ...


1

You can send sound waves of any wavelength into your instrument, but the trouble is that only specific wavelengths correspond to standing waves. The other waves will just die out because of destructive interference. When your sound wave collides with the closed end of a pipe for instance, it gets reflected back. If the wavelength is not right, the ...


1

The most obvious targets are protostar disks (T Tauri, Serpens FIRS 1), the Milky Way's central black hole Sgr A*, and nearby large stars (Betelgeuse). The MPIfR interferometry group web page has an impressive sample



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