The Shield vs Wyatt Family at Wrestlemania 30????? Dream Match?
Actually, the red you see in humans' eyes is a reflection of the blood vessels at the back of the retina. The camera captures their color. Which animals are you talking about? Cats and dogs? Dogs generally do have red eyes in pictures, since their eyes are more like ours than like cats. Cats, being nocturnal, have special eye morphology to help them see at night. Basically, the retina is shiny and reflects the photons back to the lens, then back to the retina again, so that the available light is amplified. Not sure why this would make it green, though. Maybe it has to do with the speed of light in the vitreous humor (the fluid in the back of the eye), which could cause the light to have a different wavelength. . .
Detecting EM waves of different frequencies need different techniques. Because the signals in any particular wavelength are extraordinarily weak, the detector shall have large aperture to gather as much as one could. Split the EM spectrum into 2 parts; one below (infra) and the other above (ultra) the visible portion of EM spectrum. The 'below' spectrum is Radio waves, microwaves and heat waves. For Radio microwaves you need sensitive antenna systems called Radio telescopes. A typical element is a metal rod quarter of the wavelength. For infra red (IR), there are IR detectors made of semiconductor materials and focal plane arrays much like optical arrays (CCD cameras) are to be used. 'Above' portion of EM detectors operate in UV, X ray, Gama rays and cosmic rays. We have extensive instrumentation methods in these. Only the sensitivity should be above the ambient noise level so as to be meaningful and as much of the flux as possible should be collected in direct proportion to distance of the stellar object under investigation.
radio waves travel though dust. we can see things in the dust like new born baby stars. they cry a lot, and when they do, they make blue light. we can detect radio waves from excited hydrogen. we can't detect radio waves from hydrogen that is mellow and/or chilling out. we can detect the comic background radiation from the big band.
