Skip to main content

No Night Darkness in the Infrared

Human beings perceive objects by seeing in the "normal" optical range. This is purely an evolutionary imperative. Evolution could just as easily given us eyes that work in the infrared to know what is going on around us. If this was the case we would experience no night at all. The night sky would be just as clear as the sky in the day.

At night the sky would be lit by hydroxyl molecules emitting infrared light in the form of a mass of narrow emission lines. It would be like daylight, though a few stars could be seen along with the Sun and the Moon.

Telescopes operating in the infrared get over this problem by using limited apertures and special filters. These filters use a photonic lantern system to move the light into parallel tracks. A Bragg filter reflects out the tracks and lets wavelengths between lines through. Many IR telescopes are in space where such a filter is unnecessary. The space telescopes beam data back to Earth.
. . . . . . . . . . . . . . . . . .
Science

Labels

Labels:

Popular posts from this blog

Albert Einstein's Genius Was Due to His Unusual Brain

Albert Einstein wasn't only a genius her was a very odd human being. His brain shows peculiar differences from the norm; it had many more folds than the average person. This gave the brain a greater surface area. It is like using a larger computer to do calculations. Upon his father's death in 1955, Thomas Einstein gave the pathologist permission to preserve the brain of Albert Einstein. It was photographed then dissected into 2,000 ultra-thin slices. The slices and slides of them were later distributed to researchers. The brain had more neurons and glia cells, well outside of the normal range; pariental lobes were unusual in the pattern of ridges and grooves. Einstein only had a brain of average size. The area controlling the tongue and face was larger, as was the region that involves attention and planning. Overall, Einstein's brain was complex. Many people think in words. He said his thinking was like a physical activity. If selection based on "healthy...
Read more

Natural History Museum Human Evolution Gallery

 The Human Evolution gallery at Natural History explores the origins of Homo sapiens by tracing our lineage back to when it separated from that of our closest living relatives, the bonobos and chimpanzees. Around 200,000 years ago, Africa was where modern humans developed. They have smaller faces and brow ridges, a chin that is more prominent than that of other ancient humans, and a brain case that is higher and more rounded. Modern human fossils from Israel (around 100,000 years old), Africa (around 195,000 years old), and Australia (around 12,000 years old) are among the casts on display. These fossils demonstrate that typical characteristics of modern humans evolved over time rather than emerging fully formed from Africa. They also suggest that at least two waves of people leaving Africa may have occurred, one about 100,000 years ago and the other about 60,000 years ago. We are all descendants of those who left during that second migration wave outside of Africa. Source: Natural...
Read more
  Home-made saucer that flies down the road.
Read more