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After a while I noticed that the sun and all the stars in his neighborhood were ruddy. Those at the opposite pole of the heaven were of an icy blue. The explanation of this strange phenomenon flashed upon me. I was still traveling, and traveling so fast that light itself was not wholly indifferent to my passage. The…
Our Sun is significantly enriched, having formed when the Universe was more than 9 billion years old in the plane of a spiral galaxy, one of the most enriched places in the Universe. Yet, when our Sun formed, it was still made out of — by mass — 71% hydrogen, 27% helium, and about 2% “other” stuff. If we convert that…
Imagine the history of the galaxy with respect to extraterrestrial intelligence. Very early there were only first generation stars, no heavy metals and therefore no possibility of life, much less intelligence. That's Stage One. In Stage Two planets with heavy metals form from the starstuff processed in the previous…
The zodiacal light is caused by sunlight reflecting from meteoric dust that orbits the sun in the plane of the solar system, remnants of the vast nebula of dust and gas out of which the solar system was born more than four billion years ago. Like the planets, this diffuse stream of particles reflects light, although…
Chemical analysis and synthesis go no farther than to the separation of particles one from another, and to their reunion. No new creation or destruction of matter is within the reach of chemical agency. We might as well attempt to introduce a new planet into the solar system, or to annihilate one already in existence…
Water is so uniquely favorable to life as we know it, it is hard to imagine life without it. Where did it come from, this planetary wrap of fluid, this liquidy bower? A standard story is that the heat of the young Earth drove hydrogen and oxygen out of chemical combination in minerals like mica, and these atoms then…
Explosions are seldom one hundred per cent efficient. When a star ends as a supernova, the nuclear explosive material, which includes uranium and plutonium together with large amounts of iron and other burnt-out elements, is distributed around and scattered in space just as is the dust cloud from a hydrogen bomb test…