Hydrogen Levels in the Universe

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 into “number of atoms” and treat the Sun as typical of the Universe, that means, over the first 9.3 billion years of the Universe, the fraction of hydrogen ha...

 Outline of the Natural Sciences Pt. I

The heavens are enriched for the man of science with new stars, and he applies his knowledge to determine and foretel with accuracy their positions and movements. Natural philosophy, gradually delivered from the vague explanations of Descartes, in the same manner as it before was disembarrassed from the absurdities of the schools, is now nothing more than the art of interrogating nature by experiment, for the parpose of afterwards deducing more general facts by computation. The weight of the...

 Lenses Supplement the Infirmities of the Senses

The next care to be taken, in respect of the Senses, is a supplying of their infirmities with Instruments, and, as it were, the adding of artificial Organs to the natural; this in one of them has been of late years accomplisht with prodigious benefit to all sorts of useful knowledge, by the invention of Optical Glasses. By the means of Telescopes, there is nothing so far distant but may be represented to our view; and by the help of Microscopes, there is nothing so small, as to escape our inq...