The following excerpts are taken from the book, “A Short History of Nearly Everything”. These are truly awesome statements.
Welcome to the Solar System
Astronomers these days can do the most amazing things. If someone struck a match on the Moon, they could spot the flare.
With their radio telescopes they can capture wisps of radiation so preposterously faint that the TOTAL amount of energy collected from outside the solar system by all of them together since collecting began in 1951 is “less than the energy of a single snowflake striking the ground,” in the words of Carl Sagan.
The Measure of Things
Henry Cavendish is often credited with being the first person to use Newton’s law of gravitation to calculate the mass of the earth, but he did so with a machine developed by a man named John Michell, who died before he could use it.
Delicacy was the key word. Not a whisper of disturbance could be allowed into the room containing the apparatus, so Cavendish took up a position in an adjoining room and made his observations with a telescope aimed through a peephole. The work was incredibly exacting and involved seventeen delicate, interconnected measurements, which together took nearly a year to complete…
Today, scientists have at their disposal machines so precise they can detect the weight of a single bacterium and so sensitive that readings be disturbed by someone yawning seventy-five feet away, but they have not significantly improved on Cavendish’s measurements of 1979.
more to come…
Tags: history of physics