I sit upon this old stone, and dream my time away.
Reblogged from thedemon-hauntedworld
How the Moon Formed: Lunar Rocks Support Giant Impact Theory
A new analysis of lunar rocks now supports the idea that the moon was born in a gigantic collision between the nascent Earth and a mysterious planet-size rock, scientists say.
Earth formed about 4.5 billion years ago, and scientists think the moon came into being shortly afterward. The prevailing explanation for the moon’s origin, known as the Giant Impact Hypothesis, is that it resulted from two protoplanets (or embryonic worlds) that slammed together — the Earth as it was forming, and a Mars-size object called Theia. A lot of debris went on to form the moon.
[Scientific theories can be accurate and even make novel predictions, whilst being ultimately wrong. Scientific theories can also be inaccurate, whilst being ultimately right.]
Consider specifically the state of ætherial theories in the 1830’s and 1840’s. The electrical fluid, a substance which was generally assumed to accumulate on the surface rather than permeate the interstices of bodies, had been utilized to explain inter alia the attraction of oppositely charged bodies, the behavior of the Leyden jar, the similarities between atmospheric and static electricity and many phenomena of current electricity.
Within chemistry and heat theory, the caloric æther … explain[ed] everything from the role of heat in chemical reactions to the conduction and radiation of heat and … standard problems of thermometry.
Within the theory of light, the optical æther functioned centrally in explanations of reflection, refraction, interference, double refraction, diffraction and polarization. (Of more than passing interest, optical æther theories had … made … startling[, true] predictions, e.g., Fresnel’s prediction of a bright spot at the center of the shadow of a circular disc; a surprising prediction which, when tested, proved correct. If that does not count as empirical success, nothing does!)
There were also gravitational (e.g., LeSage’s) and physiological (e.g., Hartley’s) æthers which enjoyed some measure of empirical success. It would be difficult to find a family of theories in this period which were as successful as æther theories; compared to them, 19th century atomism (for instance), a genuinely referring theory … was a dismal failure. Indeed, on any account of empirical success which I can conceive of, non-referring 19th-century æther theories were more successful than contemporary, referring atomic theories.
[According to] J.C. Maxwell…the æther was better confirmed than any other theoretical entity in natural philosophy!
Reblogged from isomorphismes
Larry Laudan’s ‘A Confutation of Convergent Realism’, Philosophy of Science, 48(1), 19-49
via David Corfield(via isomorphismes)