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Many such sites have hominin bones, teeth, or footprints, but unless they also include evidence for tools or tool use, they are omitted here. This list excludes tools and tool use attributed to non-hominin species. See Tool use by non-humans. Since there are far too many hominin tool sites to list on a single page, this page attempts to list ...
In two papers outlining his "theory of atomicity of the elements" (1857–58), Friedrich August Kekulé was the first to offer a theory of how every atom in an organic molecule was bonded to every other atom. He proposed that carbon atoms were tetravalent, and could bond to themselves to form the carbon skeletons of organic molecules.
In the 1830s chemist Justus von Liebig began the synthesis of organic molecules, stating that "The production of all organic substances no longer belongs just to living organisms." In 1832 produced chloral hydrate, the first synthetic sleeping drug. In 1833 French chemist Anselme Payen was the first to discover an enzyme, diastase.
The Stone Age is a broad prehistoric period during which stone was widely used in the manufacture of implements with a sharp edge, a point, or a percussion surface. The period lasted roughly 2.5 million years, from the time of early hominids to Homo sapiens in the later Pleistocene era, and largely ended between 6000 and 2000 BCE with the advent of metalworking.
1701 — Newton publishes anonymously a method of determining the rate of heat loss of a body and introduces a scale, which had 0 degrees represent the freezing point of water, and 12 degrees for human body temperature. He used linseed oil as the thermometric fluid. [6] 1701 — Ole Christensen Rømer made one of the first practical ...
Collected from dairy cows within the first several days after birth and processed and pasteurized to be safe for human consumption, bovine colostrum is available in forms such as powders, pills ...
Historically, the definition of a scientific instrument has varied, based on usage, laws, and historical time period. [1] [2] [3] Before the mid-nineteenth century such tools were referred to as "natural philosophical" or "philosophical" apparatus and instruments, and older tools from antiquity to the Middle Ages (such as the astrolabe and pendulum clock) defy a more modern definition of "a ...
Primordial soup, also known as prebiotic soup and Haldane soup, is the hypothetical set of conditions present on the Earth around 3.7 to 4.0 billion years ago. It is an aspect of the heterotrophic theory (also known as the Oparin–Haldane hypothesis) concerning the origin of life, first proposed by Alexander Oparin in 1924, and J. B. S. Haldane in 1929.