Woodbank does not monitor or record these emails. Here you will find a brief history of technology. Initially inspired by the development of batteries, it covers technology in general and includes some interesting little known, or long forgotten, facts as well as a few myths about the development of technology, the science behind it, the context in which it occurred and the deeds of the many personalities, eccentrics and charlatans involved. You may find the Search Engine , the Technology Timeline or the Hall of Fame quicker if you are looking for something or somebody in particular. Pre B. We think of a battery today as a source of portable power, but it is no exaggeration to say that the battery is one of the most important inventions in the history of mankind.
20 American Inventions That Changed the World
Dating Techniques | mpbd.info
Radiometric dating , radioactive dating or radioisotope dating is a technique which is used to date materials such as rocks or carbon , in which trace radioactive impurities were selectively incorporated when they were formed. The method compares the abundance of a naturally occurring radioactive isotope within the material to the abundance of its decay products, which form at a known constant rate of decay. Together with stratigraphic principles , radiometric dating methods are used in geochronology to establish the geologic time scale. By allowing the establishment of geological timescales, it provides a significant source of information about the ages of fossils and the deduced rates of evolutionary change. Radiometric dating is also used to date archaeological materials, including ancient artifacts. Different methods of radiometric dating vary in the timescale over which they are accurate and the materials to which they can be applied. All ordinary matter is made up of combinations of chemical elements , each with its own atomic number , indicating the number of protons in the atomic nucleus.
Mortar is a workable paste which hardens to bind building blocks such as stones , bricks , and concrete masonry units , to fill and seal the irregular gaps between them, spread the weight of them evenly, and sometimes to add decorative colors or patterns to masonry walls. In its broadest sense, mortar includes pitch , asphalt , and soft mud or clay, as used between mud bricks. The word "mortar" comes from Latin mortarium , meaning crushed. Cement mortar becomes hard when it cures, resulting in a rigid aggregate structure; however, the mortar functions as a weaker component than the building blocks and serves as the sacrificial element in the masonry, because mortar is easier and less expensive to repair than the building blocks.
Dating techniques are procedures used by scientists to determine the age of rocks, fossils, or artifacts. Relative dating methods tell only if one sample is older or younger than another; absolute dating methods provide an approximate date in years. The latter have generally been available only since Many absolute dating techniques take advantage of radioactive decay , whereby a radioactive form of an element decays into a non-radioactive product at a regular rate. Others, such as amino acid racimization and cation-ratio dating, are based on chemical changes in the organic or inorganic composition of a sample.