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🔗 Technology 🔗 Physics 🔗 Color 🔗 Chemistry 🔗 Science

Vantablack is a material developed by Surrey NanoSystems in the United Kingdom and is one of the darkest substances known, absorbing up to 99.965% of visible light (at 663 nm if the light is perpendicular to the material).

The name is a compound of the acronym VANTA (vertically aligned nanotube arrays) and the color black.

🔗 Science 🔗 Academic Journals

FUTON bias (acronym for "full text on the Net") is a tendency of scholars to cite academic journals with open access—that is, journals that make their full text available on the Internet without charge—in preference to toll-access publications. Scholars in some fields can more easily discover and access articles whose full text is available online, which increases authors' likelihood of reading and citing these articles, an issue that was first raised and has been mainly studied in connection with medical research. In the context of evidence-based medicine, articles in expensive journals that do not provide open access (OA) may be "priced out of evidence", giving a greater weight to FUTON publications. FUTON bias may increase the impact factor of open-access journals relative to journals without open access.

One study concluded that authors in medical fields "concentrate on research published in journals that are available as full text on the internet, and ignore relevant studies that are not available in full text, thus introducing an element of bias into their search result". Authors of another study conclude that "the OA advantage is a quality advantage, rather than a quality bias", that authors make a "self-selection toward using and citing the more citable articles—once OA self-archiving has made them accessible", and that open access "itself will not make an unusable (hence uncitable) paper more used and cited".

The related no abstract available bias is a scholar's tendency to cite journal articles that have an abstract available online more readily than articles that do not—this affects articles' citation count similarly to FUTON bias.

🔗 Biology 🔗 Engineering 🔗 Science

Xenobots, named after the African clawed frog (Xenopus laevis), are synthetic organisms that are automatically designed by computers to perform some desired function and built by combining together different biological tissues.

Xenobots are less than a 1 millimeter (0.039 inches) wide and composed of just two things: skin cells and heart muscle cells, both of which are derived from stem cells harvested from early (blastula stage) frog embryos. The skin cells provide rigid support and the heart cells act as small motors, contracting and expanding in volume to propel the xenobot forward. The shape of a xenobot's body, and its distribution of skin and heart cells, are automatically designed in simulation to perform a specific task, using a process of trial and error (an evolutionary algorithm). Xenobots have been designed to walk, swim, push pellets, carry payloads, and work together in a swarm to aggregate debris scattered along the surface of their dish into neat piles. They can survive for weeks without food and heal themselves after lacerations.

🔗 Religion 🔗 Biology 🔗 History of Science 🔗 Science 🔗 Evolutionary biology 🔗 Molecular Biology 🔗 Creationism 🔗 Tree of Life 🔗 Molecular Biology/Genetics

Evolution is change in the heritable characteristics of biological populations over successive generations. These characteristics are the expressions of genes that are passed on from parent to offspring during reproduction. Different characteristics tend to exist within any given population as a result of mutation, genetic recombination and other sources of genetic variation. Evolution occurs when evolutionary processes such as natural selection (including sexual selection) and genetic drift act on this variation, resulting in certain characteristics becoming more common or rare within a population. The evolutionary pressures that determine whether a characteristic would be common or rare within a population constantly change, resulting in a change in heritable characteristics arising over successive generations. It is this process of evolution that has given rise to biodiversity at every level of biological organisation, including the levels of species, individual organisms and molecules.

The theory of evolution by natural selection was conceived independently by Charles Darwin and Alfred Russel Wallace in the mid-19th century and was set out in detail in Darwin's book On the Origin of Species. Evolution by natural selection was first demonstrated by the observation that more offspring are often produced than can possibly survive. This is followed by three observable facts about living organisms: (1) traits vary among individuals with respect to their morphology, physiology and behaviour (phenotypic variation), (2) different traits confer different rates of survival and reproduction (differential fitness) and (3) traits can be passed from generation to generation (heritability of fitness). Thus, in successive generations members of a population are more likely to be replaced by the progenies of parents with favourable characteristics that have enabled them to survive and reproduce in their respective environments. In the early 20th century, other competing ideas of evolution such as mutationism and orthogenesis were refuted as the modern synthesis reconciled Darwinian evolution with classical genetics, which established adaptive evolution as being caused by natural selection acting on Mendelian genetic variation.

All life on Earth shares a last universal common ancestor (LUCA) that lived approximately 3.5–3.8 billion years ago. The fossil record includes a progression from early biogenic graphite, to microbial mat fossils, to fossilised multicellular organisms. Existing patterns of biodiversity have been shaped by repeated formations of new species (speciation), changes within species (anagenesis) and loss of species (extinction) throughout the evolutionary history of life on Earth. Morphological and biochemical traits are more similar among species that share a more recent common ancestor, and can be used to reconstruct phylogenetic trees.

Evolutionary biologists have continued to study various aspects of evolution by forming and testing hypotheses as well as constructing theories based on evidence from the field or laboratory and on data generated by the methods of mathematical and theoretical biology. Their discoveries have influenced not just the development of biology but numerous other scientific and industrial fields, including agriculture, medicine, and computer science.

🔗 United States 🔗 Military history 🔗 Military history/North American military history 🔗 Military history/United States military history 🔗 United States/Military history - U.S. military history 🔗 Military history/Military science, technology, and theory 🔗 Physics 🔗 Women's History 🔗 History of Science 🔗 Tennessee 🔗 Military history/World War II 🔗 Physics/History 🔗 Science

The Calutron Girls were a group of young women, mostly high school graduates who joined the World War II efforts in Oak Ridge, Tennessee in 1945.

Although they were not allowed to know at the time, they were monitoring dials and watching meters for a calutron, a mass spectrometer that separates uranium isotopes. The enriched uranium was used to make the first atomic bomb.

Calutron Girls were trained and employed at the Y-12 National Security Complex. Wartime labor shortages forced the Tennessee Eastman Corporation to hire women to work at the Y-12 plant.

According to Gladys Owens, one of the few Calutron Girls, a manager at the facility once told them: "We can train you how to do what is needed, but cannot tell you what you are doing. I can only tell you that if our enemies beat us to it, God have mercy on us!"

🔗 Climate change 🔗 Environment 🔗 Science

There is a nearly unanimous scientific consensus that the Earth has been consistently warming since the start of the Industrial Revolution, that the rate of recent warming is largely unprecedented,^{: 8 : 11} and that this warming is mainly the result of a rapid increase in atmospheric carbon dioxide (CO₂) caused by human activities. The human activities causing this warming include fossil fuel combustion, cement production, and land use changes such as deforestation,^: 10–11 with a significant supporting role from the other greenhouse gases such as methane and nitrous oxide.^: 7 This human role in climate change is considered "unequivocal" and "incontrovertible".^{: 4 : 4}

Nearly all actively publishing climate scientists say humans are causing climate change. Surveys of the scientific literature are another way to measure scientific consensus. A 2019 review of scientific papers found the consensus on the cause of climate change to be at 100%, and a 2021 study concluded that over 99% of scientific papers agree on the human cause of climate change. The small percentage of papers that disagreed with the consensus often contain errors or cannot be replicated.

The evidence for global warming due to human influence has been recognized by the national science academies of all the major industrialized countries. In the scientific literature, there is a very strong consensus that global surface temperatures have increased in recent decades and that the trend is caused by human-induced emissions of greenhouse gases. No scientific body of national or international standing disagrees with this view. A few organizations with members in extractive industries hold non-committal positions, and some have tried to persuade the public that climate change is not happening, or if the climate is changing it is not because of human influence, attempting to sow doubt in the scientific consensus.