User:Aarchi science

Hydrogen chloride, also known under the name HCl, is a highly corrosive and toxic colorless gas that forms white fumes on contact with humidity. These fumes consist of hydrochloric acid which forms when hydrogen chloride dissolves in water. Hydrogen chloride gas as well as hydrochloric acid are important chemicals in chemistry, science, technology, and industry. The name HCl often refers somewhat misleadingly to hydrochloric acid instead of the gaseous hydrogen chloride.

Hydrogen chloride forms corrosive hydrochloric acid on contact with body tissue. Inhalation of the fumes can cause coughing, choking, inflammation of the nose, throat, and upper respiratory tract, and in severe cases, pulmonary edema, circulatory system failure, and death. Skin contact can cause redness, pain, and severe skin burns. Hydrogen chloride may cause severe burns to the eye and permanent eye damage.

The Hubble Space Telescope (HST) is a telescope in orbit around the Earth, named after astronomer Edwin Hubble for his discovery of galaxies outside the Milky Way and his creation of Hubble's Law, which calculates the rate at which the universe is expanding. Its position outside the Earth's atmosphere allows it to take sharp optical images of very faint objects, and since its launch in 1990, it has become one of the most important instruments in the history of astronomy. It has been responsible for many ground-breaking observations and has helped astronomers achieve a better understanding of many fundamental problems in astrophysics. Hubble's Ultra Deep Field is the deepest (most sensitive) astronomical optical image ever taken. Meanings and types of eugenics The word eugenics etymologically derives from the Greek word eus (good or well) and the suffix -genēs (born), and was coined by Francis Galton in 1883.

Eugenics has, from the very beginning, meant many different things to many different people. Historically, the term has referred to everything from prenatal care for mothers to forced sterilization and euthanasia. Much debate took place in the past, and takes place today, as to what exactly counts as eugenics.[3] Some types of eugenics, such as race-based eugenics and class-based eugenics, are sometimes called 'pseudo-eugenics' by proponents of strict eugenics that deals only with beneficial and detrimental intrinsic traits.

The term eugenics is often used to refer to movements and social policies that were influential during the early 20th century. In a historical and broader sense, eugenics can also be a study of "improving human genetic qualities". It is sometimes broadly applied to describe any human action whose goal is to improve the gene pool. Some forms of infanticide in ancient societies, present-day reprogenetics, preemptive abortions and designer babies have been (sometimes controversially) referred to as eugenic.

Because of its normative goals and historical association with scientific racism, as well as the development of the science of genetics, the western scientific community has mostly disassociated itself from the term "eugenics", although one can find advocates of what is now known as liberal eugenics. Ideological social determinists, some of which have obtained college degrees in fields relevant to eugenics, often describe eugenics as a pseudoscience. Modern inquiries into the potential use of genetic engineering have led to an increased invocation of the history of eugenics in discussions of bioethics, most often as a cautionary tale. Some ethicists suggest that even non-coercive eugenics programs would be inherently unethical, though this view has been challenged by such thinkers as Nicholas Agar.[4]

Eugenicists advocate specific policies that (if successful) would lead to a perceived improvement of the human gene pool. Since defining what improvements are desired or beneficial is perceived by many as a cultural choice rather than a matter that can be determined objectively (e.g., by empirical, scientific inquiry), eugenics has often been deemed a pseudoscience. The most disputed aspect of eugenics has been the definition of "improvement" of the human gene pool, such as what is a beneficial characteristic and what is a defect. This aspect of eugenics has historically been tainted with scientific racism.

Early eugenicists were mostly concerned with perceived intelligence factors that often correlated strongly with social class. Many eugenicists took inspiration from the selective breeding of animals (where purebreds are often strived for) as their analogy for improving human society. The mixing of races (or miscegenation) was usually considered as something to be avoided in the name of racial purity. At the time this concept appeared to have some scientific support, and it remained a contentious issue until the advanced development of genetics led to a scientific consensus that the division of the human species into unequal races is unjustifiable. Some see this as an ideological consensus, since equality, just like inequality, is a cultural choice rather than a matter that can be determined objectively.

Eugenics has also been concerned with the elimination of hereditary diseases such as haemophilia and Huntington's disease. However, there are several problems with labeling certain factors as "genetic defects":

In many cases there is no scientific consensus on what a "genetic defect" is. It is often argued that this is more a matter of social or individual choice. What appears to be a "genetic defect" in one context or environment may not be so in another. This can be the case for genes with a heterozygote advantage, such as sickle cell anemia or Tay-Sachs disease, which in their heterozygote form may offer an advantage against, respectively, malaria and tuberculosis. Although some birth defects are uniformly lethal, disabled persons can succeed in life. Many of the conditions early eugenicists identified as inheritable (pellagra is one such example) are currently considered to be at least partially, if not wholly, attributed to environmental conditions. Similar concerns have been raised when a prenatal diagnosis of a congenital disorder leads to abortion (see also preimplantation genetic diagnosis).

Eugenic policies have been conceptually divided into two categories: positive eugenics, which encourage a designated "most fit" to reproduce more often; and negative eugenics, which discourage or prevent a designated "less fit" from reproducing. Negative eugenics need not be coercive: a state might offer financial rewards to certain people who submit to sterilization, although some critics might reply that this incentive along with social pressure could be perceived as coercion. Positive eugenics can also be coercive. Abortion by "fit" women was illegal in Nazi Germany, and William Shirer (in The Decline and Fall of the Third Reich) mentioned unsubstantiated reports that Aryan women unwilling to become pregnant were often forced into pregnancy through state-supported rape.

During the 20th century, many countries enacted various eugenics policies and programs, including:

Genetic screening Birth control Promoting differential birth rates Marriage restrictions Immigration control Segregation (both racial segregation as well as segregation of the mentally ill from the normal) Compulsory sterilization Forced abortions, or, conversely, forced pregnancies Genocide Most of these policies were later regarded as coercive, restrictive, or genocidal, and now few jurisdictions implement policies that are explicitly labeled as eugenic or unequivocally eugenic in substance (however labeled). However, some private organizations assist people in genetic counseling, and reprogenetics may be considered as a form of non-state-enforced "liberal" eugenics.

There are 3 main ways by which the methods of eugenics can be applied. They are:

mandatory eugenics, in which the government mandates a eugenics program. promotional voluntary eugenics, in which eugenics is voluntarily practiced and promoted to the general population, but not officially mandated. private eugenics, which is practiced voluntarily by individuals and groups, but not promoted to the general population. There are also different goals of eugenics.[5] They are:

intrinsic eugenics, which seeks to exclusively improve a person's genetic traits that are intrinsically beneficial or detrimental to them, such as physical health, mental health, attractiveness, reproductive ability, physical aptitude, intelligence, and self-control racial eugenics, which emphasizes selectively breeding a specific race or races extrinsic social eugenics, which selectively breeds people that have high social status and the genetic traits thereof, such as wealth, attendance at popular colleges, college degrees, popularity, extroversion, personality, and humour