Vaccination is the use of vaccines to prevent specific diseases. Many diseases that once caused widespread illness, disability, and death now can be prevented through the use of vaccines. Vaccines are medicines that contain weakened or dea...

Viewpoint: Yes, a properly run voluntary system could produce higher vaccination rates while also protecting parents' rights. Viewpoint: No, mandatory vaccinations have greatly reduced the incidence of many diseases and should be ma...

Vacuum is a term that describes conditions where the pressure is lower than that of the atmosphere. A sealed container is said to be "under vacuum" in this case whereas it is "pressurized" when the pressure is higher than atmosphere. In a ...

In 1917, just one year after the publication of his general theory of relativity, German American physicist Albert Einstein wrote a short paper titled Cosmological Considerations on the General Theory of Relativity. For the first time the ...

A vacuum is a space completely devoid of matter. A pure vacuum does not exist--even outer space has many particles per cubic meter. In practice one uses a vacuum pump to partially exhaust a space to the highest degree possible, and this pa...

The unsaturated zone is that portion of the subsurface in which the intergranular openings of the geologic medium contain both water and air. The unsaturated zone, also known as the vadose zone or the zone of aeration, extends downward fro...

Vaira Vike-FreibergaPresident (pronounced "VAHY-rah VEE-ke FRAY-behr-guh") "We are the inheritors of our past, but we are not slaves who should live in the shadow of our past. We are the builders of our own future...

Hinduism: Vaishnavism FOUNDED: c. 500 B.C.E. RELIGION AS A PERCENTAGE OF WORLD POPULATION: 9.5 percent Overview Vaishnavism is the name given to the faith and practices of those Hindus who hold Vishnu ("the all pervasive one"...

VAJRADHARA (Tib., Rdo rje chang [Dorje chang]; Mongolian, Ochirdana) is, in the last stages of Indian Tantric Buddhism and in the continuing Tibetan traditions, the distinct embodiment of the highest state of being, the primordial Ā...

A major Central Asian river also known as the Kunduz in its lower course, the Surkhob is one of the major tributaries of the Amu Dar'ya (Oxus). The river rises in Afghanistan in the Baba Range of the Hindu Kush and flows for 420 kil...

Valdemar Poulsen was a Danish engineer who invented the magnetic recorder in 1898. His ideas were the basis of magnetic recording and led to crucial developments in communications and computer technology. Born in Copenhagen on November 23,...

1745-1822 French abbot and inventor who is credited with the conception (1771) of an embossed letter system to educate persons with blindness. In 1783-84 Abbot Haüy founded the Institute for the Blind and began training his blind stud...

1629-1683 Irish man who, with what would today be called faith healing, cured many people suffering from psychosomatic illness—illness that originates or is made worse by the patients' belief that they are ill. His ability to...

Valentine's Day (Also known as St. Valentine's Day) Symbols: hearts, cupid, flowers, chocolate, and doves/ U.S. holiday colors: red & pink Valentine's Day is a Christian Festival commemorating the martyrdom of St. Valentine on February ...

Valerie Harper was a little-known actress-dancer when she was cast as Rhoda Morgenstern, neighbor and best buddy of Mary Richards, on CBS's landmark 1970s TV sitcom The Mary Tyler Moore Show. Harper emerged as one of television hist...

1939- Russian astronaut who served as flight director of the Salyut-7 and Mir space stations from 1981-89. Ryumin spent a total of 362 days in space, primarily on two missions to the Salyut-6 space station—175 days in 1977 and 185 d...

VALKYRIES, supernatural female figures of Norse myth and literature, share many features with the dísir, fylgjur, hamingjur, Norns, and landvættir in the extant texts, and there is little terminological consistency. A primary...

Between December 19, 1777, and June 19, 1778, the American Continental Army camped on about 2,000 acres of ground in a Pennsylvania community called Valley Forge, approximately twenty miles northwest of Philadelphia. While there, approxima...

VĀLMĪKI. Legendary sage and author of the Hindu epic Rāmāyaṇa, Vālmīki also plays a role in the epic itself. The first book of his Rāmāyaṇa tells the story of the invent...

The concept of value is more complex than it might initially appear. Values can range across personal preferences as indicated by pleasures, desires, wants, and needs to more objective goods such as health, efficiency, progress, truth, bea...

With regards to computing, the term value is a quantity assigned to an element such as a variable, field, symbol, or label. The quantity involving a particular value can refer to (and be assigned to) alphabetic as well as numeric data. Val...

Pluralism is a term used to describe a number of positions from different fields. This entry will confine itself to a discussion of ethical—as opposed to political, social, or metaphysical—pluralism. Ethical pluralism (also ...

No creature haunting Western society's collective imagination has proven more enduring, more compelling, or more alluring than the vampire. But it was only with the his transformation from emaciated, plague-carrying "nosferatu" (literally,...

A Van der Waals force between molecules is a relatively weak intermolecular attraction. All neighboring molecules in liquids and solids attract each other. The nature and strength of these interactions depends on the types atom groups or f...

Van Morrison is one of the most gifted singers, performers, composers, and songwriters in the history of popular music. Born August 31, 1945 in Belfast (Northern Ireland), Van Morrison (real name: George Ivan Morrison) left school at age 1...