Satori

Satori (悟り^?) (Chinese: 悟; pinyin: w; Korean: 오 o; Vietnamese: ngộ) is a Japanese Buddhist term for awakening, "comprehension; understanding". It is derived from the verb satoru.

In the Zen Buddhist tradition, satori refers to the experience of kenshō, "seeing into one's true nature". Ken means "seeing," shō means "nature" or "essence."

Satori and kenshō are commonly translated as enlightenment, a word that is also used to translate bodhi, prajna and buddhahood.

D.T. Suzuki: "Looking into one's nature or the opening of satori" "This acquiring of a new point of view in our dealings with life and the world is popularly called by Japanese Zen students 'satori' (wu in Chinese). It is really another name for Enlightenment ("Annuttara-samyak-sambodhi")"

Satori and kenshō

Satori is often used interchangeably with kenshō. Kenshō refers to the perception of the Buddha-Nature or emptiness. According to some authors, kenshō is a brief glimpse, while satori is considered to be a deeper spiritual experience.

Distinct from this first insight, daigo-tettei is used to refer to a "deep" or lasting realization of the nature of existence.

Importance of satori

According to D. T. Suzuki,

Satori is the raison d'tre of Zen, without which Zen is no Zen. Therefore every contrivance, disciplinary and doctrinal, is directed towards satori.

This view is typical of Rinzai, which emphasizes satori. The Soto school rejects this emphasis, and instead emphasizes "silent illumination" through the practice of zazen.

Attaining Satori

Satori is considered a "first step" or embarkation toward nirvana:

Ch'an expressions refer to enlightenment as "seeing your self-nature". But even this is not enough. After seeing your self-nature, you need to deepen your experience even further and bring it into maturation. You should have enlightenment experience again and again and support them with continuous practice. Even though Ch'an says that at the time of enlightenment, your outlook is the same as of the Buddha, you are not yet a full Buddha.

The student's mind must be prepared by rigorous study, with the use of koans, and the practice of meditation to concentrate the mind, under the guidance of a teacher. Koans are short anecdotes of verbal exchanges between teachers and students, typically of the Song dynasty, dealing with Buddhist teachings. The Rinzai-school utilizes classic collections of koans such as the Gateless Gate. The Gateless Gate was assembled by the early 13th century Chinese Zen master Wumen Hui-k'ai (無門慧開).

Wumen himself struggled for six years with koan "Zhaozhou's dog", assigned to him by Yuelin Shiguan (月林師觀; Japanese: Gatsurin Shikan) (1143, 1217), before attaining kenshō. After his understanding had been confirmed by Yuelin, Wumen wrote the following enlightenment poem:

A thunderclap under the clear blue sky

All beings on earth open their eyes;
Everything under heaven bows together;

Mount Sumeru leaps up and dances.

Nova

A nova (plural novae or novas) is a cataclysmic explosion in a white dwarf star. It is caused by the accretion of hydrogen on to the surface of the star, which ignites and starts fusion in a runaway manner. Novae are not to be confused with supernovae or luminous red novae. A nova is a sudden brightening of a star. Novae are thought to occur on the surface of a white dwarf star in a binary system. If these two stars are close enough, material from one star can be pulled off the companion star's surface and onto the white dwarf.

Development

If a white dwarf has a close companion star that overflows its Roche lobe, the white dwarf will steadily accrete gas from the companion's outer atmosphere. The companion may be a main sequence star, or one that is aging and expanding into a red giant. The captured gases consist primarily of hydrogen and helium. The gases are compacted on the white dwarf's surface by its intense gravity, compressed and heated to very high temperatures as additional material is drawn in. The white dwarf consists of degenerate matter, and so does not inflate as its temperature increases, while the accreted hydrogen is compressed upon the surface. The dependence of the hydrogen fusion rate on temperature and pressure means that it is only when it is compressed and heated at the surface of the white dwarf to a temperature of some 20 million kelvin that a fusion reaction occurs; at these temperatures, hydrogen burns via the CNO cycle.

While hydrogen fusion can occur in a stable manner on the surface of the white dwarf for a narrow range of accretion rates, for most binary system parameters the hydrogen burning is thermally unstable and rapidly converts a large amount of the hydrogen into other heavier elements in a runaway reaction, liberating an enormous amount of energy, blowing the remaining gases away from the white dwarf's surface and producing an extremely bright outburst of light. The rise to peak brightness can be very rapid or gradual and is related to the speed class of the nova; after the peak, the brightness declines steadily. The time taken for a nova to decay by 2 or 3 magnitudes from maximum optical brightness is used to classify a nova via its speed class. A fast nova will typically take less than 25 days to decay by 2 magnitudes and a slow nova will take over 80 days.

In spite of their violence, the amount of material ejected in novae is usually only about ¹⁄_10,000 of a solar mass, quite small relative to the mass of the white dwarf. Furthermore, only five percent of the accreted mass is fused during the power outburst. Nonetheless, this is enough energy to accelerate nova ejecta to velocities as high as several thousand kilometers per second higher for fast novae than slow ones with a concurrent rise in luminosity from a few times solar to 50,000 100,000 times solar. In 2010 scientists using NASA's Fermi Gamma-ray Space Telescope were surprised to discover, for the first time, that a nova can also emit gamma-rays (>100 MeV).

A white dwarf can potentially generate multiple novae over time as additional hydrogen continues to accrete onto its surface from its companion star. An example is RS Ophiuchi, which is known to have flared six times (in 1898, 1933, 1958, 1967, 1985, and 2006). Eventually, the white dwarf could explode as a type Ia supernova if it approaches the Chandrasekhar limit.

Occasionally a nova is bright enough and close enough to be conspicuous to the unaided eye. The brightest recent example was Nova Cygni 1975. This nova appeared on 29 August 1975, in the constellation Cygnus about five degrees north of Deneb and reached magnitude 2.0 (nearly as bright as Deneb). The most recent was V1280 Scorpii which reached magnitude 3.7 on 17 February 2007.

Etymology

During the 16th century, astronomer Tycho Brahe observed the supernova SN 1572 in the constellation Cassiopeia. He described it in his book De stella nova (Latin for "concerning the new star"), giving rise to the name nova. In this work he argued that a nearby object should be seen to move relative to the fixed stars, and that the nova had to be very far away. Though this was a supernova and not a classical nova, the terms were considered interchangeable until the 1930s