Liturgy

Liturgy (Greek: λειτουργία) is the customary public worship performed by a specific religious group, according to its particular beliefs, customs and traditions.

The word, sometimes rendered by its English translation "service", may refer to an elaborate formal ritual such as the Eastern Orthodox Divine Liturgy (Greek: Θεία Λειτουργία), Catholic Mass, the Eucharist or Mass (Anglican Communion) or a daily activity such as the Muslim salah and Jewish services. As a religious phenomenon, liturgy is a communal response to the sacred through activity reflecting praise, thanksgiving, supplication, or repentance. Ritualization may be associated with life events such as birth, coming of age, marriage and death. It thus forms the basis for establishing a relationship with a divine agency, as well as with other participants in the liturgy. Methods of dress, preparation of food, application of cosmetics or other hygienic practices are all considered liturgical activities.

Etymology

The word liturgy, derived from the technical term in ancient Greek, leitourgia, signifies the often expensive offers of service to the people, and thus to the polis and the state. Through the leitourgia, the rich carried a financial burden and were correspondingly rewarded with honours. The leitourgia became both mandatory and honorific, supporting the patron's standing among the elite. The holder of a Hellenic leitourgia was not taxed a specific sum, but was entrusted with a particular ritual, which could be performed with greater or lesser magnificence. The chief sphere remained that of civic religion, embodied in the festivals: M.I. Finley notes "in Demosthenes' day there were at least 97 liturgical appointments in Athens for the festivals, rising to 118 in a (quadrennial) Panathenaic year." Eventually, under the Roman Empire, such obligations, known as munera, devolved into a competitive and ruinously expensive burden that was avoided when possible.

Liturgy (disambiguation)

Liturgy is a Christian term with several meanings:

Liturgy may also refer to:

Helix

A helix (pl: helixes or helices) is a type of smooth space curve, i.e. a curve in three-dimensional space. It has the property that the tangent line at any point makes a constant angle with a fixed line called the axis. Examples of helices are coil springs and the handrails of spiral staircases. A "filled-in" helix – for example, a spiral ramp – is called a helicoid. Helices are important in biology, as the DNA molecule is formed as two intertwined helices, and many proteins have helical substructures, known as alpha helices. The word helix comes from the Greek word ἕλιξ, "twisted, curved".

Types

Helices can be either right-handed or left-handed. With the line of sight along the helix's axis, if a clockwise screwing motion moves the helix away from the observer, then it is called a right-handed helix; if towards the observer, then it is a left-handed helix. Handedness (or chirality) is a property of the helix, not of the perspective: a right-handed helix cannot be turned to look like a left-handed one unless it is viewed in a mirror, and vice versa.

Phelix

Phelix is a high-speed stream cipher with a built-in single-pass message authentication code (MAC) functionality, submitted in 2004 to the eSTREAM contest by Doug Whiting, Bruce Schneier, Stefan Lucks, and Frédéric Muller. The cipher uses only the operations of addition modulo 2³², exclusive or, and rotation by a fixed number of bits. Phelix uses a 256-bit key and a 128-bit nonce, claiming a design strength of 128 bits. Concerns have been raised over the ability to recover the secret key if the cipher is used incorrectly.

Performance

Phelix is optimised for 32-bit platforms. The authors state that it can achieve up to eight cycles per byte on modern x86-based processors.

FPGA Hardware performance figures published in the paper "Review of stream cipher candidates from a low resource hardware perspective" are as follows:

Helix

Phelix is a slightly modified form of an earlier cipher, Helix, published in 2003 by Niels Ferguson, Doug Whiting, Bruce Schneier, John Kelsey, Stefan Lucks, and Tadayoshi Kohno; Phelix adds 128 bits to the internal state.

Helix (newspaper)

After a series of organizational meetings held at the Free University of Seattle involving a large and eclectic group including Paul Dorpat, Tom Robbins, Lorenzo Milam and others from KRAB-FM, John Ullman of the Seattle Folklore Society, Unitarian minister Paul Sawyer, and many others, the Helix first appeared on March 23, 1967. A member of both the Underground Press Syndicate and the Liberation News Service, it published a total of 125 issues (sometimes as a weekly, sometimes as a biweekly) before folding on June 11, 1970. The first issue was produced by Paul Dorpat with $200 in borrowed capital, out of a rented storefront on Roosevelt Way NE. After being turned down by the first printers they approached, they found a printer in Ken Monson, communications director of the International Association of Machinists local, who had recently acquired a printing press. 1500 copies were printed of the first issue. By the fourth biweekly issue sales had reached 11,000 copies. After the first two issues a "split-font" rainbow effect was sometimes used to print psychedelically colorful front covers; issues averaged 24 pages, with illustrations and graphics clipped from old magazines and having little to do with the adjoining copy crammed into the interior pages.

Human skull

The human skull is the bony structure that forms the head in the human skeleton. It supports the structures of the face and forms a cavity for the brain. Like the skulls of other vertebrates, it protects the brain from injury.

The skull consists of two parts, of different embryological origin—the neurocranium and the facial skeleton (also called the viscerocranium). The neurocranium (or braincase) forms the protective cranial vault that surrounds and houses the brain and brainstem. The facial skeleton is formed by the bones supporting the face.

Except for the mandible, all of the bones of the skull are joined together by sutures—synarthrodial (immovable) joints formed by bony ossification, with Sharpey's fibres permitting some flexibility.

Structure

Bones

Human skull symbolism

Skull symbolism is the attachment of symbolic meaning to the human skull. The most common symbolic use of the skull is as a representation of death and mortality.

Humans can often recognize the buried fragments of an only partially revealed cranium even when other bones may look like shards of stone. The human brain has a specific region for recognizing faces, and is so attuned to finding them that it can see faces in a few dots and lines or punctuation marks; the human brain cannot separate the image of the human skull from the familiar human face. Because of this, both the death and the now past life of the skull are symbolized.

Moreover, a human skull with its large eye sockets displays a degree of neoteny, which humans often find visually appealing—yet a skull is also obviously dead. As such, human skulls often have a greater visual appeal than the other bones of the human skeleton, and can fascinate even as they repel. Our present society predominantly associates skulls with death and evil. However, to some ancient societies it is believed to have had the opposite association, where objects like crystal skulls represent "life": the honoring of humanity in the flesh and the embodiment of consciousness.