Light

A powerful reality in science and religion

Light is the term for visible light to the human eye, which has a wavelength of 400-700nm. Light travels at 186,282.397 mps (miles per second). Light is composed of elementary particles called photons, which are both a wave and a particle (?).

Jesus said, "x" -x:x-x. (There are 76 verses with "light" in them in the NT, KJV; Jesus' burden is light). In the Roman Catholic Church a liturgical candle must be made of at least 51% beeswax. But maybe that's "none of your beeswax". It is commonly believed that candles made of beeswax burn more cleanly than those made from petroleum based paraffin waxes. Beeswax is a byproduct of honey collection. The Egyptians and Cretans made the candle from beeswax, as early as 3000 BC.

Some candle facts: a candle maker is a chandler. It's the root of chandelier. The hottest part of the flame is just above the very dull blue part to one side of the flame, at the base. At this point, the flame is at 1,400°C. Candles typically burn at about 13 lumens of visible light. They produce 40 watts of heat, although a 40 watt light bulb produces approximately 500 lumens. The modern SI unit of luminous intensity, the candela, was based on an older unit called the candlepower, and was chosen such that a candle's luminous intensity is still about one candela. Besides illumination, today candles are used mainly for their aesthetic value, particularly to set a soft, warm, or romantic ambiance, and for emergency lighting during electrical power failures. Scented candles are used in aromatherapy.

Religious uses of flame

Sikhism: The candle is used on Diwali, the festival of light.

Buddhism: As light is used as a metaphor in Buddhist scriptures, candles are placed before Buddha statues as a sign of respect.

Hinduism: the diya, a clay lamp, is a strong symbol of enlightenment and prosperity.

Christianity: Candles represent the light of Christ. Votive candles or tapers (thin candles) may be lit as an accompaniment to prayer. The Paschal candle, specifically, represents the Resurrected Christ and is lit only at Easter, funerals, and baptisms.

In Judaism, the yahrtzeit candle is lit on the Hebrew anniversary of a loved one's death. The 8 days of Hanukkuh each have a candle, placed in the special candelabrum. Candles are also lit prior to the onset of the Three Festivals (Sukkot, Passover, and Shavuot) and the eve of Yom Kippur. During Passover, a candle is lit to symbolically represent the search for leavened bread, which they do not eat on that day.

Kwanzaa, the African-American holiday, uses 7 candles, three red, one black, three green.

Humanists use it on the festival of HumanLight, as a symbol of reason and rationality.

In the worship of Unitarian Universalists, candles are lit upon the expression of a joy or concern to the community.

Wiccans and Neopagans use candles to represent Gods, Goddesses, the 4 elements (earth, fire, air, and water), and for magical and meditative purposes.

Light is a common Western metaphor of good and evil, knowledge and ignorance, and similar concepts.

In a scientific context, the word light is sometimes used to refer to the entire electromagnetic spectrum. Moreover, in optics, the term "visible light" refers to electromagnetic radiation with wavelengths of ~300 nm (near UV) through ~1400 nm (near infrared).

Three primary properties of light are Intensity, Frequency or wavelength, and Polarization.
Light can exhibit properties of both waves and particles. This property is referred to as wave–particle duality. The study of light, known as optics, is an important research area in modern physics.

The speed of light depends upon the medium in which it is traveling, and the speed will be lower in a transparent medium. Although commonly called the "velocity of light", technically the word velocity is a vector quantity, having both magnitude and direction. Speed refers only to the magnitude of the velocity vector. This fixed definition of the speed of light is a result of the modern attempt, in physics, to define the basic unit of length in terms of the speed of light, rather than defining the speed of light in terms of a length.

Some scientists were able to bring light to a complete standstill by passing it through a Bose-Einstein Condensate of the element rubidium.

The modern theory that explains the nature of light includes this notion of wave–particle duality, described by Albert Einstein in the early 1900s, based on his study of the photoelectric effect and Planck's results. Einstein asserted that the energy of a photon is proportional to its frequency. More generally, the theory states that everything has both a particle nature and a wave nature, and various experiments can be done to bring out one or the other. The particle nature is more easily discerned if an object has a large mass, and it was not until a bold proposition by Louis de Broglie in 1924 that the scientific community realized that electrons also exhibited wave–particle duality. The wave nature of electrons was experimentally demonstrated by Davission and Germer in 1927. Einstein received the Nobel Prize in 1921 for his work with the wave–particle duality on photons (especially explaining the photoelectric effect thereby), and de Broglie followed in 1929 for his extension to other particles.

Pretty weird, huh? You and I have both particle and wave natures.

The word 'light' sums to 2.

How heavy is light?

In Lewis Carroll's Through the Looking Glass, Alice dreams the Red King is asleep. Tweedledee tells her that the king is dreaming about her and if he were to wake, "you'd go out -Bang!-like a candle!" Row, row, row your boat... Harrold, with your Purple Crayon.