Light (disambiguation)

Light is an electromagnetic radiation, part of which stimulates the sense of vision.

Light may also refer to:

Devices producing light

In religion

People

Places

Food or beverages

In music

Albums

DNA

Deoxyribonucleic acid (ⁱ/diˈɒksiˌraɪboʊnjʊˌkliːɪk, -ˌkleɪɪk/;DNA) is a molecule that carries most of the genetic instructions used in the development, functioning and reproduction of all known living organisms and many viruses. DNA is a nucleic acid; alongside proteins and carbohydrates, nucleic acids compose the three major macromolecules essential for all known forms of life. Most DNA molecules consist of two biopolymer strands coiled around each other to form a double helix. The two DNA strands are known as polynucleotides since they are composed of simpler units called nucleotides. Each nucleotide is composed of a nitrogen-containing nucleobase—either cytosine (C), guanine (G), adenine (A), or thymine (T)—as well as a monosaccharide sugar called deoxyribose and a phosphate group. The nucleotides are joined to one another in a chain by covalent bonds between the sugar of one nucleotide and the phosphate of the next, resulting in an alternating sugar-phosphate backbone. According to base pairing rules (A with T, and C with G), hydrogen bonds bind the nitrogenous bases of the two separate polynucleotide strands to make double-stranded DNA. The total amount of related DNA base pairs on Earth is estimated at 5.0 x 10³⁷, and weighs 50 billion tonnes. In comparison, the total mass of the biosphere has been estimated to be as much as 4 TtC (trillion tons of carbon).

Lia Marie Johnson

Lia Marie Johnson (born November 23, 1996) is an American actress, singer and Internet personality notable for appearing in a various web series created by the Fine Brothers, including the Emmy-winning web series Kids React, and for her own vlogging and social media output. In 2012 her personal YouTube channel, "Lia Marie Johnson", was reported to have received 13 million views. In 2014, this was reported to have increased to 39 million views and 705,000 subscribers, while her Instagram account was followed by 1.3 million followers. In a 2014 Adweek profile she was referred to as one of "12 of the biggest young stars on YouTube".

Early life

Johnson was born in Wahiawa, Hawaii, the daughter of a military family. Her family eventually settled in California.

Career

Johnson's YouTube account was created on December 17, 2007, with early videos uploaded by her mother which featured her performances at talent shows, and church recitals. After two years, Johnson began to control the output of the channel, creating content that has come to include personal commentary, sketch comedy, and musical performances. In 2010, Johnson began to work with the Fine Brothers as a recurring member of their Kids React series. This exposure increased the traffic to her own channel and became an early source of her online fame. In the aftermath of the initial series episodes, she was surprised by the phenomenon of strangers knowing her and approaching her as fans, and remarked "I think Kids React was my very first viral video, 'cus everyone knew my name after that."

Marie Odee Johnson

Marie Odee Johnson (July 23, 1897 – September 25, 2004) was an American who was one of the last surviving female veterans from the First World War. As a Yeoman (F), Johnson was among the first group of women to serve in the United States Navy in a non-nursing capacity.

Biography

Marie Odee Johnson was born in Quincy, Illinois, but her family moved to Dallas, Texas, when she was an infant. She was serving as a secretary with the Federal Bureau of Investigation (FBI) in Dallas when the United States entered World War I. Two of her brothers joined the Armed Forces and her sister was a Red Cross Nurse. The Navy recruiting office was near her office and the men who worked there convinced her that she would have a better job in the Navy. Johnson joined up at age 20. She didn't tell her "single parent father" that she joined at first. However, when she told her father that "he'd have to put a fourth star in the window" he congratulated her.

Johnson was one of 12,000 women (other than nurses) who worked for the Navy "handling clerical duties in the United States to free men for fighting." Johnson was stationed in New York City and Washington, D. C. during the war. She recalls that there were no facilities or barracks for women in the Navy at the time and so she and the other Yeomen were given $90 a month for room and board on top of their $30 a month salary.

Light

Light is electromagnetic radiation within a certain portion of the electromagnetic spectrum. The word usually refers to visible light, which is visible to the human eye and is responsible for the sense of sight. Visible light is usually defined as having wavelengths in the range of 400–700 nanometres (nm), or 4.00 × 10⁻⁷ to 7.00 × 10⁻⁷ m, between the infrared (with longer wavelengths) and the ultraviolet (with shorter wavelengths). This wavelength means a frequency range of roughly 430–750 terahertz (THz).

The main source of light on Earth is the Sun. Sunlight provides the energy that green plants use to create sugars mostly in the form of starches, which release energy into the living things that digest them. This process of photosynthesis provides virtually all the energy used by living things. Historically, another important source of light for humans has been fire, from ancient campfires to modern kerosene lamps. With the development of electric lights and power systems, electric lighting has effectively replaced firelight. Some species of animals generate their own light, a process called bioluminescence. For example, fireflies use light to locate mates, and vampire squids use it to hide themselves from prey.