Husky 10,000-Lumen Twin-Head LED Work Light

10 (ten) is the even natural number following 9 and preceding 11. Ten is the base of the decimal numeral system, the most common system of denoting numbers in both spoken and written language.

A head is the part of an organism which usually includes the ears, brain, forehead, cheeks, chin, eyes, nose, and mouth, each of which aid in various sensory functions such as sight, hearing, smell, and taste. Some very simple animals may not have a head, but many bilaterally symmetric forms do, regardless of size.

Heads develop in animals by an evolutionary trend known as cephalization. In bilaterally symmetrical animals, nervous tissue concentrate at the anterior region, forming structures responsible for information processing. Through biological evolution, sense organs and feeding structures also concentrate into the anterior region; these collectively form the head.

Husky is a general term for a type of dog used in the polar regions, primarily and specifically for work as sled dogs. It refers to a traditional northern type, notable for its cold-weather tolerance and overall hardiness. Modern racing huskies that maintain arctic breed traits (also known as Alaskan huskies) represent an ever-changing crossbreed of the fastest dogs.

Huskies have continued to be used in sled-dog racing, as well as expedition and trek style tour businesses, and as a means of essential transportation in rural communities. Huskies are also kept as pets, and groups work to find new pet homes for retired racing and adventure-trekking dogs.

Light, visible light, or visible radiation is electromagnetic radiation that can be perceived by the human eye. Visible light spans the visible spectrum and is usually defined as having wavelengths in the range of 400–700 nanometres (nm), corresponding to frequencies of 750–420 terahertz. The visible band sits adjacent to the infrared (with longer wavelengths and lower frequencies) and the ultraviolet (with shorter wavelengths and higher frequencies), called collectively optical radiation.

In physics, the term "light" may refer more broadly to electromagnetic radiation of any wavelength, whether visible or not. In this sense, gamma rays, X-rays, microwaves and radio waves are also light. The primary properties of light are intensity, propagation direction, frequency or wavelength spectrum, and polarization. Its speed in vacuum, 299792458 m/s, is one of the fundamental constants of nature. All electromagnetic radiation exhibits some properties of both particles and waves. Single, massless elementary particles, or quanta, of light called photons can be detected with specialized equipment; phenomena like interference are described by waves. Most everyday interactions with light can be understood using geometrical optics; quantum optics, is an important research area in modern physics.

The main source of natural light on Earth is the Sun. 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.

Lumen may refer to:

• Lumen (unit), the SI unit of luminous flux
• Lumen (anatomy), the cavity or channel within a tubular structure
• Lumen (tech company), the health and wellness tech company
• Lumen (band), a Russian rock band
• Lumen (branding agency), a design and branding company headquartered in Milan, Italy
• The Lumen (Cleveland), a skyscraper in downtown Cleveland
• Lumen (website), a database of Digital Millennium Copyright Act takedown requests
• 141 Lumen, an asteroid
• Lumen Martin Winter (1908–1982), American artist
• Lumen Pierce, a fictional character in the television series Dexter
• Lumen Technologies, telecommunications company formerly known as CenturyLink
• Stellar Lumens, a cryptocurrency and payment network
• USS Lumen (AKA-30), a US Navy ship
• Lumen (dating app), a dating app for people over fifty
• Lumen, an office building in Warsaw, Poland, part of Złote Tarasy complex
• Lumen (novel), an 1887 novel by Camille Flammarion

Twins are two offspring produced by the same pregnancy. Twins can be either monozygotic ('identical'), meaning that they develop from one zygote, which splits and forms two embryos, or dizygotic ('non-identical' or 'fraternal'), meaning that each twin develops from a separate egg and each egg is fertilized by its own sperm cell. Since identical twins develop from one zygote, they will share the same sex, while fraternal twins may or may not. In very rare cases, fraternal or (semi-) identical twins can have the same mother and different fathers (heteropaternal superfecundation).

In contrast, a fetus that develops alone in the womb (the much more common case in humans) is called a singleton, and the general term for one offspring of a multiple birth is a multiple. Unrelated look-alikes whose resemblance parallels that of twins are referred to as doppelgänger.

Work may refer to:

• Work (human activity), intentional activity people perform to support themselves, others, or the community
  • Manual labour, physical work done by humans
  • House work, housework, or homemaking
  • Working animal, an animal trained by humans to perform tasks
• Work (physics), the product of force and displacement
  • Work (electric field), the work done on a charged particle by an electric field
  • Work (thermodynamics), energy transferred by the system to its surroundings
• Creative work, a manifestation of creative effort
  • Work of art, an artistic creation of aesthetic value
• Career, an individual's journey through learning, work and other aspects of life
• Employment, a relationship between two parties where work is paid for