Sound waves are travelling vibrations of particles in media such as air, water or metal. So it stands to reason that they cannot travel through empty space, where there are no atoms or molecules to vibrate.

In empty space, light travels at a speed of about 300,000 km/s. Light travels so fast that light emitted from the Sun travels 150 million km to Earth in only about eight and a half minutes. However, when light travels in matter, it interacts with the atoms and molecules in the material and slows down.

Electromagnetic waves

In empty space, the wave does not dissipate (grow smaller) no matter how far it travels, because the wave is not interacting with anything else. This is why light from distant stars can travel through space for billions of light-years and still reach us on earth.

5,878,499,817,000 miles

In empty space, a photon can travel indefinitely. A photon does not “die” out. Eventually, a photon ends up interacting with matter and might be absorbed. We can see them from 13 billion light years away (really detect them as radio waves).

Ergo, light is made of electromagnetic waves and it travels at that speed, because that is exactly how quickly waves of electricity and magnetism travel through space.

Darkness is usually described simply as the absence of light; this description also works pretty well as a physical description. By this standard, “light” and “darkness” are just a binary toggle between “radiation” or “not radiation”. There are two major reasons for darkness in the universe.

Light is emmitted by a radiator and is absorbed by a conductor, yet both radiators and conductors hang in the deep of darkness, so both our Sun and Earth hang and move into their inertial destiny within the deep of darkness. The Sun hangs in the dark and lights it up.

In the visible spectrum, black is the absorption of all colors. A black pigment can, however, result from a combination of several pigments that collectively absorb all colors. If appropriate proportions of three primary pigments are mixed, the result reflects so little light as to be called “black”.

Darkness doesn’t exist, and therefore cannot spread or move, but light (which obviously does exist) can. And in doing so it can also leave an absence of light, and this absence will grow or shrink at the speed of light.

Light is primarily defined as the thing which makes things visible, and before this point the universe did not have the conditions to be visible and therefore there was no light. Darkness is not a thing, it does not exist. So we can’t say that darkness existed first, but that there was darkness first.

Eigengrau (German for “intrinsic gray”; pronounced [ˈʔaɪ̯gŋ̍ˌgʁaʊ̯]), also called Eigenlicht (Dutch and German for “intrinsic light”), dark light, or brain gray, is the uniform dark gray background that many people report seeing in the absence of light.

Chiaroscuro is an Italian artistic term used to describe the dramatic effect of contrasting areas of light and dark in an artwork, particularly paintings. It comes from the combination of the Italian words for “light” and “dark.” Film Noir, of all the film genres, is the best example of chiaroscuro.

Chiaroscuro modelling The more technical use of the term chiaroscuro is the effect of light modelling in painting, drawing, or printmaking, where three-dimensional volume is suggested by the value gradation of colour and the analytical division of light and shadow shapes—often called “shading”.

Light soy sauce is saltier, thinner, and more “refreshing” than dark soy sauce. Light soy sauce is typically used for Cantonese-style stir fries and dipping sauce, such as sauce for sushi and fried tofu. Dark soy sauce is sweeter, thicker, and full-bodied compared to light soy sauce.

The darker the brown sugar, the more molasses it contains. For light brown sugar, that usually means 3.5% molasses. For dark brown sugar, that amount is nearly doubled—6.5% molasses! This helps dark brown sugar have a more deep, complex flavor that’s closer to toffee or caramel.

Using dark brown sugar when a recipe calls for light will give your final product a more robust taste and a darker color, and it might slightly affect the texture. Because acidic molasses reacts with baking soda, using dark brown sugar in place of light might cause a higher rise and/or a wider spread.

A wide variety of colors are perceived as brown or brownish including colors that are close to black, green, yellow and orange. Perceptions of brown are influenced by browns found in nature such as wood, earth and sand.

Demerara sugar is a darker sugar than some types of brown sugar. In addition to having more molasses flavor, demerara sugar has undergone less processing which may give it a purer flavor profile.