The sun, stars, fire, and lightning are all natural sources of light. Some creatures and plants, such as fireflies, jellyfish, and mushrooms, can even generate their own light. This is known as bioluminescence. Humans generate artificial light. This is done using gas lamps, electricity, and more recently, lasers and LED lights.
Biological systems are very efficient at converting energy into light emissions. For example, the green algae called scotoductae uses the energy from sunlight to produce chemicals that itself can conduct an electric current- this allows it to pump sodium ions into its cells which produces a potential difference across its cell membrane which can be used to power chemical reactions. Other organisms have evolved ways to make use of other energy sources but they all share the property of being extremely efficient at converting energy into light emissions.
People often say that the only true dark matter is money. This is because all else being equal, the more money there is in existence the more useful technology will become and thus we should be able to create more dark matter with our investments or research projects than anything else. However, this assumption is not always true and sometimes less money leads to more progress. For example, when NASA started funding lunar lander projects in 1969, nobody thought they would be able to send humans to the moon within 10 years. Today, private companies are working on technologies that could help us go back to the moon within five years.
The sun, stars, and candles are a few examples of natural light sources. Light bulbs, lamp posts, and televisions are a few examples of artificial light sources. Many things, such as tables, trees, and the Moon, merely reflect light from a light source. Examples include reflection in a mirror or glow-in-the-dark paint.
Artificial light sources have many advantages over natural light sources. An example is that with artificial light, you can see at night. Natural light sources are mostly invisible until sunrise or sunset when they are available. Artificial light also does not emit heat-trapping gases like carbon dioxide or ozone while giving off some amount of heat itself. These gases are called greenhouse gases because when they enter into the atmosphere, they will trap heat inside the atmosphere which would otherwise be released back to space. This has been a problem for our planet because the increased temperature due to these gases has caused ice shelves to melt, sea levels to rise, and wildfires to increase in frequency. Greenhouse gas emissions come from cars, trucks, airplanes, and factories among other things. Electric lights are better for the environment than oil lamps or natural gas lamps because they use less energy to produce the same amount of light.
Solar power and wind power are other forms of renewable energy. Solar power uses the energy from the sun while wind power uses the wind's kinetic energy. Both methods do not cause pollution nor do they emit any greenhouse gases.
Natural light, which generates heat and color, is produced by the sun's radiation. It is then absorbed by plants after being filtered via the Earth's atmosphere. A filament that glows with electricity or halogen gas, or an electrical gadget that emits light, are examples of artificial light sources.
These days, almost everything used to produce light is technological: lamps, candles, fire, windmills, and even sunlight itself. But before there were technologies, people found many ways of producing light. In fact, humans have been using optics to illuminate their environment for thousands of years. The ancient Chinese invented glass in about 600 B.C., which was followed by other materials such as clay and bone. During the Renaissance era (1350-1550), oil lamps became popular. They were followed later on by electric lights in 1880. Today, almost all forms of illumination we use every day are based on technology-from flashlight beams to laser lights to plasma screens. Technology has also helped us see what nature isn't giving us out of the blue: photography has revealed much about the beauty of flowers and trees, while astronomers have learned a lot from observing stars.
Artificial light is used everywhere today, even in places where the sun should be enough to do the job. Some industries need artificial light because they process substances that would be contaminated by sunlight. For example, factories that make chemicals or medicines need light to work with.