Science & Nature

A star light is a projection of laser lights on your ceiling in a way that looks like stars. It is a unique machine that can give you a moment of peace, even when you find yourself full of...

Most people are familiar with the strange, fluorescent glow produced when ultraviolet radiation--commonly called a "black light"--strikes certain liquids or other materials. This unusual glow is...

Lighting is an important element in viewing specimens through a microscope. Proper lighting aids in contrast, definition and resolution of the specimen being viewed. Microscopes are available with...

Technology for electricity has evolved over time, but the basic principles of positive and negative charges can be demonstrated by creating a simple battery with supplies around the house and from...

Color in scientific terms is a mixture of the individual wavelengths of light. The color humans see is the different wavelengths of light reflected by an object.

Photosynthesis is a biological process used by green plants, algae and some bacteria to convert carbon dioxide and water into simple sugars using energy from the sun. The formation of these sugars...

With the growing popularity of DVD recorders, medium-power laser diodes are more widely available. The 150 milliwatt (mW) devices record by burning tiny pits in a blank DVD. They can burn other...

When scientists struggled to describe the vast distances between celestial objects, they came up with the concept of the light-year. Rather than a measurement of time, the light-year is a...

Although human eyes cannot see the ultraviolet light emitted by black light bulbs, certain objects glow under black light. This occurs because those objects reflect that light back as part of the...

Developed in the late nineteenth century, the polarizing microscope was made for studying rocks and minerals. Polarizing microscopes may also be used in the biology and medical fields. These...

Visible light normally travels through air. Occasionally light passes through a transparent medium like glass or water. Most of the light strikes the medium perpendicular to the surface and passes...

Ultraviolet (UV) light comes from the sun and is invisible to the human eye. All life needs some UV light to survive. Humans also need UV light to make vitamin D, a hormone essential to bone...

The particular qualities of light given off by the Sun have shaped the way we see. Our eyes have evolved to take advantage of this form of energy. The sun's output, filtered by the Earth's...

Black light reveals phosphors or materials which glow under the ultraviolet light by definition of Encyclopedia Britannica. Because phosphors exist all around us, the black light can be used in a...

When a person is light-headed, it is usually because his blood is not flowing to his head properly. This is a condition not to be taken lightly, especially if it happens frequently, as it can be...

Without far infrared rays, life on Earth as we know it likely could not exist. Unlike visible light, infrared rays usually are not seen with the naked eye. The average home contains products that...

Although it might seem like there is a world of difference between a candle and an electric light bulb, in fact an incandescent light bulb like the one perfected by Thomas Edison produces light...

The rainbow colors of the light spectrum are as useful as they are pretty to look at. Each chemical element has a unique pattern of colors. Scientists use this information to identify substances,...

Light-emitting diodes, or LEDs, are low-power lighting devices used in many applications today. Light-emitting diodes have no filament, which can burn out; therefore, they last longer than...

Curved mirrors have a variety of uses, from photography in replacing glass lenses, to security and safety, to the whimsical, like fun-house mirrors. Chiefly, they either provide wide-angle views...

The moon's presence during daylight astounds children and puzzles adults. The moon's phases and reflective properties are key to understanding this natural wonder.

Just behind the protective layer of the lens, there is an infrared/ultraviolet light filter that blocks all incoming light that is not in the visible spectrum. This includes the IR-A, -B and -C...

White shirts appear to glow under black light because they contain fluorescent compounds. This can often be traced to laundry detergent.

The smaller a piece of matter is, the more it displays wavelike characteristics. For example, protons are 1,830 times more massive than electrons and so act like particles concentrated in the...

Life on earth is dependent on visible light radiation. Without it, food chains would fall apart and surface temperatures would plummet; although visible light is integral to our survival and is...

Light is electromagnetic waves, and the frequency is one of the wave characteristics. While the period is the duration (in seconds) of one full wave, the frequency is the number of periods per...

A black light is an incandescent or fluorescent lamp that emits almost exclusively ultraviolet light. Because of the way UV light interacts with certain molecules, some materials, including new...

While each plant is different in its ability to withstand light, all plants convert light into the energy they need to grow and develop. Ultraviolet (UV) light provides benefits to plants but also...

A compound light microscope has many different parts that work together to produce a magnified image of a specimen. In order to obtain an image that is sharply focused, it is important to...

Lasers are being used increasingly as machine tools. The heat from its intense light can cut many materials. The light is precisely guided by a computerized machine, making the laser cutter...

Ultraviolet (UV) light has many useful features. It carries more energy than visible light, making it a potent germ killer. It causes certain substances to glow, aiding in crime detection and...

Photosynthesis is the process by which certain organisms, including plants, create sugars from the carbon dioxide in the air and the oxygen atom of water. The energy that drives this process comes...

Spectroscopy is the study of the spectral nature of light, that is, its ability to be separated into a series of colors. A rainbow created by white light from the sun being separated into a...

Rocks and minerals exist in a number of forms. One of the more interesting and visually stunning varieties are fluorescent rocks. These rocks glow various colors under a black light. They are...

Gemologists are able to identify gems such as diamonds, rubies and sapphires to find out if a stone is genuine or synthetic. Identifying gems involves observing and testing them for their...

Can you imagine having to live and work in the dark? Before the invention of the light bulb, people used a variety of different ways to light their way at night. Wax candles and lamps that burned...

Fiber optic lights feature optical fibers that have pulses of light sent through them. Typically, the light will be emitted at the tip of the fiber and will appear to glow. Since the light...

If you've got a drawer or bag full of batteries all mixed together, it's impossible to tell just by looking at them which ones are "good" and which ones are long past being useful. Buying a...

Watches, stickers, toys-- all of these can glow in the dark. Most glow-in-the-dark products employ phosphors, a type of chemical. Glow-in-the-dark seems like magic, but is really a matter of...

While there are many artificial sources of ultraviolet light, there is only one important natural source: the sun. The ultraviolet light from the sun accounts for most of that type of radiation...

A plasma ball is a glass ball with a miniature Tesla coil inside. When the plasma ball is turned on, you can see what looks like purple lightning shooting out from the center of the ball to the...

Colored lights affect plant growth due to the role of light in photosynthesis. Photosynthesis is the process by which plants use light energy to create glucose for food from carbon dioxide and the...

Light enters the eye to cause vision, and the cornea and pupil are integral to this action. Both parts of the eye need to function correctly if you want to see clearly, and any damage or illness...

If you want your reflecting telescope to work at its optimum level, you need to determine the focal length of the telescope's concave mirror. A concave mirror's reflecting surface curves inward...

Light-emitting diodes are commonly seen in our everyday lives. These small devices use less electricity than similarly sized incandescent lights. For that reason, LEDs are used for applications...

Everything seen must get carried to the eye through light. The eye functions to take light and send it to the brain, which translates the light into images. Light does not enter the eye from one...

The moon takes a little less than 30 days to go through its entire cycle. During that time, it goes from a new moon to being completely full, then back to being a new moon again.

Photocells are semiconductors that are light detectors. They are essentially light dependent resistors, because they have an output that is proportional to the amount of light that falls upon...

The 21st century affords the option of purchasing incandescent and/or fluorescent light bulbs for our homes. The bulb varieties are considerably different in construction, in mode of operation,...

Eye types range from simple to the complex and the compound. Eyes are organs that detect light. Simple eyes detect whether it is light or dark; while complex eyes can detect color, motion, depth,...