Science & Nature

Sound travels as pressure waves through the air. Sound insulation is the resistance to sound; in this case, insulation material reflects the waves. Sound absorption converts the sound to energy or...

As the world's population continues to grow, and with the economies in developing countries expanding rapidly, there is a greater demand for energy than at any other time in human history. In...

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...

The pulse energy of a laser is total energy contained in a single laser pulse.

A steam turbine is a mechanical device whose purpose is to convert thermal (or heat) energy into work. Thermal energy is the type of energy that manifests itself as an increase in temperature. The...

For thousands of years, cultures around the world have used crystals and gemstones in jewelry and as raw stones for religious and metaphysical purposes. Today you can find a variety of crystals...

Before an object begins moving, it has an amount of potential energy. Once that objects begins to gain motion, that potential energy converts into kinetic energy. Calculating this equation doesn't...

Plant respiration is the opposite of photosynthesis, which is a biological process performed by green plants that creates oxygen and releases it into the air. During respiration, plants absorb...

Energy, usually generated in the form of electricity, can be drawn from a number of sources. These include different types of finite natural resources drawn from the earth, as well as renewable,...

Stones, minerals and crystals have long been used in metaphysical divining. The quartz crystal has special significance, and it's used in many rituals. Quartz is also thought to be a strong...

Wind energy is mechanical or electrical energy generated by harnessing the power of the wind. According to the U.S. National Renewable Energy Laboratory, one of the earliest devices to harness...

Dextrose is another word for D-glucose (or dextrorotatory glucose), a sugar used for energy by most living organisms. The term "dextrose" is commonly used in the food industry.

Perpetual motion is a theoretical notion that drives inventors to attempt to create machines that continue on forever. But creating a perpetual motion machine is impossible.

Cellular respiration is the means by which all heterotrophic life forms create energy. By breaking down food into glucose and harvesting electrons from the glucose, animal cells can create...

In the atomic world, heat can be equated with energy. Some elements give off energy very well--they are good conductors. Others are very poor at giving off energy--they are good insulators. Since...

While it may be hard to believe, most of the food a young plant needs to get its start is stored inside the seed that it grew from. Until the plant can produce leaves and make its own food, it is...

Wind turbines are used to capture wind and convert the kinetic energy (energy generated through motion) into mechanical or electrical power. Most turbines are used in wind farms to generate bulk...

Solar energy collectors have been in common use since the 1890s. A solar collector in a sunny spot has been used to heat water or make electricity. The limitation has always been times when the...

The compressor is one of the most important parts of the air conditioning system. Air conditioners work using the laws of thermal energy and heat transfer. The medium by which heat is moved around...

Flywheels have many uses in modern machinery. Probably the most common is to store rotational energy to help drive internal combustion engines. The engine spins a flywheel mounted at the...

A bird spends a lot of energy flying, molting, breeding, rearing young and defending its territory. It actively searches out foods that can help it meet these needs. Birds eat more than one type...

During photosynthesis, "producers" like green plants, algae and some bacteria convert light energy from the sun into chemical energy. Photosynthesis produces chemical energy in the form of...

Nuclear and solar power are products of quantum physics. Instead of the smooth, continuous, predictable world we're familiar with, quantum physics is a realm of discrete bundles of matter and energy.

The resistance of a wire refers to the ease at which current is able to flow through it. A wire with a higher degree of resistance will not perform as efficiently as a wire with less resistance.

Trophic levels are used to categorize the feeding relationships within a food web or energy pyramid. The four main trophic levels are primary producers, primary consumers, secondary consumers and...

Water as an element is not destroyed. But, the costs of treating water for safe use are the same whether the water is used for drinking or is wasted through leaking faucets. Wasted water has...

With all of the attempts to come up with cheap, dependable energy, tidal generators have been receiving a lot more attention than they have in the past from the public and from the engineering...

When speaking about cell balance, it is common to run into the term "homeostasis." A cell must maintain homeostasis, literally a permanent condition where everything remains the same. For a cell,...

Earth has given us many resources that allow us to survive. We make use of renewable (like sun and air) and nonrenewable (like minerals) resources. Water is one of the main resources we use and...

A primary source of energy is any source of energy found in nature that has not been converted. Different primary sources of energy are used in different regions of the world for a variety of...

Energy is necessary to power many items that people normally use, including appliances, lighting, and vehicles. Energy sources can be classified as renewable (able to be recreated repeatedly) or...

Wave motion arises from the shifting of energy. That energy may be in a photon, in a water wave or a solid medium. It can be from oscillation between stored energy and kinetic energy, or strictly...

The term "greenhouse effect" refers to the presence of gases in the Earth's atmosphere that trap the sun's energy and increase the planet's temperature as a result. Examples of greenhouse gases...

As you plug along through your chemistry class, you're bound to run into the concept of (gasp!) electron configuration. What's that supposed to mean and how the heck do you find the electron...

Recycling saves energy primarily because it reduces the need to extract and refine natural resources. For many materials, the energy to recycle is less than the energy needed to make it from...

A cold soft drink on a hot day can be very refreshing; keeping that soft drink cold on a hot day can be quite challenging. In the past, soft drinks were packaged exclusively in glass bottles....

Solar energy has been harnessed by humans for thousands of years for heating purposes, and more recently for electricity generation. Solar power is an extremely vast resource, but it has some...

A kilowatt-hour is an electrical unit of energy. It is the amount of work done when 1 kilowatt is expended or consumed in an hour. Power stations that supply electricity to buildings use...

Solar energy comes from the sun and travels through outer space to the earth. Solar energy comes in the form of light, and when the light comes to planet Earth, sometimes the solar energy is...

Plants use a complex chemical reaction called photosynthesis to create food from light energy, carbon dioxide from the atmosphere, and water. Each of these performs a critical portion of the...

Laser eye surgery refers to a handful of refractive eye surgeries that use powerful lasers to alter the shape of the cornea. The goal of refractive eye surgery (be it laser-assisted or otherwise)...

Every chemical reaction starts with one or more reactants. Atoms, molecules or free electrons can participate. They combine, swap atoms or decompose into the reaction's products. If a reactant is...

Food chains track the progress of energy through organisms, and food webs show the interconnectedness between food chains. All food webs begin with the sun. Generally, plants take the energy from...

Thermodynamics arose out of the observations that steam engines produced heat and were not entirely efficient. In the 19th century, scientists articulated three laws of thermodynamics, which...

The term "living" can describe either a single or a multitude of organisms that make up a larger organism. Living organisms have evolved and adapted to their environments for billions of years,...

Camp settings can provide many possibilities besides outdoor recreation. Camp counselors and participants can also explore options for going green during a camp session. You can use green...

Chemical heat packs can be used to apply heat to specific areas on the body to help with pain and injury recovery. They are most popular in sporting events where athletes suffer from various...

The natural world is awash in sound. This is even more true of the man-made world. Whenever an object sends out vibrations you can hear, that is, between 20 and 20,000 cycles per second, it...

The periodic table is organized into columns and rows. The number of protons in the nucleus increases when reading the periodic table from right to left. Each row represents an energy level. The...

Most people understand that the process of photosynthesis takes place in the leaves of plants. However, a plant actually uses a number of specialized structures that conduct the chemical reactions...