You are reading our best questions and answers in the How does it work? category

For our eyes to see images the lens of our eyes focuses the image of what we see around us onto the retina in the back of the eye. Unfortunately, this lens can sometimes focus the light in front of or behind the retina. This leads to the conditions myopia (near or short-sightedness) or hyperopia (far or long-sightedness). Many people choose to wear eyeglasses or contact lenses for these conditions, but this does not permanently correct the problem with the lens. Laser eye surgery is one of the most popular ways to permanently correct these eyesight problems. Let’s take a look at how it works.

Parachutes are used to slow down an object falling through the air. They can carry a variety of different loads such as people, food, bombs, equipment and much more. They are most commonly made of nylon, which is capable of handling the conditions in the atmosphere. The modern parachute was invented in 1783 by Louis-Sébastien Lenormand, who also named the invention. If you have ever wondered how this amazing device works, keep reading to find out.

Wind power has been harnessed by humans for a variety of purposes throughout history. Some of these uses include sailing ships, windmills and, more recently, power generation. Today, it is used to generate approximately 200 gigawatts of power throughout the world. Wind turbines are commonly used throughout Europe, but China currently has the world’s highest wind power capacity of any country. There have been at least 9 accidents relating directly to power generation from wind, but it is still considered to be one of the safest and environmentally friendly methods of power generation. You may have seen the large wind turbines that are used to generate this power, but have you ever wondered how they work?

Geothermal energy is one of the leading forms of sustainable and environmentally friendly energy production. It is also commonly used for heating and the oldest operating geothermal heating project dates back to the 14th century. However, the idea to generate electricity with geothermal energy didn’t develop until much later. 24 countries in the world now use some form of geothermal energy and that number is expected to increase substantially with further development and success. The United Sates currently has 77 geothermal power plants and leads the world in geothermal energy production. Iceland produces over 30% of their total power from geothermal energy.

Paternity testing is done to prove whether a man is the biological father of a child. It is mostly done for legal matters such as adoption or child custody rights. If the man is biologically related to the child the test will return a result greater than 99.9% if they are not biologically related the test will return a 0% result.

A lifejacket, or personal flotation device, is a piece of safety equipment that is essential to have when on the open water. Lifejackets are used by people undertaking water sports and boating trips and you can even find them on airplanes. They come in all different shapes, sizes and colors and have been made to fit both adults and children. The main purpose of a lifejacket it to keep a person’s head above the water. They are designed to help you stay afloat even when unconscious.

Windmills are useful and beautiful structures that are often found on farms or homesteads. They are used for a number of reasons such as pumping water, grinding grain or generating power. They have been around for centuries and the earliest recorded windmills were used in Persia to grind corn. Windmills have 3 sail like blades that are connected to a shaft and sit on top of a large triangular base. These blades catch the wind and rotate harnessing the power of the wind. Windmills come in many shapes and sizes depending on their use. Grinding windmills tend to be larger than other types of windmill because they need to house the grinding stone. These days windmills are most commonly used to pump water or generate electricity.

Batteries are used in many everyday objects such as remote controls, clocks, cell phones, laptop computers and vehicles. They are an integral part in keeping the world running. Batteries store electrical energy in chemical form for use when we are unable to access a power source. They come in all different shapes, sizes and power outputs. There is a battery to power almost anything that you can imagine. Have you ever wondered how a battery actually works? If so read on to find out more.

The ear is a very important part of our auditory system. It receives the sounds from around it and transfers those sounds to the brain for processing. Without our ears we would not be able to hear language, music, danger and many other important sounds. Our ears also help us to maintain our balance and when damaged can cause our balance to be upset. The ear has three main parts, the outer ear, the middle ear and the inner ear. Each has an important role to play in how we hear.

A barometer is a piece of scientific equipment that measures atmospheric pressure or air pressure. This helps with the forecasting of the weather. A barometer measures the change in pressure in the atmosphere which occurs when the weather pattern changes. In this way it is able to help in the prediction of whether it will be wet or dry. There are three main types of barometers, mercury barometers, water-based barometers and aneroid barometers.