Science

Holograms are made by recording the light from a laser onto a holographic film. The result is an image that will change as the viewer's orientation changes, making the image appear to be...

The human spine is made up of approximately 32 vertebrae and houses the spinal cord and provides an overall stability to the human body. These instructions will help you to create an impressive...

While laser pointers are available for just a few dollars almost anywhere, laser guns like those seen on Star Trek can't be purchased at your local drugstore. It is possible to put a laser inside...

Holographic images can be a lot of fun to make and even more fun to look at. Using readily available holography kits that contain lasers, holographic plates and processing chemicals, you can make...

Atoms unite to form molecules by means of available electrons. Bonds can form by electron transfer or by electron sharing. Many chemical bonds are intermediate between those two. Elements combine...

A Zener diode is a diode designed to operate in the breakdown region. Normal diodes will become destroyed, but a Zener will conduct. It may be used for voltage regulation. To check one, use a...

You can make an electric doorbell as a science project. This project will demonstrate the concept of magnetic suction. Your doorbell works when an iron rod is sucked through a coil of copper wire...

Transistors are semiconductor devices usually used for amplification. The most popular ones are bipolar. Bipolar transistors have either NPN or PNP layers, with a lead attached to each one. The...

Organic chemists use infrared spectroscopy (IR) to study molecular bonds. Potassium bromide is a salt used in IR spectroscopy as a support because it has no absorption band in the infrared region....

Electrical schematics represent circuits by drawings. Circuits are composed of electrical components that are connected by conductors. The components manipulate currents in various ways. They may...

Electrical diagrams are drawings used to represent circuits. Circuits are electrical components connected to each other by conductors such as wires and solder. These components manipulate and...

Circuits are formed from electrical components connected to each other with conductors such as wires and solder. Electrical schematics are drawings that represent circuits. Commercial software...

When working with heavy-duty, high voltage electrical or electronic systems, the megger, more properly called a "megohmmeter," is used to test continuity and the insulation qualities of conductors...

Nuclear Magnetic Resonance Spectroscopy is useful in obtaining data on unknown organic compounds. A sample is placed in a powerful magnetic field, which aligns hydrogen nuclei (protons) along an...

A hydrogen ion concentration in a solution results from the addition of an acid. Strong acids give a higher concentration of hydrogen ions than weak acids, and it is possible to calculate the...

Drawing dinosaurs and animals can be exciting and challenging. The main problem in drawing dinosaurs is where to find one. Because they are extinct, the closest you can come to one is in a museum...

Light-emitting diodes are small semiconductors that give off energy in the form of light when electricity flows through them. Some LEDs emit visible light, and some emit infrared or even...

When you diagnose problems in a natural gas system, it is very useful to know the rate of gas flow, or the velocity of the gas in the pipes. Because natural gas requires a precise mix of oxygen to...

Many high voltage outlets that are 220 to 240 volts typically have three openings. Two of them are live and ground respectively, and they are across from each other. They normally are slanted at...

In electronics, an oscillator is a circuit that generates a signal at a certain frequency. You can make a simple oscillator with an inductor (a coil) and a capacitor (two parallel plates). The...

A multimeter is a device used to make electrical measurements. One of the ways it can be used is to test an electrical outlet. You may test an outlet to see if electricity is actually going...

To check an electrical outlet, use either an outlet tester or a multimeter. An outlet tester is a small device used to test if a three-pronged outlet is working, and also if it is wired properly....

There are some electronic parts that are found in nearly every circuit. These include resistors, capacitors and inductors. Resistors are made from materials such as metals or carbon and are used...

Making weapons-grade tear gas is dangerous, complicated and, in many places, illegal. No civilian would ever have legitimate use for such a chemical weapon. However, capsicum pepper spray is a...

It's easy to solve number ciphers if you know the trick: some letters are more frequent in the English language than others. That means solving a cypher is usually a matter of looking for high...

Rust accumulates on many types of iron alloys that are exposed to air. Oxygen from the atmosphere gradually binds with the iron in the metal to form various iron oxides, all of which are forms of...

Rust is a combination of the oxides of iron. It forms when some types of iron alloys are exposed to the atmosphere for a prolonged period of time. You can prevent rust by passing an electrical...

Forensic anthropologists can tell a lot about a deceased person from the skeleton. Among the physical characteristics that can be roughly deduced is the person's height. Most valuable in this...

Telepathy is the ability to either send and/or receive messages with your mind. Many do not believe in this ability but in all reality its actually one of the most basic tools of human communication.

Titration is a chemical analysis used to determine the concentration of a solution. The strategy is to take a sample and add a reactant to it until the solute of unknown concentration is fully...

This article is a simple, short yet scientific description of the process of how fabrics and hence garments are produced from fibers.

Experimenting with paper airplanes teaches physics, aerodynamics, creativity, gravity and provides fun, competitive play. Hang time refers to the length of time the plane stays or "hangs" in the...

Newton's cradle is a toy consisting of balls hanging as pendulums. Each ball hangs from two strings instead of one---from opposite supports---to ensure centering. The balls rest in contact and in...

In 1938, Charles Drew, an African-American medical resident at Columbia University, recognized that a liquid solution in blood called "plasma" would solve problems associated with blood storage,...

The Gregorian calendar is the main calendar used throughout most of today's world. The calendar derives from the Christian calendar of the Middle Ages and Renaissance, which in turn derived from...

To reduce a 9V battery to 3.3 volts, use a zener diode, such as a 1N746 or a 1N4728A. Choose the appropriate one based on how much power it can dissipate. A 1N4728A has a 3.3-volt and a 1 W power...

Thermals are upflows of air. They occur as the air nearest to the ground heats up and becomes lighter than the surrounding air, causing it to rise until it meets air of equal density. These...

Amplifier technology gives us the ability to increase the power of an AC electrical signal. An older technology for power amplification uses vacuum tubes. One method in particular uses a special...

Legos, the definitive children's building blocks, are an apropos way to model the building block of organic matter, deoxyribonucleic acid, more commonly known by its abbreviation, DNA. The process...

Electrical diagrams range from the very simple to the very complicated, but they all are based on the same elementary principles. To learn how to read them, it is necessary to have a basic...

Transistors are made from semiconductors such as silicon or germanium. They are constructed with three or more terminals. They may be viewed as electronic valves because a small signal that is...

Knowing how to balance a chemical reaction is a fundamental part of chemistry. The first law of thermodynamics says that energy cannot be created or destroyed. Yet when you first look at some...

Expected or predicted probabilities can be calculated empirically or from functions that predict or model the probability of an outcome or range of outcomes. For example, suppose the result of...

Analysis of covariance (ANCOVA) is a more sophisticated form of analysis of variance. It accounts for a shared variable between populations that may be explaining variation. For example, three...

In memorizing the periodic table of the elements, a layered approach is desirable. One cannot expect, for example, to use a single phrase as a mnemonic for the whole table. Multiple mnemonics are...

A phase vector, or phasor, is a representation of a sine wave whose amplitude, phase and frequency are time invariant. The projection of phasors onto the vertical axis gives their instantaneous...

Students should be reasonably fluent in the lighter elements of the periodic table, so some memorization should be taught. Mnemonics are available to help. However, most of the emphasis should...

Determining the number of floats for building a floating dock is a straightforward process. But it requires preparation, including designing your floating dock, doing a "takeoff" for materials --...

Air is a mixture of Oxygen, Nitrogen and small amounts of other gases. Theoretically (and in practice) it is possible to separate these gases from each other, and extract them.

Stream flow information is important to home owners, builders and developers and is essential in conducting foundation calculations in areas near the water; studying the hydrologic cycle to...