An electrifying topic.

A battery, by definition, consists of a group of two or more primary or secondary battery cells, which convert chemical energy into electrical energy. A portion of the chemical energy a cell produces is transformed into heat, and a portion into an electric current.

Primary battery cells can only be renewed during down time, when they replenish their chemicals. When one reach for his or her emergency flashlight, which contains a type of primary cell named an ordinary cell, and it fails to light up, one falls victim of this very principle.

Each and every primary cell uses various chemicals, and contains electrodes and an electrolyte, a liquid. Electrodes, a.k.a. "cell elements," consist of either two different metals, or one metal and carbon. Element number one, the cathode, is primarily zinc. Element number two, the anode, is primarily carbon.

A chemical action sets the electrons free, when it triggers the cathode slowly to dissolve into the liquid electrolyte. A circuit provides the escape route for the newly paroled electrons, and they rush down the hatch in the form of an electric current. Unfortunately, their freedom is short-lived, because, once an electrical conductor is connected to the two elements, the current flowing through it is recaptured as electricity.

Secondary battery cells merit less discussion, as they automatically recharge, when an electric current is injected through them. Primary examples of a secondary battery cells are the storage cells used to start, or not to start, our car batteries. Because a storage battery does not actually store electricity, it instills in one a false sense of security. One is well advised to carry jumper cables in our cars, for those times when, much to ones chagrin, the battery fails to start.

The misnomered "storage battery," draws its power from chemical charges. Inside a storage battery, one finds a set of plates made of metallic lead, and a set made of lead peroxide. When both sets of plates are immersed in sulphuric acid, they undergo a chemical change, which transforms them into lead sulphate, which in turn produces the electrical current in the storage battery, which does not store. A word of caution...do not try this one at home!

A thermometer measures temperature through a glass tube sealed with mercury that expands or contracts as the temperature rises or falls.

The tiny size of the bulb and micro-fine size of the tube help the mercury reach the temperature of what it is measuring very rapidly.

Bulb thermometers follow the simple principle that liquids change their volumes relative to their temperature. As temperatures rise, the mercury-filled bulb expands into the capillary tube. Its rate of expansion is calibrated on the glass scale. Two different scales can be found on thermometers--the Fahrenheit scale and the Celsius scale.

With the Fahrenheit scale, Daniel Fahrenheit decided that the freezing and boiling points of water would be separated by 180 degrees and he pegged freezing water at 32 degrees. So he made a thermometer, stuck it in freezing water, and marked the level of the mercury on the glass as 32 degrees. Then he stuck the same thermometer in boiling water and marked it 212 degrees. He then put 180 evenly spaced marks between those two points.

In Celsius scale, Anders Celsius decided that the freezing and boiling points of water would be separated by 100 degrees and he made the freezing point of water at 100 degrees. (His scale was later inverted, so the boiling point of water became 100 degrees and the freezing point became 0 degrees.)

A sundial is a simple, yet accurate, instrument, which tells time by the movement of the shadow a pointer casts upon a dial, which marks the hours of the day. The shadow moves as the sun changes position in the sky throughout the day, and the dial tracks this movement.

For a sundial to be accurate, the pointer must be slanted at an angle equal to the latitude of its location. Vertical pointers are useful at showing the correct time only at one latitude and during one season, and flat dials must have unequally spaced hour marks upon them for accuracy.

Prior to the invention of the sundial, man guessed at the time of day by observing the sun's movement from morning until night. Sunrise and sunset required no calculation, but mid day, or noon, when the sun's position in the sky was at its peak, proved to be more difficult to predict. The times in between these three reference points left them baffled.

Around 300 BC, a Chaldean astronomer invented a bowl-shaped sundial with a pointer that cast a shadow onto the dial, which marked 12 hours of the day as the shadow inched along. Because this sundial proved to be highly accurate, its use continued for centuries.

More accurate, and portable, watches and clocks replaced sundials, as time telling instruments, but sundials still exist as ornamental additions to gardens. Oddly enough, some crude vertical sundials used for telling time, may be found on the walls and windowsills of old houses, and are configured so that a nail or the edge of the window casing casts a shadow. Perhaps, they served as the poor man's answer to the Swiss watch!

Mechanical adding machines, based on rotating wheels, always have the 0 button adjacent to the 1 button. By convention, most old adding machines had the numbers increasing in value from the bottom. When the numbers were put onto a pad arranged as a 3 by 3 grid with one left over, the order of the numbers was kept the same.

On a rotary telephone dial, the 0 comes adjacent to the 9 because a 0 in the telephone number is signalled by 10 pulses on the line. When telephones acquired push buttons in a grid, the ordering of the buttons was carried over from the old telephone dial.

Electricity shocks us, because it is an outside force that interferes with the internal electricity our bodies' nervous systems generate.

To fully understand why the chance encounter of these two electrical forces results in a shock to our systems, we must first understand the fundamentals of electricity itself.

In scientific terms, electricity is considered a fundamental force, one that is extremely basic, and has been in existence since the beginning of time. Further simplified, it is so basic, that it defies explanation, and is Mother Nature's way of saying "Because I said so"!

Electricity comprises positive and negative charges, opposite charges attract each other, and similar charges repel each other. Those charges attracted to each other can be separated, with the end product being potential energy, that is, energy that will be released as voltage, should the two reunite. We pay electric companies to separate the positive and negative charges for us, so that we have electrical energy at our disposal.

In order for the charges to reunite, and for the potential energy to be released as voltage, a conductor, a channel that they can flow through, is needed. Insulators, such as paper and glass make poor conductors, while wire and water make excellent conductors. Unfortunately, since the human body consists primarily of water, it too provides a superb conductor for electrical energy, or voltage.

If, by chance, outside electrical energy enters our bodies, now conductors, we will be shocked when the voltage encounters, and interferes with, the internal electrical energy our nervous systems produce. The shocks to our bodies, and the amount of damage the electricity does to them, depends upon the voltage our bodies are subjected to, upon its level of energy, and upon how much our bodies resist the flow of the electrical energy.

When we are shocked, a variety of things may occur, none of which is desirable. Our muscles may twitch, we may experience problems in the nerve centers that control our breathing, or we may experience problems with our heart rhythms. The worst case scenario from being shocked is death.

So that they look cute?   NO!

Because the dimples maximize the distance golf balls travel. Dimpled balls travel up to four times farther than smooth-surfaced golf balls.

In the early days of golf, smooth-surfaced balls were used until golfers discovered that old, bumpy balls traveled longer distances. The science of aerodynamics helps explain the dimpled phenomenon. The dimples reduce the drag on a golf ball by redirecting more air pressure behind the golf ball rather than in front of it. The higher levels of pressure behind the golf balls force them to go far distances.

Newspaper is made up of tiny wood fibers. If you take a close look with a magnifying glass, you'll see that the fibers all line up in the same direction, up and down on the page. This gives the sheet of newspaper a grain.

When you tear the newspaper from top to bottom it tears evenly because you are tearing in the direction of the grain. But when you tear it from side to side, it tears unevenly because you're tearing against the grain.

Hot-burning "halogen bulbs" can last two or three times longer than regular bulbs because they are filled with chemically active halogen gases that preserve the filament.

The filament of an ordinary light bulb burns out because atoms of tungsten evaporate from its surface, so that it becomes thinner and thinner until it breaks. The evaporated tungsten is deposited on the inside surface of the bulb, where it forms a dark deposit.

The gas inside a halogen bulb combines with the tungsten atoms that condense on the glass, removing the deposit. When the combined molecules touch the hot filament, the tungsten is redeposited there, and the gas is released to do the same trick again.

A halogen bulb is often 10 to 20 percent more efficient than an ordinary incandescent bulb of similar voltage, wattage, and life expectancy. Halogen bulbs may also have two to three times as long a lifetime as ordinary bulbs, sometimes also with an improvement in efficiency of up to 10 percent. How much the lifetime and efficiency are improved depends largely on whether a premium fill gas (usually krypton, sometimes xenon) or argon is used.

We see objects in a mirror, because a mirror, when hit by particles of light called photons, reflects the photons back to us and some reach, and enter, our eyes. Photons that hit a rough surface will bounce off of the surface in a haphazard manner, while those that hit a smooth surface, such as a mirror, only bounce off of the surface at the same angle at which they hit the object. The scientific term for this phenomenon is reflection.

Not all smooth surfaces reflect photons back to us, even though, technically, they should bounce back at the same angle at which they hit the surface. This exception to the rule results, because some smooth surfaces absorb the light particles hitting them, making it impossible for them to bounce back.

Another apparent exception to this rule is that, although our bodies are rough, uneven surfaces, off of which light bounces at random angles, our images reflect off of a mirror. The reason for this apparent contradiction is simply that when we stand in front of a mirror, some, but not all, of the light particles bouncing off of us will hit the smooth surface of the mirror. The ones that do reflect our images back to our eyes at exactly the same angle at which they hit the mirror.

In other words, photons that bounce off of any part of our bodies and hit the mirror reflect back to our eyes from only one place on the mirror, and at only one angle. It follows that each point on our bodies that reflects back to our eyes from one point on the mirror produces an image in the mirror. All of the images together make up our reflections, like it or not. And remember that mirrors don't lie!