Page 99 - August 2015 Life In Naples Magazine

WHAT IS A MAGNET?

A magnet is a material that produces a magnetic field. When a material is
magnetized the spin of the atomic electrons are aligned in a uniform direction.
Iron, nickel and cobalt can be readily magnetized as can many compounds called
ferrites. Magnets are used to hold refrigerator doors tightly closed, in compasses,
in speakers and in microphones plus many other uses. Ferrite magnets are used on
credit cards, audio and video tapes and hard drives.The magnetic fields surrounding
a magnet are shown with iron filings.

Magnetic fields are also produced when electrical current is passed through a
coil of wire.The field ceases to exist when the current is stopped.Two major uses of
electromagnets are electrical generators and motors.

WHAT IS ATMOSPHERIC PRESSURE?

The weight of a column of air one square inch from sea level to outer space is 15 pounds. Thus
the air pressure at sea level is 15 pounds per square inch, psi. At higher altitudes the pressure
decreases as the weight of the air above that point decreases.

WHAT IS STATIC ELECTRICITY?

Static charges are produced on objects when electrons are removed thus making one object
positively charged and another negatively charged. This normally occurs with friction such as
rubbing a balloon which will then stick to a wall because of its charge. On a cold winter day
a static charge of thousands of volts can be produced on your body by walking on a carpet.
The accumulation of static electrons is discharged through a spark when a finger approaches
a metal conductor.

Voltage does not harm cells, it is current when too high that causes the damage. Using a Van de
Graaf static generator volts of 100,000s can safely be placed on a human body or on other objects.
Note effects of high static charges on humans.

HOW DOES A MICROWAVE OVEN WORK?

Molecules that contain a dipole, that is one side of the molecule has a plus charge and the
other negative, absorb microwave radiation which causes them to vibrate and bounce around.
That movement heats the material and thus cooks the food. Microwave absorbing molecules
include water, sugars and fats. Non polar materials like glass, paper and plastic are not heated
by microwaves.

HOW DOES REFRIGERATION WORK?

When a gas is compressed it gives off heat as the molecules are forced closer together. In a refrigerator or air
conditioner a motor compresses a gas, which heats it up. The heated gas is then passed through a radiator where it
gives up the heat to the room or outside air. The compressed gas at a temperature close to the room or outside air
is than forced through a small opening into a tube where it expands. As the gas expands it cools as the molecules
move away from each other. In a refrigerator the tube wherein the gas expands and cools is inside the refrigerator.
The radiator is on the outside of the refrigerator.

HOW MANY STARS ARE THERE IN OUR UNIVERSE?

Thanks to the Hubble telescope in space that question can be largely answered. Our galaxy
contains over 100 billion stars. The universe contains about 100 billion galaxies. That brings the
total to over 1022 or 10,000,000,000,000,000,000,000 stars. Our sun is one of those stars. The
number of stars in the universe is greater than all of the grains of sand on all of the beaches on
earth. Recent observations suggest that the planets in the universe outnumber the stars. And
the number of moons probably exceeds the number of planets. The universe also contains many

massive gas clouds. It is in these clouds that new stars are born.