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| The gray color in this cloud is caused by a shadow. |
Elementary teachers will find these science facts useful for enrichment and for addressing common topics that students often ask.
Events in the world are often not as they seem. Science teachers armed with facts that clarify and inform inspire learning by making science more relevant.
Weather Facts
Clouds are white,
not gray. The gray appearance is an illusion created by lighting and shadows.
Parts of clouds in the shade appear gray. The same effect can be demonstrated
by projecting light from an overhead projector on a white screen. Holding the
hand in front of the screen produces a shadow and an apparent change to gray
color, but people know the screen is white, no one “sees” it as gray.
Snow is rare at the
South Pole. About 1 inch of snow falls on the South Pole in
a year — this is approximately equal to 0.1 inch of rain in water equivalent.
The extreme cold prevents water vapor from entering the air in large amounts.
When snow falls it stays, blows around and accumulates. Snow depth has reached
nearly three miles over inland regions over millions of years.
Don’t open windows
to equalize pressure if a tornado is expected! Tornadoes do
have low pressure, but it is the savage wind that causes the destruction. Winds
in a tornado can reach 300 mph and commonly exceed 200 mph. Opening windows
simply invites these winds into the house with less resistance.
Physics Facts
Tires do not have
treads to increase friction. Treads provide channels that let rain flow from
beneath the tires so that contact with the road is maintained and the car does
not hydroplane. A slick or tread-less tire is used on racing cars to actually
increase friction. Electric fans don’t
cool the air; they cool people by speeding up evaporation of moisture from the
skin. The fan motor actually adds a bit of heat to the room. There is no need to leave
the fan running if no one is in the room.
The sound of
snapping fingers is made when the middle finger strikes the base of the thumb
at a high speed. The sound does not come from an interaction between the thumb
and finger. The thumb allows potential energy to be stored briefly by holding
the finger. Place a piece on cotton at the base of the thumb and the impact
will be softened preventing the “snap.”
Earth and Space Science Facts
The total amount of gold ever
mined from the Earth could fit into a cube about 60 feet on each side. That’s
about equal to filling two Olympic swimming pools. Gold, by the way is very
dense. A cube of gold 15 inches on each side weighs a ton — 2,000 pounds!
Sunspots are not
black. They only appear to be so because they are contrasted against the
brilliance of the Sun’s photosphere. If it were possible to look directly at a
sunspot away from the Sun, it would still be bright enough to harm the eyes.
The Earth’s tectonic
plates are still moving. The distance between South America and Africa is
increasing about as fast as fingernails grow — two or three cm. a year.
Chemistry Facts
Oxygen does not
burn. It supports combustion. A spark in a pure oxygen environment
will not result in an explosion. Objects burn better in the presence of oxygen
as it combines chemically. More oxygen increases the intensity and heat of the
fire, but the oxygen is not burning.
The atoms of one
object cannot touch the atoms of another. Pushing against a wall may bend the
fingers, but that is due to the electromagnetic repulsion of the electrons.
Atoms can get very close, but they do not touch.
Atoms are mostly
space. A scale model of
a hydrogen atom is basic — one proton and one electron. Using a soccer ball as
the proton in the nucleus, the single electron would be the period at the end
of this sentence ten miles away.
Information like
that above helps students understand the world as it truly is — often beyond
our perception. The Internet is rich with similar science facts.
Teachers can offer questions based on the preceding facts as a topic for an
information “scavenger hunt" in the school media center.
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