Larry Scheckel

QUESTION:

I wonder what Saturn’s rings are made of?

ANSWER:

            If you ever get an opportunity to peer at Saturn through a telescope, even a small one, you are looking at one of nature’s most majestic sights. You will be inspired, as Galileo was in 1610, when he became the first person to observe the beautiful ring structure of Saturn.

            Four robot spacecraft have visited Saturn. The latest, named Cassini, went in orbit around Saturn in July, 2004. Cassini sent back thousands of colored pictures of the rings and moons of Saturn. Cassini carried a detachable vehicle, Huygens, which parachuted onto the surface of Titan, a moon of Saturn. Stunning pictures of this alien world were sent back by the wheelbarrow sized Huygens.

            The rings of Saturn are composed of ice and some rock and dust. They are 240,000 miles wide but only about 300 feet thick. The smallest particles are smaller than a grain of sand and the largest are about the size of a bus.

            There are between 500 and 1,000 rings, with gaps in the rings. Each little particle could be thought of as a moon. Saturn has 31 “regular” moons, but 6 are considered major moons. Titan is the largest moon and is much bigger than our own Moon.

            We know that the Moon pulls on the Earth and the Earth pulls on the Moon. It is that gravitational tug on each other that causes the tides here on Earth. But tides affect solid objects also. When an object, such as a moon, gets too close to the planet, the tidal forces will tear that object apart and shatter it into thousands of pieces.  

            There is a mathematical rule, termed the Roche limit, that determines how close an object can get to a planet and not be torn apart. The Earth’s Roche limit is about 12,000 miles. Not to worry, though, our Moon is 240,000 miles away.

            Saturn in almost 100 times more massive than our Earth. So the Roche limit extends out quite far from Saturn’s surface. Billions of years ago, moons, rocks, comets, and any other debris that got too close to Saturn was pulverized and trapped in orbits forming the rings. Asteroids and other objects are continually bombarding the solar system. All that stuff gets caught in the ring system.

            The other gas giants of Jupiter, Uranus, and Neptune also have rings around them. They are quite faint and not easily seen. They are more like wispy circles. Saturn has the most material inside that Roche limit, and hence has the most elaborate set of rings.

            There are many gaps in the rings. The biggest gap is Cassini’s Division. From Earth, it looks like a thin black gap in the rings. It was first seen in 1675 by Giovanni Cassini from the Paris Observatory.

            Saturn is now a “morning star”, along with Venus. Look in the Eastern sky just before dawn. Each morning it will appear higher in the sky. If you have a small telescope, the ring tilt is about 19 degrees in December, and Saturn will show off

her magnificent rings.

The Southwest Wisconsin Book Festival will be held Saturday November 24, 2012 at Mineral Point, Wisconsin. Ann and I have been invited to participate. The events start at 9:30 AM at the Mineral Point Library with several sessions. Attendees pick among several sessions.

Book signing and reading is from 1:00 PM to 5:00 PM at the Quality Inn. Ann and I will sign our book “Ask Your Science Teacher“.

www.amazon.com/Ask–Your–Science–Teacher…/dp/1461044499

No need to buy a book, just stop by and say hello and get a free bookmark and Girl Scout cookie. (We bought 4 boxes from granddaughter Marit and we can’t or shouldn’t eat them all). Of course, if you want a book (nice Christmas present), we will part with one for $10.

There is an evening session at the Mineral Point Opera House, next door to the Mineral Point Library at 7:00 PM. Featured speakers are John Ivanko and Lisa Kivirist. swwibookfestival.com

ASK YOUR SCIENCE TEACHER                by Larry Scheckel

This week’s question was asked by:    Adrian Gomez, Miller Elementary, Grade 3

School Teacher:  Ms. Gonia

QUESTION:

Why do some people drink water and then laugh and it comes out of their nose?

ANSWER:

Excessive jocularity can cause water, milk, or soda to come out the nose.  Food and drink should be going down the esophagus and into the stomach. Air should be going down the trachea, then into the branching bronchial tubes, and ending into the lungs.

But those two tubes, the trachea and the esophagus, are quite close to each other. So the drink can go down the trachea and bronchial tubes, which is the wrong pipe, and then be expelled out the nose. Instead of being swallowed, the fluid goes up the nasal passages and out through the nostrils.

There is a saying that says “the joke was so funny it caused him to have nose cola”.

There is no real danger medically. Perhaps there is some social embarrassment for an adult.  Absolutely no embarrassment for a pre-teen or teen boy!

The human body has safety devices that prevent food and drink going down the wrong way. There is a flap of skin in the back of the throat called the epiglottis. The epiglottis covers the trachea when you swallow food. Sometimes if a person is talking or laughing while swallowing food or drink, the epiglottis does not block the larynx completely and food enters the wrong pipe. It can spurt out the nose.

The larynx sits atop the trachea. The larynx contains the vocal cords that are needed to speak and sing. These vocal cords will close up and go into a spasm if food or fluid gets to them.

As a final defense, if food or drink gets into the trachea or windpipe, you have a cough reflex that should expel any intruders.

The above three mechanisms can be dismantled by excessive alcohol. Food and drink can get into the bronchial passages and cause death by asphyxiation.

What about a cow? If a cow laughed really hard, would milk come out her nose? The answer is no. It’s udderly impossible.

QUESTION:

Why do the wheels on car commercials on television appear to go backwards? Ed G

ANSWER:

            It is called the wagon-wheel effect or stagecoach-wheel effect. The old oater westerns where the stage pulls into town, and the spoked wheels are turning in the wrong direction. When the stagecoach slows down a bit, the wheels are seen turning in the correct direction. The same phenomena  is observed in airplane propellers and helicopter rotors.

            Many modern cars have wire wheels that mimic stagecoach wheels. It is a stroboscopic effect. Movie cameras take 24 individual pictures every second, while television cameras take 30 pictures every second.

            Consider the following. A wheel  has only one spoke and it is turning clockwise. A movie camera is filming at the normal rate of 24 frames per second. The wheel is turning at a rate of 24 times every second and the film camera shutter opens each time the spoke is at the 12 o’clock position. When viewing the film, the wheel would appear to be stationary. They spoke would only be seen at the 12 o’clock position.

            If the rotating wheel slowed slightly, so that the spoke made it only to the 11 o’clock position, it would appear as if the wheel rotated backward.  The wheel would be behind the position it was in when the previous frame was taken. It would appear that the wheel turned slightly counterclockwise, even though it was turning clockwise.

            Let’s say the wheel rotates slightly faster and would make more than one rotation before the camera shutter opened, and the spoke would appear at the one o’clock position. The wheel would seem to be moving clockwise, in the “correct” direction, but much slower than its actual rotation rate. 

            Wheels have many spokes. How we view the rotation of the wire wheel on a car or stagecoach wheel depends on the position of those spokes and when the camera shutter takes a picture.

            Researchers are of varying opinions on what is going on in our perception and our brain. The wagon wheel phenomena can be complex and is not thoroughly understood. They use such terms as beta movement, Schouten’s theory, and temporal aliasing theory.

            This strobe effect is used in industry. The ignition timing on some cars uses a strobe. This is especially true on older models. The printing industry uses a strobe to adjust the rollers as newsprint comes off the press machine. The stroboscope flash rate is adjusted to the rate at which the newsprint comes off the rollers. Tweaking can be done to make sure the colors are lined up properly. Strobes are used to measure the rotation rate of motors, shafts, and rollers. They usually read out in revolutions per minute (RPM).

QUESTION:Why are tennis balls stored in a pressurized can

ANSWER:  The air inside a tennis ball is slightly higher than normal atmospheric pressure or what we might call outside pressure. If tennis balls were stored out in the open, not in a pressurized can, some of the air would slowly leak out, especially over a period of months or years.  You would have a less lively ball.

By storing the tennis ball in a pressurized can, the air outside the ball is higher than the air pressure in the ball. This prevents air from leaking from the ball.

Once the ball is out of the can, the leakage can be kept to a minimum by storing the ball in a freezer. This reduces the pressure of the air inside the ball and lessens the leakage rate.

A few minutes out of the freezer, the air inside the ball warms up, increases  the pressure, and you have a normal ball.

Sometimes people think that tennis balls are vacuum packed. Simply not true and it would be counterproductive. If tennis balls were vacuum packed, the air would leak out of the ball rather quickly, in a matter of hours. Instead, the air is sort of packed into  the can, rather than taken out.

A pressurized metal tube that held three balls with a church key on the top was introduced in 1926. A plastic can with a full-top pull-tab seal and plastic lid to hold three or four balls per can was brought out in the early 1980’s.

Why is a tennis ball fuzzy? That fuzzy felt covering increases air resistance and reduces the speed of the ball through the air. It also reduces the bounce. A fuzzy tennis ball is easier to control. A bald tennis ball has more speed, more bounce, more spin, and is harder to control.

A tennis ball is tested for bounce by dropping it from 100 inches onto concrete. A bounce of 53-58 inches is acceptable, based on sea level and standard temperature and humidity conditions.

Most tennis balls are fluorescent yellow, known as optic yellow. People describe them as a greenish- yellow color. They were introduced in the early 1970’s. It made them easier to see and more visible on color television.

The most common use for an old tennis ball is to cut a hole in the ball and attach the ball to the bottom of chairs in schools and nursing homes. This technique reduces noise and prevents scuffing or scraping the floor.

Wimbledon tennis balls are recycled by becoming a home for the Eurasian field mouse.

QUESTION:
How does a corn seed know which way to grow?
ANSWER:
A plant response that involves a specific movement is called tropism from the Greek word “to turn”. And any factor that brings forth such a response is called a stimulus.
Tests done way back in 1806 confirmed that gravity was the primary cause of plants growing in the correct direction. The tests showed that moisture was not the cause. Plant shoots kept in the dark still grew up and roots grew down, so light was not the primary reason.
How did they prove that gravity was the culprit? A Dr. Knight put seedlings in a rotating wheel, so they had an artificial gravity-like pull of centrifugal force. The plant roots grew downward at a 45 degree angle. The 45 degree angle was the result of both centrifugal force and gravity.
So the tropism responsible for plants growing in the correct direction is geotropism, a response to gravity. NASA uses the term gravitropism.
Thigmotropism is a response to touch. It accounts for the twining or wrapping of a vine around an object and the climbing plants and ivy you see up the sides of buildings and old windmills out in the country.
Cells that are touched produce auxin, a plant hormone, and transport it to untouched cells. The untouched cells on the outside of a bend grow faster than the touched or contact cells. This causes the tendril or vine to curve toward the side of contact. It’s almost a miracle how that happens!
The Scheckel boys had to go through certain areas of the corn fields on that Seneca farm and pull the Morning Glories that wrapped around a corn stalk. We didn’t know at the time that we were at war with thigmotropism.
Another tropism is phototropism, where light is the stimulus. Some sunflowers exhibit this phenomena. The sunflower plant head bends toward a light source, the sun, allowing more light to reach more cells to produce photosynthesis. That same plant growth hormone, auxin, moves to the dark side of the stem. The dark side grows longer causing the plant head to bend toward the light.

QUESTION:

Why do people get color blind and what exactly do these people see?

ANSWER:

            Total color blindness is extremely rare. The most common type of color blindness is the inability to distinguish between red and green. Light enters the eye through the cornea, lens, eye fluid, and hits the retina, a meshwork of tightly packed nerve cells.

            There are three types of receptors packed near the center of the retina. The light fires the nerve impulses and the electrical signals travel to the brain via the optic nerve. The center of the retina is lined with nerve cell receptors called cones that respond to red, green, and blue light. Red-green color blindness is due to a lack of those red receptors.

            Color blind people learn by experience to compensate for their defect by associating certain colors with changes in the brightness of the light. Therefore, many color blind people don’t know they have the defect. That’s why we take those ink blot tests at the drivers license bureau.         

            Colorblindness is hereditary and is caused by a recessive gene on the X chromosome. Only one healthy or dominant gene is needed for correct color vision. Since boys get a Y chromosome from their father and an X chromosome from their mother, boys who are colorblind must receive it from their mother. About 8% of men are colorblind, and about one-half of one percent of women are colorblind. These men cannot pass on the colorblind condition to their sons, since they pass on only a Y chromosome, not an X, to their son. Because females have two X chromosomes, if one is deficient or recessive, the other one is likely to be dominant and makes up for it.           Again, males have an X and a Y chromosome, so if a boy is colorblind, he got it from his mother, who gives him only X’s. He can’t get colorblindness from his colorblind father, because he gets a Y chromosome from his father.

            In order for a girl to be colorblind, she must receive a recessive X from the mother and a recessive X from the father. That rarely happens, so colorblindness is sixteen times more prevalent in boys compared to girls.

            Colorblindness is not contagious. It is a lifelong condition, and there is no way to prevent it and no way to treat it. It is just something people learn to live with.

            What are the primary colors anyway? In grade school, children sometimes learn that the primary colors are red, yellow, and blue. Actually, we should use the terms, magenta (a light shade of red), yellow, and cyan (a light shade of blue). Magenta, yellow, and cyan are the primary colors for the subtractive process of pigments, paints, and printing.

            The primary colors for light are red, green, and blue. When we mix them together we get white light. These are the colors we use for visionnnn and for color television.