Chapter 14

This chapter is a world of light. Light is essential to life. Plants and animals are governed by the rhythm of day and night. Sunlight provides the energy for the food-making process in green plants. The fossil fuels are the store of the solar power that winged down from the sun millions of years ago. When the fuels are burned, the sun energy locked in their molecules is liberated as heat and light.

Scholars and scientists at all times tried to explain what is light. Some of oldest people believed that light was a kind of emanation from the eye. Newton proposed that light was a stream of particles or corpuscles shot off by a luminous body. A few people were in favor of the theory that light was a vibration. Einstein theorized that a beam of light is a shower of small packets of energy, which he called photons.

The white light is the combination of red, orange, yellow, green, blue, and violet lights. When a beam of white light passes through a triangular glass prism, a rainbow of all these colors will appear on a screen. Certain objects have their own property. They absorb some kinds of colors while reflecting some at the same time. The reason for the red we see in the rose petals is that these petals absorb most of other kinds of colors while reflecting the red light.

That the sky is blue is because the lower parts of atmosphere scatter more of the blue light than the others. That the sun appears yellow is due to the combination of the remaining colors apart from blue in the sunlight.

Light is bent or refracted when it passes obliquely from a medium of one density to another. That is why chopsticks look crooked when part of them is in the water.

Two types of lenses people use everyday are convex lenses and the concave lenses. The convex lenses are used for converging light, whereas the concave lenses are used for diverging light.

Visible lights resemble other forms of radiation, such as radio waves, x rays, and cosmic rays in that they travel at the same speed in the same medium. The only difference is the wave length.

Chapter 13

This chapter is the story of sounds it is the story of how sounds are made, how sounds differ, how they travel, how they are detected, and how they may be controlled.

Our language reflects our keen awareness of sound. In the country we mark the hum of mosquitoes, the rustle of leaves, the lowing of a cow, the flutter of wings, the roar of a waterfall. In the city we note the blare of automobile horns, the rumbling of trains, the blast of factory whistles, the patter of children’s feet, the cries of street vendors. Each season, each mood of nature is announced by its own special sound. Humans also make sound combinations evoked from musical instruments, such as violin strings, organ pipes, and drums.

Whenever a sound is produced, there must be something quivering, trembling, and shaking back and forth. In other words, vibration leads to sound. How is sound transmitted? When something vibrates, it imparts its trembling motion to the air particles around it. These molecules, in turn, pass the vibratory motion to the air molecules adjacent to them. In this way the vibration travels out ward in all directions form its source. How do we hear sound? A small part of the wave strikes a little membrane in your ear and cause the trembling of the eardrum which is then converted into electrical energy and triggers the nerve impulses. These impulses travel along the auditory nerve to the brain. We then perceive sounds. How do we distinguish among many sounds? We identify sounds by three characters of sounds which are loudness, pitch, and quality. Loudness of sounds depends on how powerful the source of sound is and the distance of listeners from the sources. It is measured by the decibels. The larger the decibels of sound are, the greater the amplitude of the sound wave is. Loud sounds are universally disliked because they cause hearing impairment of people who are not immunized from it. The pitch of the musical notes is another way of saying the frequency of the vibration in the instruments. Three factors response for the difference in the pitch of various strings in an instrument. They are length, weight, and tightness. Low notes are produced by long, heavy, and loose strings. High notes are made by the opposite kinds of strings. Two sounds of the same loudness and pitch can be different. That is due to the “shape” of the sounds are different. The quality of sounds is an obscure terminology.

Let’s stop writing boring and tedious academic English. Let’s relax and try some funny and easy English dialogues. Here is a book called everyday English. It is not hard, but the content is practical.

Chapter 1—in the morning

I turn off the alarm clock. I wake up. I stretch. I fold my quilt. I flush the toilet. I jog. I heat up some water. I wash my face. I make some coffee. I spread butter on my toss. I brush my teeth. I rinse my mouth. I shave. I take off pajama. I change into business suit. I comb my hair.
I hear the alarm clock buzzing.
I sprinkle water on the flowerbeds. Potted plant. Ornamental plant. Flowerpot. Weed.
I do exercises. I exercise. I take a walk. I walk my dog in the park.
I yawn. I let out a yawn. I still feel stiff and tired from yesterday’s work.
A bedding. I spread/ lay out/ make up the bedding.
Washroom. Restroom. Men’s room. Ladies’ room. Powder room.
I go into the bathroom. I turn on the faucet. I splash water on my face. I dry my face with a towel. I take a shower and wash my hair.
I boil some water. I put the kettle on the stove. I pour the hot water into a thermos.
Fix coffee. Prepare coffee. Brew coffee. Coffee maker. Instant coffee.
I butter my toast. He buttered his boss up for a raise.
Toothpaste. Cavity. Mouth wash.
Safety razor. Disposal razor. Beard. Whiskers. Mustache.
Undress. Slip off his shirt. She stepped out of her shoes.
I set my hair. I untangle my hair. I blow-dry my hair. I curl my hair.
I make up my face. I take off my make-up. Lipstick. Powder. Lotion. Blusher. Perfume.
I lock up the house. I chained my bike. I bolt the door.
Dispose of trash, rubbish, and garbage. Trash can. Garbage truck. Garbage collectors.
The alarm clock goes off.
The delicious smell of chicken soup is filling the room. My stomach is growling.
I feel dizzy. I am not a morning person. I have trouble waking up this morning. I shouldn’t stay up late.
My face looks awful.
I don’t feel like eating. Coffee brings me around.
The sun is shining. Not a cloud in the sky.
Soap has gotten in my eye. It stings.
My heart is pounding. I cannot quiet my thumping heart.
The rice is cooked.
Smooth out the wrinkles.
Throw out nonburning trash.
My eyelids are heavy. Rub the sleep out of my eye. Still sleepy.
I feel groggy. I feel feverish. I feel nauseous. I feel sick. My body feels heavy.
Night person. I am no good early in the morning.
Oversleep. I have been having insomnia. I have no choice but to get up.
My face is covered with pillow marks. I have poor appetite this morning. I am not in good shape this morning.
Coffee lover. I cannot imagine getting through the morning without coffee. Coffee perks me up. I’ll come around once I had some coffee.
Hurry up. Get a move on. Search for train pass inside purse. Not again.
The window is fogged up.
It is dangerous. That was a close call.
I have to settle for a banana today.
I take off my shoes to change into my sandals before going to the beach to get a suntan.
He locked the safe to protect his jewels which he received from his mother.
It is already time to leave for the airport to catch the plane bound for Paris.
I haven’t ironed the laundry yet.
My eye looks a little swollen.
Gargle with mouthwash.

Chapter 12

This chapter reveals the fact that magnetism and electricity are in close relation. The electricity can generate magnetism, and so does the reverse.

Scientists now believe in the modern atom theory which explains the nature of magnetism plausibly. As we all know, there are lots of electrons revolve around the nucleus. We can loosely say that these electrons spin in two directions which are clockwise and counterclockwise. The electron spin cause magnetism, but the amount of electrons rotating in one direction is usually the same as that of the other; therefore, the magnetic effect is neutralized. However, in elements, such as iron and nickel, there is a significant surplus of electrons spinning in one direction over the other; thus the atoms reveal the magnetic behavior. When all of the atoms in the iron bar are arranged in order, that means they face in one direction, the bar becomes a magnet. That iron bars are not magnetic is because the atoms in the bars are in disorder. They neutralize each other’s magnetism.

The generator is invented with the underlying idea that magnetism and electricity are interchangeable. If you thrust magnet into the coil, you will discover that electricity flow in one way through the wire. When you pull the magnet out, you will find the flowing electricity again, yet in the opposite direction. If you continue to move the magnet back and forth over the coil, an alternating current will be produced. The above basic principle applies to generator. I will take hydroelectricity energy as an example. The rush of falling water spins turbines that turn huge coils of wire near giant magnets, which generates electricity.

A great use of magnetism and electricity is the invention of telephone. There are two important parts of the telephone which are the transmitter and the receiver. Inside the transmitter there is a little filled with thousands of grains of black carbon. These grains are part of the electric circuit. When you speak, your voice cause the vibration of these grains to be compressed. The squeezed grains have lower electricity resistance. On the other hand, when you stop speaking, these grains spring apart, and the electricity resistance increased. The change of resistance results in the impulse of electricity flow. The impulse causes the disk in the receiver to vibrate, which generate sound.

By using magnetism and electricity, scientists invented many practical things. Lots of new powerful machines will come out because of the application of magnetism and electricity.

Chapter 11

This is one of my favorite chapters. I appreciate this chapter very much because it demonstrates a world of mechanics which is a field that I am likely to study in. to begin with this chapter the book quotes a remarkable ancient saying which is “give me a fulcrum on which to rest, and I will move the earth.” --- Archimedes, 2nd century B.C. I knew this quote when I was in elementary school, and I was intrigued by the mysteries of mechanics at that time.

Not only the modern technologies but also the ancient civilizations depend greatly on the use of machinery. Without the help of mechanical tools, the giant pyramid would not be completed, nor would the great wall and the Stonehenge. Machinery such as lever, pulley, wheel and axle, intermeshing gears, inclined plane, wedge, and screw provide extremely effective and energy saving assistance to people because these basic machines serve three purposes which are increasing speed, increasing force, and change the direction of a force. Intricate machinery combines these simple machines and serves two or three of the functions simultaneously. One outstanding superiority of machinery is the reduction of the amount of force put into the work; however, a saving of force in a machine is at the expense of long distance because according to the law of kinetics, disregarding the losses due to friction, the work put into a machine equals the work put out and there is a formula that work is the result of the multiplication of distance and force; therefore, when the force is reduced, there must be an increase of distance if the total amount of work is identical.

The law we refer here is just theoretical; in fact, all machines lose some of their efficiency because of friction in reality, and friction occurs when any two substances rub together. Some frictions are totally awful, for they waste energy; in addition, the heat that results from these frictions cause severe damages to machines. In order to reduce the harmful frictions, people fill lubrication into the irregularities of the contacting surfaces of the parts in machines. On the other hand, frictions can also be an asset in consideration of they preventing slipping and making possible thousands of every day activities.

Chapter 10

This chapter indicates one physical phenomenon which is heat. People often feel heat in the nature that they are not surprise any more. When we rub hands on a cold day, we feel warmer. We burn gas under a kettle of water, the kettle gets hot, and the water boils. Electricity runs through coils of wire in a toaster, and they get red-hot. In the glare of the summer sun a sandy beach heats up. However, there is a fundamental question which is what the nature of heat is. The heat is a kind of energy. When being heated, the molecules of substances move with more speed. To summarize, heat in a substance is the energy of the motion of its molecules.

Heat is measured by temperature. The common measuring device is the thermometer. In order to make sense to readers, the book gives some examples ranked from high temperature to low temperature. The surface of the sun is 5500 Celsius. Kitchen range flame is 1700 Celsius. Water boils at the temperature of 100 Celsius. The temperature of human body is 37 Celsius. Ice melts at 0 Celsius. Absolute zero that represents the lowest temperature that matter can theoretically reach is –273 Celsius.

Heat moves in three ways which are conduction, convection, and radiation. Conduction is a method of heat movement in which energy is transferred from molecule to molecule by collision or bombardment. The excellent heat conductivity of metals is due to the fact that the electrons of its atoms can flow along through the metal very rapidly and transfer energy to the atoms in cooler regions. In nonmetals, electron movement is restricted and heat energy is passed stepwise from atom to atom, but the process is much slower than in metals. Different materials vary in their ability to conduct heat. Those conduct heat slowly are called insulators. Clothing, blankets, and some house-insulating materials are effective in preventing the loss of heat Convection is responsible for the currents of heat which circulate hot and cold things and transfer energy from hot things to cold things. The difference between conduction and convection is that conduction happens in one thing, whereas convection occurs between two or more separate things. Radiation is quite different from both of these. The transmitting of radiation does not rely on any substance. Sun heating the earth is an good example of radiation because there is particular nothing to be heated in the space between sun and the earth. The sun is as giant broadcast station that emit many invisible waves which are picked up by earth and converted into the energy of heat.

A discussion of refrigeration belongs in a chapter of heat because to cool something means to subtract heat from it. Basically refrigeration depends on the principle that evaporation is a cooling or heat-removing process. Certain type of vapor is compressed into fluid in the pump which evaporates again and absorbs heat at the same time. The vapor then come back into compressor and is turned into liquid. The cycle is repeated in the refrigerator.
.