Science 3024 Conductors, Insulators, and You

Science 3024 Conductors, Insulators, and You
What would you do if you saw a power line on the ground?
Electricity is a great power source. It runs our computers, starts our cars, lights our homes—the list of uses is nearly endless. But electricity is also dangerous. It can hurt, or even kill, if it isn’t handled safely. This powerful force is controlled with conductors and insulators.
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Electricity flows through some things more easily than it does through others. These materials are called conductors. When you want electricity to flow, you send it through a good conductor. One of the best conductors is metal. Wires, plugs, and batteries are all made of metal.
One place you never want electricity to flow is through your body. Water is an excellent conductor, and you are mostly made of water. If you touch something that contains an electrical current, the electricity will quickly enter your body.
Some materials don’t allow electricity to flow very well. They are called insulators. Plastic, rubber, and glass are common insulators. That’s why wires are coated in plastic. Electricians often wear rubber gloves so that working with electricity is safer.
If an electrical current is strong enough, though, it will even flow through an insulator. For example, air isn’t a very good conductor, but that doesn’t stop lighting from zapping through it. The shock you get from static is also electricity jumping through the air. You must always be careful around electricity.
Never put anything but a plug into an outlet. You could get shocked.
Never go near a downed electrical line. They carry huge amounts of electricity and are very dangerous. Even if you don’t touch them, the electricity is strong enough to go through the ground or the air. It can cause serious injury or even death.
Don’t use electrical devices anywhere near a shower or bathtub.
If you’re carrying a ladder or other long object, be aware of overhead electrical lines. If you touch a line with the object, you could get hurt


電力是一個強大的力量來源，他能應用在我們的生活之中，是如此的不可或缺。但是，電力除了為我們所用外，他可以傷害甚至可以殺死我們。因為，電可以藉由導電體移動流竄，而構成我們身體大部分的元素水便是其中之一。

 

Science 3032 Colors in the Sky

Science 3032 Colors in the Sky
What makes rainbows form, and when can you see them?
Next time you see the sun come out during or just after a rain, look outside. This is the perfect time to spot a rainbow. Many cultures have stories that explain how rainbows form in the sky. Today, we know that rays of light pass through drops of water create rainbows.
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Sunlight is actually made of different colors. When a ray of sun enters a raindrop, it refracts, or bends slightly. Each different color bends at a slightly different angle so they separate out. The light also bounces of the back of the water drop. This is called reflection. When light bends and bounces through thousands of raindrops, you see a rainbow in the sky. A rainbow contains the colors of the spectrum.
The main colors of the rainbow appear in the same order: red, orange, yellow, green, blue, indigo, and violet. Some people remember the order using the initials in the name ROY G. BIV. It’s rare, but sometimes you can see a double rainbow. The colors in the outer, dimmer rainbow are the opposite of a regular rainbow—violet comes first, and red appears last.
A prism is a piece of glass that is used to split light into its colors. Isaac Newton was the first scientist to figure out that a prism could separate light into colors. Before that, people had thought that the prism made the colors. They didn’t realize that all the prism did was make the colors in light visible.
Using a prism is an easy way to make a rainbow at home. Try shining a flashlight through a prism onto a sheet of white paper. The light changes speed as it enters the prism. It bends and reflects onto the paper as the colors of the spectrum.


甚麼時候是看見彩虹的完美時機?下次當太陽出現於下雨時或下雨後，你只要往外一看便可以看到彩虹。陽光其實是由數種顏色的光所組成的，只要使他穿過例如水滴或三稜鏡使他在其中轉折分散便會形成如彩虹一般多重的顏色。



 

閱讀筆記 S3016 The Sound of Food

Science 3016
The Sound of Food
Is a reflex something that happens naturally, or can be taught?
In the late 1800s, Ivan Pavlov was a scientist living and working in Russia. He had been studying how dogs digest food. He noticed something very interesting. Before he fed the dogs, they would begin to salivate, or produce saliva. When they saw Pavlov take out their food, they knew he would feed them soon. The saliva helped them digest the food.
Watching this made Pavlov curious. He wondered if something other than food could have the same effect. He decided to do some experiments to test his idea. Just before he fed the dogs each day, he rang a bell. After doing this many times, he tried ringing the bell without feeding the dogs. Sure enough, the dogs salivated at just the sound of the bell. Each time Pavlov rang the bell, he got the same results.
In Pavlov’s experiments, the bell was the stimulus.  It caused the effect—salivation—that he was trying to produce.  Before Pavlov trained the dogs, the sound of a bell didn’t have any effect on them. Pavlov trained the dogs to link the sound of the bell with food. The animals got so used to this idea that even when there was no food, they still reacted the same way.
The dogs’ response was a reflex. If you tap just below the center of your knee, your leg will kick. You don’t kick on purpose, it’s just a reflex. If you put your finger in a newborn baby’s hand, the baby will grasp it. Shine a light at someone’s eyes, and their pupils will shrink. Living things are born with all kinds of reflexes. Each time a stimulus is present, the body behaves the same way. Through his work with dogs, Pavlov was able to show that reflexes can be taught, too.

閱讀筆記 S3008 The Good Scientist

Science 3008
The Good Scientist
Do you think you have what it takes to be a successful scientist?
 When you picture a scientist, you might think of a person in a white lab coat hunched over a test tube. He or she might be entering numbers into a computer or taking notes about the habits of wild animals. But what makes these people good scientists?
One of the most important qualities of a good scientist is curiosity. Curiosity makes a scientist ask why things happen. It makes him or her eager to learn more or test an idea. Remember the story of Newton and the apple?  He might never have discovered gravity if he hadn’t asked himself why the apple fell.
 Scientists must be good observers. They must watch the world around them in order to make sense of it. As they observe, they must keep an open mind.  They must be sure that their opinions don’t get in the way of the facts and evidence they find.
 Creativity is also important to scientists. They have to be able to see solutions in unusual places. Some of the greatest inventions might never have been made if scientists didn’t have great imaginations. Think of the telephone, the automobile, and TV.
 Communication is a must for scientists. Science is built on the work of earlier scientists.  If someone doesn’t share what he or she has found, it loses importance. Louis Pasteur found that disease is caused by organisms too tiny to be seen by the human eye. What if he had never shared his discovery?
 Scientists must be persistent. They have to be willing to try again and again if they don’t succeed the first time. The Wright Brothers had to try many times before their plane finally flew. People worked for years to find a vaccine for measles before they had any success. If they had given up too soon, the world might be a different place.
 Now that you know some of the qualities of good scientists, how do you measure up? 

閱讀筆記 S3010 The Scientific Toolbox

Science 3010
The Scientific Toolbox
How do scientists see bacteria? How do they measure the distance to the moon?
To build a house, a carpenter needs a hammer and a saw. To fix a car, a mechanic needs a wrench and a screwdriver. Having the right tool for the right job makes work easier. Like any other worker, a scientist needs tools as well. The exact tool he or she uses depends on what needs to be known.
Measuring is one of the most common scientific tasks. Whether it’s time, weight, temperature, or length, every measurement needs to be accurate. If a measurement hasn’t been made carefully, the result can’t be trusted, and neither can the experiment.
 Scientists use the metric system for their measurements. Rulers, used to check length, have marks on them showing centimeters and millimeters. Measurements longer than a meter are often made using a measuring tape. The tape is several meters long. Because it is thin and flexible, it can be rolled up and stored in a small case.
 The longest measurements are made using lasers. The amount of time the laser beam needs to hit an object and reflect back shows the distance. 
 Thermometers help scientists find temperature—the amount of heat something has. Scientific thermometers use the Celsius scale. For many years, thermometers were filled with mercury.  It rose or fell inside them based on the amount of heat. Today, most thermometers are electronic. Mercury is a poison, and electricity is safer. It is also much more accurate.
 Often what a scientist needs to study is too small or far away to be seen without help. Microscopes and telescopes are tools that magnify things. For both devices, lenses are placed inside tubes. Looking through the tubes makes objects easier to see.
 Microscopes let scientists peer into the tiny worlds of bacteria and viruses. Telescopes allow them to watch what is happening in space billions and billions of miles from Earth.

科學家如何用顯微鏡觀察細菌?如何用望遠鏡觀察月亮?
就如其他行業的人一般，科學家也需要工具
而精準的儀器能夠提供這人需要知道的資訊

閱讀筆記 S3012 The Metric System

Science 3012
The Metric System
Why has the metric system become the scientific standard for measurement? 
If someone asks how tall you are, you’ll probably answer in feet and inches. If you were a scientist, though, you’d most likely answer in meters.
 The metric system was created in France during the 1700s. Scientists wanted a simpler way to compare things. The old way was complicated.  For example one gallon of water weighs 8.33 pounds. If you want to know the weight of 14 gallons of water, the math is not simple.
French King Louis XIV asked his scientists to invent an easier system. Their answer was the metric system. All of its measurements are based on the number ten and a length called the meter.
 The oldest measurements began as body parts. This is where the term foot comes from. The French scientists wanted their new system to be based on something more precise. They decided the meter would be a small fraction of the distance between Earth’s two poles.
For many years, an official meter stick was kept in France. All other meters were based on it.  Soon, scientists tired of having to rely on this one meter. They wanted to be able to find the exact length without having to travel to France. Today, one meter is defined as the distance light travels in1/299,792,458 of a second. Now, that’s accurate!
 A meter is divided into one hundred centimeters. One thousand meters makes one kilometer. Conversion is much simpler when a system is based on tens — you just need to move the decimal point. For example, something that is 350 meters long is also 0.35 kilometers long or 35,000 centimeters long.
 Different types of measurements are linked with each other as well. Metric length, weight, and volume are related based on water. If you could form water into a box shape that was one centimeter on each side (length), it would be one cubic centimeter. One cubic centimeter of water equals one milliliter of water (volume), which weighs about one gram (weight).
 Because these conversions are so simple, most scientists and nations use the metric system.  


為甚麼公制的系統會變成科學家測量的標準?
當一個人問你的身高時，你可能會用英呎或英吋來表達
而如果你是一位科學家的話，你會偏好用公尺回答
公制的系統在18世紀的法國被建立出來
當時的國王路易XIV要他的科學家們創造出一個較簡單的測量系統
也因此制定了距離為10的長度叫公尺

'There is nothing left': Family's $4MILLION medieval-style dream mansion that took them three years to build burns to the ground

• Fire broke out when luxurious 22-room country home was empty
• Cause of intense blaze which spread quickly is under investigation

By Daily Mail Reporter
PUBLISHED: 04:43 GMT, 11 January 2014 | UPDATED: 14:00 GMT, 11 January 2014

A sprawling $4 million mansion built by an Ohio family has been gutted after a fire broke out on Friday afternoon.
Homeowner Maria Decker, who had only added the finishing touches to her family's dream home last year, was on vacation when the fire broke out.
Plumes of smoke and flames as high as 30ft could be seen as the fire ripped through the 22-room stone-built mansion. 

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Gutted: The fire spread quickly through the two-storey home, making it too dangerous for firefighters to go in

About 70 firefighters were called in to tackle the blaze, but the house was quickly engulfed, making it too dangerous for the crews to go inside.
It took Mrs Decker and her husband Jeff three years to build the house, which had vaulted ceilings, stone arches and a turret.


Mr Decker had gone out for lunch when the fire started. His 44-year-old wife was on vacation in Florida, and their sons were at college and school.
'They're devastated at this point in time. What they've worked for and the beautiful, big house they built is no longer standing the way it was,' Fire Captain Clarence Smith told WLWT.
Mrs Decker's 20-year-old son Chase, left a message on Facebook telling friends they had lost everything in the fire, but that the family's dogs had managed to survive.

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Dream home: The 22-room house took three years to build and was valued at $4 million

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Inferno: Flames can be seen covering the whole property

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Heartbroken: Jeff and Maria Decker, and their sons Chase and Austin, were away at the time of the fire

In a post written at 4pm, he said: 'You will soon see on the news that our home has burned down and there is nothing left of our possessions.'
He added: 'Thankfully everyone is safe, including our dogs.'
Because the two-storey home was set back from the road, in five acres of land, and didn't have a sprinkler system, the firefighters struggled to control it.
A fire hydrant that was on the property didn't have a large enough supply of water to tackle the flames, WCPO reported.
The sprawling five-bedroom home, which had an elevator, flag pole and outside pool, was built in 2006, although Mrs Decker had put photos of it nearing completion last year.
As well as being the family home of Mrs Decker and her sons Chase and Austin, the house was also the site of J.R. Decker Builders Inc.

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Family home: Chase and Austin, pictured in the luxurious kitchen in December 2009

The cause of the fire is under investigation. At first, it was thought to have been a blaze in a field, as neighbors called in reports of smoke.
Paula Maxwell, who lives behind the Decker's property, said: 'I at first thought the woods were on fire behind my house.' She added that she could see balls of flame through the trees.
Another neighbor, who was not named, told Fox 19: 'I hang out with the kids and play golf with them, [we're] actually good friends with them and it breaks my heart that they don't have a house to come back to or a place to live for a little bit.'



一棟4百萬的中古世紀風格兩層樓豪宅於一周五下午毀於一場火災
那火勢、煙霧至大以致於在大老遠便可瞧見
由於屋內並無裝設自動灑水器幫助滅火，以致消防員難以在短時間內撲滅火勢
無神傷亡屋主卻失去所有屋內的財物