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。