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Sat 9 Aug, 2014 02:18 pm
I'm adam 13 and need some help with this assignment I'm doing on lasers, here's what I've done so far
Science Assignment - Light Technology and Optical Devices
Lasers
We may not realise it but lasers ( which is short for Light Amplification by Stimulated Emission of Radiation) play a significant part in making our day to day lives easier. In supermarkets bar code readers in stores use lasers. Doctors use them to preform delicate eye surgery. Without lasers TV and telephone signals could not be carried. Metal workers use lasers to cut and weld metal into everything from street light poles to cars.
The interesting thing about lasers is that the are a special form of light because Laser light does not exist in nature. Only human technology can create laser light. But first what is "ordinary" or natural light? Ordinary light, like sunlight, is made up of many different wavelengths, or colours, of light. If you put all the different colours together, you get white light. Now there are three main differences between a laser and natural light.
Firstly, the light from a laser contains exactly one colour or wavelength rather than a lot of different wavelengths. Scientists say that laser light is "monochromatic," meaning of one colour. Secondly, all the wavelengths are in phase. That is, they are all "waving" together, like a well-timed audience "wave" at a football game. All the wave crests (high points) and troughs (low points) are lined up. Scientists say the laser light is "coherent."
Thirdly, while light waves from ordinary sources (such as flashlights, lightbulbs, or the Sun) spread out in all directions laser light waves all travel in the same direction, exactly parallel to one another. This means that laser light beams are very narrow and can be concentrated on one tiny spot. Scientists say the laser light is "collimated."
Because the laser light is monochromatic, coherent, and collimated, all of its energy is focused to produce a small point of intense power. This focused power makes laser light useful for cutting and welding. It also makes it possible to control laser light very precisely and make it do all kinds of useful things.
Any comments on what I could improve or new areas I could expand on would be very much appreciated, thanks
@Jimmyswag101,
I think you've got a great essay so far. It's interesting and well-written.
I'd change Firstly, etc. to First, Second, etc. I don't think you need the adverb form. You might or might not want all of your reasons in one paragraph. It seems to flow better if you put a paragraph break before your third reason.
I'd also ditch the double quotation marks and instead italicize those words (if you're hand-writing this essay, and it's hard to distinguish regular script from italics, then feel free to ignore this suggestion).
After the part you've already got, it's time to start listing some of the uses of lasers. You already have some but the statement you make at the end suggests more - maybe go in a different direction with your list, e. g. with medical applications or the like.
Hope this helps!
Good essay Jimmy, here's a bit more if you want to add it-
The military have been experimenting with "Dazzler Weapons" for many years, they're lasers intended to temporarily blind enemy troops and pilots etc.
The drawbacks are that the narrow beam is very difficult to hit a moving enemy's eyes at long range, so he might just as well be hit by a bullet or missile in the first place instead.
Also Dazzlers can be defeated if the target is wearing special goggles or tinted glasses.
http://en.wikipedia.org/wiki/Dazzler_(weapon)
@Romeo Fabulini,
Thanks I'll take a look at the link
@jespah,
Thanks a lot, very helpful
You may wish to look at some of the problems. People have been arrested for directing laser pointers at aircraft flying overhead.
There were a couple of kids shining pen-lasers from their bedroom window at night here in Plymouth a few years ago, and I was in two minds whether to tip off the police in case they dazzled a motorist and caused an accident.
Then one of them targetted ME as I stood at my window, the little red dot was moving around my walls and over my chest, so I thought "Right kiddies, you're in for it now!", so I called the cops who went and took the lasers off them and gave the parents a ticking off ..
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