|
|
|
Lasers are made up of photons and electrons. You know how you’ve been taught that every nonliving thing is made up of atoms. Well, guess what, their wrong, lasers are made up of electrons, but no protons or neutrons. As you know, ordinary light is incoherent light. This means, it has many waves and many wavelengths that sometimes intersect. Lasers are coherent light. This means, the waves are very organized or in phase. All the peaks move in step with one another and in the same direction. They all have very similar lengths, too. This can be compared to marchers in a parade all moving with the same stride in the same direction. American Theodore Maiman built the first working laser in 1960. Theodore was not the first to try though. First, Charles Townes tried to make a laser, but it never made laser light. Second, Arthur Schawlow tried but he died in the process. Third, Theodore Maiman tried and was successful. Today, people have many uses for lasers, such as: medical operations (eye surgery, un-clog arteries, and to remove unwanted birth marks and scars), military needs (missile guidance and laser aimed guns) and every day activities (shopping, listening to music, and laser light shows.) Lasers vary greatly in size. There are lasers that can fill a large room. Or, there are lasers as small as a grain of salt. People also use lasers to measure distance. United States astronauts placed a laser reflector on the moon. Then, Using a high powered laser, scientists measured the distance from earth to the moon with accuracy of 5 centimeters. The beam, sent from a telescope on earth bounced off of the reflector on the moon and gave the measurement.
|
|
|
We all know that people think that the surface of the sun is the
hottest thing in the universe. Well, think again, scientists have made lasers
that are 2 times hotter than the sun. Now, think of a pinhead, and think of 200
tiny holes in it. How many things can you think of that can do that? I can think
of one, "lasers".
Lasers can be very, very dangerous, and lasers can be very
harmless. . Many people tell you not to shine a laser pen on a TV or a computer,
but it won’t do anything all it can do is reflect in the other direction. But,
if you shine a laser pen at some ones eye you can blind that person. There is a
1 in 100 chance of that laser hitting their pupil, but if it does it can hit the
retina and tear it or scar it causing blindness. So, used wisely, lasers can be
both, useful and safe.