Did you know that the word LASER stands for Light Amplification by Stimulated Emission of Radiation? And that a MASER is a laser beam with wavelengths in the microwave part of the spectrum? Most lasers fire a monochromatic (one color) narrow, focused beam of light, but more complex lasers emit a broad range of wavelengths at the same time.

In 1917, Einstein figured out the basic principles for the LASER and MASER by building on Max Planck’s work on light. It wasn’t until 1960, though when the first laser actually emitted light at Hughes Research Lab. Today, there are several different kinds of lasers, including gas lasers, chemical lasers, semiconductor lasers, and solid state lasers. One of the most powerful lasers ever conceived are gamma ray lasers (which can replace hundreds of lasers with only one) and the space-based x-ray lasers (which use the energy from a nuclear explosion) – neither of these have been built yet!

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19 Responses to “Laser Basics”

  1. Carolyn Halvorsen says:

    I saw a very small dot in the sky with some help finding it> It was really hard to see most of the time.

  2. I’ve never heard of a red laser to point out the stars, as you can’t really see it in the dark sky. Were you able to see a red line, or just a dot?

  3. Carolyn Halvorsen says:

    Lasers are the best thing ever in life. I also went to a scout camp and did the astronomy merit badge and they used a red laser to point at the stars not a green laser. Why is that Aurora?

  4. Lorelei Grecian says:

    How do you make jelatin, cause that looks really cool!!!!!!! 🙂 😀 😛

  5. Mary Thomas Jackson says:

    Thanks Aurora,

    -Charli(7th grader)

  6. Check amazon or your hardware store.

  7. I don’t recommend using green lasers at all, because it’s too easy to damage your eyes permanently, especially in the hands of kids. They originally were intended for astronomers during their outdoor field presentations. However, hey are on the market and people continue to buy them because they are ‘cool’. so my next best recommendation is to use them ONLY outdoors pointing up at the stars. They are too powerful for indoor experiments. That said, watch out for airplanes, because you can blind the pilot. In fact, the police are cracking down on these cases and when pilots report a green laser flash in flight, they quickly notify the local police in that area, who find and fine the culprit quickly.

  8. Mary Thomas Jackson says:

    Aurora, why can green lasers only be used outside?

    -Charli (7th grader)

  9. Mary Thomas Jackson says:

    Does anyone know where you can buy a laser?

    -Charli (7th grader)

  10. Marguerite Sanders says:

    Awe….. : ) Looking forward to doing this stuff tomorrow with the children. Thanks

  11. sevy keble says:

    Yeah! Man, all these experiments always have so many different endings, if you know what I mean.

  12. ‘Thinking out of the box’ means just playing around and trying stuff and seeing where it leads you – like reflecting the beam on the wall. What happens when you take your laser into the bathroom after someone’s had a hot shower? Are there mirrors in there you can use with the lights off? 🙂

  13. sevy keble says:

    Um, what do you mean i thought out of the box on my comments for lasers?.. I only commented on this one. (I think) .>.<

  14. No problem – that’s why we’re here – to help you do real science and keep your eyebrows attached. Nice job thinking out of the box on your other comments for lasers! 🙂

  15. sevy keble says:

    Yowzers. I’m really sorry.

  16. NOT a good idea you have there, Sevy. The trouble is, not all lasers are going to be as safe as the one you happened to play with. Most other lasers will leave a burn mark and a blind spot on your eyeball when you do this. What else can you think of to do that won’t affect your vision?

  17. sevy keble says:

    WHOA! I just found out something very exciting! You CAN 😛 see lasers! 😀 🙂 😛 ! I shined a red laser in my eye, and I saw tiny red circles 😀 going from the laser emiter to my eye! 😀 amazing! 🙂 😀 😛

  18. sevy keble says:

    Wow! So exciting! And, uh….. Wait, hold on a sec! My bro was shining the laser at a wall, and it reflected unto the other wall! Anyways, really exiting!