And that Chicken recipe sounds good... I'll have to copy it for Phillip. I think I have seen the dry tomato soup here at Wal Mart... I usually get the chicken at Wal Mart because you can get a 10 lb. bag of hindquarters for around 59 cents a pound... I ask for the frozen bags then divide it up into portions... I get chicken and sometimes pork at wal-mart but not beef...As far as I'm concerned their beef sucks...Phillip pounded out some swiss steak and after browning it he put into the crock pot for the day...I'm filled to the gills, it was so good...Hey Jake!! Do they have such a thing as a laser to cut rocks? If not then they need to peek in on my latest brain echo...Last night I dreamed I had a laser rock slabber that looked like a regular band saw but it was a laser beam that cut the rocks and the cut surfaces were like they had been polished...This saw was weird in that I don't know what contained the beam on the other end and assume it must be something or it would cut right thru past the floor and all...Don't know how lasers work, but this one had a blue light beam...In fact I don't know what produced the beam at the top either, but the darn thing sure did cut rocks...Who said you have to have sensible dreams?
I think we caught the edge of the storm that hit Denver. Having yo-yo weather here...10 degrees above normal or 10 below normal...Garden is at a stand still...Ice froze on the rock washing basins the last 4 nights...Good thing I still have the cukes and squash in pots so I can bring them in at night...Got all 3 tumblers going...I've been making up key chains with stuff I got at the thrift store and crystals and tumbled rocks...Got a gross of key chains and a gross of different kinds of clip back earrings for only 3 bucks...I took the earrings apart and glued the rocks and crystals in them and attached them to key chains...Gotta pat myself for this trick...Should sell I think...
Granny
3 comments:
Sounds like you are and have been busy!! Oh, and I love a good meal............THAT'S WHY I COOK. Tee hee!!
Hey Grandma, Good Question! It got me to thinking and doing some good boning up on the ol' knowledge base! It has been a while since I took a class that dealt with lasers. I think it was my undergraduate optics class I took in 1999! I have to say that I was a bit rusty on the subject so I did a little refresher research. Ok, so first off let me tell you a bit how lasers work. I have a textbook ("Optics" by E. Hecht) that has a chapter talking about the 'laser' or Light Amplification by Stimulated Emission of Radiation. I read through it and I think I can tackle this question. So basically a laser works like this:
1) create an electron "population inversion". What this means is that you need to get a bunch of electrons excited to higher energy levels from the ground state. I think of this as like having marbles on the floor (where the marbles represent electrons) which is the lowest energy they can have. Then you grab a few handfuls of marbles and put them on the table (a higher energy state). You do this enough times until you have more marbles on the table than you have on the floor. This is where the "inversion" part comes from. Ok, this did not happen for "free" you had to spend energy to move these marbles. The same thing happens in a laser. You have to "pump" the material with some kind of energy to create this electron population inversion. This can be done with electrical, chemical or optical energy.
2) Ok, so you have a bunch of marbles on the table. Unfortunately, my nice analogy doesn't work so much anymore because what happens is that when these electrons fall to the ground state and a tiny bit of light or a photon is emitted. If a marble falls off the table nothing happens other than the marble makes a thud. Ok, maybe we can think of that "thud" as a photon. Ok, so as this photon is released and collides with another excited atom that kicks out another photon or two. So as the laser is pumped it dumps energy into the material in the laser and more and more photons are produced. So to continue with our table analogy lets say that the "thud" jiggles a few marbles loose that then roll off of the table. So as you pick up the marbles and put them on the table to maintain the population inversion the constant "thuds" keep shaking them loose and rolling off of the table.
3) So these photons are produced in a resonant cavity (this totally doesn't work with my table description so I'll have to abandon it here, if you want me to describe resonant cavities I can tell you about it in another message) and these photons bounce around in this cavity until they escape and viola you have a laser beam.
What makes lasers special is that all the photons are in phase, which is ideal for applications such as interferometry (I'll tell you about that stuff later if you are interested) and there is great control over the wavelength (color) of the photons. In the early days just after the laser was invented in 1960 all lasers were single wavelength but nowadays you can make lasers of multiple wavelengths. I'm guessing they do this by putting different materials in the laser cavity.
Ok, so your brain echo may have told you something because they do use lasers for cutting and I'm pretty sure they could slice right through rocks. If it was a blue laser then it would be close to the upper end of the energy range of the visible part of the spectrum, so that's good. However, unless your cutting tiny rocks then you would have to have a pretty powerful laser so I think the "pump" would have to be a pretty hefty voltage source or have some serious chemical reactions involved to pump the laser. Also, you may damage the rock from the intense heat as the laser light broke down the chemical bonds in the rock or vaporized the rock material and that may not be good if you want to slice agates or something like that were you would possibly fuse the silica and damage some of the beautiful colors in it.
Alright, hopefully that wasn't too boring and hopefully I was able to share some stuff that I needed a good refresher on myself.
Oh, yeah one more thing a laser is not contained in the sense that it is "capped" at both ends. A laser is like a flashlight in that it shoots out and goes until it runs into something. I guess you could put a mirror in front of it and direct the beam back into the source, but lasers are not like the "light sabers" in Star Wars where they go out a certain distance and just stop.
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