Tuesday, June 19, 2012

microwave

I grew up in the era before microwave ovens, and probably could have gotten on without them perfectly well for the rest of my life, but have instead had a sort of all or nothing relation with them over the past fifteen years or so. If  there's one in the place I'm renting I use it, but if there isn't, I don't miss it. Currently I'm living in a place which like many studios here, has one in lieu of an oven. There's also a two-burner hot plate, but one of the dials has broken off, and in any case, it takes a long time to heat and a long time to cool off too. So the microwave is in for some pretty heavy usage.

The other day I was reading a short piece in Newsweek by Brian Greene on the multiverse theory. He ably explains the general idea to the non-scientist--it's kind of a Multiverse for Dummies approach, which is definitely the approach for me. Anyway, microwaves came up quite a bit in his explanation, and the one that stuck with me was the idea that measuring microwaves might be a possibility if some otherwise  undetectable universe collided with ours. Seems like  a slightly higher form of use than heating up frozen tamales. Although not as practical.

Anyway, it led me to realize that I really have no idea what a microwave is. It really is time to change all that.

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Let me just start by saying that my default position of checking out Wikipedia for this kind of info--largely because it usually pops up first in any kind of Google search, was not particularly helpful here. It was not of the Microwaves  for Dummies variety. But there is a really clear and simple website that NASA puts out on the Electromagnetic Spectrum, which you can find HERE. If you want to just cut through all my fol de rol, or if you want to learn about the whole spectrum, you might as well pop over there, as I am not going to be better at explaining this. But for the purposes of my own education, which is really what this all about in the end, I'll proceed.






A microwave is a wave on the electromagnetic spectrum lying in the frequency between radio waves and infrared. It is actually at the higher end of the radio wave spectrum, but is differentiated because there are different technologies used to access them. There are actually subbands of microwaves, such as C-bands, L-bands and so on, which are each on their own distinct part of the spectrum.   



I turned to the FDA website on radiating products  to get some simple information about how microwaves cook. The important points are that microwaves are reflected by metal, but can pass through paper, plastic, glass and, presumably ceramics, and then can be absorbed by food. The microwaves cause water molecules to vibrate, which produces the heat that cooks the food that lives in the house that Jack built.

Sorry, got carried away.

A couple of popular misconceptions about microwave cooking. It doesn't actually cook the food from the inside out. The outer layers are what get cooked, and the inner layers are heated by conduction of that heat. It's also why that microwave permeable bowl you're holding is so damn hot.

And microwaves don't cause food to become radioactive or contaminated with radiation. The microwave energy is converted to heat as it is absorbed by food.

The Holmdel Horn antenna

 
So, skipping right through the lengths of microwave that are used to penetrate clouds to detect weather conditions beneath them, let's turn right to those microwaves that are used to explore the reaches of space. As the NASA website explains it, in 1965, two Bell Lab scientists in Holmdel, New Jersey, Arno Penzias and Robert Wilson, accidentally discovered a strange background noise, with the help of a  special low noise antenna. The strange thing about this noise was that it did not seem to come from any particular direction, and in fact seemed to come in unvaried intensity from everywhere. This cosmic microwave background radiation, as it is termed, fills the entire universe, and is a clue to what eventually became the Big Bang Theory.

To return to the beginning, the way that microwave study would allow observers to deduce a collision of universes is that in theory, this cosmic collision might cause some changes in the temperature of the microwave background radiation.

I guess we shouldn't expect to just feel it as a little jolt.  
 
Got the Nobel Prize for it, too.
   

22 comments:

  1. Wait, so if I zap a hunk of frozen meat, am I messing up someone's study of the history of the universe?

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  2. No, it's a different subband. Those cosmic microwaves can't cook anything. Luckily for us.

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  3. I learned that from this somewhat too jocular article.

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  4. I enjoyed the article's first paragraph, especially its optimism (We're half-done rather than half-undone.)

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  5. It starts off well, but it ends up being pretty silly.

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  6. I was afraid it might. That's why I was loath to read beyond that rather nice opening.

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  7. The first sentence is good. Then the author starts babbling and doesn't stop until the end of the second paragraph.

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  8. Well, I don't really like to trash anyone, but it's not like it gets better from there.

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  9. The NASA sight is great, although it did go from very simple to very obscure within a few paragraphs when it came to microwaves.

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  10. Well, some of that stuff can't help but be obscure? Particle-wave duality? That's counter to what most people think of as logical, I think.

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  11. Sorry for the extraneous question mark in the first sentence. That sort of thing is a point of honor with me.

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  12. No, it wasn't the particle wave duality, it was when they wandered off into passive and remote sensing and the end about the infant earth that I thought the prose was not as lucid as it could be.

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  13. I didn't read the site's many pages carefully, and I missed that part. I scorn obscure prose, so I will look for those parts.

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  14. I think it's more that they suddenly jump to addressing a more advanced readership. More technically savvy. The remote sensing might just have been off track for what I was trying to discover, though.

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  15. That's intriguing. I feel like my brain is about to be challenged for the firs time since I was 8 or 9 years old.

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  16. I'm sorry, Peter. I doubt that you will find it difficult at all.

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  17. Oh. I don't know about that. I'm not the science guy I was when I was in Grade 2 or 3.

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  18. Yeah that is fascinating stuff...and well written!
    It is amazing how the human eye only detects light wavelengths of between 400-700 nm, which is a teensy part of the entire electromagnetic spectrum....
    As for microwaves, ya gotta love the crackpot theories that abound about how 'dangerous' they are to food. The only real dangerous thing is trying to eat a donut filled with jam straight from the thing...as i tried to last week (and still have the blister on my lip!)

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  19. Yes, the heat factor can give you some unpleasant surprises.

    I think one of the things that most fascinated me about this is the idea that there is this vast spectrum of waves that don't require water or air as a medium. Like so much of the circumstance around me, I hadn't really thought about it. Although microwaves are actually fairly small, though by no means microscopic, they pale beside some of the large waves, which can be the size of a planet. It's pretty cool stuff.

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