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.
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.|