microwave

More microwave oven vision nonsense!

More microwave oven vision nonsense! 0

Here are a few other things that I wanted to say about microwave ovens and our vision. First, there’s a window in the door so you can see your food cooking. I don’t know that I’ve ever seen a microwave oven without a window. Yesterday I wrote a post about the frequency of the energy that microwave ovens generate (actually 2.45 GHz) but I didn’t say how long the wavelengths are. They are about 4.6 inches. There’s a simple formula to calculate that. I’ll be honest, this next part kinda makes sense but then I can’t fully explain this. Yet.

That screen in the microwave oven door has little holes so we can see through it. The spacing of those holes is about 1 mm. Or in inches, 0.039. Because the wavelength of the microwaves is so much larger than the hole size in the screen, the microwaves can’t get through. But visible light can get through because the wavelength of light is way smaller than those little holes. So in essence, that screen is like a solid wall for microwaves but not for visible light.

This next thing about that screen is something I can’t fully explain either but I think I have an idea why this thing I do works. If I don’t move my head when I’m looking through that screen I don’t see what’s inside very well. But if I move my head back and forth (side to side) in front of the screen I can see what’s inside much better. I looked up persistence of vision in wikipedia and of course, there was nothing about me moving my head side-to-side and cooking my food. But, the reason I can see better in the microwave when moving my head is that the images are quickly changing. I’m making a movie (sorta in reverse) by moving my head! I made that up but I think I’m pretty close to getting this right.

Movies are just a bunch of pictures that when shown at a certain rate it makes you think something is moving. A typical “frame rate” is 24 pictures per second. There is a fraction of time when there is nothing but we don’t see that. We don’t see that “black” moment. If you move your head in front of that microwave screen I’m guessing that those little holes are so small that you’re moving faster than 24 holes per second or enough to be obviously better than 1 hole per second. Because our visual system has a persistence that lasts the teeniest bit longer than when the actual image was there, it’s able to combine all those images into a clearer picture. Don’t hold me to this explanation too much but I’m onto something….I think. Someone else told me this is saccadic masking.

Try it anyway. Just move your head from side-to-side in front of the microwave while telling your family you’re not crazy.

http://www.exploratorium.edu/snacks/persistence_of_vision/

microwave oven screen

microwave oven screen

 

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Microwave oven cataracts

Microwave oven cataracts 0

I really wanted to write a post about microwave ovens and the very cool sparks that result from some metals that might accidently have found their way into the microwave. I think I have a lot to write about (or at least further study by me) when it comes to microwave ovens though. After reading a couple of websites and watching some fun videos I saw that microwave energy can affect the lens in our eye. I had no idea.

The lens in our eye, that many of my patients think is the outer clear part of the eye (that’s called the cornea), has no blood supply. And the cornea doesn’t either, incidently. Microwave energy, if powerful enough, could heat up the lens. The theory this could cause damage is because there’s no blood flow in the lens. If there were, ¬†blood could carry the heat away. Amazing that neither our lens nor our cornea have a blood supply.

But what are the chances of getting a cataract from a microwave oven’s radiation? I don’t know and I couldn’t find too much about the “incidence” but it boils down to this. If your microwave was dropped or somehow bent, there could be leaking microwaves coming out. I suppose leaking microwaves wouldn’t be that big of a problem unless you put your eye right in front of that leaking spot. But, no sense is putting your eye right in front of it either way unless you’re just checking your hot pockets.

Now how are you going to tell if your microwave leaks! Have I got a funny one for you. And this makes sense. The microwave energy is about the same frequency as our wireless networks wavelength at home. That’s around 2.4GHz (yeah, I know, there are other wireless frequencies too). Unplug your microwave, put your wirelessly connected laptop in your microwave with the door closed. If you can access your laptop through some sort of remote program on another computer, or just ping your laptop successfully, you have a leak. The wireless signal went through to the inside of the microwave oven. But that’s not the only way! I’ll just give you a link below to read other interesting ways.

I think the bottom line is this is all highly unlikely to happen…cataracts from microwave ovens…goes to show you that the everyday stuff has potential for harm though. And now I’ll go try one of those experiments I found you can do using a microwave oven. To my kids, don’t do this when daddy isn’t here.

http://en.wikipedia.org/wiki/Microwave_burn

http://www.wikihow.com/Check-a-Microwave-for-Leaks

microwave oven diagram

microwave oven diagram

electromagnetic spectrum

 

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