Crazy Bored Science – The Double Slit Experiment (Almost)

Posted in Humor, Mixed Nuts, Photography Tricks on December 4th, 2008 by MadDog
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I am bizarrely attracted to old computer chips. I can’t explain this, so don’t ask. I have a giant bag full of them. Some are genuine antiques dating back to the middle 70’s.

I have made earrings, pendants, wall decorations, and a variety of other improbable items from them. I’m thinking about a belt buckle.

My daughter-in-law paints pictures on them. This was her first effort – a view of Tabat Island as seen from the beach at Wongat Island:

Tabat Island on a computer chipI rode the Harley in to the office today, so I was able to get in much earlier than usual. Tummy rumbling for sustenance, I got out some biscuits and sat to ponder if I could fake something amusing to write about.

I remembered a couple of nights ago when I was re-reading Stephen Hawking’s wonderful “A Brief History of Time.” In it is a short discussion and photo of the famous Double Slit Experiment. The explanation of this would be fascinating for some and a giant yawn for others. So, if you’re interested, click the links above. Otherwise, move along folks, there’s nothing to see here.

I thought about how computer chips are constructed and wondered if you could get the same results if you bounced a beam of monochromatic light off one. Hmmmmm . . .

Monochromatic light . . . Now, where in the world am I going to find that?

Then I remembered that the last time I was in the US of A I succumbed to my penchant for collecting useless gadgets and bought a couple of cheap laser pointers. I just happened to have one at the office.

I rummaged through my vast storehouse of high-tech gadgetry sent to me in a constant and useless stream by my secret-hungry bosses at Langley. Here are the instruments that I found were necessary to re-create a facsimile of the famous Double Slit Experiment:

Equipment necessary to simulate the Double Slit ExperimentThe mouse is not part of the experimental equipment. I was just too lazy to move it. We need an old computer chip, a hammer (a stone would do as well), a piece of paper, and a cheap laser pointer.

Here’s a close up of the exposed surface of the chip:

Close view of the now defunct computer chip

If you click to enlarge, you can make out the patterns on the chip. (The actual chip is the tiny dark square in the middle. It’s much smaller than your little fingernail.) The pattern is formed of hundreds of thousands of extremely closely spaced lines on the surface. These should act in a similar way to the slits (okay, that’s not very scientific, but this is Crazy Bored Science, remember?)

So, we set up our experiment and hold everything just so, and . . .

Eureka! - The dots appear (click to enlarge)

Eureka! . . . We see the expected pattern of dots.

What scientific conclusions might we draw from this?

As near as I can tell, absolutely none, unless there is some conspiracy theory out there that claims that light is really cream cheese and we have all been hoodwinked into believing that it is something more important.

The interference patterns predicted by the wave theory of light are clearly visible even in this goofy setup.

And, I was finished in time to get some real work done. I guess that that also is important if I plan to continue eating.

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