Mystery in a cloud chamber

Jon W Mooney · science forum beginner Joined: 23 Dec 2005 Posts: 16

Hi all,

I filmed a peculiar "ghost" in an aquarium cloud chamber that my 17 yo son
built.

The movie is http://www.jwmooney.com/cloud1tcmooney.mpg It is 5.4 Mb

The first few times I viewed it, I thought the glow was a reflection of my
camera in the aquarium glass. There is a reflection of my younger son's
arm at the end of the film.

Then I noticed the alpha trails in the middle of the chamber. Finally, I
noticed that there is at least one alpha trail at every point where the
direction of this thing changes.

I drew a map of what I think I see http://www.jwmooney.com/map.pdf

Questions we have include...

1) What is this? (I guess that was the obvious one.)
2) What causes the glow? (It's not a condensation trail.)
3) At two locations, there are alpha trails that appear to either end or
change direction at the 'point of collision' with the 'glow.' How did
these alpha particles know when and where to appear and in what direction
to head for a collision?

One thing that I'm not sure of is if this glow is in the infrared. The
camera does have a nightshot feature. I saw the thing on the camera
viewscreen when I was shooting it but neither of the two boys commented
about seeing anything except the alpha trails.

Thanks for your help!

- Jon

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