Human powered IR detector – 2

Continued  from page 1 of “Human powered …”

Using the electrical tape, we affix the visible-light-blocking filters to the front of the welder’s glasses.   As we walk into that bright spot on the trail, once again, we observe that we do not squint at all.  Our eyelids do not involuntarily flap, and there’s no tingling or pressure in our heads.  Apparently, since we’ve killed off both the IR and the blue / UV light, the green that was remaining did not have the intensity to make us squint.

So, in the way of the accountant who adds the vertical column, and compares to the horizontal one – we’ve doubly proven our theory.

Now, I take walks in the woods all the time.  I guess I’m a nature guy.  Doing so, I made yet another discovery.  I found that I like the “look” of the welder’s glass field of view.   It looks quite a lot like regular IR photography, with emphasized shadows, usually more crisp than with visible light.  I seem to be able to read signs better (so long as they aren’t red in color) – probably due to the “crispness” factor.  I don’t walk without care however; especially at stop lights, where I cannot see the red signal.  So, I make sure to check the pedestrian “go” signal before I cross intersections.

I’ve done this so much that my eyes have adjusted to the new “IR” condition.  In other words, my eyes have grown to expect very little IR.  They’ve (sort of) adjusted their calibration.  What has happened is that my eyes have become very sensitive to IR.   It’s not permanent. If I don’t use the welder’s glasses for a few days, then my eyes revert to “normal” sensitivity.

So, imagine my amazement when I discovered all sorts of night-time IR sources ?!   Simply walking around, I could detect (by that same feeling I’ve described on page one of this article) – dozens of very strong IR sources, where there was no visible light.  Storefronts almost all have strong IR presence, whether or not they have any kind of tungsten lit signs, or even any signs at all.   This infrared radiation seems to be detectable for about 30-40 feet in front of buildings, usually out to the parking lot or street, but not beyond that point.   Walking back and forth, I easily convince myself of the presence of the IR.  But, what wavelength?

In another article on this blog, I referenced a little gadget I built to detect IR radiation.

To be continued …

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