This interesting and easy-to-build home experiment may provide a hint on the path to solving a question I've been pondering (or not as the case might be).
I have a theory that everyone gets a certain number of "time particles" to get them through each day, and some swine is stealing half of mine! (I can imagine him basking on the beach enjoying the benefit of his after squandering mine doing his job – the end result is that I have far too much to do and far too little time to do it all in.)
One result from this is that I have links to interesting websites piling up without my getting round to visiting them. This is a shame, because there's so much mega-cool "stuff" out there that's crying out for my attention. One really interesting site, for example, shows how to build Your Very Own Spectrometer using only an old CD-ROM and a cereal box of your choosing.
This is interesting in its own right, and I'm certainly going to make one and play with it, but there's something else. Do you recall a few blogs ago when I was waffling on about Free Graphics Software? In that blog I showed an illustration of a curve representing the relative intensity of moonlight at different wavelengths.
At that time I mentioned that I was trying to lay my hands on hard data with which to create an accurate version of this curve. As it happens, I did run across a couple of such curves on different websites, but they disagreed with each other, which made them useless for my purpose.
The point is that one of these sites compared the curves for sunlight and moonlight. Now, as moonlight is reflected sunlight, I would have expected the moonlight curve to have simply been a less intense version of the sunlight curve. However, in addition to being less intense, the moonlight curve was shifted by somewhere between 25 nm to 50 nm in wavelength.
I'm still pondering why this should be so. But the point is that the first images on the spectrometer site mentioned above show that the solar spectrum changes with the Sun's altitude. I'm not sure if this has anything to do with the shift in the moonlight curve, but I'd love to hear from anyone who could explain any of this to me.
Questions? Comments? Feel free to email me – Clive "Max" Maxfield – at firstname.lastname@example.org). And, of course, if you haven't already done so, don't forget to Sign Up for our weekly Programmable Logic DesignLine Newsletter.