Profile cover photo
Profile photo
John Seymour
John the Math Guy
John the Math Guy

John's posts

Post has attachment
The Triumph of Science over science
February the 17 th , 2017 marks the 417 th anniversary of the death of Giordano Bruno. I know that many of my ardent readers are still trying to get
over that. Giordano Bruno's rather angelic looking Senior picture Aristotle taught that the Earth is the cen...

Post has attachment
The long, medium, and short of the cones
Color is three-dimensional. I've said that before. Almost four years ago, I blogged about how it is not possible to arrange all your crayons in a line . This led to a discussion about how you need three numbers to uniquely identify any color, because color ...

Post has attachment
Comparison of inexpensive digital microscopes, part 3
I promised that my review of inexpensive digital microscopes would be a trilogy, and by golly, that's what it's gonna be. In part 1, I looked at the Celestron USB microscope . In part 2, I had a quick peek at a lens that turns your smart phone into a micros...

Post has attachment
Comparison of inexpensive digital microscopes, part 2
In the previous blog post, I reviewed one popular USB microscope , an inexpensive one from Celestron, which can be had for about $40. Not a bad price, you say? Well, have I got a deal for you! How does $7.50 sound? Note the decimal point... Yes, I can get y...

Post has attachment
Comparison of inexpensive digital microscopes, part 1
I frequently find myself in need to a digital picture of something really tiny. Sometimes it's halftone printing dots or the pixels on a computer monitor. Sometimes, I just would like to have a closeup picture of an interesting specimen of hemiptera. After ...

Post has attachment
Unambiguous regions in color space for the basic chromatic colors
I am going to start this blog post with the punchline. The image below shows the range in color space of the eight basic chromatic colors. I assert that any color that is within a given set of limits will be unambiguously identified by the corresponding col...

Post has attachment
What's with the new version of the X-Rite eXact???
I got a question the other day from my good buddy Steve (not to be confused with my mediocre friend Steve, or my sworn enemy Steve).  Steve was asking about the kerfuffle surrounding a new version of the X-Rite eXact. Something or other to do with polarizat...

Post has attachment
Explanation of "Cool tricks with polarized light" video
I saw a cool YouTube video yesterday. Let me warn you, if you don't like being barefoot, then I suggest you invest in a pair of sock garters before you watch this next video, cuz without them, this video will knock your socks off. Wow. The guy in the video ...

Post has attachment

Post has attachment
Statistical process control of color difference data, part 4
Warning: If you were considering whether to jump off the diving board into this blog post because this series is getting too deep mathematically, then I would suggest for you to get off at this stop and wait the next bus. On the other hand, if you were one ...
Wait while more posts are being loaded