April 9, 2020: Clipper Guards, Wheel Alignment, Capillary Action

Clipper Guards

With all of the hair salons temporarily closed due to the COVID-19 pandemic, many people are resorting to having their hair cut at home. This is something that many of us haven’t experienced or even attempted for decades. Clippers make the job much easier, especially for the boys, who often opt for a short buzz in the back if not all the way around. Of course, this coupled with the current health situation has led to a sudden shortage of clippers on the retail market. Ours will arrive eventually. In researching the options, I paid special attention to the accessories, and the guards most of all. These are the plastic combs that attach to the head of the clippers that keep the blades a constant distance from the scalp, resulting in a uniform cut (i.e. no uneven patches were the clippers got too close!). For a long time, my default request was a #3 cut, scissors on top. But what exactly does “#3” mean and is it the same for all clippers? As it turns out, the guard sizes are more-or-less standardized. The most common interval is 1/8-inch increments, so a #1 guard is 1/8-inch, #2 is 1/4-inch, and so on. Most clipper sets will include guards up to and including the 1-inch #8. There is some variation between manufacturers. Out of curiosity, I did a search for European clipper guards, and it appears that the same English/Imperial increments are used, but an approximate length in millimeters is presented to differentiate them. An eighth of an inch is approximately (but not exactly) 3mm, so the first eight guards are listed as 3, 6, 10, 13, 16, 19, 22, and 25mm.

Wheel Alignment

True story. I recently put my car in for an oil change and a few other minor services, including an alignment. When the report came back at the end of the visit, it said that one of the angles (caster/camber/toe; I don’t recall which it was now) was off by 0.25°. I decided to test the service rep a bit and asked him if that was a lot. I could tell immediately that I caught him off guard, because he asked to see the report, uttered a long “ummmmm”, and looked around the room (I assume) for a nearby mechanic. After a short pause, he pointed to the 0.25° pre-alignment metric and with confidence said, “You know what a 45° angle looks like, right? This is about half that, so yeah, that was pretty big.” I just nodded, thanked him, and drove away amazed that I had managed to get around town for so long without doing donuts up and down the road.

Capillary Action

Here is a neat experiment for the kids. Place six juice glasses on the counter or table arranged in a circle (or hexagon?) as close together as possible. Fill every other glass with water (i.e. empty, full, empty, full…etc.) all to the same level, about three-quarters full. In the three glasses containing water, add a few drops of food coloring (different colors; red, yellow, and blue are good choices) and stir well. Now take six napkins or paper towel squares, roll or fold each, and bend in the middle. Drape the napkins over the rims of the glasses such that one end of each napkin is in a glass with colored water and the other end is in one of the empty glasses adjacent to it. When finished, the six glasses should be “chained” together with the napkins. Now wait. Eventually you will see water gathering in the bottom of the empty glasses. The colors will mix, proving that some of the water is coming from the glass on the left and some from the glass on the right. If you took my advice on using the three primary colors (red, yellow and blue), then the glasses that started off empty will contain the secondary colors (orange, green and purple). This transfer of water will continue until equilibrium is reached and all of the glasses contain the same amount. This effect, called capillary action (and a few other names) is caused by a combination of surface tension and adhesive forces. [Note: the adult version of this experiment works as follows. Brew a cup of coffee. Place a napkin – or better yet, a super-absorbent paper towel – on top of the cup because a fly is loose in the house. Get distracted with some other vital task, like checking your blog stats or killing the fly. When the center of the napkin or towel eventually absorbs enough steam from the coffee, it will sink into the cup and a few minutes later, coffee will have transferred from the cup to the place mat and/or the super-absorbent and now super-stained table cloth.]