Monthly Archives: January 2018

Electrical Conduit Math

Posted on 14-January-2018 by mathscinotes

As I have mentioned in other posts, I am building a large garage in northern Minnesota (Figure 1). I would show you some pictures of the interior, but I have promised my son that I will not post anything that could ruin his surprise when he sees it in April.  As part of this construction effort, I am using quite a bit of electrical conduit. Conduit consists of metal pipes (often called EMT) through which the wires pass and it must be bent to go around any barriers it encounters. Conduit is a very efficient way to wire a working area because it directly attaches to the wall and does requires opening holes in drywall and  repairing the damage. Conduit can also be updated and modified easily by running new/additional wires through it. Continue reading →

Posted in Construction | 12 Comments

Minor Planet Eccentricity versus Perihelion Chart

Posted on 9-January-2018 by mathscinotes

While searching the web for information on the outer solar system, I encountered the graph shown in Figure 1. This graph is made using eccentricity and perihelion data for ~1000 outer solar system objects. As I looked at it, I though I could generate a similar chart using data from the JPL Small Body Database Search Engine – a wonderful tool for solar system data exploration efforts. Continue reading →

Posted in Astronomy, Excel | 1 Comment

A Funny Stock Photo Error

Posted on 5-January-2018 by mathscinotes

We have been laughing at some stock photos of people soldering. An engineer was looking for a stock photo of a person soldering, so she went out to Shutterstock to find something. The first photo she found was Figure 1, which she immediately passed around to the group. It turns out that she found a number of photos that were equally bad. Apparently, a lot of people have never soldered. I was raised with a soldering iron in my hand, so I was a bit stunned to see this. Continue reading →

Posted in Humor | 1 Comment

Using Excel to View US Pre-School Attendance Rate

Posted on 4-January-2018 by mathscinotes

Jeffery Sachs was on CSPAN this weekend giving a talk on the competitive challenges the US faces with other nations. During his presentation, he showed a chart (Figure 1) that ranks the US as 30th among reporting OECD countries with respect to preschool participation rates for 4-year-old children. The discussion was interesting, but I found myself focusing on the technical aspects of the graphs he was using. I am always looking for good Excel examples for use in training my staff, and the y-axis in Figure 1 contains formatted text, which is something I have not shown my staff how to do. Continue reading →

Posted in Excel | Comments Off on Using Excel to View US Pre-School Attendance Rate

Dealing with Furnace Condensate At Low Temperatures

Posted on 2-January-2018 by mathscinotes

While working on my retirement home and workshop in northern Minnesota, I have noticed that my furnace is generating between five and seven gallons of condensate per day. The furnace is on quite often this time of year because the outside temperature is running about -30°F (-35°C). I currently pipe the condensate over to a floor drain, which is connected to my septic system. Continue reading →

Posted in Construction, General Science | 13 Comments