Author Archives: mathscinotes

Dimensional Analysis and Accounting

Posted on 16-March-2015 by mathscinotes

It has been reported that 90% of spreadsheets have serious errors (source). These errors occasionally are large enough that they have international implications (e.g. London Whale). In my small part of the world, one small company I worked at had an error in a cost estimation spreadsheet that cost it hundreds thousands of dollars on one contract. This caused that company great hardship. Continue reading →

Posted in Financial | Comments Off on Dimensional Analysis and Accounting

Math Anxiety with the Pythagorean Theorem

Posted on 12-March-2015 by mathscinotes

You might be amazed the amount of math anxiety I deal with at work. Folks often stop by my cube for help – I always try to help because I remember how I felt when I was in school and did not understand any math. Continue reading →

Posted in Math Education | 1 Comment

Use Care When Mixing Cleaning Chemicals

Posted on 11-March-2015 by mathscinotes

When I was a boy (early 1970s) I worked in a nursing home as a night janitor. At the home, we had many WW1 veterans. I will never forget one WW1 veteran who had been permanently disabled during a chemical attack. I do not know what gas he was exposed to (he mentioned chlorine gas, mustard gas, and phosgene), but I do know he had a bad case of emphysema that made his life miserable. Continue reading →

Posted in General Science | 4 Comments

Domain Transfer Status

Posted on 5-March-2015 by mathscinotes

Hi folks, Sorry for the length of time involved in the domain transfer. I THINK everything is back. I will not go into all the gory details, but every post needed some work (latex did not transfer cleanly). This post … Continue reading →

Posted in Administration | Comments Off on Domain Transfer Status

A Little Geometry for Laying Out a Drawer Pull

Posted on 3-March-2015 by mathscinotes

I finished building a cabinet a couple of months ago just as the extreme cold arrived, which made my garage shop uninhabitable.. The ten-day forecast is now showing rising temperatures, so I am starting to think about my next cabinet construction effort. Continue reading →

Posted in Construction | 2 Comments

Large Quantity of Manganese Nodules on the Atlantic's Seafloor

Posted on 2-March-2015 by mathscinotes

I had a deja vu moment this week. Yahoo had an article on how a large amount of manganese nodules have been found on the Atlantic Ocean's seafloor (Figure 1). Back in the 1960s, I remember reading about Howard Hughes building the Glomar Explorer to mine manganese nodules from the bottom of the ocean. It turned out this story was a CIA cover story for Project Azorian, but that is another story. Continue reading →

Posted in Geology | Comments Off on Large Quantity of Manganese Nodules on the Atlantic's Seafloor

Retirement Savings Rules of Thumb

Posted on 1-March-2015 by mathscinotes

I have had a number of posts recently on saving for retirement. These posts ALWAYS follow discussions I have had with my family on the importance of starting to invest early – both for retirement and general financial health. I do not want my family members to get to retirement without an investment portfolio (Figure 1), a situation that I have seen and is not pretty. Continue reading →

Posted in Financial | Comments Off on Retirement Savings Rules of Thumb

Snowballs and Investing

Posted on 20-February-2015 by mathscinotes

Because I am an annoying father who wants to encourage his sons to invest, one of the things I like to collect on this blog are stories of successful, long-term, investors. I loved this story about a janitor, Ronald Read (Figure 1), who recently died at 92 and left an estate worth nearly $8 million dollars. Continue reading →

Posted in Financial | Comments Off on Snowballs and Investing

Fan Airflow Versus Static Pressure Diagram

Posted on 19-February-2015 by mathscinotes

I was so happy with my previous fan installation that I am considering replacing some old fans with new, higher throughput, and quieter fans. The installations will be similar to that shown in Figure 1.

I have been using a nomograph (Figure 2) for my home HVAC calculations (example). I have decided that I am now living in the 21st century and I should figure out the formula that this graph represents. In this post, I will generate part of this nomograph to verify that I have put together the correct formula. Continue reading →

Posted in Construction, General Science | 3 Comments

Cars With Zero Driver Deaths from 2009 to 2012

Posted on 18-February-2015 by mathscinotes

I saw an interesting article on Yahoo Autos about 9 cars in which zero drivers died during the time period from 2009 to 2012. I thought this was interesting information – it sure stimulated some discussion in my family. Continue reading →

Posted in Health | Comments Off on Cars With Zero Driver Deaths from 2009 to 2012