Tag Archives: scales

Scales and Scientific Notation

On Friday’s class, we talked about how large astronomical bodies can get, but we did not look at the numbers. We also did not talk about the small objects scientists study like DNA, molecules, atoms, high-energy waves like gamma rays and subatomic particles like electrons.

To find the numbers for particular scales you can check out this list here: http://www.falstad.com/scale/

These numbers can provide a point of reference when you are trying to estimate values.

A fun interactive that helps you develop a sense of these scales can be found here: Scale of the Universe 2. To navigate the scales, use the sliding bar at the bottom. I’ve posted a screenshot of the software below, which shows how a white blood cell, a red blood cell, e-coli, a clay particle, an x-chromosome, a y-chromosome, red light and violet light compare.

Screen Shot 2015-01-19 at 11.09.54 AM


This is the home page for MATH 033 – Mathematics for Sustainability.  This is a new course at Penn State which I expect to teach for the first time in the Fall Semester of 2014.

The goal will be through a General Education Mathematics course, to enable students to develop the quantitative and qualitative skills needed to reason effectively about environmental and economic sustainability.  That’s a lot of long words!   Let me unpack a bit:

  • General Education Mathematics At most universities (including PSU), every student, whatever their major, has to take one or two “quantitative” courses – this is called the “general education” requirement.  I want to reach out to students who are not planning to be mathematicians or scientists, students for whom this may be the last math course they ever take.
  • quantitative and qualitative skills I want students to be able to work with numbers (“quantitative”) – to be able to get a feeling for scale and size, whether we’re talking about gigatonnes of carbon dioxide, kilowatts of domestic power, or picograms of radioisotopes.  But I also want them to get an intuition for the behavior of systems (qualitative), so that the ideas of growth, feedback, oscillation, overshoot and so on become part of their conceptual vocabulary.
  • to reason effectively A transition to a more sustainable society won’t come about without robust public debate – I want to help students engage effectively in this debate. Shamelessly stealing ideas from Andrew Read’s Science in Our World course, I hope to do this by using an online platform for student presentations. Engaging with this process (which includes commenting on other people’s presentations as well as devising your own) will count seriously in the grading scheme.
  • environmental and economic sustainability I’d like students to get the idea that there are lots of scales on which one can ask the sustainability question – both time scales (how many years is “sustainable”) and spatial scales.  We’ll think about global-scale questions (carbon dioxide emissions being an obvious example) but we’ll try to look at as many examples as possible on a local scale (a single building, the Penn State campus, local agriculture) so that we can engage more directly.