Thursday, March 23, 2017

Units! Units! Units!

I am spending more time with undergraduates lately: helping in a lab (scary!), lecturing, marking assignments, supervising small research projects, ...

One issue keeps coming up: physical units!
Many of the students struggle with this. Some even think it is not important!

This matters in a wide range of activities.

  • Giving a meaningful answer for a measurement or calculation. This includes canceling out units.
  • Using dimensional analysis to find possible errors in a calculation or formula.
  • Writing equations in dimensionless form to simplify calculations, whether analytical or computational.
  • Making order of magnitude estimates of physical effects.

Any others you can think of?

Any thoughts on how we can do better at training students to master this basic but important skill?
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1 comment:

  1. Peter JonesApril 11, 2017 at 8:28 PM

    Hi Ross,
    I use python with the matplotlib and quantities packages. For examples, check out the figures in my recent paper: http://dx.doi.org/10.3389/fnins.2016.00138 (python scripts are included as supplemental data).
    With the quantities package, I'm more confident that my calculations are correct, even for complex physical calculations whose solutions may span many orders of magnitude.
    Peter

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