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Numeracy refers to a quantitative understanding of natural and human phenomena. Numeracy allows one to interpret phenomena in a manner that allows for constructive, fact-supported action, as opposed to responding emotionally response via a triggered reptilian brain. Thus, it is critical for a movement entrepreneur working on the open source economy to understand basic applications of numeracy - in order to take effective action.

Key Points

  • Kardashev Scale - implications that we can improve the earth - or worsen it - via human impact using available energy - by a factor of 10,000

OSE Case

For OSE, numeracy refers to being quick with numbers: understanding magnitudes, orders of magnitude, back of the envelope calculations, basic physics formulas like F=Ma, sizes (like acres and square miles), distances, weights, etc. This refers to working knowledge for quantifying things to one order of magnitude:

  • how much power does it take to drive a human?
  • How many square miles are there is the USA?
  • How many cubic meters of biochar one need to apply 1/4" of biochar per acre?.006 m * 4000 sq m = 24 cubic meters
  • How much does a cubic yard of soil weigh?
  • How many millimeters of topsoil is lost per acre if the figure is 5 tons per acre?
  • How much does one cubic meter of water weight? Of steel? Of rock? Wood?
  • Based on a 1% annual growth rate of world population, how many people are born each year?


  • about 1M calories in a kW hr.
  • a human needs 3000 Calories in a day, 2000 if inactive
  • note that 1 Calorie (human diet calories) = 1000 calories (pure energy sense calories)
  • Ie, a human needs 100w on average
  • average crop photosynthesis (conversion of energy to sugar - 1-2%. [1]. 7% for sugarcane.
  • thus, 10 square meters of crop is required per person for 100% energy! theoretical, conservative, assuming the lower photosupynthetic conversion rate.
  • Converted to sugars is theoretical. Upon eating, we get 40% of food value [2]
  • this makes it 225 square feet per person assuming vegetarian diet.
  • mowing for conversion to further feedstock (grass for fungi, worms, chickens, fish ) then we essentially multiply the area used, while allowing for operation of a small greenhouse.


  • Wikipedia definition - [3]
  • Metric quantities and unit conversions - [4]
  • Weight of manure - 1200-1700 lb per cubic yard, or 45-60 lb/cu ft -[5]. 62 lb wet, 55 lb dry - [6]