diff --git a/food_energy.pdf b/food_energy.pdf index f67dc48..0cef86d 100644 Binary files a/food_energy.pdf and b/food_energy.pdf differ diff --git a/food_energy.synctex.gz b/food_energy.synctex.gz index efd962f..d71263c 100644 Binary files a/food_energy.synctex.gz and b/food_energy.synctex.gz differ diff --git a/food_energy.tex b/food_energy.tex index 282b8c4..201db15 100644 --- a/food_energy.tex +++ b/food_energy.tex @@ -106,6 +106,8 @@ This estimate is again surprising to students. Five trips up the bluff to burn The point of these energy calculations is not to give students an eating disorder. Rather, the numbers show food's amazing power. A single slice of toast will bring a car up to the residential speed limit! A day's food, $3000kcal$, will power you up an $8000m$ mountain peak! The body-work food allows us to do is astonishing, and increases in food production have made modern comforts, unimaginable 150 years ago, possible to the point of being taken for granted. +\clearpage + \subsection{Where does food energy come from?} One feature of the aught's ``homesteading'' culture \cite{homesteading} is the idea that a person should probably be able to move to the country, eat a lot of peaches, and grow all their own food. Learning that farming labor is \textit{skilled} labor can be brutal and disheartening. Eating $3000kcals$ each day means planting, weeding, harvesting, and storing more than a million kcals each year \cite{Haspel}. Where will those Calories come from? Is your backyard enough to homestead in the suburbs \cite{backyard_homestead}? @@ -161,7 +163,7 @@ From figure \ref{1917_yields} we can estimate 1.9 million kcals per acre of pota \eea The choice of operation is difficult to make without seeing the units present, which is again a learning opportunity for the students. -What does the answer of $2.3$ acres mean? The university's $91m\times49m$ football field has an area of about $1.1$ acres, so you could say that a football field planted in potatoes will probably feed a family through the winter. Can a person enjoy the benefits of urban living and grow all their own food? The population density of New Jersey is $1,263~people/mile^2 \approx1.97~people/acre$ and our 4 person family needs 2.3 acres for their potatoes. +What does the answer of $2.3$ acres mean? The university's $91m\times49m$ football field has an area of about $1.1$ acres, so you could say that a football field planted in potatoes will probably feed a family through the winter \cite{Deppe}. Can a person enjoy the benefits of urban living and grow all their own food? The population density of New Jersey is $1,263~people/mile^2 \approx1.97~people/acre$ and our 4 person family needs 2.3 acres for their potatoes. Unless the social model is one of a country Dacha or an endless suburb with no duplexes or apartment buildings, urban living and food self-sufficiency seem mutually exclusive. % This is interesting, but probably a weak argument because organic yields can be as high as ~ 140bu/acre BUT must be grown in a 3 or 4 year rotation vs corn's 2-year rotation. @@ -178,6 +180,8 @@ More emotionally charged conversations can be had about converting the United St % 180bu/acre / 35bu/acre = 5.1x (less) % 113M acres / 5.1 ~= 22M acres +\clearpage + \section{Example: How big could Tenochtitlan have been?} The questions described thus far have largely been centered within a physics context. The paper closes with two more examples that leverage this food energy picture to make historical claims. The first example relates to the pre-columbian capital of the Aztec Empire, Tenochtitlan, now known as Mexico City. Tenochtitlan was build on and around a endorheic lake, Texcoco. Crops were grown in shallow parts of the lake via chinampas \cite{national_geo}, floating patches of decaying vegetation and soil. Given the proximity to water and decaying vegetation, these fields were very fertile \cite{HortTech_2019,Chinampas_1964} and some continue to be used in the present day \cite{google_earth}. @@ -203,6 +207,9 @@ This crop productivity is in remarkable agreement with the 1917 USDA yields, $35 +\clearpage + + \section{Example: Was the Irish Potato Famine a Natural Disaster?} In contrast to native cultures of the Americas, Ireland's population boomed with the Columbian Exchange and the introduction of the potato. \cite{potato,little_ice_age}. Figure \ref{ireland_population} shows that from about 1700 onward there was a dramatic growth in the island's population. There's never just one reason for historical events, but unlike grains, potatoes thrived in Ireland's cool damp climate and potatoes, kale, and milk form a nutritionally complete diet that greatly reduced hunger-related mortality among the poor working-class in Ireland. If you look closely at the data in figure \ref{ireland_population} you might believe that there were \textit{two} weather and potato related famines, the most obvious 1845-49 and the second, with much smaller effect on population in 1740-1. Both famines were precipitated by poor weather, but an important difference is that in 1740, Ireland was a sovereign state but by 1845 the island was effectively an economic colony of the British Empire \cite{little_ice_age}. @@ -332,6 +339,8 @@ Average USDA per acre yields for a number of commodity crops over time. This `` \end{figure} +\clearpage + \section{Estimating land area devoted to chinampas with ImageJ} \label{appx_imageJ} @@ -355,7 +364,7 @@ Three screen captures showing chinampa areas and the calibration stick used to c - +\clearpage \section*{References} \begin{thebibliography}{99} @@ -457,7 +466,7 @@ Government Printing Office \bibitem{math_encounters} -https://www.mathscinotes.com/2017/01/calorie-per-acre-improvements-in-staple-crops-over-time/ +\url{https://www.mathscinotes.com/2017/01/calorie-per-acre-improvements-in-staple-crops-over-time/} Mark Biegert Math Encounters 2017 @@ -471,7 +480,14 @@ American Scientist vol 63 413-419 -\bibitem{calorie_age} Is $3000\frac{kcal}{person\cdot day}$ accurate for a family? For soldiers or active athletes it is, but $2000kcal$ is the USDA reference for an ``average adult,'' e.g. the author, in his 40's, and $1000-1200kcal$ for a senior age ($>60$) female. However, weeding the garden all day is physically taxing, mice will probably eat some of the potatoes, and $3000$ is a nice round number, so that's what I'm using. +\bibitem{calorie_age} +Is $3000\frac{kcal}{person\cdot day}$ accurate for a family? For soldiers or active athletes it is, but $2000kcal$ is the USDA reference for an ``average adult,'' e.g. the author, in his 40's, and $1000-1200kcal$ for a senior age ($>60$) female. However, weeding the garden all day is physically taxing, mice will probably eat some of the potatoes, and $3000$ is a nice round number, so that's what I'm using. + +\bibitem{Deppe} +The 20 Potato a Day Diet versus the Nearly All Potato Winter +Carol Deppe +\url{https://www.caroldeppe.com/The\%2020\%20Potato\%20a\%20Day\%20Diet.html} + \bibitem{organic_corn_yield} This is an old article diff --git a/references/Vancouver_condensed_guide_2020.pdf b/references/Vancouver_condensed_guide_2020.pdf new file mode 100644 index 0000000..811f6fa Binary files /dev/null and b/references/Vancouver_condensed_guide_2020.pdf differ