Deppe
This commit is contained in:
parent
0218d44f6c
commit
b3a300f313
BIN
food_energy.pdf
BIN
food_energy.pdf
Binary file not shown.
Binary file not shown.
|
@ -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
|
||||
|
|
BIN
references/Vancouver_condensed_guide_2020.pdf
Normal file
BIN
references/Vancouver_condensed_guide_2020.pdf
Normal file
Binary file not shown.
Loading…
Reference in New Issue
Block a user