Unit 2 - The Definition of Work
Learning Objective: Be able to explain the correlation between money, work, and power and how energy resources like oil and natural gas enable exponentially more work to be done than what could be done by man or beast alone.
Unit Outline
2.1 The Definition of Work
2.2 The Definition of Power
2.3 The Evolution of Work
2.3.1 Manpower
2.3.2 Horsepower
2.3.3 Petroleum Power
2.4 Engines and Work
2.5 Labor Productivity
2.6 Energy Sources
2.6.1 Sources of Power
2.6.2 Consumers of Power
2.7 Controlling Access to and Consumption of Energy Resources
2.1 The Definition of Work
Work, as defined by Webster, is physical or mental exertion in sustained effort for a purpose or under compulsion or necessity [1].
Physicists define work being done by a constant force (F) of magnitude on a point that causes a displacement(s).
Work = Force * displacement; W=Fs [2]
Work is done when Cain displaces dirt to plant wheat that when grown will be ground (by more work) into flour that is kneaded with other ingredients into bread dough (even more work) and eventually baked in an oven to produce a loaf of bread.
2.2 The Definition of Power
Power equals work divided by time [3]:
Solving for work, work = power * time
How fast Cain works while plowing his fields–how much dirt he can displace over a given period of time–is a function of how strong or powerful he is. If Cain can plant a row of wheat in five minutes and it takes his brother ten minutes, Cain is 2 times more powerful. Power and productivity go hand-in-hand. Because Cain has more power (muscle) and can plant 10 rows in 50 minutes (5 minutes/row), he is twice as productive as his brother who can only plant 5 rows in 50 minutes (10 minutes/row).
2.3 The Evolution of Work
In the beginning, it was Adam who was supposed to sweat to get bread. Clever men soon learned to harness horses and use horsepower, together with manpower, to get the work of planting and harvesting done. In only the last 75 years or so, petroleum power has almost entirely replaced manpower and horsepower.
2.3.1 Manpower
A healthy man can perform work equivalent to 75 watts per hour while burning approximately 300 calories per hour [4].
2.3.2 Horsepower
A healthy horse can generate roughly 750 watts per hour and will burn approximately 3,000 calories per hour while performing farm work [5]. A horse is ten times more powerful than a man or, stated differently, is ten times as productive as a man. Harnessing horsepower led to impressive productivity gains for the sons of Adam.
2.3.2 Petroleum power
One gallon of gasoline contains roughly 36,000 watts of power, which is equivalent to 30,000 calories! [6] (See https://www.convertunits.com/from/kWh/to/gallon+[U.S.]+of+automotive+gasoline) That’s just one gallon! The energy density, or amount of work, in one gallon of gasoline is astounding. One gallon of gasoline can power an amount of work equivalent to 50 horses working for 1 hour or Cain working for 10 days.
2.4 Engines and Work
An engine is a system of work that is “designed to convert one form of energy into mechanical energy” [7]. With the invention of the steam engine in the late 1700s and, later, the internal combustion engine, gasoline/diesel-powered engines eventually displaced man and horsepower. These engines–marvels of engineering–were able to do prodigious amounts of work, assuming they could get the calories they needed in the form of gasoline/diesel fuel.
It wasn’t until 1944 that petrol-powered tractors overtook horse-powered plows on farms in the U.S. [8]
2.5 Labor Productivity
Unleashing the energy in fossil fuels produced unfathomable amounts of economic activity and work. Labor productivity shot through the roof. Labor Productivity is the amount of real gross domestic product produced by an hour of labor. For the last 1,900 years, GDP was mostly flat.
In 1 A.D., world GDP was $182.74 billion per the chart below:
In 1940 A.D., world GDP was $7.8 trillion per the chart below:
In 2015, world GDP was $108.12 trillion per the chart below:
While GDP increased astronomically, the amount of time spent working was cut in half:
Miraculous gains in labor productivity and GDP were brought to you by the marvelous engine and its amazing fuel source–refined fossil fuels.
The chart below shows energy consumption by source in 1900:
Compare the amounts a hundred years later (y2k):
Finally, what do you suppose happened to population growth? It also increased exponentially:
2.6 Energy Sources
Saying our lives today are different than Cain’s is the understatement of the year (or century or millennia!) So much has changed in just the last 100 years that our world would be entirely unfathomable to people living even 200 years ago. With the discovery of oil and the invention of the internal combustion engine, we now need to do very little work in the form of physical exertion to survive. There is no need to sweat. 20 gallons of gas in a tractor can plow, plant, and harvest the same amount of land that it used to take an entire village a month to complete. Add the invention of electricity (electrical power generated by coal and gas-powered power plants) and kitchen appliances, and you can mill your own flour and bake your own bread right in your cozy, climate-controlled kitchen while you personally burn less than 100 calories. Or, better yet, just drive to the local grocery store in your gasoline-powered car and choose from numerous types of bread that cost only a few dollars, and then you don’t even have to do any work. Unless you think driving a car is work? If that’s not the height of convenience, what is?
So clearly, the sons of Adam and the daughters of Eve no longer have to get bread by the sweat of their brow–at least not in developed, industrialized countries where access to the miraculous energy sources that power their standard of living are abundant. But, you might ask, how abundant are those energy sources? Furthermore, if you love your way of life, it might be interesting for you to consider what it takes to power it.
2.6.1 Sources of Power
According to the U.S. Energy Information Administration (EIA), 90.7% of our energy/power comes from non-renewable sources. [9] Only 9.3% comes from renewable energy sources. Note that Oil (Petroleum) and Gas (Natural) account for over 60% of our energy used. And remember, as Einstein said, “Energy cannot be created or destroyed, it can only be changed from one form to another.”
Minimal changes have occurred since 2013. The chart below is for 2021:
2.6.2 Consumers of Power
On a per-person basis, North Americans (Americans and Canadians) consume considerably more energy than their brothers and sisters living in lower, less-energy intensive locales:
Data source: http://data.worldbank.org/indicator/EG.USE.PCAP.KG.OE/countries/1W?display=default
Chart: TheSubjectOfMoney.org
As of 2022, the world consumes over 4 billion gallons of oil every day (97 million barrels/day * 42 gallons/barrel).
2.7 Controlling Access to and Consumption of Energy Resources
Can you see why coal, oil, and natural gas are so important? Our entire way of life (for North Americans and Europeans, at least) is dependent on the availability of energy-dense, low-cost coal, oil, and gas. Energy usage and money production are directly correlated. The more energy a country has, the more products/money it can produce. And whoever controls the energy supply, controls the money supply.
Money equals work.
Summary
The definition of work is physical or mental exertion. Work is a force that causes a displacement. Unprecedented amounts of work can be done today because of the invention of the internal combustion engine and the discovery of oil to power it. This has led to enormous/miraculous gains in productivity, so much so that today we can get bread, and almost anything else, with very little work.
And because it takes work to make/produce/manufacture money, the amount of money is proportional to the amount of work done to produce something valuable enough to be used as money.
What is value? What makes something valuable? Jump to Unit 3 to find out.
Endnotes
- “Work”. (n.d.). Retrieved from https://www.merriam-webster.com/dictionary/work
- Wikipedia contributors. (2015, November 8). Work. In Wikipedia, The Free Encyclopedia. Retrieved from https://en.wikipedia.org/w/index.php?title=Work&oldid=925172776
- Wikipedia contributors. (2015, November 11). Power (physics). In Wikipedia, The Free Encyclopedia. Retrieved from https://en.wikipedia.org/w/index.php?title=Power_(physics)&oldid=925652648
- Wikipedia contributors. (2019, November 8). Human power. In Wikipedia, The Free Encyclopedia. Retrieved from https://en.wikipedia.org/w/index.php?title=Human_power&oldid=925214963
- Wikipedia contributors. (2019, October 20). Horsepower. In Wikipedia, The Free Encyclopedia. Retrieved from https://en.wikipedia.org/w/index.php?title=Horsepower&oldid=922169546
- “Convert Units – Measurement Unit Converter.” (n.d.) ConvertUnits.com. Retrieved from https://www.convertunits.com/from/kWh/to/gallon+[U.S.]+of+automotive+gasoline
- Wikipedia contributors. (2015, November 9). Engine. In Wikipedia, The Free Encyclopedia. Retrieved from https://en.wikipedia.org/w/index.php?title=Engine&oldid=925404281
- White, William. (2008, March 26). Economic History of Tractors in the United States. EH.Net Encyclopedia, edited by Robert Whaples. Retrieved from http://eh.net/encyclopedia/economic-history-of-tractors-in-the-united-states/
- “U.S. energy facts explained”. (2015, August 18). Retrieved from https://www.eia.gov/energyexplained/us-energy-facts/