Welcome back. Today we will be talking a bit about energy. So, what is energy? Energy is
the amount of work that can be performed by a system, but where does that energy come
from? It comes from lots of different spots. Perhaps the most common are from fossil fuels,
also from nuclear, and then there are a variety of other ones. Sun, wind, tides, geothermal.
The last of those groups are generally considered to be renewable resources. Ultimately though,
all of these are on a scale from completely renewable to not renewable at all. For example,
you might consider solar energy to be renewable, and that's true on the scale of the human
species, but if you were thinking about it in terms of billions of years it is not necessarily
renewable because at some point it is going to run out. Nevertheless, fossil fuels and
nuclear are seen as nonrenewable whereas sun, wind and tides and so on are seen as renewable
energy sources. So, gasoline which comes from oil is one of the main energy sources that
many of you encounter in the form of it is what makes your car go. Gasoline is mostly
composed of hydrocarbons which are groups of carbon atoms that are attached in a chain
with a bunch of hydrogen atoms around them. So for example Heptane, which is one of the
things that makes up gasoline, is 7 carbon atoms attached to each other with a bunch
of hydrogens around them. But, octane which is another thing, when you go to get gas and
it says like percent octane 89 octane, this is the octane they are talking about, it is
8 carbon atoms in a row surrounded by hydrogens. So, I just wanted to talk to you a little
bit about the process by which energy is released by octane combustion. So, here we see an octane
molecule, or actually two octane molecules, as well as the chemical formula for the octane
combustion process. This is an excerpt from a graph, one that gives off heat. So essentially
what happens is that all of these octane molecules and a bunch of 02 molecules are in the same
spot, and a chemical reaction happens where two of the hydrogens and one of the oxygens
branch off and become an H20, and one of the carbons and two oxygens become carbon dioxide.
So, this is why from the octane combustion you get C02 and H20. So, the water comes out
as water vapor out of your tailpipe, and the C02 is the reason that fossil fuels lead to
significant greenhouse gas production. So, here we see a chart of the U.S. energy usage
in 2012. On the lefthand side there are all different sources of energy, and on the righthand
side is where they go. So, petroleum is the dark green one at the bottom and it mostly
goes to transport. Renewables tend to be the smaller ones at the top. One thing that is
striking about this graph is that about half of all of the energy that gets used goes to
waste, so the gray box at the top, the light gray box at the top right is called rejected
energy, and the bottom darker gray box is energy services. So, that I found really striking
that about half of all of the energy we use goes to waste either as excess heat or other
forms of waste. In particular electricity generation which is the top yellowish box,
and transportation which is the bottom pink box, are profoundly inefficient. You can see
the light gray coming out of each one and it is significantly bigger than the energy
that is actually being utilized by people from those processes. So, there is a book
title that I find really interesting in terms of thinking about fossil fuels. It's called
"The Last Hours of Ancient Sunlight." What this book title points out is that fossil
fuels are ultimately the residue of ancient sunlight that fell on the Earth. Over millions
of years the sun shined down and was absorbed by plants and produced photosynthesis which
is where the energy came from that was then buried under the earth and compressed into
oil, natural gas and coal. So, what this book title suggests is that we are now using the
last hours of ancient sunlight, that we are running out of all of this ancient sunlight
that has been stored underneath the earth from photosynthesis going on across millions
o f years. One thing that these fossil fuels have supported is a thing called the Cognitive
Surplus. This is something that a researcher named Clay Shirky from NYU thought up. He
ties this back to the industrial revolution, that in the industrial revolution humans started
to use more and more machines to do the things that previously human labor had done. What
this caused as people had to do less and less work to get the food and other resources that
we relied upon is that freed up a lot of time, and he calls this collective group of time
that everybody has, the free time, the Cognitive Surplus. What he suggests is that in the industrial
revolution when people didn't know what to do with this cognitive surplus they turned
to gin and they went on a decades-long bender where gin effectively absorbed the excess
time. He makes a comparison between gin and the industrial revolution, and currently things
like television and a lot of discretionary Internet use as being the thing that we do
to occupy these vast hours that we no longer have to be out hoeing the ground and finding
roots and berries and stuff. He coins in this work a new unit of measure which he calls
the Wikipedia. A Wikipedia is about 100 million hours of human thought. That he says as a
back of the envelope calculation is about how much work went into all aspects of Wikipedia.
That's writing all the code, every edit, every article that has ever been done, it is about
100 million hours which seems like a lot. Wikipedia is a big production, but what he
suggests is that we have about 2000 Wikipedias worth of time watching television every year
around the world. He suggests that we watch a Wikipedia worth of ads every weekend in
the United States alone, and this was actually a conservative estimate. Since his writing
about this 2000 Wikipedias, some other analyses could point to the idea it might be 5000 Wikipedias
every year of TV. He calls this big batch of free time the Cognitive Surplus, and what
some of his research has been doing is looking at what should we be doing with it? He discusses
the notion that participatory culture is one of the things that is arising from the surplus,
participatory culture being the creation of things on the Internet. Everything from cat
videos up to Kickstarter and Amazon Mechanical Turk are all parts of this participatory culture.
In his book, Clay Shirky talks about using this cognitive surplus for civic benefits,
for promoting various different causes and making the world a better place in those sorts
of ways. He does not explicitly mention sustainability, but it can certainly be one of these items.
Ultimately though, where does the cognitive surplus come from? This is an important question,
and what I would offer is that the cognitive surplus comes from labor-saving devices, and
those labor-saving devices are using the energy from coal, oil and natural gas to enable them.
So, ultimately the cognitive surplus is made out of fossil fuels. So, in terms of preparing
for the future if there is some possibility that fossil fuels might become scarce as many
researchers are suggesting, the cognitive surplus might become scarce as well, that
we humans will need to spend more time in the satisfaction of basic human needs rather
than having all of this free time to be building web pages and such. So, one approach that
I would encourage is using the current cognitive surplus to reduce future reliance on the cognitive
surplus. So, effectively to try to take the cognitive surplus out of the critical path
so that we don't necessarily need it because if it's so reliant on fossil fuels, and if
those fossil fuels dry up, we will not necessarily have it at our disposal and it seems like
it is better to figure that out now than at a later date.