What is energy?
First attempt at a definition
Something has energy if...
- it has the potential to physically change itself or its environment,
One kind (a dramatic kind) of change is damage or destruction!
Some of your associations
...from the writing exercise
- Energy is power to operate things so that they run.
- Fuel and food, needed by our bodies, coal as a fuel (x 6)
- Lactic acid ("anaerobic" or no oxygen) vs aerobic exercise
- "Life is the constant search for energy"
- =Life (x 2)
- But..."There is energy in everything living or not": Yes! "thermal energy", or the motion of atoms is one kind of energy. "Chemical energy" is the energy of chemical bonds between atoms. And most everything has some nuclear energy (though it might be something you can only release in a star, not in your digestive system.)
- 'Work', which does have a scientific meaning
- We use energy to turn on lights.
- Many types, electric, solar, nuclear, hydro. Friction, Batteries (X 10)
Can be used to put things in motion, "kinetic energy", "anything that involves movement". (X 5)
"not something that can be man made"
- Energy cannot ever truly be erased. (X 3) $\to$"not something that can be man made"
- The science definition differs from the everyday definition (x 2)
- Renewable vs non-renewable (X 5)
- Non-renewables are finite (X 2)
- Energy conservation / using energy sparingly (X 2)
Distress because "It's almost like society makes it so people have to use gas" - Inequalities in access to energy
- everyday... "something that moves a lot and has trouble being still"
- putting time into something = putting energy in
- motivation for doing work
- feelings about a space or a room (neg or positive) (x 2)
- listening to music and dancing energize me
- I need it to complete my job well
- "mental strength", gained from coffee, really gets rolling after 3 classes
- spiritual energy
More definitions and characteristics
Energy is not an atom or an object. But an object can possess energy.
We might include a tank of gasoline, a battery, water backed up behind a dam, a stretched out piece of elastic material, or a flying brick.
Heat is energy that can raise the temperature of matter.
Energy and global warming
Burning fossil fuels (coal, gasoline, diesel, natural gas...) releases carbon dioxide into the air. Increased carbon dioxide is the most important contributor to global warming.
Do you know where your electricity comes from??
It can come from a coal-fired or nuclear plant, a solar panel, water passing through a hydro-electric dam, or many other sources.
Regional electricity generation (Center for Climate and Energy Solutions)
How the electricity is generated does not affect what we can do with electricity.
The idea of energy is a way of separating out issues of human impact, allowing us to think separately about issues of consumption/lifestyle and the technical details of how that's accomplished.
Energy can be transformed from one form to another--The chart shows the many different energy sources that can be turned into electricity.
The human condition in the world of 2017
...and beyond
We are having an ever greater impact on the world around us through the product of our numbers (getting around 7.5 billion) and our resource use.
We are the third-most-populous country in the world. But we have a higher per capita consumption than the #1 and #2, whether measured by our energy consumption, or by other measures.
We might like to see ourselves as stewards of the more attractive bits of the world around us...
But we understand only imperfectly our own dependence on the world in which we have grown up, and how it works.
(The story of the Kill a Sparrow Campaign).
Both science and religion offer perspectives on the human condition...
Cuyahoga river fire, 1969
The Cuyahoga river flows into Lake Erie at Cleveland.In 1969, oil slicks on the surface of the river caught fire.
Clean Water Act, 1972
Woodward and Bernstein, the 2 reporters who broke the Watergate Scandal which ultimately resulted in the resignation of President Richard Nixon were told by one source to follow the money.
The flow of money ultimately revealed the relationships between the Watergate burglars and President Nixon's Whitehouse staff.
When money leaves one bank account, it has to go into someone's pocket, or some other bank account.
Most people do not *destroy* money!
Energy works the same way. It reveals relationships. It is never destroyed (the law of conservation of energy) but passes from form to another.
What associations do you have with energy?
Using energy to think
...about our relationship with the natural world, and with technology.
Looking at numbers can offer some surprises, and insights. What do you find surprising in this table?
Energy content (calories per gram)
Bullet (moving at speed of sound) 0.01 Butter 7 Battery (auto) 0.03 Gasoline 10 Battery (alkaline) 0.15 Natural gas (methane) 13 TNT (trinitrotoluene) 0.65 Hydrogen 26 Modern explosive (PETN) 1 Asteroid @ 30 km / s 100 Chocolate chip cookies 5 Uranium 235 20,000,000 Coal or Ethanol (alcohol) 6 Water behind a dam ?? From Richard Muller, Physics for Presidents.
Context is also important in understanding numbers: What important considerations are missing from this table.
Aspects that are missing from the table include costs, info about byproducts of energy generation, and safety considerations, to name just a few...
