Transcript Conservation of Stuff (with some type of energy thrown in)

Conservation of Stuff
(with some type of energy thrown in)
Mike Hannigan
(and Galileo’s Dad)
Intro to Sustainable Energy
Wed., January 24, 2007
Conservation
(Webster’s Dictionary) n. the act of keeping
free from depletion, decay, or injury
 If you search the Microsoft Office images
for ‘conservation’ you get …

Conservation of Mass
a.k.a. Conservation of Matter, Lomonosov’s Law

Mikhail Lomonosov
 Born in far north
Russia in 1711
 Walked to Moscow at
Lomonosov’s Chemistry Lab
17
What does this mean?  Father of modern
chemistry
"All changes in nature are such that inasmuch is taken from one object insomuch is
 First to formulate this
added to another. So, if the amount of matter decreases in one place, it increases
concept
elsewhere. This universal law of nature embraces
laws of motion as well, for an
object moving others by its own force in fact imparts to another object the force it
loses" in a letter to Leonhard Euler dated July 5, 1748
Conservation of Mass
The most fundamental ‘scientific law’.
Let’s take a sideways step


Who remembers the big
drought a few years ago?
What were the headlines
saying?
“Water Police Visit City Council
Members”
water
(7/13/2002) Boulder Daily Camera

What happens to water once
you have consumed it?
 Water is conserved only it’s
location changes.
At Niwot Feed Store, I heard “flush twice for the farmers.” This is solid thinking.
What about other forms of matter?

Gasoline
 Coal
 Natural Gas
 Steak

So what is really conserved?
Carbons, Oxygens, Hydrogens
Conservation of Energy

Galileo (1638)



Thomas Young (1807)


Coined ‘life force’ to be
energy
Karl Mohr (1837)


Pendulum
Potential to Kinetic
"besides the 54 known chemical elements there
is in the physical world one agent only, and this
is called Kraft [energy or work]. It may appear,
according to circumstances, as motion,
chemical affinity, cohesion, electricity, light and
magnetism; and from any one of these forms it
can be transformed into any of the others."
First to publish idea
Julius von Mayer &
James Joule (1840s)

Kinetic to Heat
Joule's apparatus for measuring the mechanical
equivalent of heat. A descending weight attached to a
string causes a paddle immersed in water to rotate.
Conservation of Energy
Definition from the Handbook of Chemistry and Physics, 65th edition, CRC press
“Energy can neither be created nor destroyed
and therefore the total amount of energy in the
universe remains constant.”
Why should I switch off the
lights to conserve energy,
when there is a law which
states that energy is always
conserved?
Conservation of Energy
a.k.a., 1st Law of Thermodynamics
 Does anyone know what the 0th, 2nd, or
3rd Laws of Thermodynamics are?

You have to play the game
 You can’t win
 You can’t break even
 You can’t quit


Leo is learning the 0th Law
So what does energy consumption mean?
Consumption means Conversion

When you consume gasoline, what are you doing?

Internal energy


Heat


Bonds between atoms have energy
Kinetic energy of the molecules present - temperature
Mechanical energy

Pistons moving to drive shaft moving to axle moving to tires
rotating (and the car moves gaining kinetic energy)

How about making toast?

Need to understand different forms.
Forms of Energy
Kinetic
 Potential (gravimetric potential)
 Heat (kinetic energy of atoms)
 Electrical (electric potential)
 Electromagnetic (oscillating electric potential)
 Chemical energy (kinetic and electric potential)
 Nuclear (strong nuclear potential)

References

Lomonosov

Information from wikipedia (accessed on 1/24/2007) and photo from
http://max.mmlc.northwestern.edu/~mdenner/Demo/poetpage/lomonosov.htm

Conservation of Energy


Karl Mohr quote is from Über die Natur der Wärme, published in the
Zeitschrift für Physik in 1837
Poetic versions of the laws of thermodynamics were penned by Allen
Ginsberg