Title: Science, Systems, Matter, and Energy
1Chapter 2
- Science, Systems, Matter, and Energy
2Core Case Study Environmental Lesson from
Easter Island
- Thriving society
- 15,000 people by 1400.
- Used resources faster than could be renewed
- By 1600 only a few trees remained.
- Civilization collapsed
- By 1722 only several hundred people left.
Figure 2-1
3Feedback Loops How Systems Respond to Change
- Outputs of matter, energy, or information fed
back into a system can cause the system to do
more or less of what it was doing. - Positive feedback loop causes a system to change
further in the same direction (e.g. erosion) - Negative (corrective) feedback loop causes a
system to change in the opposite direction (e.g.
seeking shade from sun to reduce stress).
4Feedback Loops
- Negative feedback can take so long that a system
reaches a threshold and changes. - Prolonged delays may prevent a negative feedback
loop from occurring. - Processes and feedbacks in a system can
(synergistically) interact to amplify the
results. - E.g. smoking exacerbates the effect of asbestos
exposure on lung cancer.
5Organic Compounds Carbon Rules
- Organic compounds contain carbon atoms combined
with one another and with various other atoms
such as H, N, or Cl-. - Contain at least two carbon atoms combined with
each other and with atoms. - Methane (CH4) is the only exception.
- All other compounds are inorganic.
6Organic Compounds Carbon Rules
- Hydrocarbons compounds of carbon and hydrogen
atoms (e.g. methane (CH4)). - Chlorinated hydrocarbons compounds of carbon,
hydrogen, and chlorine atoms (e.g. DDT
(C14H9Cl5)). - Simple carbohydrates certain types of compounds
of carbon, hydrogen, and oxygen (e.g. glucose
(C6H12O6)).
7States of Matter
- The atoms, ions, and molecules that make up
matter are found in three physical states - solid, liquid, gaseous.
- A fourth state, plasma, is a high energy mixture
of positively charged ions and negatively charged
electrons. - The sun and stars consist mostly of plasma.
- Scientists have made artificial plasma (used in
TV screens, gas discharge lasers, florescent
light).
8Matter Quality
- Matter can be classified as having high or low
quality depending on how useful it is to us as a
resource. - High quality matter is concentrated and easily
extracted. - low quality matter is more widely dispersed and
more difficult to extract.
Figure 2-8
9CHANGES IN MATTER
- Matter can change from one physical form to
another or change its chemical composition. - When a physical or chemical change occurs, no
atoms are created or destroyed. - Law of conservation of matter.
- Physical change maintains original chemical
composition. - Chemical change involves a chemical reaction
which changes the arrangement of the elements or
compounds involved. - Chemical equations are used to represent the
reaction.
10Chemical Change
- Energy is given off during the reaction as a
product.
11Types of Pollutants
- Factors that determine the severity of a
pollutants effects chemical nature,
concentration, and persistence. - Pollutants are classified based on their
persistence - Degradable pollutants
- Biodegradable pollutants
- Slowly degradable pollutants
- Nondegradable pollutants
12Nuclear Changes Radioactive Decay
- Natural radioactive decay unstable isotopes
spontaneously emit fast moving chunks of matter
(alpha or beta particles), high-energy radiation
(gamma rays), or both at a fixed rate. - Radiation is commonly used in energy production
and medical applications. - The rate of decay is expressed as a half-life
(the time needed for one-half of the nuclei to
decay to form a different isotope).
13Nuclear Changes Fission
- Nuclear fission nuclei of certain isotopes with
large mass numbers are split apart into lighter
nuclei when struck by neutrons.
Figure 2-9
14Stepped Art
Fig. 2-6, p. 28
15Nuclear Changes Fusion
- Nuclear fusion two isotopes of light elements
are forced together at extremely high
temperatures until they fuse to form a heavier
nucleus.
Figure 2-10
16ENERGY
- Energy is the ability to do work and transfer
heat. - Kinetic energy energy in motion
- heat, electromagnetic radiation
- Potential energy stored for possible use
- batteries, glucose molecules
17Electromagnetic Spectrum
- Many different forms of electromagnetic radiation
exist, each having a different wavelength and
energy content.
Figure 2-11
18Electromagnetic Spectrum
- Organisms vary in their ability to sense
different parts of the spectrum.
Figure 2-12
19Relative Energy Quality (usefulness)
Source of Energy
Energy Tasks
Electricity Very high temperature heat (greater
than 2,500C) Nuclear fission (uranium) Nuclear
fusion (deuterium) Concentrated
sunlight High-velocity wind
Very high-temperature heat (greater than 2,500C)
for industrial processes and producing
electricity to run electrical devices (lights,
motors)
High-temperature heat (1,0002,500C) Hydroge
n gas Natural gas Gasoline Coal Food
Mechanical motion to move vehicles and other
things) High-temperature heat (1,0002,500C)
for industrial processes and producing
electricity
Normal sunlight Moderate-velocity
wind High-velocity water flow Concentrated
geothermal energy Moderate-temperature
heat (1001,000C) Wood and crop wastes
Moderate-temperature heat (1001,000C) for
industrial processes, cooking, producing steam,
electricity, and hot water
Dispersed geothermal energy Low-temperature heat
(100C or lower)
Low-temperature heat (100C or less) for
space heating
Fig. 2-13, p. 44
20ENERGY LAWS TWO RULES WE CANNOT BREAK
- The first law of thermodynamics we cannot create
or destroy energy. - We can change energy from one form to another.
- The second law of thermodynamics energy quality
always decreases. - When energy changes from one form to another, it
is always degraded to a more dispersed form. - Energy efficiency is a measure of how much useful
work is accomplished before it changes to its
next form.
21Mechanicalenergy(moving,thinking,living)
Chemical energy (photosynthesis)
Chemical energy (food)
Solar energy
Waste Heat
Waste Heat
Waste Heat
Waste Heat
Fig. 2-14, p. 45
22SUSTAINABILITY AND MATTER AND ENERGY LAWS
- Unsustainable High-Throughput Economies Working
in Straight Lines - Converts resources to goods in a manner that
promotes waste and pollution.
Figure 2-15
23Sustainable Low-Throughput Economies Learning
from Nature
- Matter-Recycling-and-Reuse Economies Working in
Circles - Mimics nature by recycling and reusing, thus
reducing pollutants and waste. - It is not sustainable for growing populations.
24Inputs (from environment)
System Throughputs
Outputs (into environment)
Energy conservation
Low-quality Energy (heat)
Energy
Sustainable low-waste economy
Waste and pollution
Waste and pollution
Pollution control
Matter
Recycle and reuse
Matter Feedback
Energy Feedback
Fig. 2-16, p. 47