Chapter 2
Science, Matter, Energy, and Systems
Science is an endeavor to discover how nature
works. It has limitations and hypothesis are tentative
and testable statements that must be capable of
being supported or not supported by observational
evidence.
Data – information required to answer the scientists
questions
Model – an approximate representation or
simulation of a system being studied.
Scientific Theory – a well-tested and widely accepted
scientific hypothesis or a group of related hypothesis
Scientific Law – a well tested and widely accepted
description of what we find happening over and over
again, the exact same way in nature.
Peer Review – scientists sharing information with
other scientists working in the same field.
Inductive Reasoning – using specific observations and
measurements to arrive at a general conclusion or
hypothesis.
Deductive Reasoning – using logic to arrive at a
specific conclusion based on generalization or
premise.
Paradigm Shift – when the majority of scientists in a
field accept new ideas and discoveries and build a
new framework for laws and theories, overthrowing
older laws and theories.
Tentative Science/Frontier Science – hypotheses that
have not been widely tested or studied and have not
been accepted by peer review; tend to capture news
and headlines.
Reliable Science – consists of data, hypotheses,
theories, and laws that are widely accepted
Unreliable Science -
Essentially 100% of the energy that
fuels the earth comes from the sun
EARTH’S ENERGY BALANCE
Solar Energy Enters Ecosystems via
Photosynthesis
Terrestrial Ecosystems
Aquatic Ecosystems
PHYTOPLANKTON
Elements important to the Study of
Environmental Science
Hydrogen
Carbon
Oxygen
Nitrogen
Phosphorus
Sulfur
Chlorine
Flourine
Bromine
Sodium
Calcium
Lead
Mercury
Arsenic
Uranium
Ions Important to the Study of
Environmental Science
Hydrogen - H+
Sodium – Na+
Calcium – Ca2+
Aluminum – Al3+
Ammonium – NH4+
Chlorine – ClHydroxide – OHNitrate – NO3Sulfate – SO42Phosphate – PO43-
Compounds Important to the Study of
Environmental Science
Sodium Chloride – NaCl
Carbon Monoxide – CO
Carbon Dioxide – CO2
Nitric Oxide – NO
Nitrogen Dioxide – NO2
Nitrous Oxide – N2O
Nitric Acid – HNO3
Compounds Important to the Study of
Environmental Science Cont.
Methane – CH4
Glucose – C6H12O6
Water – H2O
Hydrogen Sulfide –H2S
Sulfur Dioxide – SO2
Sulfuric Acid – H2SO4
Ammonia – NH3
Law of Conservation of Matter
When a chemical or physical change occurs, no
atoms are created or destroyed.
DUH.
Law of conservation of Energy
(also known as the 1st law of thermodynamics)
When energy is converted from one form to
another in a physical or chemical change, no
energy is created or destroyed.
Once again, DUH.
Energy Input always = Energy Output
2nd Law of Thermodynamics
When energy changes from one form to
another, we always end up with lower-quality or
less usable energy than we started with.
Energy always goes from a more useful to a less
useful form when it is changed from one form to
another.
What are Systems and how do they
respond to change?
System – a set of components that function and
interact in some regular way.
Most systems have the following key components:
Inputs from the environment
Flows or throughputs of matter and energy within
the system at certain rates
Outputs to the environment
Feedback Loops
Feedback – any process that increases or decreases a change
to a system.
Feedback Loop – when an output of matter, energy, or
information is feed back into the system as an input and leads
to changes in that system.
Positive Feedback Loop – system changes further in the same
direction. (Decreasing Vegetaion in a valley)
Negative Feedback Loop – system changes in the opposite
direction. (Your thermostat at home)
Negative/Positive Feedbacks
• http://www.bozemanscience.com/positiveand-negative-feedback-loops/