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What do you really need
to know about science? Of course, the answer to that question depends
on your objective. We've tried to sort out the core concepts we
think are particularly significant given the objective of developing
a perspective on how your actions fit into the framework of society,
Earth, and the universe as a whole. This page provides an overview
of these core ideas, along with links to resources that allow you
to investigate any topic in progressively greater depth, following
your interests as your time permits.
"What is required...is
not a detailed understanding of the content of each science, but
rather a kind of synthesis of many different strands from many
different sciences." --Gerald Feinberg
Chapter 5 of An
Ordinary World provides
a more detailed description of the motivation and the filter used
to determine the set of concepts described here. The Cosmo-02
Forum organized by Kim Coble gives a specific example of the
process of filtering concepts from scientific cosmology that are
useful for building your perspective.
This is always a work
in progress. If you would like to suggest or develop resources to
add to this list or submit comments, please contact
us.
Topics
List
The
scientific process
- essential
distinguishing feature of science: scientific knowledge
is subject to observational or experimental test
- understand key elements
in the process of science
- the role of mathematics
in describing nature
- basis for our beliefs
- How do we decide what to believe? (especially when belief leads
to action)
- assessing risks
(comparisons, statistical significance)
- how we interpret
evidence
A sense of
scale
- Appreciating distance and time scales for structures and events
in the Universe
- timeline of key events
in the history of the Universe (cosmic calendar)
- scale model of arrangement
of planets, stars, galaxies, etc.
- placing yourself within
the scale of things
Evolution
- Everything in the Universe is changing with time as new structures
emerge and complexity increases
- self-organization
- simple rules can
underlie complex phenomena - identical building blocks produce
wide variety of structures
- patterns that
are similar in different physical systems (spatial and behavioral)
- cosmological evolution
(early evolution of elements, galaxies, etc.)
- chemical evolution
(development of complex chemical structures)
- biological evolution
(origin and development of life)
- cultural and societal
evolution (development of social knowledge; advancing of our
thoughts, knowledge that is passed down through interactions
instead of through genetic adaptations)
- linguistic
evolution
- evolution
of emotions
- cultural/religious
traditions
- transportation
systems
- notions of
beauty/cosmetics
Interdependence
of systems - Processes
and structures in the Universe form a system of relationships in
which everything is connected to everything else.
- energy
as a unifying theme (everything that happens in the world involves
an exchange of energy)
- energy sources
- you can't get something for nothing
- not all forms
of energy are equally useful, and the quality of energy tends
to degrade with time
- information
as a unifying theme - many superficially different physical systems
play a common role in storing and transferring information
- DNA, silicon-based
computers, neurons, internet, etc
- developing concrete
awareness of connections - examples tying everyday things to the
rest of the universe (tapestry principle)
- stardust-
tracing origins
- constraints and
limitations experienced in daily life
- Nothing can
travel faster than the speed of light
- We get hungry
if we do not eat - we need the energy
- Technology (How
stuff works!) basic principles underlying technology (em radiation,
friction, energy conservation, etc.); being aware that technologies
organize nature to make us feel a certain way or think certain
way....all this external stuff matters to us for our internal
frame of mind
- Properties
of materials
- Instruments
(Physics of )
- Engines
- Computers
- Electricity
Core concepts
for describing reality
Tying it together:
tips for incorporating
these concepts into your worldview
Topic
Descriptions
The
Scientific Process
What distinguishes
science as a way to gain knowledge about the world? Most importantly,
it is distinguished by letting observations of nature
have the final say in settling disagreements. Science is essentially
a trial-and-error process of choosing explanations that work in
describing what we see in the world, and discarding explanations
that are found not to work. We observe ourselves and the world
around us, develop models to explain what we see in nature, make
observations and set up experiments to test these models in new
situations, and then revise the models and repeat the process.
There is much room for individual creativity and different styles
for how the models are developed, and the scientific process is
often not so systematic and linear; sometimes models can come
before detailed observations, for example. The key point is that
no matter what, nature (observation) has the €nal say in ruling
out an explanation.
Unknown
Object exercise
Stephen Carey book
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A
Sense of Scale
Physical
Scale of Things:
| Portland
to Eugene |
~
100 miles |
| Earth (circumference) |
~ 25,000 miles |
| Earth to Moon |
~240,000 miles
(~1 light-second) |
| Earth to Sun |
~ 8 light-minutes |
| Earth to nearest
star beyond Sun |
~ 4 light-years |
| Milky Way Galaxy
(diameter) |
~ 100,000 light-years |
| Distance to nearby
galaxy |
~ 3 million light-years |
| Most distant visible
galaxies |
~ few billion
light-years |
You get
an idea of how incredible these distances are when you know that
light travels at a pretty good clip of 186,000 miles in a second!
(more than 7 times around the Earth in a second).
Atlas
of the Universe Web site - A great way to tour the universe
and get a sense of our physical place in the scheme of things
(seems to work best with Internet Explorer)
Powers
of 10 Web site
1994 book by Edward
Packard, Imagining the Universe: A Visual Journey ("From
inside the atom to the ends of space and time, the whole cosmos
scaled to the human eye")
October 2001 issue
of Astronomy magazine (page 84) contains a complete and concise
answer to the reader question "If the Earth were the size
of the period at the end of this sentence, how large would our
solar system, galaxy, and universe be in comparison?"
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Evolution
Eric Chaisson's Cosmic
Evolution Web Site
Science
Integration Origins lecture by Craig Tyler
Include an overview
of biological evolution
Biological
Evolution Intro (from Westview Senior Inquiry Class)
Darwin's Dangerous
Idea: Evolution and the Meanings of Life. Daniel C. Dennett
(1995)
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Energy
In all aspects of our
lives we experience constraints on what we can do and
on what kinds of relationships exist between different parts of
the world. The concept of energy developed as people
attempted to organize and unify their understanding of many of
these constraints. Every change that occurs in the world involves
an exchange of energy, so an understanding of energy and how it
flows through the world can help you develop a deeper sense of
connection to your surroundings. For example, when you buy an
apple and eat it, you can trace the flow of energy that makes
this process significant to you: Energy that was once in the form
of mass in the sun was transferred to the light that pours onto
Earth from the sun, then captured in the chemical bonds of the
growing apple, then stored in your body, then tranferred into
gravitational potential energy and heat as you climb a flight
of stairs after eating the apple. (Add diagram illustrating this
flow)
Suggested starting
points:
For further
investigation:
- Hobson, Art, Physics:
Concepts and Connections (chapter 6)
- Feynman, Leighton,
Sands, The Feynman Lectures on Physics, vol. 1, Chapter
4 (Conservation of Energy).
- von Baeyer, Hans
Christian. Warmth Disperses and Time Passes: The History
of Heat. New York: Random House, 1998.
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Information
as a unifying theme
The Bit and the
Pendulum: From Quantum Computing to M Theory - The New Physics
of Information, by Tom Siegfried, John Wiley & Sons,
2000.
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Stardust
Where did it all come
from? Most everything we see around us has a history that can
be traced to the stars. The building blocks that compose us and
our immediate environment were either made in the big bang 14
billion years ago or emerged from the depths of ancient stars.We
are all made of stardust! By fully appreciating this fact we can
gain a sense of deep connection to the cosmos.
NASA's
Imagine web site provides an excellent introduction to the
cosmic history of common elements in our daily lives, and helps
you gain a concrete appreciation of our connections to the cosmic
processes that made these elements.
Other References
SII
lecture on the origin of the elements by Aparna Venkatesan
http://thegreatstory.org/Stardustbackground.html
Lawrence M. Krauss,
Atom: An Odyssey from the Big Bang to Life on Earth...and
Beyond. Little Brown & Company, (April 2001). Traces
the history of a single oxygen atom from its formation through
the many astronomical and more familiar systems it has been a
part of.
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Space,
Time, & Relativity
Space,
Time, & Relativity lecture (SII Key Concepts of Physics
lecture series)
Davies, Paul. How
to Build a Time Machine (good concise description of relativity
concepts, but point out the few misleading statements)
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Quantum
Physics
Quantum physics is
often viewed as applying only to the realm of the very small.
But because it challenges very basic assumptions about the nature
of reality, it impacts our view of the world on all levels.Quantum
physics gives us an overall picture of reality that is very different
than our common-sense perception. If you really want to know how
the world works, then you need to know the basic principles of
the quantum description of reality. Experiments that led to the
development of quantum theory show that our very notions of the
identity, locality, and even reality of objects no longer hold
in the usual way.
“Quantum
phenomena challenge our primitive understanding of reality;
they force us to re-examine what the concept of existence means.
These things are important, because our belief about what is
must affect how we see our place within it, and our belief about
what we are. In turn, what we believe ultimately affects what
we actually are and, therefore, how we behave.” --Euan
Squires
A nice way to highlight
the basic difference between the classical and quantum view of
reality is through contrasting versions of the familiar "Twenty
Questions" game (this analogy was suggested by John Wheeler).
In the classical version of the game, one person thinks of a specific
object (a pink elephant, for example) and holds it firmly in mind
while others ask her yes/no questions in order to pin down what
the object is. (Is it bigger than a person? - Yes ; etc.). The
key feature of this classical version of the game is that reality
is well-defined all along. The answer is always a pink elephant,
and the questions serve only to allow participants to learn this
already-defined fact. By contrast, in the quantum version, the
person does not start by thinking of a definite object and holding
it in mind throughout the game. Instead, she simply answers each
question as it is asked, not restricted by the necessity of making
the answers match with the properties of a specific, real object.
She only has to make sure that all the answers are consistent
with one another. There is still a great deal of structure and
many restrictions in the quantum version of the game. But there
is a freedom also that is different from the classical version
- answers given from one round to the next in the game can have
a more flexible relationship to one another than is possible in
the classical version.
Here's a summary
of the conceptual highlights of quantum physics:
- Questions about
nature are "answered" only when they are specifically
"asked". Properties of quantum systems do not have
definite values unless a measurement (which need not
require a human observer) forces them to choose definite values.
- Interference of
possibilities - If there are different possible ways for a quantum
event to happen, these possibilities can interfere
with each other. As a result, what we observe when there are
2 (or more) possible ways for something to happen is not
just the sum of what we get by considering each of the 2 possibilities
separately.
- Fundamental uncertainty
- Quantum theory gives as its final answer only a prediction
of probabilities for what we will find when we observe
something. This reflects a fundamental uncertainty about observable
properties of reality. You can prepare an experiment the same
way every time, yet get different results each time (though
usually within a very narrow range of results, according to
the probabilities predicted by quantum theory).
- It's important
to note that quantum uncertainty is fundamentally
different than classical ignorance. Classical ignorance
is something we’re all familiar with. It’s what
we experience when we don’t know something, but the
answer is well defined and already decided. We just don’t
happen to have the information in our heads. So for example,
if I opened one of the books on my shelf, and turned to
page 123, some word would be the first word on that page.
None of us knows what that word is - that’s classical
ignorance. But I think we’d all agree that there really
is a word printed there, already, waiting for us to look
at it and eliminate our ignorance. Quantum uncertainty is
different. It means that the answer does not exist until
a measurement of some kind forces the system to commit to
an answer - even nature has not “decided” and
doesn’t “know,” prior to measurement,
what the answer will be. This idea, well established by
experiment, will take some getting used to.
- Entanglement - parts
of a system don't always have isolated identities with independently
defined properties. This bizarre property of the quantum world
is the basis for quantum teleportation and for several important
applications such as quantum computing and quantum cryptography.
Entanglement occurs when a conservation law (conservation of
energy or angular momentum, for example) forces a relationship
between parts of a system even when the properties of the individual
parts are not well-defined. For example, 2 particles might be
prepared so that their "spins" (which you can think
of as the orientations of little arrows, like compass needles)
must be in opposite directions when they are measured. These
particles are entangled because even though their individual
orientations are not decided until a measurement occurs, we
know for sure that the first spin will always be found with
an orientation opposite that of the second spin, even if the
2 particles have traveled a great distance from each other.
Suggested starting
points:
Squires, Euan. The
Mystery of the Quantum World (Second Edition), Institute
of Physics Publishing, 1994. A good non-technical overview of
the conceptual highlights of quantum physics, emphasizing the
challenge they present to our common-sense view of reality.
Centre
for Quantum Computation (University of Oxford)- Has many
nice tutorials (for all levels of expertise) introducing key
concepts of quantum physics that are important for the emerging
field of quantum computation. Note especially the tutorials
on entanglement and quantum teleportation.
Introduction
to Quantum Cryptography (pdf file) - A good overview of
the concepts involved in sending coded messages using the bizarre
quantum aspects of reality.
Visual
Quantum Mechanics resources at KSU Physics Department. Interactive
tutorials for gaining intuition about how quantum physics really
works.
Atom
in a Box. An excellent shareware application that provides
real-time visualization of quantum mechanical atomic orbitals
for hydrogen atoms.
For further
investigation:
Baggott, Jim. The
Meaning of Quantum Theory, Oxford, 1992. A good overview
of quantum theory, includes technical details but from a perspective
that focuses on, "what does this mean?"
Greenstein, George
and Zajonc, Arthur. The Quantum Challenge: Modern Research
on the Foundations of Quantum Mechanics (1997). For those
with a college-level background in physics, this book provides
an excellent introduction to the key experimental results from
quantum physics that challenge our commonsense worldview. Bridges
the gap between popular books that leave out the technical details
of the experiments, and standard textbooks with very little
discussion of the meaning of these results for our worldview.
Mermin, N. David,
"Is the moon there when nobody looks? Reality and the quantum
theory," April 1985 Physics Today, p. 38. Great way of understanding
the essence of the EPR paradox and Bell's Theorem.
Feynman, R.P. QED:
The Strange Theory of Light and Matter. 1985. Good for gaining
the intuition for understanding the strange behavior inherent
in quantum mechanics. Simplified, but accurate so that you don't
have to unlearn anything when you add the math.
Science News: 11/20/99,
p. 334 (article on quantum entanglement)
Stapp, Henry. Mind,
Matter, and Quantum Mechanics
Links
to quantum tutorials, provided by the University of Oklahoma
Physics Dept.
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Complexity
Jack Semura's Complexity
& the Universe Course at PSU.
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