.: Knowledge and understanding
The longest journey has to start somewhere and
somewhen. If not here, where? If not now, when?
Hi there. My name is James D. Jones and you are apparently
someone who wants to understand the world around you. Please
excuse me for getting all philosophical on you in this
introduction. It has been my experience that having had this sort
of discussion helps keep me focused when the going gets tough.
The objective, as it turns out, is to drain the swamp. If you at
times feel that I have lead you in amongst the alligators, then
think back to the following few paragraphs.
Understanding is different from
knowledge.
In a preceding paragraph I used the word "understand". Let's
make a distinction between understanding and knowledge. Knowledge
involves facts. I may know that the Earth is closer to the Sun at
some times than it is at others. Understanding involves patterns
among bits of knowledge. I may understand that the conservation
of angular momentum in a central force guarantees that all
orbiting objects cover equal areas of their orbit plane in equal
intervals of time. Knowledge allows me to answer a single
question. Understanding allows me to answer all the questions of
a certain sort.
Unfortunately understanding is not something that can be given
to you. If it were, than everyone would have it. Real
understanding comes from making internal mental connections among
bits of knowledge that we pick up in a lifetime of learning. At
some point a pattern emerges from the connected bits of knowledge
and understanding begins. For most folks this understanding
provides a framework into which new bits of knowledge may be
placed. It helps us make sense of the world and organize our
thinking. For a few talented people, this understanding allows
them to predict new facts that would fit the pattern of the
universe. Then they can go looking for those facts to further
validate their understanding.
There are levels of understanding also. We may accumulate a
number of facts related to physics, for example, and after a
certain amount of playing with them, arrive at some understanding
of the subject. It is like finding a little island of
understanding in the swamp of ignorance. Then later we may study
chemistry, accumulating some facts in that area and discover
another island of understanding which gives structure to the
chemistry knowledge. Likewise with biology, electrical
engineering and so on and so forth. Then if you are very
persistent or talented, you may find that you begin to actually
drain the swamp of ignorance, revealing previously submerged
connections of understanding among the islands. People who have
gone before you may tell you that these connections exist but
until you drain your own personal swamp of ignorance you cannot
really see that it is so.
As you read the words I have written, try to really understand
the topic. This is not easy to do if you are under the pressure
of a short timeframe and looming exams. That is the advantage of
the sort of learning venue we have here. There is no end date for
this course, no exams and no cost. The absence of pressure does
require a certain discipline on the part of the student. You have
to dedicate some of your most valuable resource, your time. I am
available to answer questions by email and I look forward to
interacting with students. I will probably not do your homework
for you but may have some words of advice to get you over a
sticky point. I take great satisfaction in witnessing the "Ah ha!
I get it." moments that a student experiences.
The ideal time to work through this course is during the
summer between high school and college. If you read the text and
play with the displays included in this course, you will enter
your freshman physics course in the fall with a distinct
advantage over most of your classmates. Nothing succeeds like
success and success in freshman physics can set the tone for your
whole college career. Your classmates will be coming to you for
help, which is a good thing. You will find that you really begin
to understand when you have to explain something to someone
else.
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.: The nature of physics
What is physics?
The study of the natural universe, as opposed to the
supernatural I guess, was called in ancient times, natural
philosophy. As the knowledge and understanding of the natural
universe grew, people had to specialize, and parts of natural
philosophy were separated out and given different names. Subjects
like chemistry, astronomy, geology and so on got a life of their
own. Today there is a name for those parts of natural philosophy
that were left over, not captured exclusively in one of the other
named sciences. The Greek word for "natural" in physikos so in
recognition of the ancient Greek origins of the subject, it is
now called physics.
Physics is unique in its central location among the islands of
understanding in the swamp of ignorance. Because all the other
sciences were extracted from it, physics is most visibly
connected to all the other islands of understanding. Also because
physics is the "everything else" subject, it is not very easy to
define. In any event physics is the customary starting point for
serious students of the sciences and engineering, so here we
are.
Physics is not easy.
Introductory physics has gotten a reputation in recent times
as being a difficult subject. I think there are a few reasons for
this and we may as well get to them right up front. First of all
it is not easy. Physics requires a level of abstraction from the
student that may come as a shock to folks making the transition
from high school to college. Secondly, introductory physics is
taught in a language that is not spoken in the home of any of the
students... mathematics. Thirdly, introductory physics being
common to many sciences tends to be taught to large groups at a
rapid pace so as to get it out of the way early in a student's
career. Finally, many schools do little to ease the student's
burden, using introductory physics to wash out students with only
average aptitude for scientific thinking so as to have manageable
numbers of students in the higher level courses. The upshot of
all this is that the average student of introductory physics
feels like he or she is getting a drink from a fire hose. It
tends to be a bit overwhelming.
The order of proceeding
For as long as physics has been taught as a distinct subject,
it has been taught sort of in chronological order of the
discovery of the concepts. This has the advantage that the
concepts were discovered in the order of intuition. Those ideas
that were most intuitive were naturally first to be recognized.
Lately I have been wondering if that is the most efficient
approach. Since from the student's point of view it is all new
anyway, perhaps there would be a benefit in starting with the
most profound principles and working from there. This particular
notion is presently only half-baked in my mind so we will proceed
from Newton onwards as is the custom.
With that in mind, I recommend that beginning students work
with the course that is named, without much imagination,
Physics-1. There are two ways to go. My recommendation is that
you download the free program and install it on your computer.
The Physics-1 program has been tested in Windows XP, Win 7 32 bit and 64 bit and Win 8 32 bit and 64 bit.
The installation program in which it is wrapped will match the installation to
your operating system. The installed size of the program on the hard
drive is about 2 megabytes. Before running the installation file, see the
installation instructions
for detailed suggestions on the steps to follow in installation. Click on the Physics-1 Install link and
click on "Run". Depending on the security system settings
you have, you will probably have to, in spite of perhaps multiple dire warnings, "Allow" the program to
access your computer.
I have made available an online version that lacks some of
the convenience and power of the native version, running Java
applets rather than native code. The contents of the course is
the same in either version.
Unfortunately the Oracle
Corporation, which now manages the Java programming language, in 2014
implemented a security change that prevents applets that have been
running without problems for decades from working. I have decided to
leave the online version available because the text gives you a
good idea of the contents of the downloadable program. You will
not be able to use the dynamic illustrations until Oracle fixes
this issue.
Both versions were last updated several years ago when
M Casco Associates was selling the course.
You may see some reference to the commercial operation in the
text. Someday I may do a re-write to clean that up but since I
retired I have been too busy to get to it yet.
Just click on the online version link above to get
started.
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