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Introduction |
Because this is a web-based course, navigating through the course is basically the
same as normal navigation through the internet. I suspect you are already
familiar with such navigation or you would not be reading this sentence.
However, you may obtain further instruction on internet navigation by clicking
the navigation button on this page.
Once you are
familiar with the navigation procedure, you should familiarize yourself with
the structure of this course. You should
understand that the course is structured like a tree with the more basic
concepts located on the lower branches and the more advanced topics on the
higher branches.
By remaining
on the lower branches, curious students can explore the fundamental principles
without worrying about the mathematics, and serious students can build a firm
conceptual foundation before proceeding further up the tree. By climbing higher
and higher into the tree, students can obtain an ever-increasing level of
comprehension of the subject.
In
principle, this tree of knowledge could extend without limit to higher and
higher levels of understanding. So, to limit the amount of material in the
course, the upper branches of the tree have been trimmed. Hopefully the amount
of trimming is appropriate for a three-semester hour college physics course
plus some optional material to allow for course flexibility and student
curiosity.
Physics is the study of the most basic laws of nature - the fundamental principles
governing the universe in which we live. Classical physics, one of the prerequisites to this course, is
the physics discovered prior to 1900. It deals with the familiar macroscopic
world we encounter every day. Modern physics, the physics discovered after
1900, deals with the unfamiliar world of extremes. More specifically, it
explores the world of extremely fast objects, extremely strong gravity, and
extremely small particles.
Even classical
physics requires students to cast aside many of their pre-conceived notions of
how the world operates in order to grasp the true nature of the universe. For
example, most people grow up believing that a force is required to keep an
object moving in a straight line at constant speed. But classical physics takes
the exact opposite viewpoint. It asserts that a force is required to prevent an
object from moving in a straight line at constant speed. As a result, classical
physics often challenges the common sense notions of many students. Perhaps
this is one reason so many students find classical physics such a difficult
subject to master.
What is true
for classical physics is even truer for modern physics. If classical physics
defies our common sense, modern physics pushes our imagination to the limit. It
demonstrates that the world around us is considerably stranger than it first
appears. As we look below the surface of classical physics we find an
absolutely amazing sub-structure to the universe that often requires us to
adopt a completely new and different view of reality.
For example,
contrary to the common misconception that we live in a time-varying
three-dimensional universe, special relativity shows that we actually exist in
a four-dimensional reality. Contrary to the obvious appearance that space is
flat, general relativity asserts that it is really curved. Contrary to our
intuitive notion that particles and waves are fundamentally different, quantum
mechanics shows that they are really two aspects of the same thing. And
contrary to the logical conclusion that any two objects can, at least in
principle, be distinguished from one another, statistical quantum physics
demonstrates that certain fundamental particles in nature are absolutely
indistinguishable -- so much so that even God cannot tell them apart.
Obviously, a
modern physics course can be quite challenging. But this course can do little
more than simply introduce the student to the topics of special relativity,
general relativity, quantum mechanics, and statistical quantum physics and show
how each is related to classical physics through the Correspondence Principle. In order to
really appreciate the physics of the 20’th century, a student would need
to follow Modern Physics 1 with a second modern physics course that introduces
such topics as molecular structure, solid state physics, superconductivity,
nuclear physics, particle physics, and cosmology. And to thoroughly understand
all aspects of modern physics, the student should take one or more follow-up
courses in each of these topics. Of course, by then the student would most
likely find himself to be a full-time graduate student majoring in physics.
Fortunately,
one does not have to understand thoroughly all aspects of modern physics in
order to gain an appreciation of its fundamentals. Hopefully this course will
help provide that appreciation with at least a reasonable amount of
understanding.
Q1. Classical
physics includes which of the following: (A) The physics of the macroscopic
world of everyday life. (B) The physics of fast moving objects. (C) The physics
of strong gravity. (D) The physics of extremely small objects. (E) The physics
of a large number of identical particles.
Q2. Which of the
following deals with objects moving at extremely high speeds – speeds
comparable to the speed of light? (A) Newtonian Physics, (B) Special
Relativity, (C) General Relativity, (D) Quantum Mechanics, (E) Statistical
Physics.
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