OUTLINE OF PHYSICAL SCIENCE

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NOTE TO THE STUDENT: This is an outline of the Physical Science course with links to the reading assignments for the course. For each topic, you should follow the link (click on the blue text). This will take you to a list of what to read for the topic. Frequently, you will find a discussion of the reading to amplify it or to suggest some of the things to watch for as you read.

Some of the reading is from Internet sites (with links). Such sites have a way of changing, so there could be changes in this part as the semester goes on. So, even if you print the list of assignments, you should check this web page from time to time.

The books from which you are supposed to read are all on reserve at the Clinton Community College Library. Ask at the library desk.

I. What Science Is

A. Theory, experiment, observation, and making them agree

B. Science as a process for the curious

C. Science as what the process reveals

D. Models and Laws

E. How can you know what to take seriously? (Think of this as supplemental material. There may not be time for it. If there is time, it will probably be taken up late in the course.)

F. Simple examples of doing science (Is the earth flat?)

G. Some very early science

II. Modeling the Solar System

A. Early ideas of the ancient Greeks

B. Ancient Greek heliocentric models (Does the earth move?)

C. Ancient Greek geocentric models and epicycles

D. What the geocentric models explained

E. What the geocentric models did not explain

F. The work of Copernicus (Maybe the earth does move.)

G. The work of Kepler

H. The work of Galileo (Who probably didn’t really say, “and yet it moves” but wanted to.)

III. How Planets Move (Laws of Motion)

A. Newton’s First Law of Motion, mass, and inertia

B. Why the planets do not move in straight lines (gravitation)

C. Newton’s Second Law of Motion, acceleration, and force

D. Newton’s Third Law of Motion – making the sun move too

E. Predicting the motion of a planet

F. Halley and predicting the motion of a comet

G. When Newton’s Laws do NOT work, a quick glance at relativity

IV. A Quick Trip Around the Universe (Part IV is a supplemental part that may be skipped for lack of time.)

A. How to discover a planet – Uranus, which was almost named “George”

B. Another way to discover a planet – Neptune

C. Finding Pluto and discussing whether it is a planet

D. The rest of the solar system

E. What a star is

F. What a galaxy is

G. Attempting to figure out what the universe is

V. Beginnings of Nuclear and Modern Physics

A. Waves and electromagnetic waves – what to do with them and how to detect them

B. Electric charge and where to find it

C. How to make electromagnetic waves

D. Unique spectra of different atoms and molecules

E. Discovery of x-rays

F. Discovery of radioactivity

G. Discovery and study of the electron and a model of the atom that did not work

H. Rutherford and the nuclear model of the atom

I. Why the nuclear model seemed both necessary and impossible

J. Planck and the quantum idea – why you don’t get a sunburn from the wall

K. The photoelectric effect and what Einstein did with the quantum idea

L. Thinking about whether light is really a wave or a particle

M. How quantum theory resolves the issue of what light is

N. How quantum theory describes electrons, protons, atoms, and spectra

VI. Nuclear Fundamentals

A. Atoms made of protons, neutrons, and electrons, some of which are made of other things.

B. Elements and isotopes – how the nucleus determines what they are

C. Fundamental forces and why the nucleus does not explode in spite of all the positive charge packed into it

VII. Radioactivity

A. Transformations (not explosions) of some nuclei and what they produce.

B. What it means to be random - examples: nuclear transformations and half life

C. Use of radioactive materials for dating, tracing, and for medical reasons

D. How to measure radioactivity

E. What radioactivity might do to you based on how much exposure there is

F. Sources of radioactivity in the environment

VIII. Nuclear Weapons

A. Nuclear fission, Uranium, Plutonium, and the chain reaction

B. How to exploit the fission chain reaction to make a bomb (but not even close to enough detail to actually make one!)

C. Nuclear fusion and how to use it for an explosion (but - again - not enough detail to actually do it)

D. Conservation and conversion of energy and how to use energy to describe what a nuclear explosion will do

E. Nuclear explosions: flash heat, shock waves, and radioactive fallout

F. A quick trip around the world: how many bombs and where are they?

IX. Nuclear Reactors

A. How to control a fission chain reaction

B. How to extract heat from a reactor

C. Are they safe?

D. Why a reactor makes Plutonium and whether it matters

E. Why is there radioactive waste and whether there is any place to put it

F. Whether there might be fusion reactors sometime

G. A fusion “reactor” – why the sun shines

X. Fundamentals of Chemistry

A. Atoms and elements – molecules, crystals, and compounds – what you can see and feel determined by microscopic structure

B. A few examples of which atoms can combine into compounds and in what proportions

C. What a chemical reaction is and a few examples

D. Chemical equations representing chemical reactions

E. Acids, bases, and salts

F. Carbon and organic compounds based on carbon

G. Hydrocarbon chains, alcohols, and a few other examples of organic chemicals

XI. Energy for Human Use

A. Chemical structure of natural gas, gasoline, and a few other hydrocarbon fuels

B. The origin, discovery, extraction, and refining of hydrocarbon fuels

C. Common chemical reactions involved in burning hydrocarbon fuels

XII. Physical Environment

A. Carbon dioxide as a product of fuel burning and global warming

B. Particulate emissions

C. Hydrocarbons that are not completely burned

D. Oxides on nitrogen and sulfur – acid rain

E. SMOG

F. Ozone problems

XIII. Structure of the Earth

A. A journey all the way to the center of the earth – how you can know what is there

B. Plate tectonics – how anyone could ever detect slowly moving continents

C. A consequence of drifting tectonic plates – volcanoes

D. Another consequence of plate tectonics –earthquakes

XIV. Geological History

A. Some types of rock and a few examples

B. What fossils are and where they are found

C. How to measure the age of a fossil or a rock that might be a hundred billion times older than you are

D. An abbreviated chart of the history of the earth (not human history – the earth’s history!)

E. Extinctions – some life forms disappear from the fossil record.

F. Evolution – many new life forms (related to older ones) appear at different times in the fossil record

G. A few examples of what appeared and what disappeared including dinosaurs and hominids

READING ASSIGNMENTS AND SOME DISCUSSION:

Science in General

Nobody can introduce science like Carl Sagan (1934-1996). He was a professional astronomer who worked on planetary science, was involved in many of the planetary space probes, did the commentary for the Cosmos series on TV, and wrote the novel Contact, which was made into a movie with Jodie Foster. If you wish, you can read about more of his work here. The assigned readings below are from his book The Demon Haunted World.

He wrote his description of science in order to contrast real science with pseudoscience (bending forks with mental power, contacting ghosts, etc.), which is the main subject of the book. This is not the usual style of writing that you find in textbooks, and Sagan is not afraid to trumpet his opinions on politics, religion, and whatever else he can find that might be controversial. There is a minimum of this in the pages assigned, however, and you naturally do not have to agree with him on politics and religion. They will not be on the test. The purpose of reading the assigned pages is to study his descriptions of the scientific process and of the uses of science.

So read the following from Sagan’s The Demon Haunted World: pp. 3 – 12 (through the short dash on page 12); pp. 25-30 (to the dash); pp. 37 – 39; and pp. 321 – 329. These last pages give some of his views on science education. You might find them fun.

The Process of Science

There is a glossary of many of the terms used in this course reached through links located at various places around this web site. For example here is such a link. To explore the terms listed in the outline about the scientific process (experiment, model, theory, etc.) look for these terms in the online glossary and read about them.

When you follow the link to the glossary, you will find a long list of terms listed alphabetically. Find the term you are looking for and click on it. You will be taken to a discussion of it. There will be links to other related terms in the discussion that you should also follow.

To return, you can use the Back button, but you might have to use it many times. You can also return by following one of the links at the top of the file.

Baloney Detecting (Supplemental Material. This may be taken up late in the semester, if there is time.)

Sagan has some advice on this subject. The following pages contain some of it.

In Sagan’s The Demon Haunted World, read pp. 210 – 216.

Very Early Science

Sagan has a chapter containing various ideas about where science came from and how old it is. It might be a very recent development in human history, dating back only about 2500 years to the ancient Greeks. Although it might seem strange to consider 2500 years as recent and describe it a “only”, our species, Homo Sapiens, dates back to more than 100,000 years. Furthermore, some Hominids, similar to us but not quite us, go back several million years. Sagan also suggests that something like science might be far older than 2500 years.

In Sagan’s The Demon Haunted World, read Chapter 18 on this subject.

The pages assigned below suggest that people did at least some form of science at a very early stage of human history – much earlier than the “ancient” Greeks. For one thing, although it is not in the readings below, people who lived before about 12,000 years ago needed for their basic existence a much better knowledge of biology than I have. This also includes many people who lived later. They lived off of the land, hunting when possible, gathering whatever grew in the neighborhood at other times, and probably scavenging as well. They might have made use of 80 or 90 different plants and animals depending on what was “in season”. So they needed a very detailed knowledge of the growth cycle and habits of whatever was going to be lunch at any given time as well as knowledge of what might poison them rather than nourish them. That is biology.

These pages discuss a little bit of the discovery of various metals. Do not try to read this for a detailed knowledge of how to mine and refine metals. Mainly, think about the process of forming (or guessing) ideas and then testing these ideas that must have gone into the discoveries that are mentioned.

In the book by Henry Hodges, Technology in the Ancient World, read the following:

pp. 17 (middle of page) through 20 (setting the stage a bit)

page 29 (chemical change not yet discovered through about 5000 BC)

pp. 53 – 57 (copper)

pp. 61 (third paragraph) through page 62 (second paragraph) (gold and silver)

pp. 91 (last paragraph) through p. 95 (first paragraph) (bronze, tin, and solder)

pp. 142 through 146 (first paragraph) (bronze and iron)

Early Ideas of the Ancient Greeks

By “Ancient” in “Ancient Greeks” we mean roughly 600BC to 200AD. As mentioned above, this is not so ancient compared with the total history of humans, but it is the earliest time of intense scientific activity for which a good written record exists. Of course some if it may have been duplicated at some other time and place for which no record exists and therefore we don’t know about it.

The reading for this and the following few sections is from a book by Isaac Asimov (1920-1992), who became famous for popular factual scientific books as well as for science fiction. During his life, he wrote over 500 books, and it has been reported that he is the only person to ever write a book in each of the Dewey Decimal System classifications. Asimov’s Biographical Encyclopedia of Science & Technology, the book we are using here, is a collection of 1510 very short biographies of scientists and engineers in the 1982 hardcover edition. You might have to read from the 1976 paperback edition in which there are 1195 entries. The few entries used in this course are essentially the same in the two editions, so it does not really matter which one you use.

In each edition there is a page called HOW TO USE THIS BOOK a few pages from the front cover. You should read this page first to find out how the biographies are organized. To save some typing, the book will be called Asimov’s Encyclopedia; the hardcover edition will be referred to as HC; and the paperback edition will be called PB.

When you read the biographies, you do not need to worry about the personal details too much. Just be able to place each individual in the right century, and otherwise pay attention to the scientific content of each biography.

The purpose of this section is to show a scientific model being gradually constructed by means of a messy process that is still pretty much in use. The subject in this case is the structure of the solar system and the way in which the planets move. It took a long time to make enough sense of the observations of the planets to even speculate about what they were. Gradually a few people started to see some order in all of the chaotic motions that were being observed and tried to imagine a picture of just what kind of system it was.

To say that the first ideas were crude is being too nice to them. Almost as quickly as someone proposed an idea about the solar system, someone else shot it down by noticing that it did not really reproduce the correct motions of the planets. Then some refinement to the model was proposed, and someone else shot it down. Sooner or later someone else proposed some radically different model, which worked better than the others. But even the new one did not quite reproduce the correct motions, so someone else tried to improve that. Eventually, a “standard model” evolved that seemed to satisfy everyone for a long time.

This “standard model” was the Ptolemy model of the solar system, which lasted for about 1400 years although still with some tinkering along the way. But it was wrong too, and it was shot down at the time of Copernicus, Kepler, and Galileo, as will be shown a few sections below. Now we have what we think is the right answer, and we are so sure of it that we don’t even call it a model any more. Nevertheless the model of Ptolemy, which assumed that the sun, moon, and the other planets revolve around the earth (called a “geocentric” model), was not a bad piece of work for its day. It is true, however, that people held onto it much longer than they should have.

As all of this model building was going on, one or two people happened to guess at essentially the correct answer. But they did not know enough about the subject to be able to argue effectively for their ideas. So they were ignored. Thus even at the time of the ancient Greeks, there was at least one astronomer, Aristarchus, who proposed that the earth moves around the sun. He even argued that the other planets do the same thing. (This is called a “heliocentric” model.) His book on the subject was lost. The only way we know about this is through Archimedes, who wrote about Aristarchus in order to say how silly his ideas were.

Scientists still follow a similar process. For example they now study subatomic particles, the ones that are smaller not only than the atom but even smaller than the nucleus. They have built what they actually call the Standard Model of these particles. Occasionally someone comes along and does a piece of violence to this model and it has to be revised. Scientists seem more confident of it now than they were even 40 years ago, but they know that they have a long way to go before it can be generally accepted as reliable. Even then it might turn out eventually to be wrong!

The following sections make no attempt to give a complete picture of ancient Greek science or philosophy. Just read them to see an example of typical scientific processes.

In Asimov’s Encyclopedia, read the sections on

Thales (Entry 3, pg.2 in HC – Entry 3, pg. 2 in PB)

Anaximander (Entry 4, pg. 3 in HC – Entry 4, pg. 3 in PB)

Pythagoras (Entry 7, pg. 4 in HC – Entry 5, pg. 4 in PB)

Anaxagoras (Entry 14, pg. 8 in HC – Entry 14, pg. 8 in PB)

Plato (Entry 24, pg. 14 in HC – Entry 23, pg. 14 in PB)

Ancient Greek heliocentric models

In Asimov’s Encyclopedia, read the sections on

Philolaus (Entry 19, pg. 11 in HC – Entry 18, pg. 11 in PB)

Heracleides (Entry 28, pg. 18 in HC – Entry 25, pg. 17 in PB)

Aristarchus (Entry 41, pg. 26 in HC – Entry 36, pg. 24 in PB)

Ancient Greek geocentric models and epicycles

In Asimov’s Encyclopedia, read the sections on

Eudoxus (Entry 27, pg. 17 in HC – Entry 24, pg. 16 in PB)

Callippus (Entry 32, pg. 22 in HC – Entry 28, pg. 21 in PB)

Eratosthenes (Entry 48, pg. 32 in HC – Entry 42, pg. 29 in PB)

Hipparchus (Entry , pg. In HC – Entry 45, pg. 31 in PB)

Ptolemy (Entry 64, pg. 42 in HC – Entry 59, pg. 40 in PB)

When you finish these, read the discussion at this link on how well the Ptolemy model worked and why it had to be replaced.

Also look at this slide show about how to explain the phases of the moon in both the geocentric models and the heliocentric models.

The work of Copernicus

In Asimov’s Encyclopedia, read the section on

Copernicus (Entry 127, pg. 74 in HC – Entry 114, pg. 68 in PB)

When you finish this, read the discussion at this link on some successes, some failures, and some presumed failures of the Copernicus model.

The work of Kepler

Kepler finally found the answer to the way planets move around the sun. Working with data taken by Tycho, he found that the planets follow ellipses around the sun, and he also found out how fast they move around these ellipses. This information is contained in three laws that he announced based on his work. Since these laws involve the curve called an ellipse, start by reading this passage about ellipses. Then ---

In Asimov’s Encyclopedia, read the sections on

Tycho Brahe (Entry 156, pg. 91 in HC – Entry 137, pg. 83 in PB)

Johannes Kepler (Entry 169, pg. 105 in HC – Entry 149, pg. 96 in PB)

Also use the following links to explore Kepler’s Laws on the Internet:

Read about Kepler’s Laws and try the animations that illustrate the way planets follow these laws here, also here, and also here.

Galileo

1. The section on Galileo in Asimov’s Encyclopedia (Entry 166, pg. 100 in HC – Entry 146, pg. 91 in PB)
2. A few excerps from The Sidereal Messenger written by Galileo, in which he announced some of his telescopic discoveries. Read pp. 36 (bottom) through 38 (first few sentences) on the telescope itself. When he says that he sees objects 9 times larger, he is talking about the area of the image. That would correspond to the sides being 3 times larger for a magnification of just 3. Similarly, when he mentions objects being 1000 times larger, this means a magnification of about 32.

	Here is the object magnified 3 times (with the sides 3 times longer). The area is 9 times that of the original object.

3. Also in The Sidereal Messenger, read pp.58 (bottom) to 63 on some of his observations of stars, and pp. 64-67 and 83-86 (on the moons of Jupiter -- He calls them the Medicean Stars after the family that financed his work. We now call them the Galilean Satellites).
4. An excerpt from the Dialogue Concerning the Two Chief World Systems, which is the book that got him into trouble (by “World” he meant “Solar System” as we would say it). Read pp. 462-465. Notice that, when Galileo criticizes Kepler, Galileo is wrong. Kepler, who thought the moon causes tides, was much closer to the truth even though none of them really understood it at the time. In this excerpt, Salviati is a character that puts forward Galileo’s own conclusions; Simplicio argues the traditional earth-centered view as endorsed by the Church; and Sagredo represents something of a one-man jury that needs to be persuaded. Simplicio comes off as sort of stupid throughout the book, but in these final few pages, he is given some dignity, and Salviati softens his position a little. Galileo was probably trying to stay out of trouble by writing it this way. However, see the note about page 464 (which is on page 491). See also the note about page 103 (which is on page 474).

Isaac Newton

Go to the following link for an explanation of Newton’s First Law.

ALSO--

In Asimov’s Encyclopedia, read the sections on

Isaac Newton (Entry 231, pg, 148 in HC – Entry 201, pg. 134 in PB)

Edmund Halley (Entry 238, pg. 159 in HC – Entry 207, pg. 145 in PB) 

Newton’s Law of Universal Gravitation

Go to the following link for an explanation of Newton’s Law of Universal Gravitation.

Newton’s Second Law of Motion

Go to the following link for an explanation of Newton’s Second Law of Motion.

Go to the following Link to see how astronauts in orbit follow Newton’s Laws.

Newton’s Third law of Motion

Go to the following link for an explanation of Newton’s Third Law and some applications to the solar system.

Using Newton’s Laws to predict the motion of a comet

Read, in Asimov’s Encyclopedia, the section on

Edmund Halley (Entry 238, pg. 159 in HC – Entry 207, pg. 145 in PB)

An Extension to Newton’s Laws (Relativity)

Read the following section in Asimov’s Encyclopedia on Einstein, and concentrate on what it says about relativity, not on the photoelectric effect and Einstein’s other work:

Albert Einstein (Entry 1064, pg. 673 in HC – Entry 871, pg. 588 in PB)

How to discover Uranus (Supplemental Material)

In Asimov’s Encyclopedia, read the section on

William Herschel (Entry 321, pg. 212 in HC – Entry 272, pg. 190 in PB)

Also look at the following web sites for some information about this topic:

Here is some general information about Uranus including how to pronounce it without embarrassment. You do not need to memorize all the numbers it gives – just read for general information.

Read this one for some information on how Uranus was discovered.

Finally, read this for a little information on how it got its name.

Discovering Neptune (Supplemental Material)

In Asimov’s Encyclopedia, read the sections on

John Adams (Entry 615, pg. 400 in HC – Entry 507, pg. 352 in PB)

Urbain Leverrier (Entry 564, pg. 373 in HC – Entry 469, pg. 330 in PB)

Follow this link for general information about Neptune. You do not need to memorize the numbers in this site.

Then read this web page for the discussion of the discovery of Neptune and the controversy it generated.

There was a villain in the controversy, so read this one for a defense of the villain.

Finding Pluto (Supplemental Material)

In Asimov’s Encyclopedia, read the section on

Percival Lowell (Entry 860, pg. 556 in HC – Entry 706, pg. 487 in PB)

Use the following Internet sites to read about Pluto

Here is a general description of Pluto. Read it for general information. There are some scientific concepts here that are beyond what we will discuss in class. Don’t worry about them. Here is another one. In this second one, notice especially the links about whether Pluto is a planet or something else.

Here is a brief commentary on the discovery of Pluto.

Finally, just skim this commentary on the discovery by the discoverer himself. We won’t worry about most of the details in it. Until recently there was only one discoverer of a major planet living. Now there are none. We might as well take advantage of the fact that, unlike most eras, we can listen directly to one of them.

The Solar System, Stars, Galaxies, and the Universe (Supplemental Material)

Go to the file on definitions of terms and concepts, and look up these terms as well as related terms such as “Big Bang”, “Planet” and others that these terms link to.

Electromagnetic Waves

Read the article at the following link for an overview of 20^th century physics and electromagnetic waves.

For the experimental detection of electromagnetic waves, read in Asimov’s Encyclopedia, the section on

Heinrich Hertz (Entry 873, pg. 564 in HC – Entry 718, pg. 494 in PB)

Describing Electromagnetic Waves and Electric Charge

Read the article at the following link. It tells something about what electromagnetic waves are, how they are related to electric forces and charges, how they are generated, and how they carry energy. Click here for this article.

Each Chemical Element has a unique spectrum.

This title means that each chemical element emits a unique group of wavelengths of light, provided it is heated up enough to emit light. Since each element has a unique type of atom, this means that each type of atom emits a unique set of wavelengths. With a device called a spectroscope, the light emitted by an element can be taken apart so that each wavelength is displayed separately from all the others. A diagram of what a spectroscope displays might look something like this:

In this diagram, each line represents a particular wavelength of light. The human eye, of course, sees different wavelengths, as different colors. What you see with your eye when looking at the heated, glowing element is combination of all the wavelengths. The element can be identified by the pattern of lines in the spectroscope. Each pattern displayed by the spectroscope corresponds to an element the way that a fingerprint corresponds to a particular individual. The pattern in this picture was, however, just made up as an example. You should go to the following website for a demonstration of the spectra of the different elements. It contains a diagram of chemical elements that chemists call the “periodic table of the elements”. You should choose “emission spectra” at this website and then click some element. The spectrum of that element will be displayed at the top of the screen.

By the way, an emission spectrum is one of three main classifications of spectra. It is the only type that we need to be concerned with right now, although we will have to discuss another kind a little later. Also, by the way, molecules also have spectra of their own, but we will just discuss atoms right now.

Some early discoveries in modern physics

For the discovery of x-rays, read, in Asimov’s Encyclopedia, the section on

Wilhelm Roentgen (Entry 774, pg. 502 in HC – Entry 639, pg. 441 in PB)

For the discovery of natural radioactivity, and some early work on this subject, read in Asimov’s Encyclopedia, the sections on

Henri Becquerel (Entry 834, pg. 539 in HC – Entry 689, pg. 473 in PB)

Pierre Curie (Entry 897, pg. 580 in HC – Entry 738, pg. 509 in PB)

Marie Curie (Entry 965, pg. 615 in HC – Entry 786, pg. 536 in PB)

[By the way, Marie Curie and her daughter Irene both won the Nobel Prize for different – though related - work in different years.]

For the discovery of the electron and the “Plum Pudding” model of the atom, read, in Asimov’s Encyclopedia:

Joseph John (JJ) Thomson (Entry 869, pg. 561 in HC – Entry 714, pg. 492 in PB)

A famous physicist from eastern Iowa and northwestern Illinois made the first accurate measurement of the charge on the electron. Robert Millikan was born in Morrison, Illinois in 1868 and graduated from high school in Maquoketa, Iowa in 1885. That makes him the Nobel Prizewinner from our own backyard. He won that in 1923 for his work on the electron and on the photoelectric effect. That makes him an exception to the general rule in this course about no biographical details. So read the account in Asimov’s Encyclopedia about Millikan and pay attention to the biographical parts as well as the scientific parts:

Robert Millikan (Entry 969, pg. 619 in HC – Entry 790, pg. 540 in PB)

Also read the brief account of Millikan and his work in

Great Experiments in Physics, Edited by Morris Shamos, pages 238-242.

This consists of a brief biography followed by his main paper on the charge on the electron. A “paper” is what scientists write to tell the world about all of their latest research results. Since this is a science class, you might as well take a brief look at one. However, the pages listed above only include the first little bit of the research paper thus avoiding the mathematical parts of the paper and most of the highly technical parts. It does get a little technical toward the last couple of pages, but don’t let that get to you! It is not too bad. It would be very complicated if you read the whole paper. After all, the journal this was published in, the Physical Review, is in the business of publishing new research results in all of their technical glory. Someone has to!!

Rutherford shot alpha particles at gold atoms and watched how they bounced off. From this he evolved a much better model of the atom: it has a nucleus that contains most of its mass, and this nucleus is a very small particle in the center of the atom. The rest of the atom is mostly empty space although the space surrounding the nucleus does contain electrons. Rutherford’s model caused a major headache for physicists at the time, because there did not seem to be anything reasonable to do with those electrons. For an account of the nuclear model and of these difficulties, read the following:

In Asimov’s Encyclopedia, read about

Ernest Rutherford (Entry 996, pg. 635 in HC – Entry 814, pg. 555 in PB)

Here is a quick summary of why there was nothing reasonable to do with the electrons. In the first place they had to be outside the nucleus, and most of the atom had to be empty space. That is because of the way Rutherford’s experiment showed that most alpha particles simply went right through the gold atoms without hitting anything. The nucleus had to have most of the mass of the atom and a positive charge because of the way it could deflect those very few alpha particles that came close to it. If it were very light, then an alpha particle hitting it would be like bowling ball hitting a marble. Nothing much would happen to the bowling ball. The electrons did have to be very light, because nothing much happened to an alpha particle that went through the space where the electrons were. Actually the mass of the electron had already been determined to be very small, and it was already known to be negative.

If an electron were outside the nucleus, and if it were at rest, then it would be attracted to the nucleus and crash into it in a small fraction of a second. This is because of the attraction of the positive nucleus for the negative electron. At such small distances, this force is large enough to give the small, light, little electron an enormous acceleration toward the nucleus. So it could not be as rest. All of the atoms in the universe would have collapsed billions of years ago.

It was, of course, suggested that the electrons could be moving in an orbit around the nucleus like a planet around the sun. This picture of an atom is still a popular one, but it cannot be true. You may remember that anything moving in a circle (or an ellipse or any other curve) is accelerated. The electron, it turns out, would need to move at around a million meters per second around the very small, atom-sized orbit. This would give it an enormous acceleration. But it also has an electric charge. In the article on electromagnetic wave and electric charge, it was pointed out that an accelerated, electrically charged particle emits electromagnetic waves. Such a particle with such a large acceleration would radiate away all of its energy in the form of electromagnetic waves very quickly. This means, of course, that it would lose its energy and crash into the nucleus. So all of the atoms in the universe would have collapsed billions of years ago in this case too.

So the electron in an atom was either at rest or moving. If it was moving then it was accelerating. Both situations would be unstable. So there was nothing to do with the electron. Continue on down the outline for the solution of this problem.

Quantum Theory

For some of the original work on quantum theory including ideas about light and whether it is more like a wave or more like a particle, read, in Asimov’s Encyclopedia, the sections on

Max Planck (Entry 887, pg. 571 in HC – Entry 729, pg. 501 in PB)

Albert Einstein (Entry 1064, pg. 673 in HC – Entry 871, pg. 588 in PB)

(This time concentrate on what the Einstein section says about the photoelectric effect and the quantum idea rather than on relativity)

The following articles in Asimov’s Encyclopedia contain much of the basic information about the early days of quantum theory. The choice of these three people is sort of arbitrary, because so many people contributed to quantum theory. But there are too many to list, and the articles on these three contain quite a bit of the relevant information. So, in Asimov’s Encyclopedia, read about:

Niels Bohr (Entry 1101, pg. 700 in HC – Entry 902, pg. 612 in PB)

George Thomson (Entry 1156, pg. 733 in HC – Entry 949, pg. 641 in PB)

Louis De Broglie (Entry 1157, pg. 733 in HC – Entry 950, pg. 642 in PB)

[By the way, George Thomson was the son of J.J. Thomson, and both father and son were Nobel Prizewinners. The father won for discovering that there was a particle called the electron. The son won for showing experimentally that this same particle often acted like a wave.]

There is some information about fundamentals of the structure of the nucleus and the fundamentals of nuclear reactions in the article at this link. Please follow the link and read the article.

Read the account of early ideas about fission and the chain reaction in the article in Asimov’s Encyclopedia on

Leo Szilard (Entry 1208, pg. 761 in HC – Entry 992, pg. 666 in PB)

Fission and Fusion in reactors

In Payne Et. Al. read the following:

Fission Reactors pp. 545 – 551

Fusion reactors pp. 554 – 556

Model of a Star

In Payne Et. Al. read the following:

Origin of a Star pp. 368 – 369

The Sun pp. 371 – 373

Nuclear Reactions pp. 402 - 407

CHEMISTRY

The readings in chemistry are in the book Physical Science, Principles and Applications, by Charles Payne, William falls, and Charles Whidden. This book is on reserve in the Clinton Community College Library, and it will be called Payne Et. Al.

Atoms and Elements

In Payne Et. Al., read the following:

On basics of atoms pp. 266 through 270

On the Periodic table pp. 271 through 274

Chemical bonds and Compounds

In Payne Et. Al., read the following

Ions and the Octet rule pp. 275 through 278

Molecules and Chemical Equations pp. 278 through 281

Covalent Bonds pp. 281 through 283

Chemical change and Chemical Reactions

In Payne Et. Al. read the following:

Physical and Chemical Change pp. 288 through 290

Combustion, Oxidation, etc. pp. 290 through 294

Water and Ions pp. 296 through 298

Acids, Bases, and Neutralization

In Payne Et. Al. read the following:

Acids and bases pp. 298 through 299

Salts and Neutralization Reactions pp. 299 through 300

The pH scale pp. 300 through 301

Carbon and Organic Compounds

In Payne Et. Al. read the following:

Carbon and Hydrocarbons pp. 306 through 310

Hydrocarbons with double & triple bonds pp. 310 through 311

Rings of carbon atoms pp. 311 through 312

Other Organic Compounds

In Payne Et. Al. read the following:

Alcohols pp. 312 through 313

Organic Acids pp. 314 through 315

Carbohydrates pp. 317 through 318

Amino Acids and Proteins pp. 318 through 319

DNA and the genetic code pp. 319 through 320

Energy Sources

In Payne Et. Al. read the following:

Fossil Fuels pp. 542 – 545

Solar Energy and Geothermal pp. 551 – 553

Fuel Cells and other pp. 556 – 559

Pollution, Ozone and Global Warming

In Payne Et. Al. read the following:

Pollution Concerns pp. 564 – 576

Greenhouse Effect p. 379

The Atmosphere, Ozone, and Greenhouse pp. 464 – 468

Photosynthesis and Ozone p. 488

GEOLOGY

Overall Structure of the Earth

In Payne Et. Al. , read pp. 435 – 438.

Plate Tectonics (Continental Drift)

In Payne Et. Al., read pp. 439 – 445.

Volcanos

In Payne Et. Al. read pp. 507 – 510.

Earthquakes

In Payne, Et. Al. read pp. 510 – 513.

Rocks

In Payne Et. Al. read pp. 516 – 521.

Telling Time with Rocks

In Payne Et. Al. read pp. 489 – 490

Chart of Geological History

In Payne Et. Al. see the chart on page 491.

Outline of Geological History

In Payne Et. Al. read pp. 490 – 499.