Background Topics for Introductory Astronomy Classes

Instructions: 

1.  Read over the following material.  Don't just go to the sample quiz questions first. I am assuming that you already know this material or have at least seen it in middle- or high-school.  Make note of the items that you don't know, or that you think you need to review.  Some of this will seem very easy to you , but you may find some material that you do not know yet, or maybe you had a misconception about it, or maybe you could just use a refresher review.

The purpose of this is to fill in any gaps in your knowledge.  Don't panic if you have a lot of gaps, just make sure that you learn this material during the first week or so of class.

2.  Review the items that you need to.  All of the concepts listed below are common knowledge and you can learn more about them or review them in many different ways.  You can surf the web and find this information on your own, you can look it up in dictionaries and encyclopedias or other books in the library or at home, you can review the material with the free astronomy tutor in the library, or see me during office hours to ask questions about it. 

3.  After you are confident that you know the introductory material listed below, then click on the list of sample quiz questions and try to answer them.  You can show your answers to me or to the tutor to see how you would do on a real quiz.  Note that some of these questions, or ones very similar will appear on the first quiz just to make sure that everyone knows this material and is starting from the same place. 

Background Material That You Need to Know

1.  Powers of Ten

Most people know that the number "one thousand" is represented as 1,000; and that it can also be represented as 10³ , or the term "kilo" as in kilogram or kilometer.  The term "kilo" also can be represented using a prefix symbol of "k" or "K", as in kg or km (or Kg or Km).   The powers of ten that we will use the most are summarized below:

You should already be familiar with the concept of these terms and numbers, and you may know some of them.  If you are not familiar with this - now is the time for you to go learn it!  Make sure you know all of the information in the table for the quiz.  Notice the funny symbol for the "micro" prefix.  That is the Greek letter "mu" (their letter "m").  

2.  Multiplying and Dividing Powers of Ten

You know that ten times one hundred is one thousand (10 x 100 = 1000).  In powers of ten, that looks like 10¹ x 10² = 10³ .  So what is the rule?  I'm sure that you can see by just looking at the equation that when powers of ten are MULTIPLIED, the exponents (the numbers on the top), are ADDED.  Notice that the exponents are 1 + 2 = 3.  Here are two more examples:  10⁴ x 10⁵ = 10⁹ ;    and   10^-3 x 10⁷  = 10⁴ . 

Now for division.  You already know that one thousand divided by ten is one hundred (10³ / 10¹ = 10² ).  So what is the rule this time?  Clearly, when powers of ten are DIVIDED, the exponents are SUBTRACTED.  Here are two more examples: 10⁷  / 10³ = 10⁴ ;  and 10⁶  / 10^-3 = 10⁹ .

If I give you powers of ten to multiply or divide on the quiz, you should be able to provide the answer.  Note the negative exponents that I used in the last example for multiplication and division.

3.  Metric System

Meters, liters, grams, and watts.  You should know what these are.  You should know how big a meter, a centimeter, and a millimeter are.  You should know that a watt is a measure of power.

You should be able to read a metric ruler.

Can you convert 100 Km/hour to meters/second? 

4.  Basic Math

A.  Circles and Spheres.  Know the definition of: radius (distance from center to edge), diameter (distance across), and circumference (distance around) of a sphere or circle.

Note that an American football (or rugby ball) is round, but it is NOT spherical. A golf ball and a basketball are both round and spherical.  The Earth is nearly spherical.

B.  Other shapes.  Do you know approximately what an ellipse looks like?  How about a parabola or a hyperbola?  You should know what these shapes look like (you don't need to know the mathematical formulae for them).  They are easy to look up, and are even in your astronomy text.

C.  Algebra.  You should have had an algebra class at some point in your life.  You may not be good at it, and we won't use algebra very much in the class, but you should have at least taken an algebra class at some point.  Just ask me about this if you are worried.  

5.  English

A.  Making an outline for a paper.  You should have done this before.  If not, see me, the tutor, or  your English instructor. You won't need to make an outline unless you want to write an extra credit paper.

B.  Referencing your work.  If you use other people's work in a paper REFERENCE it!  The importance of this cannot be over stated.  You should know how to reference quotes or other work using footnotes or some other suitable technique.  Using other's words as your own can get you an "F" grade real fast.

6.  Atoms and Molecules

A.  Periodic Table of the Elements.  There is an example of this in one of the appendices in your astronomy textbook.  You don't need to know all of the elements.  You should have seen this table before, and you should know the five most abundant elements in the universe. They are summarized in the table below:

If you don't know the contents of this table yet, it is easy to memorize it now.  Note that the atomic number is the same as the number of protons in the nucleus.

B.  Definitions.  You should know what the following terms refer to:  atom, nucleus, proton, neutron, electron, molecule.  These should be pretty easy for you if you don't know them already.  A little harder are the following terms: element, ion, and isotope.  You need to know what those terms mean also.  If you have questions, you can bet that half of the class does also.  Ask!

C.  Atomic Structure Concepts.  Can you draw what an atom looks like?  You should know the following facts about atoms:

1. Almost all of the mass of an atom is contained in the protons and neutrons in the nucleus.  

2.  The nucleus is very tiny compared to the space that the electrons take up.

3.  Atoms are NOT  like baby solar systems. The electrons don't orbit the nucleus like planets orbit the Sun.  Electrons are so small and light that they have a lot of wave properties.  This causes them to appear in cloudlike "shells" around the nucleus.  If you draw an atom, you should represent the nucleus as very small in the center, and the electrons as a smeared-out cloud around the nucleus.

4.  And now for the hard one.  If  I write a symbol for an atom that you know, like ¹⁵N, you should know that Nitrogen is element number 7 (see the table, above), which means that it has seven protons in the nucleus.  The number 15 that appears next to the symbol is the Atomic Weight.  That number is the combined number of protons and neutrons.  We already know that it has 7 protons, since it is nitrogen.  That means there must be 8 neutrons since 7 + 8 = 15.  Get it?  Can you draw a picture of it?  Here are two more examples:  ¹²C has 6 protons and 6 neutrons.  ³He has 2 protons and 1 neutron.   Please review this.  I will go over it in class, but I will go over it quickly. 

D.  Molecules are atoms that are bonded together.  Water, H₂O consists of two hydrogen atoms bonded to an oxygen atom.

E.  Nuclear Fission and Nuclear Fusion.  When a nucleus of an atom splits into smaller ones, it is called fission.  When two smaller nuclei merge to form a bigger atomic nucleus, then it is called fusion.

7.  Basic Astronomy.  You should know the following basic facts.

A.  Solar System.  The Sun is a star.  Stars are just other suns (but they are not all the same type!).  The Earth is a planet, as are Mars and Jupiter.  These are places that you could go to if you had a good enough rocket.  Planets orbit stars (all of the famous planets orbit our Sun as part of our solar system).  Moons orbit planets.  Stars give off their own visual light.  Planets reflect visual light from the Sun.

B.  You should know the names of the planets in our solar system from the Sun, outward.  They are Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, Neptune, (and demoted Pluto).

C.  A day is the time it takes Earth to spin once.  A month is the time it takes the Moon to orbit the Earth.  A year is the time it takes the Earth to orbit the Sun.  There are some details to this that we will get into during class, but you should have this basic concept to begin with.

D.  Do you know the difference between the terms "galaxy" and "universe"?  How about the difference between "solar system" and "universe"?   Look them up in your astronomy text if you don't.

E. You should know the names of the seven continents and be able to locate them on a map and locate California as well.  If you don't know them, it is time to go learn them.  Find a globe.

F. What is a microscope used for?  A telescope?  You should know the basic answer to those.

G.  The Diameter of Earth is 12,700 km (8000 miles).  You should know this. 

8.  Basic Physics  You should know the following basic facts:

A.  Protons carry a positive charge, and electrons carry a negative one.  Opposite charges attract each other and like charges repel.  Electricity is the flow of charge from one point to another.

B.  Magnets and electrical currents give off a magnetic field around them.  The Earth has a magnetic field also.  A compass is just a magnet that lines up with Earth's magnetic field to tell us which direction north or south is.

C.  Everything falls at the same rate (unless air friction slows things down).  If you drop a wooden ball and an iron ball from your desk at the same time, they will both hit the ground at the same time even though the iron ball might be much heavier than the wooden ball.

D.  The distance that an object travels is equal to its speed multiplied by the time it traveled: D = S x T.  You know this if you know how to drive a car.

E.  Light carries energy with it (this is the reason why you are warmer when standing in the sunshine).

F.  The word "heat" has many different meanings to it, and some of these are confusing.  "Heat" is a form of stored energy to an astronomer or a physicist.  Temperature does not measure heat.  Temperature measures the average energy of motion of the atoms or molecules in a substance or object.  Absolute temperature assigns a number to this energy of motion.  These numbers are given the name of "Kelvins".  Room temperature is 300 Kelvins.  The surface of the Sun, where the atoms have a lot of energy of motion is 5800 Kelvins.  The center of the Sun, where the atoms have A LOT of energy of motion is 15 million Kelvins!  If a brick was drifting between the stars, it would get very cold.  It would be only about 30 Kelvins if all it had to warm it was star light.  Zero Kelvins is called "Absolute Zero" and would be the temperature where atoms and molecules would all stop moving.  The laws of physics don't allow this to happen, so nothing can have an absolute temperature of 0 Kelvins.

G.  Matter comes in three basic forms.  Solids, where the atoms or molecules are prevented from moving out their alignment with other atoms, liquids, where the atoms or molecules tumble over each other in close contact, and gases, where the atoms are shooting around, colliding and bouncing off of each other.  Gases are usually mainly empty space.  A plasma is like a gas, except it is really hot and electrons and ions are flying around colliding and bouncing off of each other (do you remember what an electron and an ion are from the definitions listed above?).

9.  Basic Biology

A.  DNA.   All life forms on Earth utilize a molecule called DNA as a recipe for how to make each individual of each species.  The basic structure of DNA looks like a double spiral "ladder" of carbon-based molecules.  The more similar two life forms are to each other, the more similar their DNA molecules are.  A "gene" is a piece of a DNA molecule that determines how a specific part of that life form functions.

B.  Bacteria vs. Multi-cellular Life.  The simplest life forms are viruses and single-cell bacteria and algae. Complex life forms, such as people,  are composed of trillions of cells - in other words, they are a "multi-cellular organism".  They are, in essence, giant cell colonies.

C.  Prokaryotes vs. Eukaryotes.  Prokaryotes are often simply called "bacteria".  They are single-cells, and the cells are generally simpler than eukaryotes.  Eukaryotes are the "high-tech", specialized cells in nature.  You are made of different kinds of eukaryotes.  

D.  Anaerobes vs. Aerobes.  Anaerobes are bacteria that not only don't need oxygen, they are killed by it!  They can only live where there is no oxygen that can get to them.  Tetanus is an anaerobic bacteria that can cause a serious infection in humans. Anaerobes may date back to the days before Earth had oxygen in its atmosphere.  Aerobic bacteria tolerate or even require oxygen and are quite common.  They are all over your skin right now!  Yuck? or Cool?

SAMPLE QUIZ QUESTIONS.  Click here to see a list of sample quiz questions that I will include on your first astronomy quiz that will be based upon the material described above.