Or: How to survive a science course, with special attention to the problems of studying astronomy
At the heart of all science is something called the scientific method. The simple version of the scientific method is based on the idea that the objective reality of the universe can be determined by carefully observing phenomena, recording appropriate measurements, then studying the data from these observations for patterns that can be used to describe the general behavior of classes of natural objects. When we can control the circumstances of the observations, we are performing experiments, but often we cannot control all the factors before we make observations. There are scientists who believe that the only valid scientific data is that which comes from controlled experiments; in their view, most of astronomy, meteorology, geology, and many parts of biology are not rigorously scientific. For the purposes of this course, we will use a somewhat looser definition of valid scientific observation that accepts carefully recorded, repeated observations of natural phenomena.
Man's search for patterns led him to keep track of many astronomical phenomena from very early in recorded history. Many astronomical events are periodic, that is, they happen over and over with much the same frequency, in much the same way. When scientists find periodic phenomena that occur in the same order and at the same rate, they want to study them to see if there is some kind of cause-and-effect relationship between them. When the scientist finds a reasonable explanation, he or she proposes a hypothesis, a testable statement about the phenomena. Hypotheses that stand up over many repeated observations are combined to make theories; distillations of theories that have no known exceptions may be called natural laws. In astronomy, we are particularly concerned with theories of space, time, and relativity; and with the natural laws of motion, gravity, light propagation, and thermodynamics.
Science classes are frightening for many students. They anticipate difficulties with the concepts, with the details, and especially with the math. But science is just one way of thinking about the natural world around us, and anyone can learn to think like a scientist. Don't waste energy worrying about your ability to learn the material; use your energy to learn it! Once you get the hang of it, you'll be able to discover, understand, and appreciate the complexity of God's creation better. You will also be better prepared to take your place as a steward of that creation.
Review the prerequisites for the course. These are the concepts and math skills that you should have mastered in order to succeed in learning the material. The math prerequisites for this course are described in the course overview page and the FAQs page. If you have any questions about your readiness for the course, be sure to ask for help during our first session. I will arrange to work with you so that you can gain the required skills quickly.
Every science course has as its main components lectures, reading assignments, labs, and lots of homework to prepare you for taking quizzes and exams. In addition to these, our online course has this website, the Moodle class site, and e-mail to provide the functions that would normally exist in talking to your teacher face-to-face, or looking at a bulletin board or whiteboard. Keeping track of all the components can be a daunting task, especially at first, so plan to spend some time becoming familiar with the course website, your text and CD, and the Moodle class site. Once you have mastered the mechanics of using these tools, you can concentrate on learning the material that they contain.
Why are there so many parts to the course? Well, part of the reason is that you learn in many ways. You memorize facts, you comprehend relationships, and eventually, you understand concepts. You learn by reading, by analyzing pictures and graphs, by watching demonstrations of processes, by participating in discussions, and by applying what you are learning to specific situations in the homework and labs. You "cement" what you've learned by teaching others. The organization and materials of the course require that you take all these approaches.
Make the commitment, now, to spend adequate time on coursework. While this astronomy course is not as demanding as some of the others offered at Scholars Online, you cannot do all the work for a given unit on one day ... and you shouldn't do it just before chat session! The table below is a rough guide and a suggested pace for this course. The amount of time you spend on each part of the assigned work will vary greatly from student to student, and from chapter to chapter, and your schedule will of course depend on your other commitments. Work out a reasonable work load and stick to it!
Try to do your reading as early as possible. This allows you to think about the questions and material, review it in your mind, and absorb it more critically.
Checklist for normal schedule
Check Website for instructions
Immediately after class session
Read Web Lecture
Read Text Assignment (and work through example problems!
Work through Starry Night exercises, watch videos, perform Lessons
Post assignment to Moodle
Wednesday before class
Make observations for lab
Available clear nights!
Perform calculations/reduce data
Write lab report
Take Moodle quiz
(only at the end of the chapter)
Rather than take our precious chat time by lecturing to you, all unit lectures are posted to the site. You need to read these as well as the text. The Homework and Weblecture pages between them have
The "checkpoint" exercises ask you to figure something out, then offer you the opportunity to check your answer. Try to figure things out before hitting the "answer" button! If you were correct, and your reasoning was correct, congratulations! You are ready to continue with the next concept. If you missed the answer, but understand the correction, make a note to review the concept later. If you don't understand the explanation, ask the teacher during class, or send e-mail requesting further help.
As you read the web lecture, make notes on anything that puzzles you, and be sure to raise your questions in class.
Astronomy has long been considered the queen of the sciences, the one in which the basic concepts of math, physics, chemistry and now even biology come together. Although there is not a lot of "heavy math" in this text, certainly not in comparison to the Scholars Online chemistry or physics courses, there are still a lot of concepts to master and integrate. As you plan your workload, be sure that you give yourself enough time to
There are a number of "boxes" which explain how to use mathematical formula to determine quantitative answers for many different situations. Sometimes you may figure they aren't worth the time it takes to read them, but don't be misled by this sensation! In fact, you may want to mark these somehow (I use sticky notes with a lable), since you must often refer to them when doing problems in later chapters. When you work through the "box" examples, which usually involve mathematical applications, be sure that you understand
There are also several appendices and charts at the end of the book that contain useful information for answering questions. You need to realize this material exists, since some problems will require you to look up information here.
TAKE NOTES! Outline the chapter, identify important terms, concents, and formulae. even if the text supplies you with an outline. After each section, write down the important points it makes, any items of particular interest, and any questions that you have.
Homework is not merely useful, it is essential for mastering the concepts of an astronomy course. Just as we test theories by applying them to experimental situations, you test your understanding by applying it to specific situations. You will know whether you understand a concept if you can use it to solve a "real-world" problem, and when you can teach it to someone else.
We use both techniques in this course. You will be assigned both word-essay questions and observational data analysis for each unit. You should work all of these. You will also be asked to post the answer to at least one question and one calculation problem to the Moodle. You will need to show your calculations and explain them in your posted answer. This is your opportunity to explain to your fellow students what you know.
Your reading assignment will be on both the Moodle and the Schedule page, along with links to my Web lecture and study notes for the assignment. You are expected to do any online exercises, videos, and tutorials assoicated with the reading that are mentioned in the homework page or weblecture.
The assigned problems for each chat session and your individual posting assignment will be at the Moodle forum for the day's chat.
NB: mycroft, the original bot for my science classes, has long since been freed to do other things, like attend class, make obnoxious remarks, and aid stumped students. If you really get stuck figuring out the problem you've been asked to post, mycroft has been known to accept bribes in the form of virtual Oreo cookies to finish your problem for you.
Essay questions ask you to explain a concept in words. As you answer a science essay question, be prepared to cite calculation information as well as concepts, or give examples.
For example: Why can't you see any surface features on Mercury when it is closest to the Earth?
A good answer will be grammatically and syntactically correct, using proper English, as well as contain the correct information. It will cover more than one point in supporting its argument.
You cannot see any surface features on Mercury because it is always very close to the sun. Much of the time, it's reflected light (which is low because it's abledo is only .12, meaning that it reflects only 12% of the light falling on it) is lost in the sun's glare. When it is furthest from the sun, it still can only be seen just after sunset or just before sunrise, when it is near the horizon. Its image is distorted since it is seen through the maximum amount of Earth's atmosphere.
Most astronomy concepts are based on simple physics principles. Newton's form of Kepler's law (which we discuss in chapter 4) is
which is relatively simple math. Our problem is in the application of such concepts to real situations.
So here is a "general problem solving" approach.
Let's look at an example:
Given that Jupiter's moon Io orbits Jupiter at 421600km in 1.77 days, what is the combined mass of Io and Jupiter?
Chat sessions are 90 minutes. Plan accordingly, and take a break just before class starts. Do some stretching, go to the bathroom, eat or get your drinks before you enter the classroom. Be sure to try to connect to your ISP and check mail 10 minutes before class if possible, in case any late notices have been sent by the teacher. Give yourself the extra time. High traffic on your ISP or the school server can slow you down and force you to miss the first 5 to 10 minutes of class.
If you have not already done so, post your assigned questions and answers to the Moodle before the start of class.
Bring your textbook, notes, homework calculations, calculator, and paper and pencil to class. If you are comfortable using a desktop calculator and taking notes in a text utility like Notepad (available as different applications on both Windows and Macintosh), you can use those. You may also find a dictation program like Dragon helps reduce typing, either into chat or taking notes. Take notes during class. Since Scholars Online logs the chat sessions, you do not need to document things the teacher or other students say, but it is useful to note your own questions and observations as they occur, so that you can study them later.
Take part in the discussion. Ask questions as they occur to you (or note them and ask them at the end of class).
Chat sessions in astronomy frequently involve discussion of mathematical calculations. One convention we use is underscore (_) for subscript and up-arrow (^) for superscript. The term x_1 ^2 means "take the value x-sub-1 and square it". You may be more used to seeing this written as x12, and we can actually do that in Dr. Bruce's chat, but it requires a bit of typing. If you prefer to use HTML tags, then here's a quick guide:
}F_g = (GMm)/r^2
will appear as
Your teacher will provide more instructions during the first few chats.
After chat, log into the chat window again, hit the button for past chat logs, and print the log out. As soon as possible after class, review the log and make notes on it about any points that bother you, and be sure to ask about these in our next session. Mark important points for review later. Consult your notes or the Scholars Online copy of the log to review before the next session and before semester examinations
All the physics examinations (quizzes and semester exams) which I use to evaluate your understanding and progress in astronomy will be drawn from the homework questions in the text. It is very important that you complete the homework problems, study questions, and any reports assigned to prepare for the exams for this course.
There will be an online quiz for each chapter, which will be available on the Moodle when we have finished discussing the material in the chapter. These quizzes include 10-30 multiple choice, short calculation, and other format questions and are timed. When you take the quiz, you will receive immediate feedback for your attempt. You will have a second chance to take the quiz for review during the grace period before midterm exams.
Start your review two weeks prior to the scheduled examination.
Go through the Key Words listed at the end of each chapter. Are there any that you still don't understand? Note them down, and look them up. If you still have trouble remembering the meaning of the term, make a flash card for it and drill yourself.
Read the Key Ideas sections at the end of the chapter. These list the main points of the chapter. You should have any information in these points memorized, and you should be able to explain and use this information to solve problems.
Review the chat logs, and go over your notes.
Review your performance on quizzes, and make a list of the concepts with which you are still unfamiliar or which still puzzle you.
Look these up in the index or table of contents, and review the textbook discussion. If the idea still confuses you, write up a question for the review session, or e-mail the teacher.
There will be several major exams (midterms), after major sections of the text are completed. These may be mailed electronically to you, or you may take them on the Moodle. Either way, you will need your parent or other responsible adult to act as as proctor. If you take the exam (or part of the exam, such as the multiple choice section) in the Moodle, you will need to complete it before it closes. If I email the exam to you, or if you take the problem section of the exam on paper, you will need to type or scan in your answers to a computer file, and upload the file to the Moodle assignment for that exams before the assignment closes.
Most exams will include a multiple-choice or other format objective section, an essay section, and a problem section, which will often include some interpretation of data from astronomical observations. All sections are closed book. You may bring to these exams one 8.5 x 11 inch sheet of paper with whatever notes on it that you desire — so don't worry about memorizing formula. Learn concepts and applications!
Yes, of course you may study together — remember that explaining or teaching what you just learned to someone else is one of the important techniques of learning! You may also work together to solve the homework problems ... but be sure that you can solve them on your own afterwards, since you cannot work as a study group on quizzes or examinations. Let me know if you need special chat times for your study group.
One of the basic methods of science is to secure documented observations of periodic or common events in order to make some general summary about the behavior of natural objects. We can do this in several ways.
All observations of stars and planets, most observations of plants and animals in their native habitats, and many observations of geological specimens and meteorological events, are "field" observations. The situations must be allowed to occur without human direction, either because such direction is impossible (we can't control when a star will go nova), or because human intervention would interfer with the observation (we don't want to feed animals if we are researching their eating habits in the wild). The best we can do is make many observations of phenomena that are as similar as possible.
Laboratory-based observations are much more tightly controlled. Specific techniques and equipment are used for particular kinds of data collection. The experimenter can often vary only one factor at a time to see how it affects other dependencies. This allows many experimentalists to compare their results easily.
Frequently, research in one area reveals a tendency for a particular phenomena\on to behave a certain way. Rather than simply starting to observe the phenomena anew, one may choose to go back through past observations, looking for the same patterns or evidence of how nature behaved in similar circumstances. Surveys of historical data are common in weather studies, where such records exist for periods of 100 to 150 years, and in astronomical observations.
Surveys and re-examination of astronomical data are very common, since telescope plates taken in the 1920s by a researcher interested in a single star or event will contain data relevant to other events as well. The earliest photograph showing the growing magnitude due to the supernova of 1987 was taken by an Australian astronomer who was looking for something else entirely in a different part of the Magellanic Cloud. After checking the photo for his own star, he went to bed...and so missed being the "discoverer".
Universal Time: The occurance of most events is listed in the literature as though you lived in Greenwich, England, on the Prime Meridian (0 degrees longituded), in hours and minutes of Universal Time, using a 24-hour clock. If you use a program such as Starry Night or Voyager III (there are about a dozen good ones), you can set the local time display for your location. Then when you look up an event such as a lunar eclipse in Sky and Telescope, you can easily "process" to the proper Universal Time listed, and see your local time displayed as well. But it is theoretically possible that you may be without this software from time to time.
Correcting for clock time. Universal Time is 5 hours earlier than Eastern Standard Time (8 hours earlier than Pacific Standard Time.) To determine when an event scheduled for 23:15 UT will occur in your local time zone, subtract the number of hours different. UT 23:15 is 15:15 PST.
Remember that if your local time is currently using Daylight Savings Time, your clock has "sprung forward" one hour: 15:15PST is 14:15 PDT. So an event at 23:15 UT on August 15 will occur when it is 14:15 in Seattle, or in the middle of the Seattle day (and probably be unobservable).
Sidereal Time: Long-duration phenomena are not listed as occuring at any given moment; rather, the location of the phenomena is listed in terms of celestial coordinates. Suppose a comet makes an appearance, and, moving slowly, will be at 6 hours Right Ascension, -18 degrees (south) declination. You want to know when it will be visible.
Binoculars are very useful instruments for viewing large areas of the sky. Even low-power binoculars (8X) can show you the craters of the moon, the phases of Venus, the rich starfields of the Milky Way, the hazy disc of Andromeda, and the 4 large moons of Jupiter, and give you a sense of position in space that is difficulat to achieve with a more powerful telescope.
The major problem with binoculars is that they are usually hand-held, causeing the image to jump around. When using binoculars to view astronomical objects, try to brace your arms or the binoculars against a stable object (the side of the house, a fence post, the hood of your car). If possible, mount the binoculars on a camera tripod or telescope tripod.
Your lab report is the evidence of your observations of a particular phenomena. Your observations should be presented in such a way that the data is easy to understand and supports your conclusions, but also with enough detail on how you obtained them that any peer with similar equipment could repeat your experience and confirm your results (or challenge them, as the case may be).
Organization: A good science lab report has at least seven sections:
Because of the nature of astronomical observations, there are some kinds of data that you should always include for any observing session.
There are several standard forms for making observtions. Among the most popular are those used by the American Association of Amateur Astronomers. I recommend that you download the two observing forms, copy them, and use them when you observe:
Download the form for the Observing Log (PDF).
Download the form for the Sketch Template
Part of each semester's assignments is a research paper of 4-7 pages (1000 - 1500 words), written as a research proposal on some specific area of astronomy, and due at the same time as your semester examination.
You may use any and all resources at your command, including websites, text, other books, magazine articles, etc. You may spend any amount of time on the report that you wish, and you can work on it before and finish it after the exam if you so choose, but it is usually due at the same time as the semester exam.
TOPIC: You may choose a topic from the current semester's astronomy materials, where you can discuss how it is an example of a class of solar system objects (fall) or stellar or galactic objects (spring); what makes the particular object interesting, and how it might be studied. For example, you could choose planetary atmosphers, a particular moon like Io, or a particular application Roche limit theory (formation of planetary rings around Uranus). You must submit your proposed topic to the teacher and have it approved before continuing your research.
REPORT FORMAT: The report should include the following sections:
From a grading standpoint, I would like you to show me that you understand something about the general characteristics of one of these areas:
You will upload your paper as to the Moodle assignment location by its due date. It must be in acceptable format (Word DOC (not DOCX), RTF, Ascii text (TXT), PDF, or Mac Pages format). If you use another word processor, please check with me before uploading the file; I may not be able to read it.
Mycroft's Sample Research Proposal: Is the Moon made of cheese? (a PDF file)
Starry Night will show you the positions of the stars and planets, the sun, the moon and its phases, for a given observing time.
Sky and Telescope and Astronomy Magazine both contain articles on observing techniques for amateur astronomers, general articles on recent discoveries, and monthly star charts with planet locations, lunar phases, meteor showers, comets, and other information. Both magazines maintain webpages as well.
The local newspaper may carry similar information on its weather page.
NASA's website carries important information about current manned missions (mostly to the International Space Station) and unmanned missions (Cassini to Saturn, Galileo in orbit around Jupiter, various Mars missions).
The Hubble Telescope site carries the best of the Hubble's pictures, plus extensive information about the latest pictures and their implications.
Astronomy is the most popular of the sciences from the public's point of view: who can resist the pretty pictures? or eclipses? There are more books available on astronomical topics than almost any other science (counting computers and programming as something else entirely!). Consequently, there are many textbooks which range from simpler than the one we are using to much more firmly based in physics and mathematics. When looking at texts, try to find more recent editions, since information and theories in astronomy change rapidly, even at the fundamental level!
© 2016, 2017 This course is offered through Scholars Online, a non-profit organization supporting classical Christian education through Internet-based courses. Permission to copy course content (lessons and labs) for personal study is granted to students currently or formerly enrolled in the course through Scholars Online. Reproduction for any other purpose, without the express written consent of the author, is prohibited.