This is a transcript of introductory remarks for the ASTR110G course.

Click on the links shown below to jump to various sections of the discussion.

Syllabus

Introduction

The textbook will in fact not be your primary reference for this course. We have roughly 200 lecture slides that tie directly to the most important material in this course, and these are the most important thing for you to read. You'll be solving problems tied to every lecture, and every time that you solve a problem you'll have access to a hyperlink that leads you to the relevant lecture slide. One way that you can read through the lecture slides – the most important thing to be reading in the course – is to do your homework problems and simply read the lecture slides as they apply to these questions. We will talk more about that later.

Laboratory Manual

The online textbook and the online lab manual are provided online at no charge, so you don't need to go to the bookstore to buy any texts for this course.

Exams

You've got lab work, and it's worth a quarter (25%) of the course. We have two types of laboratory exercises in this course: hands-on and data-driven. In the hands-on labs you get to build something yourself out of basic household objects, and you get to do things like observe the movements of stars and planets in the sky. We also have data-driven labs and in these you get to work with observations made at telescopes all over the world, and to understand how astronomers work with those data in order to produce images and spectra of celestial objects.

You do not need to come to campus to perform any of these lab exercises. They have all been designed so that you can do them wherever you are in the world. Each lab exercise lasts for two weeks, and it's very important you begin the exercise at the beginning of the two week period. This will give you time to work with the teaching assistant and to make sure that you fully understand the concepts used in the lab. Each level will have an initial deadline after one week, and then a final one after the final week. Your lab report will be written online as well, like everything else in this course.

The midterm exam is worth 15%, and it's generally a learning experience. The final exam is worth 25%.

Class participation is worth the big +10%. I'm pretty serious about that; I like people to participate. It keeps me awake, and it keeps you awake! It gives me an idea of how much of what I'm saying is getting through to you, so if something is not clear, let me know – ask me a question. If something I say reminds you of something you read in the newspaper and you want to know more about it, or if you want to know more about a topic, let me know. If I ask a question, I really do expect someone to answer it! We want to have an engaged discussion here. I know this is a big group, but I really urge everyone in the room to get involved in class discussions. It makes it so much more interesting, for me and for you.

Class Policies

If you have a personal concern that you need to share with me, feel free to write me an email directly so that you and I can discuss it one-on-one. We also have office hours face-to-face and through the computer, and we're very happy to set up video chats through the Google Plus Hangouts system so that we can talk wherever you are in the world. We find that people who make use of these resources tend to do better in the course than people who soldier on alone even if they have questions where we could help.

Homework Assignments

To log on, you enter your last name and the last four digits of your Aggie ID. If your last name is hyphenated or if you have two names in your last name, please enter only the first part of your last name, and if you have a name like de Dios or van der Graaf, please leave the space out before the prefix. This same access code will work for all of the online resources in the course where you need to log in, like the plotting tools that we'll use in our lab exercises.

You use the library by selecting a lecture or range of lectures to study. When you've chosen your material, the library will give you a set of five questions to answer related to that material. Within each question you'll find two hyperlinks. One leads back to the most relevant lecture slides in the course, so this is a nice way to run through the lecture slides while solving problems, and a second hyperlink gives you a specific hint for the problem. Sometimes this is an idea about how to set up and solve the problem, and sometimes it's the first step of the problem worked so that you can see how to get moving on the question.

We're asking you to work through 20 of these quizzes each week, so that's 20 × 5, or 100, practice problems each week, and this forms your homework. As long as you solve at least 100 questions per week, you're guaranteed a score of 100% on your homework.

Some students like to read through the lecture slides for a lecture in their entirety before solving problems, while other students like to jump into solving problems immediately and to read the lecture slides within the questions, to see how they connect to the questions. Either of these approaches is just fine; you should do whatever you are most comfortable with as a student. Now it's natural that when you begin to work with new material you may not understand it at first. Your initial scores on your first quizzes may thus be a bit low for new material, and that's fine – it's no problem! Remember that as long as you solve at least 100 problems each week, you're guaranteed a score of 100% on your homework. You can relax and work through the initial problems, and gain confidence as well as knowledge as you go.

Weekly Quizzes

Keep in mind that you get only one shot at each weekly quiz, so you want to make sure to study and to be prepared before you take it. How will you know that you're ready? If you solve one hundred questions for the week and you're routinely scoring four out of five or five out of five (80% or 100%) on your homework quizzes that means you're ready for the weekly quiz. If you've completed 100 questions but you're still having trouble with the material, you need to study a bit more. We also encourage you to contact us if you have questions that you'd like to discuss in person; we're happy to review the material with you. Sometimes it just takes a few minutes of discussion to clear up an issue that's been bothering you.

Take a look at the options for each quiz that are shown on the portal to the self-review library. Each weekly quiz is available for three weeks. It becomes available a week before we cover the material in class, it is available the week the material is featured in class, and it stays available for an extra week. We do this because we know that everyone has a second, real life in addition to their lives in this astronomy course. Because of travel, illness, a child's illness, or some other reason, you may need to work a week ahead or a week behind at some point during the semester. We thus provide the weekly quizzes over a three-week period to give you a buffer week ahead and after the material is covered in case your schedule requires that you flex the time at which you study briefly. Do not make a habit of taking your weekly quizzes late, however. This leads to difficulties.

You'll notice that above the button for selecting weekly quizzes is a button labeled review your most challenging questions. This is for use when studying for quizzes, and before the midterm and final exams. When you begin studying, just select a lecture or a range of lectures and dive into the material. As you become more confident, however, you may want to focus on the questions which initially gave you trouble. If you click this button to review your most challenging questions, then you'll get material focused on the questions that you've missed most while studying previously. This can be particularly useful when studying a range of lectures before the midterm or final exam. This way, you can hit up the lectures where you want to focus your attention quite easily. You can select the entire range of lectures 1 through 13 before the midterm, for example, and get the material that you want to focus on for studying.

Some students like to download the audio recordings of lectures for this course and listen to them while exercising, for example. When you sit down to do your homework and quizzes each week, however, try to create a quiet study environment that is most productive for you. If you can find a place that is quiet, that doesn't have a television or radio playing, that's a great idea – and try to minimize distractions from friends and family. If you can schedule blocks of time to focus on astronomy, that's a good idea as well. And if you need to work at a coffeehouse for the free Wi-Fi for hours at a time, at least try to keep the coffee running through your veins!

Laboratory Exercises

Each time you begin a lab you download a template for your lab report, and you immediately share this as a Google Drive document with the teaching assistant and with me. There are clear instructions for how to do this in the video tutorial for Lab 1, for example, so it's a great idea to watch that tutorial before beginning to work on our first lab.

Once you share your lab report with us, we can see everything that you write within it. If you get a problem and you have some questions or you're not sure how to approach it, a great thing to do is to place a comment in the margin at your lab report and just ask us whatever your question is. Because we can see your document at all times, not just when you turn it in at the end of the two weeks, we can reply in real-time to you and help you get through your questions as they pop up during the lab exercise.

Note that there are eight lab exercises on the GEAS website which holds all of our lab work. We will be doing only six of them this semester, and we won't necessarily do them in chronological order. This is because we can't control things like when the Moon attains various phases in the sky, so we have to adjust our lab schedule to the movements of celestial objects.

I emphasize strongly how important it is to begin each lab exercise at the beginning of the two week period. We'll have two deadlines for each lab: after one week, and then after the second week, and for each of those deadlines there is specific material that you need to have completed. If you begin your work at the beginning of the two week period, you'll have lots of time to interact with us and to get help on areas where you have questions. The worst thing to do is to wait until the last minute and then frantically try to cram the entire lab into a brief period of time. This is not very pleasant for you, and not very good for us either, so please make a real point of starting the lab exercises early and getting help when you need it. Again, we're here to help you with these exercises.

Some of our labs are hands-on, which means that you build simple tools for yourself out of household objects. Make a point of checking the lab exercise the week before you begin it so that you know if you need to obtain any particular items to create the equipment.

And to be clear, when you ask a question during the course of doing a lab we do not take points off for asking questions – we are delighted to see questions! Grading is done at the end of the two weeks, and that's based on the material that you have done by yourself and then improved upon by working with us, so don't be shy about asking questions.

Because this course satisfies a general-education requirement, writing is an essential component of the course. Because of this, each lab report is finished with a summary where you describe what you've done, how you've done it, and how you've learned. Set aside some time to complete these summaries at the end of each lab exercise, so that you can write clearly and give us a good picture of what you've done.

Exams

We do not do make up exams in this course. I had a great story last semester. I had a guy who actually missed the midterm, and this is a cardinal sin in this course (missing an exam). He said to me "I'm very sorry, but two days before the exam I had a car crash", and his car was demolished, and he lives in Anthony, Texas (a ways down the road from Las Cruces), and so he was getting a ride to campus from his roommate. Unbeknownst to him, the night before the exam his roommate got thrown into jail. So he woke up the next morning, to find no roommate, no car – nothing! I thought, that's a pretty sad story. You win – you win a free make-up exam! But your story has to be that good or better.

Grading

These are all of our science topics as well, so if you want to get an advanced idea of what's in the course, we start in the solar system, we talk about the Earth, we talk about the seasons, about the Moon, about the other planets, and then we talk about atoms, we talk about other galaxies, and we talk about the formation of the Universe. It's kind of the course in 10 seconds; we'll fill it in as a semester develops, however. It's all there, and feel free to browse ahead if you'd like to do so.

Assignments

The White Sands park has sky viewing parties, and these are quite fun, and you get to go out to White Sands at night, and it's really dark out there so it's quite a neat experience (sometimes you'll see little foxes as well).

Las Cruces has an amateur astronomy group, so if you'd like to learn how to build a telescope, for example, they have (I think) open meetings once a month, and they're very friendly, always eager to have new members, so go ahead and get involved with that if you'd like to do so.

Books

We've got a book here called The Moon is a Harsh Mistress written by Robert Heinlein. Who has heard of Heinlein? This is so sad. Who has heard of Shakespeare? Okay, Shakespeare is a dead English guy, and Robert Heinlein was an American, and he was a fundamental cultural phenomenon. You owe it to yourself to learn about his life, to learn about how many things in the future that he predicted came true, in technology, engineering, artificial intelligence, colonization of the Moon, or other star systems, really cool stuff. This is a great book about a lunar colony, similar to Australia. It's a colony that was formed as a penal society, which means they sent criminals there, or, say, people who objected to the politics of the government. Then, as inevitably happens, these people had children. Were they criminals? Of course they weren't criminals – they just happened to be born on a low-gravity satellite. So in this case it means that they are living on the Moon, and their bones are so fragile that they really can't go back to Earth. So they're stuck living in a prison, but they have committed no crimes. It won't surprise you to know that they endured taxation without representation. What could be more American than a revolt to free the Moon from the harsh tyranny of Earth? This is a great book, and I recommend that you all read it by the end of the semester.

If you like lighter stuff, First Light is a book written by an astronomer. You get to learn what sort of sandwiches everyone eats when they go observing, and a lot of other little details about observing. It's fun.

2001: A Space Odyssey. It comes out of the sixties – do I really need to say more?

Some books about alien civilization, about exploring the solar system, about meeting our first alien civilization, and what that interaction would be like. Who expects that if aliens are out there they look just like us? Yes, probably not. They might not have eyes, or ears, they might not listen to sounds in the same range that we do. Maybe they are giant jellyfish, or communal intelligences, much more like a beehive than individual people. Interesting problem, interesting challenge. These books talk about how that might play out.

There are some great books by Larry Niven, who went to the same college that I did (Caltech). I finished my degree but he flamed out, as we say, but he ended up a majorly rich (I hope) author of science fiction books, so it turned out pretty well for him. He wrote some of the best speculative science fiction in the 1960's, with ideas about anti-matter, about space exploration, about physics going wrong, about low-gravity environments. It's really good stuff, so if you are in the mood for short stories pick up some Larry Niven and read them – they're great!

The Cosmological Distance Ladder – this is a real science book again, so if you're interested in galaxy evolution and how the Universe formed, this is a nice book to read.

Movies

We start with four short films created by my own research group. When people think about astronomy and astronomers, the image that comes to mind is often of someone like Albert Einstein, living in an ivory tower far away from reality, thinking great thoughts amongst the clouds. That's a nice image, but it has absolutely nothing to do with modern astronomy or modern science. The reality is that there are people involved in science today with widely varying levels of education. You don't need a PhD to actively contribute to astronomy – in fact, you can have a great, well-paying job with a Bachelors degree or a Associates degree and a bit of experience in the field. These films showcase various individuals working in the field of astronomy who might not fit your image of what an astronomer looks like. These are great films to watch with children, if you have them, and we encourage you to do so.

We have great stuff, we have The Right Stuff and For All Mankind, which are about the space program that was primarily driven by the Americans in the past, though not so much today. We've got The Dish, a wonderful movie about an Australian radio telescope and about the first manned mission to the Moon and all the things that went wrong that they never tell you about. It's got sheep! We've got Contact, which is about a first contact with an alien intelligence, not a hand-to-hand (face-to-face) contact, but with information being transmitted between civilizations. And many more! If there is a movie that is not on this list that is actually science and you want to watch that instead, come up and talk to me, and we'll probably okay it too.

Music

That's the syllabus! Are there any questions about the technical issues of the course? Excellent! Now we're going to get started on the science.

Self-Review Library (worked example)

If you want to take a particular lecture and review the material in it, you go to this database, where everyone who was properly registered into this course has an account. You put in your last name, and we cut off hyphens and we cut off spaces (de Dios becomes deDios, van der Graaf becomes vanderGraaf, Hertzsprung-Russell becomes Hertzsprung), and for everyone else your last name is your last name. Your access code is the last four digits of your Aggie ID.

Now you want to pick a topic. We're just starting out, so let's pick the first lecture of the semester, The Contents of the Universe. Then, I just click on the button labeled create quiz. Ping! Okay, so what do we have?

Sometimes we have some people who come straight from high school into this class whose idea of studying is memorizing. They take out the book and they memorize all of the words. It's a lot of work, and it's not very helpful. Eventually you forget those words, typically about two minutes after the final exam. We would prefer instead that you learn about general concepts, ways to solve problems, and ways to take data and do something with it. Where was I? Quizzes – so this is a way to test your knowledge. You go through a lecture and you think it all makes sense, and then you take a quiz, and you test what you know. I'm kind of jumping the gun by showing one of these before we go through the lecture, but I want to show you how easy it is to use the library.

Our first quiz question is If the radius of Jupiter (which is a planet) is one-tenth that of the Sun (our star), what is its volume? So we are trying to connect the idea of a radius of an object (how big it is, or its length), to its total volume (the complete space that it occupies).

Let's say you are looking at the question and thinking, hmm, I don't remember that from lecture. You go over here (to the bottom of the question) and you click the "i" button, and that will throw up the most relevant lecture slide. In this case you're getting a slide which tells you the size of Jupiter and of the Sun.

Let's say you think, okay, that's nice, but I need more! Just click on the little "?" button to get a hint. This hint specifically describes the problem that you're solving here. In this case, what is the relationship between the size of an object (its radius) and the volume (the total space it occupies)? So we're going from a length-scale, like a unit of centimeters, to a volume, like centimeters cubed. How does that work? This slide will talk us through that process. It will talk about the volume of a sphere, the volume of a cube, and do some simple examples.

So for example, here we have a sugar cube, with a radius of one (centimeter) on each side. So it has a volume of one cubic centimeter (this is the audience participation part). Okay, now we've got a horse's dream ... this sugar cube is five times as wide, five times as tall, and five times as deep. If you count all of those cubes up the horse gets really excited, and we've got five across, five tall, and five back. That's five times five, or 25, times five again, for 125 cubic centimeters. That's the volume of that cube (it is made up of 125 single cubes). The little guy, that's one cube. We've increased the size by a factor of five, so how did the radius change? The radius of a single cube is still one. The radius of the super-cube is five. Everybody with me? Five times as wide, good. What is the volume of the single cube? One – or we could say 1 × 1 × 1. What is the volume of the super cube? It is 125, right, or 5 × 5 × 5, for 125 cubic centimeters. If you wanted to check me on that you could just count up all the cubes there. You can see that it's five by five on the front, for just 25 cubes, and you do that five times in a row, so it is 125 sugar cubes. How many people thought that sugar cubes would feature in this course? (Not too many!)

That's the idea. Now let's go back to our question and say If the radius of Jupiter is one-tenth that of the Sun (so now we're comparing one to one-tenth), what is its volume? I know it's a little tricky (math! the first day!) so let's break up into little discussion groups. If the radius of Jupiter is one-tenth that of the Sun, what is its volume, in terms of the volume of the Sun? I just want a relative comparison. If the radius is one-tenth, what does that make the volume? And remember that your lives hang in the balance! This is fun, there's not really a wrong answer here in the group discussion.

Okay, what do we think? So we've got five answers from the different discussion groups. How many groups think it's one-thousandth (and you show this by raising your hands!). How many groups think it's one-tenth? Excellent. How many think it's one-hundredth? How many think there's no connection, and I made this problem up? Very good. How many people think we need more information to answer the question? What additional information might we need? That's interesting. A student is saying we've got the word roughly in the question, so just how good does the answer need to be? (Answering to the nearest power of ten is fine.) So a lot of people are saying one-thousandth. They're saying that you've got Jupiter with a radius of one (with a volume of one by one by one) and then you got the Sun which is 10 Jupiters across and 10 Jupiters high and 10 Jupiters deep (so that's a thousand).

A student is asking how good does our answer need to be – how good is roughly? The answer to that is that in this class, one digit (one significant digit) is often good enough. So actually one-thousandth is perfectly fine as an answer, because I'm just asking you to scale things in your head. My question is whether you understand the relationship between the radius of an object and its volume. In certain circumstances you would be absolutely right that we would need more information to give a more accurate answer. In this kind of problem, however, we're looking for big scaling. It's really hard to measure things in astronomy. If you take an engineering course, you might measure 3.625678 ... but we won't do that in this case. We stick with very broad measurements and we don't have a lot of accuracy, because it's very difficult to measure the distances or the sizes or almost any of the other properties of objects in the Universe. We're often all about the qualitative nature. I'm gonna go with one-thousandth for the answer to the quiz question.

We've got twenty minutes remaining, and I want us to do some work on the sizes of things in the Universe, so I think we're going to stop working through the rest of this quiz. The take-home message here would be that you've got one of these running for you under your own account, and it's just as easy as what I just did there with the clicking on the buttons. I'd like everyone to go home and play with this and see how it works for you as a study tool.

We're going to quickly run through these remaining four quiz problems. The first three elements in the periodic table – does anyone know their names off the top of their head? Excellent! A student is saying hydrogen, helium, and lithium. Those are in fact the first three elements of the periodic table. If you weren't sure, you'd click on the hint button here ("?"), and you'd learn a little bit about some common elements in the Universe. Hydrogen is the simplest element to build; you only need one proton in the nucleus, and one little electron. One-one; very simple. Helium is two-two, and so on. It builds up from there, so you can learn about the elements. The definition of an atom (we're going to go through this later) is the number of protons in the nucleus. That's something we will learn in the course (in Lecture 1 and Lecture 15).

A molecule – this is a structure that you get by combining atoms. I'm throwing a little bit of terminology at you, but we're going to go and review this immediately after we finish the quiz.

Then we've got sizes of objects. In each question, if you weren't familiar with the words used you could click on the hint button to learn about the meaning of the words.

Then what do you do? You've got your answers done, so you submit them. Hey, yippee, everything is in green, so we got a 100% on our quiz! That's good – everyone pat yourself on the back (especially if you picked one-thousandth as the answer for the first quiz question).

If we had gotten some of these questions wrong, we would know what the correct answers were when we looked at this form (the solution set to the quiz). You also get a description of how to solve every problem; the solution set walks you through it.

If there is a math problem, as there are a lot of in Lecture 2, it will walk you through every piece of the math for every problem. So if you are nervous about doing math take some review quizzes on Lecture 2, and you'll get all the details that you need on the math.

I wrote all of the software for the self-review library myself. It works pretty well. Occasionally, there might be a problem. If there is, send us an email – there's a feedback and commenting button that you can select on the solution set every time that you take a quiz, so if you like a question (if you think, that's a really good question!), send us a comment. The more you work with the library, and the more that we see that you are working with the library to learn the material, the kindlier we look upon you.

Now let's jump into The Contents of the Universe.