Common Misconceptions

Let me start by saying, this is Phil’s area of expertise. That said, there are certain things that as an astronomer I face over and over and over and over and … well, you get the picture. And some of them I just don’t understand.

There are the jokes, of course – Oh, you’re an astronomer? Can you tell me my horoscope? or Oh, you’re a cosmologoist? I’ve always wanted someone to tell me my colours.

There are the “Let me ask you a question that you won’t want to answer” personal questions – Are you a Christian? or Do you believe in aliens?

And then there are the questions that leave me wanting to run away from the person – When the Mayan calendar ends will there be a doomsday in 2012? No, really – I want to prepare! or With your intelligence, why don’t you build a transporter beam? If you don’t, you’re not living up to your potential!

These are all actual things I’ve heard (and that last was followed by a full-fledged “I’m disappointed in you” lecture of the style most often associated with getting a C in Spanish or something similar). While generally frustrating or freaky, these experiences don’t compare to the day-to-day misconceptions that I encounter when talking to normal folks about astronomy. The most common 3 are: The seasons are caused by the Earth getting closer and farther from the Sun, the full moon occurs when the moon is between the Earth and the Sun, and the Sun’s path is always exactly the same through the sky (rises straight east, passes straight overhead, and sets due west). The problem I run into in combating these misconceptions is I have no idea where they come from, and I can’t remember learning the real reasons for seasons and phases of the moon myself, so I don’t know what it’s like to not understand these things. This actually makes it harder for me to teach these things.

It is easiest to teach things that I, as a student, struggled to learn. For instance, basic circuits are easy for me. Electronics was by far the class that made me the most miserable as an undergrad. My personal philosophy on electronics is that circuits work by magic, and when you see smoke, that is the magic escaping. I can solve circuit diagrams when forced, and solve basic problems when forced, but it is one of the three topics I dread teaching the most (the other two are fluids and room temperature thermodynamics). Because I hate circuits, I teach them very well. Because I painfully remember what it was like to learn circuits, I can help my students avoid common mistakes (translation – all the mistakes I made).

I can’t imagine not noticing that the sun is low in the sky in the winter and high in the sky in the summer. The fact that the Sun’s path changes is just one of those observables, like winter being colder, that is just part of my life. Not everyone looks up though, and not everyone notices the world around them, and I struggle with this.

The reality is, in the Northern winter the sun rises south of east and sets south of west, and never gets all that far above the southern horizon. The steep angle of the light is part of what makes it cold. Think of the Sun as a giant flashlight beam, where the beam far larger than the size of the Earth. If the Sun is straight over head, it is like a flashlight beam aimed straight at a piece of paper, where it makes nice bright circle that gets warm to the touch. If it is low on the horizon, it is like that beam is angled steeply at the paper, with its light cooly spreading out over are large, dimly lit area. Winter’s cold is nothing more then the light hitting us at a bad angle.

But I guess I can understand where the idea of closer=summer comes from. Stand too close to a camping cook fire and you might cook yourself! We learn from a young age that close = hot. But don’t we also learn from a young age that planets orbit the Sun on near circles? (And in fact, ask someone to draw the solar system and they will always draw planets on circular orbits). I just don’t understand how the same person can have planets on circular orbits and have the Earth radically closer to the Sun in Summer (and Australia somehow experiencing winter). The sad reality is, these people just don’t think through the if A, then not B consequences of their contradictory ideas.

Now, I’m sure I’m guilty of doing the same on other topics. This is why I have to remember, when faced with an astronomy illiterate human, that there are vast areas of knowledge where I’m clueless too (art history, for instance. I know I should know something about it, but…) As an instructor, I have to get people to think through their contradictions, and challenge them to think about what they think is true and see if their understanding is built on well-aligned stones or unstable gravel waiting to collapse. Teaching people to question what they “know” is good and true is the first step in getting them ready to learn what is observable and understood based on experiment.

It is a hard walk though. Teaching the seasons is stupidly difficult for no obvious reason. I have colleagues who feel it is so important to make sure that people fully understand the moon and seasons that they spend 1/3 a semester on just the seasons and celestial motions.  (I spend 3 classes normally.) This is where things get hard for me philosophically. Is it better to beat down every student misconception (No, really, the universe won’t end when the Mayan Calendar runs out of dates. The calendar just restarts), or is it better for me to give them a taste of everything the universe has to offer and hope that they will become curious and choose to explore and learn more on their own after the class is over? My personal goal is to get them to understand enough astronomy that they can read and understand this blog and other astronomy content sources (newspapers, magazines, etc). Most astronomy news has nothing to do with the seasons or lunar phases, thus, I accept that a certain number of my students are going to “understand” the seasons just long enough to pass their first astronomy exam, and then they’re going to move on and go back to their misconceptions.

I only wish I fully understood where the misconceptions come from, and how to prevent them from ever settling in to stay.

I wish I remembered how I learned the reasons for the seasons and the facts the dictate the phase of the moon.

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12 Comments

  1. Phil Plait, aka The Bad Astronomer May 20, 2008 at 12:16 am #

    Hey, I don’t own misconceptions!

    Funny– the other day, a friend of my daughter’s made a comment that made it clear to me that she didn’t realize the Moon had gravity. This is a shockingly common belief (see “heavy boots”, of course, on Google). When I told her the astronauts walked on the moon, so there must be gravity, she immediately said “Oh, right.” So there’s hope.

    I point this out when I give talks (and I cover the height of the Sun and why we have seasons all that in the talk, too): we all have contradictory things in our head, and it’s only when they meet that we can dispel one of them. I just hope it’s the right one.

  2. Doc Kinne May 20, 2008 at 2:19 am #

    >Oh, you’re an astronomer? Can you tell me my horoscope?

    My friends do this to me purposely just to get a rise out of me. The problem is…it works.

    I had one particular friend five years ago who, completely predictably, would constantly ask me upon meeting me, “So, how’s the astrology degree coming along?” This would be followed by him holding me at (his) arm’s length while I desperately (and ineffectually) tried to punch his lights out for the next five minutes.

    And at least your husband isn’t telling you that he knows where Einstein was wrong, he just hasn’t worked out the math yet. Yea. That caused fights. 🙂

  3. Freiddie May 20, 2008 at 3:15 am #

    Oh boy, I can think of millions of examples of these… These misconceptions make me feel sick sometimes, but the good side is that I realize I one of the few people in this world who knows science (As arrogant this may sound, it is so true).

    (P.S. The seasons idea made me think a little… it’s been ages since I’ve been thought about why seasons exist)

  4. Blaise Pascal May 20, 2008 at 8:51 am #

    @Doc Kinne,

    Einstein was wrong. Many people say so. I haven’t worked the math out yet, but I know he was wrong. (I don’t fully understand the math, but I haven’t found a non-mathy description of why GR can’t be quantized, or why QFT doesn’t play well on curved space-time manifolds, but I know they don’t). Einstein being wrong is why people are working on String Theory/Loop Quantum Gravity/other ToEs.

  5. Katie May 20, 2008 at 1:15 pm #

    My college roommate once introduced me to someone as her roommate, “the astrology major.” It was just a slip of the tongue (she was an engineering major, so she certainly knew better), so it was just funny.

    Now that I have young children, I think I know where some of the misconceptions come from. It’s amazing how many children’s books and songs talk about the Moon rising as the Sun sets, as if that’s the only option. I’ve encountered adults at my astronomy outreach events who don’t realize that the Moon can be up in the daytime.

  6. Colin J May 20, 2008 at 3:30 pm #

    I once had my mom ask me why she could see the moon in the sky during the day. I thought Mom knew everything. The she phoned me and asked about how to see Mars bigger than the full moon during one of the Mars Hoax email boondoggles. Sigh…. That was the day I realized that not only doesn’t she know everything, she asks me for help! Which I guess is a good lesson for everyone.

  7. HoosierHoops May 20, 2008 at 4:35 pm #

    Einstein was wrong. Many people say so. I haven’t worked the math out yet
    Well if Pascal can’t work out the math then we’re doomed. 🙂

    Also:

    I realize I one of the few people in this world who knows science (As arrogant this may sound, it is so true).

    Too bad you didn’t learn English all that well.. you forgot ‘am’
    You’d probably get knocked out if you brought your arrogant i’m so friggin smart attitude around these parts..jeez..some people…
    -the hoopster..
    PS.. Pam I love your blog..

  8. Beth May 20, 2008 at 4:36 pm #

    I’m fairly observant of nature and like Pamela don’t remember when I learned about the seasons. But it wasn’t until I moved here where I have good horizons and points of reference that I really *saw* how much the sun moves north and south on the eastern and western horizons as we orbit.

    My favorite misconception is that Polaris (the north star) is the brightest star in the sky. My favorite time disproving that was with about forty Girl Scouts and parents in a big field. We could see Orion and Sirius in the west. They could all find Orion. We found the Big Dipper and then Polaris. Then I said, “You may have heard that the north star is the brightest star in the sky. Is that right?” The resounding “No!” accompanied by fingers pointing to Sirius as a proof by contradiction was wonderful.

    They were very disappointed that we had a full moon at the combined camping trip this year. They wanted to see stars.

    As a computer scientist, I get asked a lot of questions about why someone’s computer does this or that. My favorite answer is “I don’t do Windows.” That usually gets a laugh. I’m a Mac and Unix person although I can usually figure out the Windows problems, too.

  9. Andrew May 20, 2008 at 7:32 pm #

    So its not just me then? Thankyou for small mercies. I thought I was the only one on the internet who knew that 2012 is not going to be the “age of awakening”, or “the ascension”, or the “return of planet X/Niburu/thegreengoddessofeternalloveandlight”. One small thing though…..All these people who have published books and devoted their lives to bringing in the “Age of Aquarius”, what are they going to do when nothing happens? How bizarre.

    Keep up the splendid work Pamela/Phil/Frazer. Love the astronomy casts. Enjoyed the HST episode last week. Hugs and kisses mwwwwaaaaaa!

  10. Mark May 20, 2008 at 10:24 pm #

    Ah, how misery loves company. This reminds me of the questions often posed at science center lectures I or my friends have given.

    This is the reason I love astronomy outreach like giving science center lectures and participating in astronomy day activities. I view those activities as my tiny contribution to “stop the madness.” The most satisfying response to these questions is when you assist the questioner in finding the solution for themselves by applying facts and logic leading them to the appropriate conclusion. Watching the light go on is the best.

    Oh, yeah, my favorite was that both sides of the moon do face the earth, we just don’t see the back because its up during the day. What????? So much for synchronous rotation/revolution patterns.

  11. TK May 21, 2008 at 1:49 pm #

    Star Stryder wrote:
    “But I guess I can understand where the idea of closer=summer comes from…We learn from a young age that close = hot. But don’t we also learn from a young age that planets orbit the Sun on near circles?”

    In my experience, while most of us get at a young age that planets orbit in near circles, as we get older we learn that orbits aren’t really circles–they’re ellipses. And when most people think of ellipses, they think of a squashed circle. Therefore, planets are orbiting such that sometimes they are close to the Sun, and sometimes they are far. Never mind that would mean we should have two “summers” (when we’re close & hot) and two “winters” (when we’re far & cold), or that highly elliptical orbits do not explain why seasons are reversed in the Southern Hemisphere.

    Another possible source of confusion is that many textbooks, when showing the Solar System, show it nearly edge-on to the plane the ecliptic (as opposed to a top-down view). And with an edge-on view, circular orbits LOOK elliptical. So again, at a quick glance, it looks like planets are sometimes close to the Sun in their orbits, and sometimes far.

    Pretty much anytime I ask a group what shape orbits are, “ellipses” is the immediate answer I get. So I’m very careful to always explain that orbits are technically ellipses, but in practice they are actually pretty much circles.

    Apologies for the long reply as a first-time commenter. Dr. Gay–I love your blog, your podcasts, and everything else you’re doing for Astronomy education. Keep up the great work!

  12. Dan May 21, 2008 at 6:08 pm #

    “The sad reality is, these people just don’t think through the if A, then not B consequences of their contradictory ideas.”

    Unfortunately, that isn’t exclusive to science. The same is true for economics, religion, politics, and pretty much anything else that has to do with solving any kind of problem. I think that that is where a lot of our society’s problems come from..lack of following things through to what should be their obvious logical conclusion.

    By the way, I love the blog and the podcast. Keep up the good work.

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