“Knowledge is an island in a sea of mystery.”
from "Skeptics and True Believers" (1998) by Chet Raymo
This week I was reminded of Chet Raymo’s description of scientific knowledge as an island that we “dike and fill.” But occasionally that island is overwhelmed by a tidal wave of a new paradigm, and then we begin rebuilding.
As a student of history, I appreciate the changes and evolution that many of our mental models and scientific models have gone through. Changing mental models is what some of my astronomy students do in a lab called “The Checkerboard Universe.”
Students begin by writing a paragraph about their understanding of how scientists develop hypotheses, test them and come up with theories. Then they take turns determining specific rules about different patterns of the checkers on the board. After using their checkerboards, students reread their first paragraphs and then write another about their new or confirmed perspective of the role of the scientists.
Here are a couple of student comments from just this week:
• “I learned that you may not even have a question when you begin an experiment, but then you may stumble upon a question once an experiment has begun.”
• “When scientists fail they actually come closer to the answer.”
Our changing view of the universe is one reason I enjoy reading science writers such as Raymo, Sagan and Ferris. I think they give us science arguments in exciting, wondrous story forms.
Barbara, a professor of logic and philosophy, teaches that an argument is a group of propositions one of which is allegedly proven true by the others. I think this is what interesting science writers, these storytellers do. They describe the technological developments and the paradigm shifts. They describe our changing view of the universe around us. Maybe we should all think about becoming better “story tellers” of science.
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Saturday, January 30, 2010
Sunday, January 24, 2010
How do we know the Earth’s axis is tilted 23.5 degrees?
This is a question one of my astronomy students asked last week. That’s a perfectly good question, and I want to answer it using a different style than the one I’m use to.
Imagine you have observed that on one particular day the sun at its highest point in the sky (local noon) is actually low above the southern horizon. Some days later, you notice that the noon-sun is higher, 23.5 degrees higher in the sky than it was for your first observation. Again, days pass and you notice at noon that the sun is even higher than before, another 23.5 degrees higher!
What is making this happen? Why is the sun changing its position in our sky?
Some ideas might be mystical: maybe angels and demons are fighting over the sun, holding their own celestial rugby match.
Some ideas might be more material: maybe the Earth is wildly wobbling on its axis.
A radical idea may be that the Earth is tilted: maybe our rotational axis is not exactly perpendicular to the orbital plane of the earth around the sun.
Is there a test we can conduct to see if the Earth may be wildly wobbling on its axis? Since we’re studying celestial objects oft times we must wait for the universe to do the testing for us and we just observe. Over time we notice that the changes in the position of the sun in our sky happen slowly and consistently.
Around December 21, the noon-sun is the lowest that it’s going to get. Just 3 months later, around March 21, the noon-sun position is 23.5 degrees higher than it was in December. Another 3 months (June 21) and the noon-sun is another 23.5 degrees higher. Again, another 3 months and the noon-sun has returned to it’s mid-position. And then it repeats, over and over.
Researching astronomical records you find the same pattern described far into recorded history. Would these observations rule-out the hypothesis that the Earth is wildly wobbling? The regularity of year after year, century after century, would seem to tell us the movement is not wild.
You start noticing other aspects of the sky, both during the days and the nights. You may notice that the star called Polaris stays pretty much in the same spot of the sky, night after night, year after year. If you travel to the North Pole you may find that on June 21, the noon-sun stays 23.5 degrees above the horizon all day. Another 3 months later and the noon-Sun barely brightens the horizon. Then the North Pole sky is dark for 6 months, but eventually, on March 21, the sun begins to reappear.
Would those observations lead the discerning observer to the conclusion that the Earth’s axis is tilted 23.5 degrees? We didn’t disprove the angelic rugby match!
I’m reading Scientific Inquiry and Nature of Science, edited by L. B. Flick and N. G. Lederman, and I’m exploring this way of thinking about astronomy.
Imagine you have observed that on one particular day the sun at its highest point in the sky (local noon) is actually low above the southern horizon. Some days later, you notice that the noon-sun is higher, 23.5 degrees higher in the sky than it was for your first observation. Again, days pass and you notice at noon that the sun is even higher than before, another 23.5 degrees higher!
What is making this happen? Why is the sun changing its position in our sky?
Some ideas might be mystical: maybe angels and demons are fighting over the sun, holding their own celestial rugby match.
Some ideas might be more material: maybe the Earth is wildly wobbling on its axis.
A radical idea may be that the Earth is tilted: maybe our rotational axis is not exactly perpendicular to the orbital plane of the earth around the sun.
Is there a test we can conduct to see if the Earth may be wildly wobbling on its axis? Since we’re studying celestial objects oft times we must wait for the universe to do the testing for us and we just observe. Over time we notice that the changes in the position of the sun in our sky happen slowly and consistently.
Around December 21, the noon-sun is the lowest that it’s going to get. Just 3 months later, around March 21, the noon-sun position is 23.5 degrees higher than it was in December. Another 3 months (June 21) and the noon-sun is another 23.5 degrees higher. Again, another 3 months and the noon-sun has returned to it’s mid-position. And then it repeats, over and over.
Researching astronomical records you find the same pattern described far into recorded history. Would these observations rule-out the hypothesis that the Earth is wildly wobbling? The regularity of year after year, century after century, would seem to tell us the movement is not wild.
You start noticing other aspects of the sky, both during the days and the nights. You may notice that the star called Polaris stays pretty much in the same spot of the sky, night after night, year after year. If you travel to the North Pole you may find that on June 21, the noon-sun stays 23.5 degrees above the horizon all day. Another 3 months later and the noon-Sun barely brightens the horizon. Then the North Pole sky is dark for 6 months, but eventually, on March 21, the sun begins to reappear.
Would those observations lead the discerning observer to the conclusion that the Earth’s axis is tilted 23.5 degrees? We didn’t disprove the angelic rugby match!
I’m reading Scientific Inquiry and Nature of Science, edited by L. B. Flick and N. G. Lederman, and I’m exploring this way of thinking about astronomy.
Wednesday, January 13, 2010
School Has Begun
The new semester at High Point University has begun, and I'm returning to teach a couple introductory courses in astronomy. I enjoy teaching there, and it affords me the opportunity to continue spreading the good news about astronomy.
On the first day of class I have the students pair off and interview one another. One question they consider is what they want to learn about astronomy during our time together.
Most of my students are second semester non-science-major freshmen. Some take the class just to earn a lab credit or a science credit. Very few have any background experience in astronomy.
Here's the breakdown of responses in my Tuesday class:
want to learn about stars: 6 responses
want to learn constellations: 4 responses
want to learn about planets: 2 responses
want to learn about the universe: 1 response
want to learn about black holes: 1 response
want to learn about astrology: 1 response
want to learn about 2012 and the end of the world: 1 response
Several responses were very general interest in science or astronomy, and some did not address this question at all.
The request to learn about 2012 actually spurred one other student into a recount of her research and her conclusion that the whole "end of the world" hype is just "stupid."
On the first day of class I have the students pair off and interview one another. One question they consider is what they want to learn about astronomy during our time together.
Most of my students are second semester non-science-major freshmen. Some take the class just to earn a lab credit or a science credit. Very few have any background experience in astronomy.
Here's the breakdown of responses in my Tuesday class:
want to learn about stars: 6 responses
want to learn constellations: 4 responses
want to learn about planets: 2 responses
want to learn about the universe: 1 response
want to learn about black holes: 1 response
want to learn about astrology: 1 response
want to learn about 2012 and the end of the world: 1 response
Several responses were very general interest in science or astronomy, and some did not address this question at all.
The request to learn about 2012 actually spurred one other student into a recount of her research and her conclusion that the whole "end of the world" hype is just "stupid."
Sunday, January 10, 2010
My path
A couple years ago, friends at our church gave me a book by Chet Raymo titled "The Path." I enjoy Raymo's approach to looking at the universe. This book is about his spirituality along the footpath from his house to his work.
Today at Church our minister and a dear friend shared the pulpit to speak of their paths to inner peace. One word my friend used struck a chord with me. That word is responsibility or "response-ability." We do have the ability to be in charge of our responses to others and the world around us. "Response-ability."
The minister shared a message about creating a beautiful quilt out of the many scraps life sometimes hands us. How do we make that quilt, travel that path, and be more in touch with the intimate (to learn how to communicate from the heart) and the ultimate (to touch that which is bigger than ourselves)? The answer is simple: with practice. Some practices are meditation, prayer, cooking, gardening, and there are many more.
That led me to think of my practices, how I'm responsible for traveling down the path to spiritual growth (intimacy and ultimacy.) Riding the motorcycle, painting the house, teaching, these to me are almost Zen-like activities. During these activities, I go into a different state of mind, (most of the time) to focus on doing that activity well and not getting distracted by the worries and burdens of everyday life.
I feel these practices have been somewhat successful in helping me sometimes achieve inner peace. I've rarely given them much thought, so now I am aware of them and their possible meaning for me spiritually. I wonder if knowing them in this way, being a little more observant about their place in my life, will change their effect?
Today at Church our minister and a dear friend shared the pulpit to speak of their paths to inner peace. One word my friend used struck a chord with me. That word is responsibility or "response-ability." We do have the ability to be in charge of our responses to others and the world around us. "Response-ability."
The minister shared a message about creating a beautiful quilt out of the many scraps life sometimes hands us. How do we make that quilt, travel that path, and be more in touch with the intimate (to learn how to communicate from the heart) and the ultimate (to touch that which is bigger than ourselves)? The answer is simple: with practice. Some practices are meditation, prayer, cooking, gardening, and there are many more.
That led me to think of my practices, how I'm responsible for traveling down the path to spiritual growth (intimacy and ultimacy.) Riding the motorcycle, painting the house, teaching, these to me are almost Zen-like activities. During these activities, I go into a different state of mind, (most of the time) to focus on doing that activity well and not getting distracted by the worries and burdens of everyday life.
I feel these practices have been somewhat successful in helping me sometimes achieve inner peace. I've rarely given them much thought, so now I am aware of them and their possible meaning for me spiritually. I wonder if knowing them in this way, being a little more observant about their place in my life, will change their effect?
Tuesday, January 5, 2010
The planet formerly known as Red
Mostly I think Mars takes on a butterscotch hue, a touch of orangish rust floating on a background of ebony satin.
The fourth rock from the Sun has been rising earlier and earlier, making it a wonderful sight early at night.T here is was, rising in the East a couple nights ago them setting in the West when I went out early to get the paper the next morning.
Will humans ever get to Mars? Will I live long enough to see it happen?
There are so many obstacles to human presence on Mars. From political and economic here at home, to a lethal environment in the deep reaches of interplanetary space, we humans have quite a challenge facing us.
I rather hoped and believed we would have permanent outposts on the Moon by 2001, just the way Stanley Kubrick presented it back in the 60's. We haven't done too bad, though.
Our robotic explorers have visited many corners of our solar system and peered into far distances of the universe. We are receiving great pictures and wonderful clues from Mars from the rovers Spirit and Opportunity.
But the human presence is missing and that saddens me.
The fourth rock from the Sun has been rising earlier and earlier, making it a wonderful sight early at night.T here is was, rising in the East a couple nights ago them setting in the West when I went out early to get the paper the next morning.
Will humans ever get to Mars? Will I live long enough to see it happen?
There are so many obstacles to human presence on Mars. From political and economic here at home, to a lethal environment in the deep reaches of interplanetary space, we humans have quite a challenge facing us.
I rather hoped and believed we would have permanent outposts on the Moon by 2001, just the way Stanley Kubrick presented it back in the 60's. We haven't done too bad, though.
Our robotic explorers have visited many corners of our solar system and peered into far distances of the universe. We are receiving great pictures and wonderful clues from Mars from the rovers Spirit and Opportunity.
But the human presence is missing and that saddens me.
Monday, January 4, 2010
2010
I was born in 1951. I say that year as reading the words "nineteen fifty-one." Barbara and I got married in 1972 ("nineteen seventy-two.")
I don't say those dates as "one thousand nine hundred fifty-one" or "one thousand nine hundred seventy-two."
So consistency seems to lead me to call this year "twenty-ten" instead of "two thousand-ten."
At the same time, I'm trying to develop more of a scientific attitude, one that does not embrace tradition merely for the sake of comfort. Maybe we'll talk about the status of the dwarf planet Pluto one day, but today I'm interested in the consistency and tradition of saying the date as "nineteen something" instead of "one thousand nine hundred something."
I'm also interested in doing the work I want to do while expending the least amount of energy. So I counted syllables.
"Twenty-ten" has three syllables and "two thousand ten" has four syllables.
In the interest of efficiency and the knowledge that I'll be somewhat consistent, I'll be calling this year "twenty-ten."
Now, I wonder, all the energy I am going to save by being so efficient, was that just used up with all this rationalization?
I don't say those dates as "one thousand nine hundred fifty-one" or "one thousand nine hundred seventy-two."
So consistency seems to lead me to call this year "twenty-ten" instead of "two thousand-ten."
At the same time, I'm trying to develop more of a scientific attitude, one that does not embrace tradition merely for the sake of comfort. Maybe we'll talk about the status of the dwarf planet Pluto one day, but today I'm interested in the consistency and tradition of saying the date as "nineteen something" instead of "one thousand nine hundred something."
I'm also interested in doing the work I want to do while expending the least amount of energy. So I counted syllables.
"Twenty-ten" has three syllables and "two thousand ten" has four syllables.
In the interest of efficiency and the knowledge that I'll be somewhat consistent, I'll be calling this year "twenty-ten."
Now, I wonder, all the energy I am going to save by being so efficient, was that just used up with all this rationalization?
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