Science Buddies Blog: November 2009 Archives
As post-Halloween sugar highs ebb and trick-or-treat stashes wane, the days of pre-packaged, ready-to-eat treats give way to the smells of freshly-baked bread, pies, cakes, gingerbreads, and a variety of other family favorites. Indeed, as the year winds down and the days shorten, the kitchen can become an epicenter of activity. With classroom potlucks, family dinners, and a string of potential holiday gatherings dotting the calendar for November and December, the making and baking of traditional classics, festive treats, indulgences, and comfort foods becomes a backdrop against which the days - and dinners - unfold.
These activities also set the stage for wonderful moments of cooking chemistry. Whether you are looking to improve a favorite, hoping to boost the health factor of something on the menu, or are just curious about the ins and outs of the recipes being prepared, holiday baking offers an inviting and accessible test-bed for exploring chemical reactions.
Even my youngest, at five, likes to help mix up muffins and baked goods. Cracking eggs is, of course, one of the chief (albeit messy) satisfactions for the youngest of bakers. But curiosity about ingredients and an awareness of how many things "go into" the batter or mixture starts early. For older students and budding chemists, this curiosity can easily be channeled into questioning "why" we use certain ingredients.
What can you substitute in a pinch and why? How precise do measurements need to be? What happens if you leave this out or double that?
The list of questions that might arise as you watch the liquids and the flour mix together in a swirl of vanilla and cinnamon and pumpkin are seemingly infinite. Those questions, in fact, often are the launching point of innovation, of a new recipe, of an updated twist on a classic, and... maybe... of a science moment in the making.
Whether it's over Thanksgiving or Winter Break, just a regular rainy weekend or snow day, or a special Friday afternoon in class, there's a lot to gain from turning the kitchen into a lab. Just be sure and wash hands first!
Heat up the kitchen with the following project ideas:
- Egg Substitutes (Science Buddies' Difficulty Level: 2-5)
- Sugar vs. Sugar Substitutes: Are They Just as Sweet?* (Science Buddies' Difficulty Level: 3-4)
- Great Globs of Gluten! Which Wheat Flour Has The Most? (Science Buddies' Difficulty Level: 4)
- Chemistry of Baking Ingredients 1: How Much Baking Powder Do Quick Breads Need? (Science Buddies' Difficulty Level: 5)
- Perfecting Pastries: The Role of Fats in Making a Delicious Pastry (Science Buddies' Difficulty Level: 5)
- Yeast Reproduction in Sugar Substitutes (Science Buddies' Difficulty Level: 6)
- Chemistry of Baking Ingredients 2: Can Baking Soda Substitute for Baking Powder in a Recipe? (Science Buddies' Difficulty Level 6-8)
Shortly after finding out she was one of thirty teachers selected to participate in a Zero-G flight as part of the Weightless Flights of Discovery Program, sponsored by Northrop Grumman, Erin Moore, an eighth grade teacher at Lincoln Avenue School in Illinois, gave Science Buddies an inside look at her sudden shift from "teacher" to "astronaut" - in her student's eyes. Her awareness that her students had already put her in orbit, left her faced with a philosophical decision: correct their assumptions or enjoy the sudden spark of enthusiasm she saw in their eyes about something related to science. Clearly Erin is a teacher who thinks a lot about her responsibility to her students, to their education, to their understanding, and to their dreams. We at Science Buddies have little doubt that Erin's students are lucky to be learning both science and life from a teacher like Erin.
She may not have gone to space, but as you'll see from Erin's recap of her flight, the experience was transformational, to say the least. Here's a look at the flight in her own words:
Recently, I had the opportunity to experience weightless flight though a program sponsored by the Northrop Grumman Foundation. Now my task is to find words to describe feelings that go beyond ordinary description. To put it simply. I felt like all the rules of the world had been broken, and I was a child in a playground finding out how it all worked again.
Here's how it went.
5:45: Day starts. Wake up and pack.
6:45: Go to the meeting area and have a nice breakfast. It was more food than I thought they would allow. There were sweet breads and many of my favorite fruits, but remembering that I could easily get sick, I tried to refrain from eating too much.
7:30: A pre-flight news and media event begins. Quickly we start to change into our flight suits and notice that our name tags are upside down. "That is on purpose, a tradition," I am informed when I point it out. The name tags should stay upside down until I have been upside down.
7:40: There are cameras flashing, breaking the darkness of the room. Our eyes struggle to adjust to the presence of the media.
8:00: Our pre-flight briefing is a movie. One of the first rules discussed is "no swimming." (We are told that the closest thing our body can relate to weightlessness is being underwater. So "no swimming.") Next, "no jumping" because we could easily hit our heads on the top of the plane. Lastly, "no kicking" because it could cause injury.
10:00: After a lengthy check and re-checks from TSA agents, we are finally aboard the plane.
The weightless portion of my flight begins, and I begin to break every rule they have carefully explained to me.
The first parabola was "martian gravity," about 1/3 my body weight. I would push off the floor and find it easy to push myself 2-3 feet in the air. I would then sink slowly back to the ground. The whole thing felt as I had dreamed for all these years that it might.
The next 2 parabolas were Lunar gravity. I experimented with 1/6th of my body weight by doing push-ups and bouncing jumps. By this point, none of the teachers on the plane tried to maintain any pretense of composure. We were laughing, screaming, and shouting for joy. Even as I was constantly bumping into people, I was filled with happiness.
The next 12 parabolas were zero g.
The first time I felt myself lift from the bottom of the plane, it was effortless. I was floating away. "I'm floating." Those were the only words I could say.
Just "being," surrounded perfectly by air, no struggle, no trying to keep that position... was magical. After 2 more parabolas, I laughed and played like a child who has just learned to balance a bike and takes off, soaring with freedom. I broke the rule of trying to swim through the air on a consistent basis. "Swimming" was the only way I could figure to try and affect my world, to move through it. Without gravity, I had no way of going from point A to B. I flared my arms like a bug turned upside down, but it was pointless.
As I grew accustomed to weightlessness, I started to pull my legs behind me. I started to think of myself only as my rib cage and arms. My legs were useless. In a zero-g environment, I existed only in my upper torso. That was the only way to affect my world.
The world had become a playground on that plane. We played with bubbling water and an air-zooka for propulsion. And, of course, there were floating M&M's, an astronaut favorite. I felt like a child with some idea of logic and no fear. I would try any experiment. Like a toddler first ready to walk, I was ready for the next step. Even in the noise of the airplane, there was a quiet stillness within me. I crossed my legs and felt... nothing, the nothing of being surrounded by air. The moment I was floating, tumbling upside, rolling over and over through air, I had achieved a dream set out by mother and myself 27 years ago.
The laws of Newton were evident during the flight. I could not move if I did not have something to push off of, pull myself towards, or collide with. The middle of the airplane was a no man's land. In the middle, I could struggle but get nowhere, until gravity returned to claim me and pull me to the floor of the plane again.
Every 20 seconds of zero-g, ended with me falling to the floor of the plane and laying on the floor. During the deep dives, gravity would take back its gift and exact a toll of 1.8gs. I felt the painful pull of Earth mostly in my ears and jaw, but I managed each time by focusing my eyes and concentrating on my breathing until I adjusted. I would spin, float, swim, and laugh for the next hour, hardly aware of the passing time.
11:15: The flight ended. Now I was back at a re-gravitation ceremony. I had snickered to myself when I first saw this part of the day on the schedule. A "re-gravitation ceremony"? But it was truly needed. When I was back on the ground, I felt the real pull of the Earth in a way I never appreciated before. I felt the Earth pulling me, and I felt my slight pull back. It was at that moment -- and every moment since -- that I marveled at Newton. Issac Newton figured out his laws of gravity and motion without any benefit of weightlessness. It wasn't until I was weightless that I could say, "I get it!"
So now the task is how to explain this experience - and the science behind it -- to my students. I will tell them that the world through the eyes of a scientist is a playground. A scientist is a person who appreciates every aspect of the world because she understands the incredible amount of magic involved. A scientist marvels at the millions of things that are going right to provide something as simple as a breath of air. To study and appreciate science means that you can dream of the incredible, fly through the air, sense the magic of life, and imagine what we can do. To look at the world in the way a scientist sees it is the happiest of ways. It reminds me of the joys of the greatest scientists, young children.
As Erin notes, it's hard to really "get" the concept of gravity until it's taken away. In talking with your students and classes about gravity, here are some Science Buddies Project Ideas that might be helpful and eye-opening:
- Centripetal Force Science Buddies' Difficulty Level: 2
- Parachutes: Does Size Matter? Science Buddies' Difficulty Level: 4
- Distance and Constant Acceleration Science Buddies' Difficulty Level: 6
- Balancing Act: Finding Your Center of Gravity Science Buddies' Difficulty Level: 6-8
Many thanks to Erin for taking time from her busy school schedule to write this post-flight piece for us to use on the Science Buddies Blog!
Earlier this week, I talked about a paper chromatography project that offers a perfect opportunity for younger students to observe the pigmentation of Autumn leaves and then a make-your-own-markers project that can turn a pile of leaves into a set of homemade art supplies.
For a different spin on fall foliage, the "Leaves and Light" project explores the two kinds of chlorophyll present in plants and the degree to which the color and wavelength of light affects the chlorophyll content of a leaf. With a Science Buddies' Difficulty Level rating of 2 and a time frame of approximately a week, this project is one that can be done at home or in a classroom over a span of days.
For more independent work with fall leaves, the "Chlorophyll Extraction" API offers an abbreviated project idea with a Science Buddies' Difficulty Level rating of 3.
One of the things that I often miss living in the Bay Area is the definitive visual change of seasons. Having spent many years in Appalachia, I grew up with the splendor of Autumn unfolding around me each September, the array of intense reds and golds giving way to barren branches poised to hold ice and snow through the winter months. It's very different when you live where there is never a hard freeze.
Given that things seem to bloom almost year-round here, I often forget about Autumn foliage, about what it looks like to drive a mountain road and see trees dipped in color, about what it means to have to rake a yard and bag up leaves, about the crisp crunch of them underfoot. Drive an hour south, however, and you run right into changing trees, even ornamental trees in parking lots and around industrial buildings are saturated with color. As I pulled into a parking spot last week for a Science Buddies' meeting, I saw the colors of "fall" in trees all around me and got to thinking about the opportunity these leaves present for studying pigmentation and even chromatography with my kids.
A quick search on the Science Buddies' site turned up a great project with which to dig beneath the surface of things and get a better understanding of what's going on within the leaves at this time of year. With a Science Buddies' Difficulty Level rating of 1 and a timeframe of less than a day, the "What Color Are the Leaves Really Turning?" project idea is perfect for even the youngest of classrooms or for a home-based after-school project. The project involves gathering leaves (a nature walk), sorting them by color (math), and then extracting the pigment by mashing (fun) the leaves in alcohol (a solvent). Once the color has been extracted, ordinary heavyweight paper towels cut into strips allow simple chromatographic analysis of the colors in each extract letting you see the range of colors at play.
There's a lot going on in this simple-to-perform experiment!
Expanding these fundamental concepts and procedures a bit, the Make Your Own Markers project uses color extracted from plants and paper chromatography to make homemade markers. This project can also be done with spices, richly colored vegetables, and other plants, but if an abundance of Autumn leaves are nearby, you've got the makings of a nice set of red and orange markers!
The November 15 deadline for the 2010 NCWIT Award for Aspirations in Computing is approaching.
All US high school girls in grades 9-12 (excluding previous winners) are invited to apply. Awardees receive both cash and technology prizes.
For more information and complete application details, visit http://www.ncwit.org/award.
The annual NCWIT Award for Aspirations in Computing is organized by the National Center for Women & Information Technology and is sponsored by Bank of America. Thanks to support from the Motorola Foundation, applicants in Texas, Illinois, and Florida will also be considered for Affiliate Awards.
To find out more about NCWIT and the Aspirations in Computing award, watch the 2009 NCWIT Award for Aspirations in Computing ceremony video.
Science Buddies offers a number of high-tech science fair project ideas. Check out our list of projects in computer science, sponsored by Symantec, and our list of projects in video and computer gaming, sponsored by the AMD Foundation.
Does it take you a bit of time to settle in once the time changes? Did you or members of your family wake up earlier the day after the time changed? Do you notice already the changes in available light during the day? Do you know "why" the time changes? Did we gain an hour or lose an hour? Aren't there just 24 hours... regardless?
It's interesting to note that while observing Daylight Savings Time is not mandatory in the United States (and not even all states participate), Daylight Savings Time is regulated by the Department of Transportation. For a look at the history of Daylight Savings Time and its connection to "travel," see National Geographic's "Daylight Savings Time 2009: When and Why We Fall Back."
The end of Daylight Savings Time last weekend and the changing of clocks "back" an hour may have generated some buzz in the teacher's lounge and in the hallways. But, whether the clocks move forwards or backwards, there are still 24 hours in the day.
The "A Matter of Time" Science Buddies Project Idea calls into question the assumption that "a day is a day is a day." The project introduces students to several systems of timekeeping used around the world: Standard Time, Sidereal Time, and Solar Time. Are all of them equally accurate? The project uses an online tool to help track and assess the accuracy of time depending on which system of measurement is used. Variations of the project can be used to consider issues related to Daylight Savings Time and Lunar Time.
After drawing conclusions about how many hours there really are in a day, the change in time and the ways in which we react to the change leads nicely to introductory discussions of Circadian Cycles, in humans and in other life forms. The following long-term Science Buddies' project ideas explore patterns of response to the time of day (or to light and dark):
- Can Your Body Temperature Tell the Time of Day? Find Out with Human Circadian Cycles. (Science Buddies' difficulty level: 6)
- Tick Tock, Tick Tock, Does Your Mouse Know the Time on the Clock? (Science Buddies' difficulty level: 7)
- Bioluminescence: Investigating Glow-in-the-Dark Dinoflagellates (Science Buddies' difficulty level: 7)
I wrote earlier about my trek to the northeastern corner of California to attend the Golden State Star Party. My objective was to photograph a galaxy, and after checking out the pristine skies during my first night of observing, I selected my targets: M81 and M82, a close-by pair of galaxies in Ursa Major (the Big Dipper).
Some nearby galaxies appear fairly large in the sky, surprisingly, almost the size of a crescent moon in the case of M81. But the surface brightness is extremely low, so such galaxies are not visible to the naked eye. Even through my telescope eyepiece, M81 is little more than a smudge of light. To see interesting detail takes a very large telescope, a long photographic exposure, or both. Since I had never taken photographs of this type, preparation took months.
There were three areas where I needed to do research, purchase equipment, and practice:
- Even though my telescope has a mount that compensates for the earth's rotation, I knew that small errors could creep in and smear my pictures unless I made corrections. I've done this by hand for relatively short exposures, but I knew that my photos of M81 and M82 would take hours of exposure, so I purchased and learned to use an autoguider, which is an auxiliary camera on a small telescope piggy-backed to the main one. If the target moves even a fraction of a pixel off center, the autoguider sends a correction to the telescope mount to compensate.
- When doing long exposures with a digital camera, one typically breaks the total exposure into pieces (5 minutes each in my case), and then stacks the resulting exposures in a program like Photoshop. This stacking reduces the noise in the resulting photograph. You can press the shutter by hand, but I chose to obtain special software and cables to remotely control the Nikon DSLR that I planned to use for the photographs. From my laptop computer, its screen covered with red Plexiglas® so as not to disrupt my night vision, I could view through and control both my autoguider and my Nikon.
- Finally, it is very difficult to focus a telescope with a camera attached because the image is so dim. I chose to purchase and use a Bahtinov mask, which is a strangely shaped mask that I put over the lens of my telescope only while I am focusing it. The mask produces a diffraction pattern around any star. This pattern indicates whether the image is in focus and, if not, in which direction to turn the focus knob - it's pretty slick!
Having worked most of the kinks out in advance, I was very happy with my results; however, there was a surprise. I found that earth-orbiting satellites were streaking across five of my exposures. Fortunately, when stacking the images, it is possible to make these streaks disappear. In my next entry I'll discuss the nature and size of M81 and M82.
Curious About Astrophotography?
Whether you come at it from an interest in astronomy or an interest in photography, astrophotography is an eye-opening field that combines art, science, and technology. If you are interested in learning more about astrophotography with digital cameras, these resources will help get you started:
- The Digital Photos and Dynamic Range Science Buddies Project Idea discusses important information that any astrophotographer needs to understand.
- Catching the Light is a good general source of information about digital astrophotography.