Science Buddies Blog: November 2011 Archives
By Kim MullinPumpkins seem to be everywhere in the fall, and with good reason. Fall is when pumpkins turn ripe, so we eat them (mmm, pie!) and use them for decorations.
If you've ever opened up a pumpkin, you know that it is full of "pumpkin guts." Stringy, messy, and full of seeds, many people just throw the guts away. Others like to roast the seeds for a tasty snack.
A pumpkin is a squash. Open up other kinds of squash, such as an acorn or butternut squash, and you'll find similar stringy guts, full of seeds. Why? Because seeds are how many plants make new plants. If you plant seeds from a fresh pumpkin, with a little water and care, you might get a new pumpkin plant next year—your very own pumpkin patch!
Why do you think pumpkins have so many seeds? After all, some fruits, such as an avocado have only one giant seed. Do all types of squash have lots of seeds? And what about size? Do you think that a large pumpkin will have more seeds than a small one? Explore more about seeds in different kinds and different varieties of fruits in the How Many Seeds Do Different Types of Fruit Produce project.
By Kim Mullin
Although most of us don't live on farms, harvest is something we think about in the fall. We decorate with pumpkins, gourds, and multi-colored corn when we celebrate fall holidays. And, in the United States, many of us eat a hearty meal on Thanksgiving Day to commemorate the Pilgrims' first harvest celebration in 1621.
You may have heard of the Harvest Moon, but the moon certainly isn't something we can harvest! It is actually a term to describe the full moon that is closest to the autumnal equinox. It happens at a time of year when farmers are busy harvesting crops—thus the "harvest" moon.
Phases of the Moon
The full moon is only one of the moon's phases during each lunar cycle. You may know that the moon plays a role in the ocean's high and low tides. But does the "phase" of the moon matter? In The Moon and Tides project, students can investigate the correlation between phases of the moon and the tides. Charting the tides in relation to the phases of the moon over a year lets students track the differences in tides during a full moon and a quarter moon, for example.
Do the phases of the moon also effect agriculture? Do plants need moonlight to stay healthy? Do they grow better when planted during a particular phase of the moon?
Thanksgiving is still a few days away, but the Harvest Moon for 2011 happened a few months ago! Still, these are questions students and families might consider as "harvest" comes to the table and the fall harvest season begins to ebb.
For many of us, Thanksgiving brings with it the feast mentality and ushers in a season full of special treats and baked items. From familiar pecan and pumpkin pies on Turkey day to dozens and dozens of cookies throughout December, 'tis the season of homemade goodies.
Clever bakers can turn the extra time in the kitchen into a scientific smorgasbord of experimentation. Starting with investigations into the role of baking powder, the use of egg substitutes, the secrets behind flakey crusts, and the quest for perfect chocolate chip cookies, the kitchen can be a hotbed of science (and math)!
But kitchen science doesn't have to be about dessert. Aspiring food chemists can find all kinds of recipes for exploration, even some that let them investigate the science behind human health and nutrition and current eating crazes. For example, what's up with gluten?
Holding It Together
Breads and bread- or grain-based dishes are, for some, the top of the comfort food list, and what you like best about certain foods may boil down to the presence of gluten, a protein found in wheat, rye, and barley. From pasta to pizza dough to giant pretzels, many familiar food items contain gluten. With its connection to wheat, this may sound like a good thing. After all, there's been a strong "whole grains" push in recent years, which accounts for more lunchboxes containing wheat or multi-grain breads. But the words "gluten-free" appear in more and more conversations, magazines, and ads these days.
There is a health condition related to gluten. Celiac disease, also known as gluten intolerance, is a genetic disorder. When people with celiac disease eat something with gluten, the small intestine reacts and can be damaged. For those with celiac disease, eating gluten-free is a necessity, not a lifestyle choice. But many people are choosing to follow gluten-free diets.
What's the gluten debate all about? What role does gluten play in familiar foods?
These are questions the student scientist can explore while experimenting with some favorite recipes. The Great Globs of Gluten! Which Wheat Flour Has The Most? project lets students investigate the role of gluten in foods. Be forewarned though, this project is completely hands-on in every sticky, gooey way!
After getting a better understanding of the influence of gluten, students can go on to taste-test recipes that contain varying amounts of gluten or no gluten.
With its emphasis on creepy, crawly, nighttime fun, Halloween is a perfect time for things that glow, from the flickering lights inside carved pumpkins to neon sticks. Last week, we took a look at the chemical reaction that happens when you snap open a glow stick—and a great chemistry project that lets students put their electronics-knowhow to use to measure the power of a glow stick's chemiluminescence.
'Glow' can be fun, but 'glow' can also be used to detect things otherwise invisible to the naked eye. Many things glow under a black or ultraviolet light, and casting a black light around a crime scene is a familiar part of a forensics investigation. A black light and a specially formulated hand "lotion" can even help students better visualize the lasting power of germs!
As the pumpkins on the stoop cave in and find their way to compost, the shifting seasons—and the 'flu shot' banners hanging in many pharmacies—bring winter colds to mind. Good hand washing is always important, and you can catch a cold at any time—not only in fall and winter months. But with Halloween over, a heightened awareness of "flu season" kicks into gear.
You may have heard that you should wash your hands for a full twenty seconds—a length of time you can approximate by singing "Happy Birthday" twice. If you wash for twenty seconds, odds are that you'll have gotten most of the germs. Right?
It depends. Are some areas of the hand harder to clean than others?
Putting It to the Test
In the Spread the Soap, Not the Germs microbiology project, students can investigate hand washing and explore questions related to length of time, parts of the hand, and even temperature of the water used for washing. Using Glo Germ, students add glow-ready germs to their hands and then wash them. After washing hands, they can use an ultraviolet light to see whether they "got" all the germs or not.
If germs always glowed, healthy hand washing habits might be a lot easier to instill!
Taking It Further
If you're interested in exploring germs—either the spread of germs or efforts to get rid of germs—you can find many ways to customize or alter the Spread the Soap, Not the Germs project. Do you use a no-wash antibacterial hand sanitizer? Put it to the Glo Germ test! Or, take a completely different approach and explore the way germs travel during typical school interactions. Get the germ train rolling by planting some Glo Germ either in a central (or much-touched) location or on someone's hands. How many students in a class will pick up the germs by the end of the day?
Wath the Glo Germ Dragonfly video with this project to see how Jordan and Sydney put Glo Germ to the test to investigate the spread of germs—and the best way to prevent germs from spreading when you sneeze!