These black seeds are from luffa sponges, genus Luffa.
The plants belong to the same family as squashes and cucumbers. The have large yellow flowers, a vining growth habit, and fruit that roughly resembles a zucchini or cucumber.
A botanical drawing by Francisco Manuel Blanco from Wikimedia.
The young fruit may be eaten. For example, in Asia the young luffas are used in stir-fries (peeling off the bitter skin is recommended).
The seeds were on the ground near a bin.
I don’t think anyone would want to eat these, but they were for sale. Why?
If you peel off the brown outsides, you will discover why.
There’s a beautiful luffa sponge inside.
We bought some seeds of two different kinds, so hopefully I’ll be able to show you more about growing luffas next fall.
Our science fun this week was inspired by the nonfiction picture book Pop!: The Invention of Bubble Gum by Meghan McCarthy. Kids will enjoy the lively story of how accountant Walter Diemer started mixing this and that ingredient (at the factory where he worked), until he had invented a gum that could be used to blow bubbles. What a sweet tale!
This book just cries out for some hands-on activities.
Activity 1. Which type/brand of gum blows the best bubbles?
Gather:
Several brands of bubble gum and regular gum
Ruler (decide on inches or cm)
Pair of tongs or cardboard bubble caliper (see below)
Volunteer(s) to chew the gum and blow bubbles
Paper and pencil to record the results
The most difficult part of this project is finding a standard way to measure bubbles that are often a moving target. Check this website for a photo of a “bubble caliper” used for measuring record bubbles. Think about how you might build something similar or find a pair of kitchen tongs that might open wide enough to accommodate the largest bubbles. Try to find the widest point of the bubble. Practice on a few bubbles to make sure your system works and is relatively consistent.
Predict which brand will produce the biggest bubble. Now give the volunteer(s) each one stick of each type/brand of gum. Allow them to chew the gum for a few minutes and then blow bubbles. When they are confident that they are blowing the best bubbles they can with that type of gum, have them blow a few more and measure them. Decide how many bubbles of each type of gum you are going to measure in advance, so you record the same number for each test.
When you are done, add up the size of the bubbles for each type, and then divide by the number of bubbles you measured for that type. This will give you an average. You might want to graph your results with a bar graph to easily see the differences between the brands/types.
Activity 2. What happens to the gum when you chew it? Does it gain weight from the moisture in your mouth, lose weight, or stay the same?
Gather:
accurate kitchen scales
gum
wax paper to protect the scale (or the wrapper)
watch or timer
First, predict what you think will happen. Take the wrapper off the gum. Place a piece of wax paper on the scale, and tare or zero the scale. If your scale does not tare, the record how much the wax paper weighs. Next place the dry gum on the scale. Record the weight (subtract the weight of the waxed paper if you did not zero it). Leave the wax paper in place.
Now chew the gum for one minute and weigh again. Record the weight. Weigh again at five minute and then at ten minutes of chewing. What is happening? Did the results follow your prediction? Try to figure out why or why not. Test more sticks and different kinds of gum, and have your friends and relatives try it, too. See if you get the same results.
Activity 3. Make your own bubble gum.
This video shows how bubble gum is made in a factory.
You can find kits and online recipes to make your own bubble gum (for example at Steve Spangler).
Try some other formulas, too. Be sure to write down what ingredients and the methods you use. Maybe with some time and the right ingredients, you could be the next Walter Diemer and discover something thrilling and new.
It is cold and windy this morning. The only insects that are still active are the fruit flies in the compost heap.
Why are they still active? Probably because the rotting compost gives off heat. It is the warmest place in the yard.
Fruit flies of the genus Drosophila are easy to identify because of their bright red eyes.
You might also recognize that the white crawly things are the fruit fly larvae. (Photo by RickP at Wikimedia)
What are not so easy to identify are these funny little brown objects.
Those are the fruit fly pupae. The larvae change into pupae, usually after crawling out of the food to a drier location. Adults emerge from the pupae.
It is appropriate to honor the fruit fly here at Growing With Science. The humble fruit fly have been been the backbone of scientific work on genetics and developmental biology for over a century. Way to go, fruit flies!
Have you ever used fruit flies for a science project?
