Discussion of Challenge Question #4:

Last week we asked you to predict what your graph will look like on March 20, 2006, the Vernal Equinox, and explain why. Predictions came in from Indiana, South Carolina, Michigan, Connecticut, Iowa, Ohio and Minnesota. As you'll see below, everyone correctly explained and predicted that the photoperiods for everyone on the Equinox should generally be about 12 hours. The unanswered question is why does this happen on Equinox? The answer lies in the fact that on the Equinox, the Earth is not tilted on its axis toward or away from the sun.

Two classes raised an interesting question for you, as they wondered whether Mystery Class #6 will actually follow all the other classes and converge at 12 hours? What do you think will happen? Keep your eyes on the graphs.

In the meantime, here are some of your answers--great job!:

Robin from Mimo Academy Homeschool, Crawfordsville Indiana wrote:
I think all of the lines will meet right at 12 hours. This is because the equinox is when day and night are the same length, and so they would each be 12 hours long.

Miss Williams' Class, Sara Collins Elementary in Greenville, South Carolina explained: On the Vernal Equinox, all 10 mystery classes will be at the same point on the graph. This will happen because during the Vernal Equinox, every body in the world will receive the same amount of sunlight.

Students from John Paul II Homeschool Academy in Minnesota gave their prediction and added some Latin translation too:
We think that each Mystery Class photoperiod will be equal (12:00), including Mystery Class #6. This would be due to the equinox, the day in which almost all places on earth have an equal amount of night. (We found out that equinox comes from the Latin word "equal night". )

The 6th Grade Science Students from Holt, Michigan raised one interesting question about a specific Mystery Class however: We think that all of the mystery locations will have about 12 hours of daylight on March 20, 2006. We're not as sure about Mystery location #6. Some rapid changes will have to take place if they only have 12 hours of daylight by then. On our line graph, if we extend the lines, they look like they will intersect at 12 hours on March 20, except for #6. Equinox means equal day and night for everyone, that should be true for all places on earth.

Chris Persell wrote:
I think that on the Vernal Equinox all the photoperiod times will come together except for the mystery class #6. It will be becoming spring or fall. I think the photoperiod for mystery class #6 will drop suddenly, but not on the Vernal Equnox.

Thanks to everyone who responded to this Challenge Question