“Questions and Answers” — Students can easily participate in a classroom lecture about basic Earth-and-Sun Relationships. Let me share a few examples of that I sometimes use:
1.Show the Earth-Sun relationships diagram from your textbook (if you use one). I use the Lutgens and Tarbuck “The Atmosphere” textbook from Pearson Publishers.
2.Make sure that you have already answered the question about the distinction between Earth rotation and revolution. They also need to know about the globe grid system (Equator, Arctic Circle, etc.) Then, you can explain the question as to “Why We Have Changing Seasons”.
3.State these are the items to watch for in the video/animation/lecture.
When is the summer solstice, winter solstice, autumnal equinox, and vernal (spring) equinox in the Northern Hemisphere?
What are the sun angle and day length conditions on these dates? Especially note where the 90 degree noon sun angle is located on these dates.
When is the summer solstice, winter solstice, autumnal equinox, and vernal (spring) equinox in the Southern Hemisphere?
Also pose this question — Are the seasons really “reversed” in the Southern Hemisphere? Explain how.
4.Show the video, or better yet use a tutorial animation to take a typical revolution around the Sun and describe the Earth-Sun relations along the way.
(Another option is to use a globe. Walk around the classroom for an example of one solar year. Remember to keep the North Pole pointed to Polaris!) Optional: Have a bright-eyed theatre major portray the Sun.
5.Earth-Sun relationships are one basic geographic concept where it is easy to write up objective multiple choice and/or True-False. The answers should not be arguable … as many “answers” in test banks are. Word these on tests so that there is only one clear answer.
For in-class purposes, this is a good opportunity for Questions and Answers! Students do not have to give an elaborate answer. All questions may be answered with a term or a phrase. Sometimes a simple grunt will suffice. They either know it, or they don’t …
Start with easy ones, and then proceed to the ‘tricky” questions …
(Ask a student) Q: Where are the vertical rays of the Sun on the June 21st solstice? They should look at the diagram, then answer “23.5 degrees N” or “the Tropic of Cancer.” (Don’t be like me, and go off on a tangent about what a “tropic” line is.)
(Ask the next student) Q: What season is it? You can leave that question hanging. You are being bad as a teacher if you do not specify the Northern Hemisphere. Likely the student will answer “Summer” – but that just shows our Northern Hemisphere bias. The date is the first day of Summer in the Northern Hemisphere.
(Ask another student) Q: Then what season is it in the Southern Hemisphere? They should answer “Winter” — as the June 21st Solstice is the Winter Solstice of the Southern Hemisphere, the first day of winter in the Southern Hemisphere.
(Ask the next student) Q: How many hours of daylight are there in North Carolina at the time of the Spring Equinox? The student should know that the answer is “12”. Also clarify that “Vernal” means “Spring”. You may then add with a smile … “And oddly, eggs will stand up on that day …”
(Ask another student) Q: Where are the vertical rays of the Sun on our (Northern Hemisphere) Winter Solstice? They should answer “the Tropic of Capricorn” or “23 ½ degrees South.
Basically, give each student a chance to answer a question by looking directly at the E-S diagram.
(Ask a student) Q: How many hours of daylight are there at the North Pole when the vertical rays of the Sun are on the Tropic of Cancer? Point to the diagram where the Sun’s rays shine over-the-pole to a latitude of 66 ½ degrees North (the Arctic Circle). Hopefully, they will say “24 Hours” and add “Yes, you would not see a sunset that day …
At some point you might get tricky …
(Ask another student) Q: Ok how about … how many hours of daylight are there on … the Arctic Circle … on the date of the Fall Equinox in the Southern Hemisphere?
That seems like a lot! You have Article Circle, Fall Equinox, Southern Hemisphere, which could all be points of confusion … and mental juggling.
Hopefully, the student will see clearly that by you asking “Equinox” there can be only one answer – “12!”. Because EVERYWHERE on Earth has 12-hour day and 12-hour nights at the time of the equinox.
You might add Q: What about at the Antarctic Circle? … the Equator? … the Tropic of Cancer? All answers are of course — 12 hours.
Also say this with a smile: “…and oddly, eggs will stand up at that time”. Who knows, you may get a “is that true?” question from a student who you know is actually paying attention.
This is only one small part of the session. There are many other ways to embellish the Earth-Sun Relationships diagram. There are also many opportunities to discuss various cultural significances to various dates in the solar year.
Of course I add in a lot more questions during live lecture. I want everyone in attendance to participate, and try to give all students an opportunity to answer at least one question.
An additional lecture resource is below: