Hate to break the bad news to you, but Punxsutawney Phil has predicted 6 more weeks of winter! Of course you know the tradition-if it is cloudy when a groundhog emerges from its burrow on this day, then spring will come early; if it is sunny, the groundhog will supposedly see its shadow and retreat back into its burrow, and the winter weather will continue for six more weeks.
Of course we know predicting the weather is not really dependent upon the groundhog (also known as a woodchuck-which by the way is a rodent of the family Sciuridae, belonging to the group of large ground squirrels known as marmots-who knew?) seeing his shadow, but the tradition is a fun one! (To learn more about the tradition, check out the post I wrote back in 2013-has some great activities you can do with your kids). Here in the Virginia Beach area we have our own weather guru known as Chesapeake Chuck and given the weather today (cloudy) his prediction might say spring is coming early to our area!
Whether spring comes early or not, Groundhog Day does allow us to answer the question how are shadows formed? Shadows are created when an object blocks light. In order for the object to block light, it has to be opaque or translucent. Depending on the grade you teach, you either may or may not have to teach these terms. If I were explaining how shadows are made to either a group of Pre-K or Kindergarten students, I would simply say that any object that blocks light makes a shadow. Don’t even worry about translucent and transparent materials just yet.
For older students, they need to know the difference between the terms. An easy way to help students remember the difference between opaque and translucent and transparent is to teach the meaning of the prefix “trans.” Trans is a Latin prefix that has the following meanings: across, beyond, and through to name a few. By teaching students that translucent, transparent means to let light “through” they can remember the difference between opaque and these two.
Okay so what do you do to help kids remember the difference between translucent and transparent because they sound so similar? Again, focus on how the words are made! Let’s start with translucent. Translucent means to allows some, but not all, light to pass through it. If we go back to the prefix of the word, remember trans simply means through. In Latin, the stem of the word was “luceo” which means to shine. So essentially translucent means shining through! Frosted glass allows some light to shine through but not always an image of the object.
Transparent allows allows all light to pass through it. Because light passes through it, transparent objects will not make any shadows, as light will pass straight through it and you can see the image. Think about a cup of water in front of a picture. You will see the picture through the glass!
And you thought you would never need Latin! If you teach PreK-K, here is a free lesson that will have your students understanding how the position of the light source can change a shadow. The lesson is called Where is Punxsutawney Phil’s Shadow? I hope you enjoy it and I hope you have fun with your kids learning about shadows!