Daaaaaaang

One of my students, Jacob, just popped open the door and said
"Question! When a space shuttle docks onto the International Space Station...does it bring its orbit closer to Earth...because of the mass change?"

Whew. I have to chew on that for a while. Here is what I am thinking....the difference in mass is so minute in comparison with the scale of the orbit of the station that it doesn't really affect the orbit distance. Kind of like the idea that technically I have a gravitational pull on the Earth, but since my mass is so much smaller than the Earth's it doesn't really matter. Hmmm....

Then the conversation turned to whether or not satellites naturally fall to the Earth. My first thought was, yes, they do. However, upon further reflection...and some searching...I realized that it has a lot to do with centripetal acceleration. A satellite reaches an optimum speed and the centripetal force outward balances the pull of Earth's gravity. Kind of like when something is swung on the end of a string. If its not fast enough it won't move in a circle and all is lost.

I guess when you breed critical thinking...your morning gets completely turned upside down in one question.

Jacob....want to comment?

Layered Liquids

In Science 8 and Science 9 we have been learning about density. We looked at the properties of different liquids to see why they might stay separated into layers.

Grace took this pic of the density column as her group investigated why it layered.

(Thanks, Grace!)

Students dropped different objects in the column to see if they sank or floated. Some objects were suspended between layers!

Check out the Science 9 Blogs for student explanations about why some objects sank and some objects stayed suspended. Remember, this was the very beginning of our investigation into density...so our thoughts are still developing. :)

SMASH DAY!

A former colleague of mine, Rosalie Whitney, gave me a great idea for incorporating problem-solving, communication, listening, and critical thinking (all the great science skills!) into science classes at the middle school level. Her version was called 5 F's (First Friday's Fanatical Findout Feat).

The HIS version is SMASH! Smith's Marvelously Awesome Science Hoopla.

The Mission:
Look at a "mystery structure" and communicate it to team members so that they can build the exact same structure without actually ever seeing it.

The Mystery Structure:
The Work:

Jean studying the mystery structure to try to describe it to her team.

Jez, Connie, and Tim working hard to understand the instructions.
Artie waiting patiently while his communicator gets instructions (I made him take a pic with me!)
Kevin and Jordan getting animated in their description
Lydia working to find the right colored block...only a few minutes left!
Kevin separating some pieces that were put together in the wrong order.
Duke using his hands to show the order of the blocks.

8th grade students really focusing on the mystery structure!Finally, the 9th grade students in action...watch them work!