Physics & Physical Science Demos, Labs, & Projects for High School Teachers

Powers of Observation

Posted on: January 7, 2009


(This was submitted by Duane, a High School teacher in Georgia.  Thank you Duane.)

One fun “observation vs. conclusion / assumption” demo that I love came from Flinn Scientific’s “A Demo A Day” for Chemistry. I call it the “Potato Candle”.

Cut a cylindrical core (apple corers work well) from a potato – rinse it in lemon juice to preserve the near-white color of the cut potato – then cut a cross in one end. Insert an almond sliver (available at any grocer in the baking goods aisle) into the sliver. Your “candle” is now ready for the discussion / demo.

Inform your students that they are to practice their powers of observation, and make as many observations about what they are about to see in a limited time frame. Turning the lights down or out aids in their “mis-observations.”

Light the almond sliver with a match – it will catch readily, and burn for about 2 minutes – so don’t give them much longer than 60 seconds to make their observations. Blow out the almond before it burns out, turn on the lights, and start taking notes on the board as to the observations the students made of the “candle.”

At some point, particularly effective after someone makes the observation that the “candle” is made of wax, note that that’s an interesting observation, calmly bite the potato candle in half, chew and swallow. Your students will be aghast for a moment, wonder if you’re as crazy as that seems, and it leads into a lively discussion on the differences between observations, conclusions, and assumptions based on previous experiences.

Hope you like it!

Duane

Advertisements

1 Response to "Powers of Observation"

I love this- great for any class any time. Almost can’t wait for school to start up so I can try this.

What do you think? Your opinion matters, leave a reply.

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s

What’s New in 2013/2014?

Every year brings a change, this one is no exception.

I will be picking up the sophomore honors Algebra II class to keep them separate from the juniors. This should help accelerate them and put them on a stronger track towards Calculus. Looks like there will be only one section each of Physics and Calculus, but still two of Robotics & Engineering.

Hot topics this year are going to be the Common-Core Standards, Standards-Based Grading (SBG), improving AP Calculus scores, and somehow adding Python, maybe as a club.

Polls in the sidebar

Just a quick poll to help me understand who is stopping by my blog.

Yeah sure, lots from America, but look who else is here…

If you are badly in need of more email or for some reason jonesing for a physics fix, enter your email address so I can bother you with my newest rant on science.

Join 312 other followers

Blog Stats

  • 1,272,104 hits by nerds like me since June 1, 2008
January 2009
M T W T F S S
« Nov   Feb »
 1234
567891011
12131415161718
19202122232425
262728293031  
%d bloggers like this: