Monday, August 29, 2011

New Year

Well, it's time for another new school year - some of you have been going strong for a couple of weeks now, others of you are still anticipating that first day, still a week away.

Next week I'll be back with regularly scheduled science ideas, 5 days a week. 

I'll admit, I don't know how long I'll be able to keep the blog going at that pace - but I'll do the best I can for as long as I can.

For this last week of summer, I'd love for anyone out there to chime in with what they find to be the most valuable and what they'd like to see more of on this blog.  I've got a few I'm kicking around in my head right now and wonder if they jive with what others would enjoy.

And while you're visiting the blog and leaving your comments (or you can send an email), check out the new poll.  I'm curious about the make-up of this blog's readership, and it will also help me prioritize ideas for moving forward. 


Friday, August 26, 2011

Blog Comments

Just a quick note...

When you leave a comment on the blog with a question, I don't have any way of getting back to you other than responding in the comments.  Despite needing to sign in with an email address, blogger doesn't share that address with me. 

So... if you're asking a question and looking for a response, check back in the comments section or leave your email address in the comment or send an email to


PS Deborah - I hope you see this.  I responded to a couple of your questions in the comments, but have some additional ideas to share with you if I can email you.

Tuesday, August 23, 2011

Summer Science Camp: Hovercraft

The summer we offered a middle school version of science camp, we had fun making hovercrafts.  The "teacher-versions" were the full 4' (diameter) circles.  We had a handful of kids and they each made their own from a 2' (diameter) circle of plywood.

We followed Daryl Taylor's instructions, which I'll let you read on your own. 

In short:
The hovercraft is basically a large circle of plywood covered with plastic.  A shop vac motor (one whose motor can be switched to blow) is attached to the craft.  The motor pushes air into the space between the wood and the plastic, creating a buble.  The plastic has several small holes in it - the air is forced out of those holes and in turn the craft is pushed up, hovering above the ground.  Left alone, the hovercraft will stay in one place - add an outside force and you'll start to see physics laws in action!

Here are some pictures to aid in your construction (sorry, no action shots - go here to see Daryl's in action).

The bottom side:

In the center you'll place something to hold the plastic down.  Most people would use a plastic lid, we used something my friend's husband had lying around in his workshop - I'm not even sure what it is! 

You'll notice that ring of duct tape - it's not just decorative!  It reinforces the plastic, so you can cut holes in it without shredding the whole thing.

The top:
A masterpiece in duct tape:
It really does take vast amounts of duct tape to make sure the plastic is held down and no air will leak out. 

In the above picture, you'll notice a small hole cut out, near the bottom of the picture, slightly to the left.  That's where your shop-vac hose will connect to the hover craft, turning it from a heavy-piece-of-plywood-covered-with-duct-tape into a hovering-piece-of-plywood-covered-with-duct-tape!

It's not the most beautiful contraption ever, but it is a very cool demonstration of all kind of physics principles and it really does work!

Tuesday, August 16, 2011

Summer Science Camp: Fossils

**Warning: when it comes to making these fossils, do as I say, not as I do...**

Fossil footprints could certainly be added to your summer camp repertoire, but summer's also a great time to break out the big-guns and make some plaster fossils. 

Before beginning, you'll want to collect a bunch of objects with interesting shapes and textures.  You can look around the house to find things or search outdoors.  You may even want to have students collect objects during a nature walk.  Seed pods of different types are interesting (gum balls - from gum trees - are really great).  Leaves are a bit tricky, but worth trying. 

To begin the activity, each student will need a paper plate and a hunk of clay.  This is where you need to follow my directions, not my pictures - you NEED to use real clay, NOT play doh.  (For photography purposes, I tried using what I had on hand, but the results were disastrous, as you'll see below).
AMACO Moist Pottery Clay, 5-Pound, Grey

Spread the clay into a pancake on the plate.  You want to leave it somewhat thick - about 1 cm or 1/4". 

Use the various objects you've gathered to make impressions in the clay. 

Following the package directions, mix up some plaster of paris.  This is good to do outside, but if you're doing it inside, be very careful to avoid having the plaster go down the drain...
Plaster Of Paris 8 Lb. Tub: White

Pour some plaster over each of the clay impressions.
Your plaster will probably run over the sides of the clay a bit - I mixed mine a little too thick. 
Then you let it sit and harden, overnight at the very least.

And this would be where I show you how to life the whole thing off the plate, peel the clay off the plaster and reveal a beautiful plaster cast.

Instead, I used play doh, which is has too much water and doesn't allow the plaster to harden properly, so I have a crumbly mess.  Use clay! 

For what it's worth, you can see a small piece of the bolt fossil:

Tuesday, August 9, 2011

Summer Science Camp: Volcano Eruption

I'm re-posting this activity, because it works well for a science camp.  Curriculum and time constraints may prevent you from actually building the volcanoes during the school year, but summer camp provides the perfect opportunity to take on such things.  Kids always love to make and erupt volcanoes - doesn't matter how many times they've done it before!

You can find all sorts of volcano making/exploding kits to buy.  (If you're interested in buying, each of those words is a link to a different product).

But you can save your money and have a little more (messy) fun by making your own.

Start with an empty bottle - a Snapple bottle or soda bottle works well.  Tape it to a paper plate - makes it sturdier and easier to work with.

Mix up some paper mache.  There are all kinds of recipes out there.  I'm partial to just flour and water - cheap, easy to procure, and easy to clean up.

Dip strips of torn up newspaper in the paper mache and start applying them to the bottle.  Build up the shape of the volcano as you wish.  Make sure you keep the top of the bottle open!

By making your own model, you have the chance to make it the shape you want... make it a shield volcano, a cinder cone volcano, a composite volcano.  Even if you don't have a sepcific plan, it gives you a chance to review and discuss those types of volcanoes and how they're formed.

A cinder cone volcano

Allow your volcano to dry - the amount of time this takes depends on the weather and how heavy-handed you were with the paper mache.

Once the volcano is dry, you can choose to paint it. 

Or you can just get on with the exploding part.

Put some baking soda in the bttle.  You can add some red food coloring, for effect, if you wish.  Pour in some vinegar and stand back and watch!

And, if you're too impatient to build the volcano and just want to get to the exploding part, you can just put some baking soda in an empty bottle, add some vinegar and watch.  It's a good demonstration of a chemical change, even if you aren't studying volcanoes!

Tuesday, August 2, 2011

Summer Science Camp: Don't Melt the Ice Cube

See who can engineer the best icebox.

For this activity, I like to have students begin with uniform boxes, but it probably isn't crucial.

The students will each be given an ice cube their goal is to keep as much of the ice cube frozen as is possible.  I place each ice cube in a small zip-top bag in order to contain the water, which allows you to record quantitative data, as well as contains the mess.

I lay out all sorts of materials for students to use in their icebox creation:
  • fabric
  • yarn
  • newspaper
  • aluminum foil
  • waxed paper
  • plastic wrap
  • cotton balls
  • balloons
  • napkins
  • markers
  • wood shavings
  • packing peanuts
  • cotton batting
  • anything else you find lying around

The students can use the materials in any way they see fit - to wrap around the outside of the box or place inside the box with the ice cube.  Make sure the students' initials are located on the box somewhere. 

After the boxes are complete and the ice has been placed inside, the boxes are taken outside and placed in a shady spot.

After an hour (or other designated period of time) has passed, return the the boxes and observe the ice cubes.  For older students, you can pour off the melted water and measure it to determine who had the least ice melt. 

This activity could be added to your Water Fest, or done independently.

If you'd like to do this activity with your class, but it's the middle of winter, you could place the boxes under a heat lamp.  Or, just leave them sitting in the classroom (but you'll want to wait longer than an hour before checking on them).