This year plans
for the week included both indoor and outdoor
activities
with enough flexibility to account for most contingencies
.
Monday the kids made rockets out of film cans and powered by carbon
dioxide gas bubbles from Alka-Seltzer tablets.
They tried different designs for their rockets, with and without fins
and nose cones and other changes.
The nose cones were made from semicircles decorated with the deep space
image from the Hubble telescope.
We thought it might motivate our rockets to go as far as they possibly
can.
If you want to know more about the image you can
click here but be sure to come back for more about
our camp.
The rockets with fins didn't go as
high as others probably because of the added weight.
Maximum altitude was more than 10 feet (3 meters).
Another of the projects was a different rocket design.
These were made from pool noodles with a rubber band secured to the
nose and streamers attached to the back.
Neither these nor the film cans are true rockets since they have only
an initial impulse as they start and no thrust from reaction to mass
discharged during flight.
But it would be correct to call them ballistic missiles.
The second and third pictures show the missiles in flight near the
upper left corners.
The campers all tried their hand at measuring the height of the
auditorium ceiling.
Each kid positioned themselves so that their line of sight was exactly
45 degrees up to a light.
Then we measured the horizontal distance from a point directly under
that light to their eye and the height of their eye above the floor.
The sum of those two numbers is the ceiling height.
This diagram may be easier to understand.
Because we selected 45 degrees as the sight angle the red Horizontal
Distance line, that we measured, is the same length as the brown HD
line.
The greenish EH line is the same as the Eye Height, that we measured,
because the horizontal distance line is parallel to the floor.
So the sum of the lengths of the HD and EH lines is the height of the
light and therefore the ceiling.
The results ranged from 16 to 18 feet with a couple very close to the
average.
We used the gage again later in the week to measure how high our water
rockets went.
Here is the gage we used.
Note the sights at the ends of the 90 degree line.
Other projects Monday included a Brain Hemisphere Hat.
It shows names for some parts of the brain and what sort of
activity is associated with each.
Make one , put it on, and think.
The instructions are
here.
And they silk screened the front of their camp t-shirts learning a
graphics art technique.
On the back was this design.
Tuesday we talked about the early balloon scientists, the challenges
they faced, the dangers involved, and what it is like to fly in one.
Then each of the kids built and flew their own hot air balloon.
It was windy so all the adults were needed to help manage the balloon
inflations so there aren't any pictures of that operation.
We were fortunate that even with the wind we didn't set any on fire
though some got scorched.
Because of the wind a couple of them pulled loose from their tethering
cord and landed on power lines.
Both eventually blew free and were recovered.
If you would like to make and fly a balloon yourself the instructions
are
here.
After the balloon flights we studied the densities of some solids and
liquids.
These blocks of different materials all have the same mass.
The small ones are much more dense than the largest.
The blocks in the top row are all less dense than water. They are oak,
pine, lithium metal (simulated), and balsa.
The bottom row will all sink. They are lead, copper, brass, zinc, iron,
aluminum, carbon, and lignum vitae (a kind of wood).
They liked the rock (volcanic pumice) that floated and wood (lignum
vitae) that sank in water.
We challenged the campers to build a boat out of a square of aluminum
foil that would float holding as many marbles as possible.
Some resembled canoes, others barges or bowls,
The kids put their boat in a basin of water and started adding marbles.
We put them in a line in order of cargo capacity.
Then they each built another boat incorporating what they had figured
out from the results of the first set.
The second set was much improved.
We then had a discussion about factors other than cargo capacity that
need to be considered by boat designers.
Things like cost, power source, waves, weather, crew, passengers and
many more factors were suggested.
We also built Cartesian Divers.
The campers used short sections of drinking straws.
They used modeling clay to close one end so that air couldn't escape
(that will be the top of our diver).
The bottom end was weighted with more clay so that it would float
upright in the water.
They used a basin of water to test the diver's buoyancy as they
adjusted the amount of clay at the bottom .
When it is right the diver will just barely float.
Put the diver in a plastic bottle nearly full of water and secure the
lid.
Squeeze the bottle and the diver will descend, release the pressure and
it will rise to the top.
Wednesday we met at the Laurel Gorge to study fossils and the geology,
flora and fauna found there.
The kids were fascinated and some more than a little repulsed by a
dinosaur coprolite (fossil poop).
Each of our campers took home a plaster replica of these Brachiopods
And this Pterodactyl fossil
They also got to select a real fossil from the limestone layer that
underlies the sandstone cliffs of the gorge.
Most selected a segment of a crinoid stem.
An intact crinoid looks like this.
We didn't find any dinosaur fossils because the rocks here are
too old.
They looked at the mix of dinosaur and bird features in this
replica of an archeopterix fossil.
We also made a plaster cast of a print in the mud near the spring next
to the trail.
Thursday the campers built and launched water bottle rockets.
and measured the altitude they reached using the angle gage we
practiced with on Monday.
Videos of three of the launches, each at normal speed and then slowed
by a factor of eight.
Some of the
campers were trying more or less water to see what would
happen.
Fin placement resulted in some of the rockets spinning rapidly so some
of the water went to the outside and not out the nozzle.
Friday was bubbleology.
Here the campers are using bubble blowers made of two drinking straws
and a loop of cord.
The bubble soap is 14 oz Joy dish washing soap, 4 oz glycerin, and 300
oz of water.
I kept the units the same so you can easily adjust for larger or
smaller batches if you want to try it yourself.
If the humidity is low you may get better results with more water (up
to 400 oz.)
Here are some of the bubbles.
We tried blowing, waving the bubble maker, and just holding it up and
letting the breeze do the work.
Then we made bubbles big enough to enclose our campers.
I like the variety of expressions on their faces.
This bubble burst just as the picture was taken so if you look closely
you can see a spray of fine droplets
Sometimes you could see shadows on the bubbles.
The question for you is why is one of the figures upside down?
Send us an
email if you think you
have a solution.
Bubbles cast colored shadows.
Look for them the next time you are making some.
Here we managed to capture pairs of campers in one bubble.
We made slime by mixing 4% solutions of polyvinyl alcohol (PVA) and
sodium borate (borax).
We used 5 times as much PVA as borax for this experiment.
The PVA is long chains of atoms that can slide over each other in
solution (imagine a pot of spaghetti being cooked).
When the borax is added it makes links between random chains turning it
to slime (the spaghetti was drained and it started to dry out).
The kids added food color to make their slime unique.
The slime is in the zipper seal bags on the table and we are making
bouncy balls.
We mixed 6 parts of white glue with 6 parts of corn starch (add color
now if you want to).
When it is well mixed add 1 part of a concentrated borax solution
(dissolve as much as you can in water)
Now stir until it forms a sticky mass on your stirring stick. (see
picture)
Take it in your hands and roll it until the reaction is complete and it
is a smooth firm ball.
It is ready to bounce.
The weather was with us for most of
the outdoor activities.
Breezes were stronger than we like for the balloon and bubbles and we
had to dodge a shower before the water bottle launch but there wasn't a
problem.
We had a great time this summer and we learned a lot of chemistry and
physics.
My sincere thanks to the Elliott County School Administration for
providing the space for our camp.