science: water play

We've done a few science experiments this morning and I thought I'd share them with you in detail outside of today's usual post.
The ingredients are simple, and the fun is big!

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For the first one you need these things.A piece of cardstock or index card, a rubber band, plastic mesh (garlic, onions, and potatoes come in these sometimes), a glass or jar, and water.

Now you know this one....
You fill up a glass (almost 100% full) and then you put a piece of cardstock on it, and then turn it over.
After your air rises to the top, you let your hand go...

and voila! It stays.

And then you get to talk -again- about air and gravity and tension and vacuums and all that really cool stuff.

Now.
To make it extra cool, try this.....

Empty the glass back into the pitcher (or whatever)

check out the plastic mesh...breathe through it, see through it, talk through it, etc...

and put the mesh over the glass, then wrap a rubberband around it to hold it.

Pour the water back into the glass, through the mesh, demonstrating water moves through it freely.

Fill it up, but not to the tippy top.

Put a piece of cardstock over the mesh, and tip it upside down.
Let the air bubbles rise, as you did before.

Keeping the glass very straight, slide the cardstock off the bottom of the glass.

woh!It works!!

Surface tension keeps the water in the glass, as long as you keep it straight!

Very, very cool.

* * * * *

Speaking of gravity....
Gravity causes things to fall straight down, right?

Now check this out.
Here's what we used.
A weight, something with a spout and handle, string (we used inexpensive yarn) and a jar or glass to pour water into.

Soak your yarn for a few minutes so it's saturated.

Tie your yarn around your weight, and place it in the bottom of your glass.

Tie the other end around the handle of your pitcher or measuring cup.

Slowly pour water into the jar with the weight,
and make sure to experiment with how far sideways you can get your flow!
The water will follow the string, and not pour straight down, defying gravity.

This works because the water molecules long to stay together, and this bond is stronger than the force of gravity.

Cool!!

* * * * *

Solar energy, anyone??
This one comes from my good ol' Home Science Tools Newletter.

Germany -a very cloudy country- uses more solar energy than any other country.

There is enough sunlight falling to earth in one hour to supply power to the entire world for a whole year. The challenge, of course, is to capture and store that energy.

Now on that note, let's do some simple experimenting.

For this one we only used two bowls of the same size, a piece of black paper, a piece of white paper, water, two ice cubes, and a timer.


First we poured the same of water into each bowl

then put an icecube in each one.

We put each bowl on a piece of paper in the sun, separated by a few inches.

We supposed about which one would get hot faster, and why.
Trev chose white.

We set the timer for five minutes
and then checked on the water temps.
Both icecubes had melted.

About a half hour later, we checked on them again, and found the black paper to be much warmer than the white, and the water warmer than the other bowl!

There you go.

Black absorbs sunlight's heat, and white reflects it.

Cool.