Last night, my 7-year-old son came to me and began to describe his idea for a new robot.
"It would pick up toys and put them away," he told me, and he proceeded to describe the mechanics of robot in great detail. (Let me tell you, I *want* one of these robots!)
I suggested that we buy a journal. "Let's get one with WALL-E on the cover," I said. "And then you can write down all of your ideas for new robots. Later on, when you're older and enter a science fair, you can read about your plans and pick one to work on."
A science journal doesn't have to be about robots, though. Pick any topic that you like. Give yourself the freedom to explore your interests.
Do you watch clouds? Write down the shapes that you see, draw them in your journal, and look them up in a cloud identification book later. Would you rather study bugs? Draw the insects in your journal and describe their behavior. Have a great idea for an experiment? Plan it out on paper before you put it into practice.
Remember, this is your journal. You can be as detailed or as simple as you want. Similar to a diary, you don't have to share your ideas about science with everyone. Let yourself dream ... and don't forget to give yourself the permission to dream big.