Share it! Science : Happy 1st Birthday "Share it! Science"!

Happy 1st Birthday "Share it! Science"!

Today marks 1 full year of "Share it! Science News". Let's celebrate this milestone with some birthday science! Whether you are hosting a science themed birthday party, or are just looking for a fun science activity this is a great place to start.

Balloons!
One of my all time favorite balloon activities to do with any age is to make "Balloon Rockets".

You will need:
• a balloon
• scotch tape
• drinking straw
• string
What you need to do:
Slide the straw onto your string. If it is a flexible straw, cut off the bend part first.

 Place the straw on the string. ©SBF 2015

Tie or tape your string taut across the room or an area outside.

Blow up your balloon, but do not tie the end. Scotch tape one side of the balloon to the straw.

Be sure the straw and balloon are at one end of the string. Countdown to rocket launch...5, 4, 3, 2, 1...LIFT OFF! Release the balloon and see what happens.

Further questions:
• What will happen if I blow more air into the balloon?
• How far can I make the balloon travel?
• What happens if I only blow the balloon up halfway?
• Can I predict exactly where the balloon might stop?
• How does the balloon travel if I do not tape it to the straw and then let it go?

The science: What makes the balloon rocket fly?
This experiment demonstrates Newton's Third Law: For every action, there is an equal and opposite reaction. When I blow up my balloon I am filling it up with gas. Gas is an excited state of matter. The molecules of gas in the balloon are bouncing around and colliding with one another. As I blow more gas into the balloons these little collisions increase. All this activity is putting pressure on the balloon. Eventually the pressure inside the balloon is greater than the air pressure surrounding the outside of the balloon. When I let go of the balloon the gas rushes out in order to balance our equalize the pressure inside and outside the balloon. The air rushing out causes a force on the balloon and propels it forward, creating the balloon rocket.

Candles!
Who doesn't love blowing out birthday candles? With adult supervision, this is a fun experiment to try. It might also inspire your party's decorations!

Heat spirals
You will need:
• a paper plate, or circular piece of paper
• candle
• clay or a candle holder (if you do not have a birthday cake!)
• matches or a lighter
What you need to do:
Cut your plate or circular piece of paper into a spiral.

Tie one end of it with the thread above the table where you will have your candle, (or cake) set up.

Be sure the end of the spiral will not be touching the flame of the candle. Light the candle and observe. What happens?

Further questions:
• Can you put several spirals above a birthday cake full of candles?
• Can the heat from the candle make other shapes move?
• If I tie the spiral higher above the candle will it still spin?
• How fast can I make it spin?
The science: What makes the paper spin?
This is an example of convection. Convection is one type of heat transfer. You've probably heard the term "heat rises". As the candle heats the air above it the air begins to rise because the warm air is less dense than cool air. The cool air begins to sink. This motion is called a convection current. The moving air puts pressure on the underside of the paper spiral and that is why it begins to spin.

Do you want to throw a science themed birthday party?
Here are some other fun ideas: