Cartesian Diver / Condiment Diver
Let's take a packet of hot sauce or ketchup from a local fast food joint and turn it into
a cool science toy. We will learn about air pressure and density as we make a
Cartesian Diver also known as a Condiment Diver. Amaze your friends as you make
the packet rise and fall at your whim.
Materials
- Clear Plastic 1 Liter Water Bottle and Cap.
- Several Ketchup or Hot Sauce Packs (the fast food type).
- Water
- Regular Glass or Cup
Process
- Test your hot sauce or ketchup packets to find one that barely floats. To do this fill
the regular glass with water. Put a packet in. If it sinks move on to another pack. Find
one that barely floats. The ones that sink have too much atmospheric pressure
pushing on the air inside to work properly. Discard those.
- Insert the hot sauce or ketchup pack into your 2 liter bottle. Fill it up to the top with
water and screw the lid on tight.
- Squeeze the sides of your bottle to make the packet rise and fall.
The Science:
When the manufacturers seal the packets of hot sauce or ketchup tiny little pockets
of air bubbles are trapped inside. When we squeeze the sides of the plastic bottle
water is pushed against the side of the condiment packet. The air molecules /
bubbles shrink as a result of the increased pressure. The volume inside the packet
is lowered as we squeeze the bottle. As a result the packets density is raised and it
sinks down to the bottom. The reverse happens when we stop squeezing. The
pressure is reduced and the air molecules / bubbles expand again. Density is
lowered and the packet floats again.
Other methods can be used to make Cartesian Divers. Instead of using a condiment
packet, many people use eye droppers or small pipettes with screw nuts attached for
ballast.
a cool science toy. We will learn about air pressure and density as we make a
Cartesian Diver also known as a Condiment Diver. Amaze your friends as you make
the packet rise and fall at your whim.
Materials
- Clear Plastic 1 Liter Water Bottle and Cap.
- Several Ketchup or Hot Sauce Packs (the fast food type).
- Water
- Regular Glass or Cup
Process
- Test your hot sauce or ketchup packets to find one that barely floats. To do this fill
the regular glass with water. Put a packet in. If it sinks move on to another pack. Find
one that barely floats. The ones that sink have too much atmospheric pressure
pushing on the air inside to work properly. Discard those.
- Insert the hot sauce or ketchup pack into your 2 liter bottle. Fill it up to the top with
water and screw the lid on tight.
- Squeeze the sides of your bottle to make the packet rise and fall.
The Science:
When the manufacturers seal the packets of hot sauce or ketchup tiny little pockets
of air bubbles are trapped inside. When we squeeze the sides of the plastic bottle
water is pushed against the side of the condiment packet. The air molecules /
bubbles shrink as a result of the increased pressure. The volume inside the packet
is lowered as we squeeze the bottle. As a result the packets density is raised and it
sinks down to the bottom. The reverse happens when we stop squeezing. The
pressure is reduced and the air molecules / bubbles expand again. Density is
lowered and the packet floats again.
Other methods can be used to make Cartesian Divers. Instead of using a condiment
packet, many people use eye droppers or small pipettes with screw nuts attached for
ballast.
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