A bottle is a narrow-necked container used to hold liquids or semiliquids. It can be made of glass, plastic, or metal. Bottles are often sealed with a cap or stopper to protect the contents from spilling, evaporation, or contact with foreign substances. Bottles can be single-use or reusable, and may be small or large. The word is also a noun, meaning the contents of such a container: a bottle of wine; a bottle of soda.
Scientists have a clear definition of the state of matter as a solid or a liquid, but a surprisingly broad set of substances fall into a gray area between these two states. For example, look at a piece of glass under a microscope and you’ll see that the molecules aren’t arranged in a regular crystalline pattern, but they aren’t completely liquid either. Some scientists, such as Michael Behe, argue that this ambiguity is why there is no unified scientific definition of what makes something a “solid.” He proposes a new way to classify things based on their viscosity: if a substance is ten times more viscous than water, it is a solid.
The first bottles were made of glass, but soon afterward chemists developed a process to make them out of plastic. This allowed them to be shaped in more complex ways, and they became much cheaper to produce than glass. They also took up less space, which was important for transporting and storing beverages.
Today, most bottles are made of polyethylene terephthalate (PET) plastic, which is derived from crude oil. It’s an extremely durable material that can be recycled over and over again. However, it’s worth remembering that single-use bottles that aren’t properly managed can end up in the ocean. Many of these bottles are carried by wind and ocean currents to the coast, where they can join other debris in an oceanic gyre—the Pacific Garbage Patch being one well-known example.
You can do a few simple experiments with a bottle to learn more about its properties. Try pushing or pulling on the cap, which will change the bottle’s moment of inertia and its angular velocity. You can also use graduated cylinders or measuring cups to explore the relationship between pressure and temperature in a gas: increasing the pressure increases the temperature, and decreasing the pressure decreases the temperature.
You can even use a bottle to demonstrate the principles of sound waves. If you blow across the top of the bottle, it will create a resonant note. This is because the bottle is effectively a closed-end air column that vibrates when you blow across it. Musical instruments such as clarinets and organ pipes work in the same way. You can experiment with this yourself by making your own bottle-based musical instrument. Just be careful not to drop your bottle, because it will break! You can find more science and engineering activities with a bottle at our Snackbot site. We’d love to hear about your results.
