Getting back to basics today. Lately I’ve been focusing solely on science news stories and neglecting some of the cool basic science of our everyday lives. I decided to start with atmospheric pressure because it influences so much without us ever realizing it.
We don’t normally think of air as having any weight, but it does. The weight of our atmosphere is 14.7 pounds per square inch. We don’t feel that weight because our bodies are generally in equillibrium with the outside (more on this a little later). But the buddy we didn’t know we had is always looking for a difference in pressure to exert some force. Over the next couple of comics I’ll touch upon some other pressure-related phenomena, but for today you get drinking straws!
The misconception is that, when you drink through a straw, you’re sucking liquid through the straw and into your mouth. What’s really happening is that you’re creating a difference of air pressure inside your mouth, which is equalized by liquid flowing in. It all goes back to breathing, where your diaphragm (a muscle stretched across your rib cage) contracts, increasing the volume of your chest cavity, and the void is filled by air rushing into your lungs.
“Maki, in the comic you said that you can’t drink from a sealed container. Then what is this?”
Pouches like this still work because the container itself is deformed by the surrounding air pressure pushing on it, and subsequently pushing the liquid out. But we’ll talk more about the crushing power of our own atmosphere in another comic.
Each Saturday Morning here at Adafruit is Saturday Morning Cartoons! Be sure to check our cartoon and animated posts both nostalgic and new that inspire makers of all ages! You’ll find how-tos for young makers, approaches to learning about science and engineering, and all sorts of comic strip and animated Saturday Morning fun! Be sure to check out our Adafruit products featuring comic book art while you’re at it!
Stop breadboarding and soldering – start making immediately! Adafruit’s Circuit Playground is jam-packed with LEDs, sensors, buttons, alligator clip pads and more. Build projects with Circuit Playground in a few minutes with the drag-and-drop MakeCode programming site, learn computer science using the CS Discoveries class on code.org, jump into CircuitPython to learn Python and hardware together, or even use Arduino IDE. Circuit Playground Express is the newest and best Circuit Playground board, with support for MakeCode, CircuitPython, and Arduino. It has a powerful processor, 10 NeoPixels, mini speaker, InfraRed receive and transmit, two buttons, a switch, 14 alligator clip pads, and lots of sensors: capacitive touch, IR proximity, temperature, light, motion and sound. A whole wide world of electronics and coding is waiting for you, and it fits in the palm of your hand.