Can you blow bubbles in space?
Before we answer that question, let's figure out how a bubble works. When you blow a bubble, you are exerting pressure onto the bubble's soapy surface. What does that mean? Well, pressure is a type of force. In fact, the equation for pressure is force/area. A force is a push or a pull. In this case, the force is a push on the surface of the bubble. The air in the atmosphere is under pressure, too. Near the surface of the Earth, there are a lot of air molecules pushing on each other. So the pressure near the surface is high. As you go higher in the atmosphere, there are less and less air molecules, so the pressure gets lower.
When you blow a bubble, you are exerting a high amount of pressure into the bubble. The bubble is being pushed on the inside by air molecules from your breath, but is also being pushed on the outside by air molecules in the atmosphere. When the bubble leaves the wand, the air inside the bubble has the same amount of pressure as the air outside the bubble.
The bubble may float for a while as it tries to maintain the equalization of pressure. Eventually, however, the bubble will pop. If the bubble floats too high in the atmosphere, the pressure inside the bubble will become too great, and the bubble will explode in a big *POP*. If the bubble sinks too close to the ground. The pressure inside the bubble becomes lower than the pressure outside and the bubble will implode. We still hear it as a *POP*.
In space, there is no pressure. Or at least, the pressure is so
infinitesimally small that we consider it to be nothing.
(Remember, pressure is force/area, so any force is considered tiny
compared to the vastness of space). So if you try to
blow a bubble in space nothing will happen because the pressure inside
the bubble is always too strong for the pressure
in space. The bubble can only exist when there is equal pressure inside
and out.
Submitted by Will (age 18, Kentucky, USA)
(November 18, 1997)
