Boiling Water Until It Freezes
Why Worldbuilding Stack Exchange recommends it
Worldbuilding Stack Exchange users link it when an answer or comment needs a clear visual of what water does in a vacuum or at very low pressure, such as on a spaceship or the moon.
Recommended by 1 people across 1 different months, 2017 to 2024.
Why Physics Stack Exchange recommends it
Physics Stack Exchange answerers link it as a visual demonstration of water boiling under low pressure and freezing from evaporative cooling, and of vapour continuing to form after the ice appears.
Recommended by 0 people across 0 different months, 2017 to 2018.
What it is
Cody'sLab places water in a home-built vacuum chamber and lowers the pressure until the water reaches its triple point, where it boils and freezes at the same time. The video shows the behavior on camera and briefly explains how the chamber's pressure sensor works. It is a short hands-on physics demonstration by a single creator.
What people said
Recommends Willk · 2017-10 · Worldbuilding Stack Exchange · on “How do you check if a room behind a door aboard a spaceship has an atmosphere/pressure?”
Cody demonstrated a sensor exactly as described here, built into his vacuum chamber. Link jumps to the point where he talks about how it is working but the whole video is cool. [this video]
Cites Ilya · 2017-03 · Physics Stack Exchange · on “Does water boiling due to low pressure convect?”
You can take a look at the videos [this video] of people doing this experiment. Logically there should be convection, since you cool the surface of the water due to evaporation, and this water goes down to be replaced by the warmer water from the bulk. However it is hard to judge, because there is insane boiling due to the dissolved gases leaving the liquid in the form of bubbles, which continues effectively until the water freezes.
Cites Joe Kissling · 2017-04 · Worldbuilding Stack Exchange · on “Can atmospheric pressure aid in sealing a wound?”
@Seeds That is exactly what happens. Here [this video] is a video of water freezing from boiling under low pressure.
Cites userLTK · 2017-11 · Physics Stack Exchange · on “If I boil water at room temp using a vacuum, will the water instantly liquify if I reintroduce air to the system?”
Let's call it a small volume of water in a large volume of vacuum. And let's say the vacuum is created instantly, and then the system is sealed. Once the air is removed, the water evaporates and becomes gas, so some of the pressure returns. There's an equilibrium of liquid water, vacuum, sealed container and temperature where some, or all of the water would evaporate. With a small amount of water and a large room, all of it would probably evaporate unless the temperature was close to freezing. To calculate how much you can look at the vapor pressure of water [LINK] . [LINK] As water evaporates it cools, so some of the water would turn to ice in your scenario and the temperature in your conta
Cites Pinback · 2018-05 · Physics Stack Exchange · on “Would steam engines be possible at zero atmospheric pressure”
In this video [this video] water is put into a vacuum chamber and made to boil by lowering the pressure and freezing as a result of effects of boiling. Notable that the water continues to make water vapour even after freezing. However the point of a steam engine is to create force from the pressure of the steam.
Cites Emilio Pisanty · 2018-11 · Physics Stack Exchange · on “Water at 0 atmospheric pressure”
The water will evaporate and fly out of the bucket; the process will not stop until there is enough water vapor in the atmosphere that the vapor pressure [LINK] stops the water from boiling further. If the scenario happens in a confined space, this has a chance of happening while there is still liquid water in the bucket, but if you're expecting the water in the bucket to provide an Earth-sized atmosphere of water vapor then there will be no liquid water left. (On the other hand, if you get things right, you might get some water ice at the bottom of the bucket, which will have been evaporatively cooled when the faster molecules leave the surface, taking energy with them and thereby lowering
Cites Monty Wild · 2024-12 · Worldbuilding Stack Exchange · on “If the moon was covered in blood, would it achieve the visual effect of deep red moonlight under a full moon?”
If we cover the surface of the moon with a four kilometre deep sea of blood - at the traditional temperature of 37°C - it will appear to be red... for a little while: [LINK] Image from [LINK] The problem is that blood is not an inert solid, it's a suspension of red blood cells in water. Now, let's consider that the surface of the moon [LINK] ranges in temperature between -133°C at night and 121°C during the day. It's also in the vacuum of space, and the moon's gravity is not strong enough to hold on to all that water. Pretty much immediately, the water is going to start to boil and sublime away into space, while the blood cells are heavy, and will start to settle to the bottom of the blood s