Zero Gravity Water Bubble
Why Physics Stack Exchange recommends it
Physics Stack Exchange answerers link it as a direct visual of what bubbles and water do when there is no gravity, for questions about air inside floating water drops.
Recommended by 0 people across 0 different months, 2011 to 2017.
What it is
A short clip of a floating water sphere in microgravity aboard the International Space Station. Air is injected into the drop to form a bubble inside it, and an Alka-Seltzer tablet is used to show gas release. It is a raw demonstration with no lecture-style narration.
What people said
Cites Greg P · 2011-01 · Physics Stack Exchange · on “Bubbles in zero gravity”
Here is a YouTube link of an experiment done on board the International Space Station. [this video] In the second part of the video, air is injected into a spherical water drop. As you can see, nothing really dramatic happens. There is certainly no explosion. The air bubble adopts a spherical shape to minimize its surface area, but otherwise it sits quite happily inside the water drop. This is probably as close as we can get to answering the lemonade question. One could easily blow bubbles (or a single bubble) into a floating drop of lemonade. There are some differences due to the lack of gravity. When you blow bubbles into a liquid here on earth, they are pulled upward by buoyancy due to gravity
Cites John Rennie · 2014-06 · Physics Stack Exchange · on “What will happen if we put balloon in water tank in space”
Exactly this experiment has been done by the astronauts on the International Space Station [this video] . The YouTube video I've linked shows a bubble within a sphere of water. In the absence of gravity there is no force on the bubble so it remains stationary within the water. The astronaut has carefully positioned the bubble at the centre of the sphere of water, but this is just to look nice on the video and the bubble would remain stationary regardless of where in the water it was. Actually the astronaut then manages to create a water drop inside the bubble inside the sphere of water.
Cites knzhou · 2017-04 · Physics Stack Exchange · on “Negative mass, or just the 'appearance' of negative mass? What's the acid test?”
You're right, there's some confusion due to the way this paper has been publicized. Negative effective mass The 'negative mass' referred to in the paper is effective mass. The idea is that while every fundamental constituent of a physical system has a known, nonnegative mass, the effective degrees of freedom of the system may behave as if they have a different mass. This isn't a new idea; it pops up in a lot of contexts: You can claim that an electron's mass is "really" zero, because if you turn off every other quantum field, electrons are massless. But what we call a physical electron is really a combination of excitations of the electron and Higgs fields, which does have a positive mass. S