A density tower is formed by layering immiscible liquids of different densities on top of each other. It is possible because Earth’s gravitational acceleration pulls denser fluid particles stronger and displace less dense ones upward.
Flat-Earthers claim that the possibility to have density towers disproves gravity. In reality, a density tower cannot form without the presence of acceleration, like Earth’s gravitational acceleration.
In a zero-G plane, the container is accelerated downward by the same amount as the liquids inside it, and therefore the liquids are not accelerated relative to the container. By nullifying Earth’s gravitational acceleration using a zero-G plane, a density tower will not form.
On Earth’s surface, everything is accelerated downward by Earth’s gravitational acceleration. It is possible to add another acceleration in addition to Earth’s gravitational acceleration already affecting the liquids. Adding these two accelerations together can result in a net acceleration which is not straight downward, and the shape of a density tower will reflect that.
Putting a density tower on a centrifuge will accelerate it away from the center, and it will change the direction of the density tower. Placing a density tower inside an accelerating car will also add acceleration to the system and affect the density tower’s direction.
References
- BOTTLE CENTRIFUGE – HINDI – Separate Kerosene from Color Water! – Arvind Gupta
- What does a Density Tower do in Zero G? – Kevin Lubick