Earth Interior
Purpose
A steel ball sinks slowly into Silly Putty over the course of a lecture, modeling Earth's mantle — solid on short timescales (seismic waves propagate through it) but fluid on long timescales (enabling convection and plate tectonics).
Figure 1:
Early stage: the steel ball has begun sinking into the Silly Putty. The putty has already flowed to fill the bowl and overflow the edges.
Figure 2:
The ball has sunk further as the putty continues to flow under sustained gravitational stress.
Figure 3:
The ball is mostly submerged. The putty flows around and over the ball while overflowing the bowl.
Figure 4:
End state: the ball is nearly engulfed. The putty — solid on short timescales — has flowed like a fluid under sustained stress.
Equipment
- 1