If the gate timings are not accurate, then the LMs will continue on their separate paths and shall not collide. If the timings are accurate, and it is taken that the two LMs are identical, then there are three possible outcomes of the collision. Firstly, that the LMs collide with some elastic property, and then continue on two distinct and new paths. Secondly, that the LMs collide with no elastic property, then continue vertically as two adjacent, but distinct, LMs. Thirdly, that on collision the LMs coalesce into a larger single LM with zero lateral velocity, which continues vertically down. Video snapshots showing both a single uninterrupted and a colliding pair of LMs, can be seen in figure . Our experiments demonstrate that LMs collide in an elastic manner. This is unsurprising, due to their previously reported soft-shell and compressible nature . It also supports the previously published, linear, non-coalescing collision of LMs . By monitoring the collisions at 120 fps, it was observed that LMs behave like two soft balls, acting in a manner described in the Soft Sphere Model (SSM), known as a Margolus gate . A video of a typical collision can be seen in the supporting information. The important distinction between the SSM and the better known Billiard Ball Model (BBM) , is the exit points of the colliding particles compared to the non-colliding particles. In the BBM, the particles are taken to be hard spheres, which instantly rebound off each other -leading to the AB paths being outside the corresponding ĀB and A B paths. In contrast, the SSM accounts for the finite and appreciable amount of time required for real-world soft spheres to rebound. The result is that the AB paths move to lie inside the unchanged ĀB and A B paths. The BBM and SSM pathways can be seen in figures 6(a) and 6(b), respectively. It was possible to break the SSM analogy by increasing the speed of the LMs. The speed of the LMs was calculated by measuring the distance travelled by the LM in a certain number of frames, and knowing the recording frames per second. When the collision happens at 0.21 m s -1 , the LMs bounce elastically following SSM paths. However, when the speed of collision is increased to 0.29 m s -1 , the two LMs coalesce. This can be seen in the video snapshots in figure .