Alpha particles have a positive charge, so they will be attracted to a negatively charged grid. Strong electric fields can be used to slow down and control the motion of alpha particles. Strong magnetic fields, such as those created by superconducting magnets, will cause the particles to move in circles, following the field lines.

We cannot be completely sure that the fundamental constants, such as the speed of light, are fixed over time and space. However, we have collected data over the course of decades that suggests these constants remain constant. If the speed of light and other constants do vary over time and space, it could indeed have a drastic impact on our understanding of the cosmos, particularly when considering phenomena like dark matter and dark energy.