Countertops and Citizen Science for Macroscopic Dark Matter

It is possible that dark matter interacts strongly with baryons, so long as the dark matter's constituents are sufficiently dense and massive that these interactions occur too rarely to produce a prominent signal. We propose a scheme to detect such 'macroscopic dark matter' (macros) using the largest medium directly available to us: the Earth. Were a macro to collide with granite in the Earth's crust, it would vaporize the rock—which would then quickly cool—leaving behind a tube of solidified obsidian, such that any slab excavated along the macro's trajectory would have a distinguishable ellipse on one surface, with a matching one on the opposite. Using the tools of citizen science, we and volunteers from the scientifically inclined public will visually inspect granite countertops for these ellipses, hoping to find definitive proof of dark matter, all while broadening physics research education and constraining the macro parameter space.