Sodium Bromate + Sulfuric Acid + Sodium Bromide + Malonic Acid + Ferroin + water = oscillating chemical reactions. AKA acid trip. (Caution: Do not ingest.)
The BZ reaction makes it possible to observe development of complex patterns in time and space by naked eye on a very convenient human time scale of dozens of seconds and space scale of several millimeters. The BZ reaction can generate up to several thousand oscillatory cycles in a closed system, which permits studying chemical waves and patterns without constant replenishment of reactants.