Or throw in vegetables. After you put anything into boiling water, the bubbles will stop, temporarily. This means leave it over high heat until the big bubbles reappear. At this point, you usually turn down the heat to maintain a simmer, which is small bubbles around the edge of the pan. A lazy simmer is when one larger bubble plops to the surface just occasionally.
Water boils faster on an electric element than it does over gas flames.
Some gas flames may not turn down low enough to achieve a very low simmer. A flat iron plate, called a flame diffuser, can sit directly over the fire. With a pan on top of it, you can achieve lower heats for delicate sauces. The more water in a pot, the more slowly it will boil. Volume matters on this one.