When it comes to Italian cooking, I'm very Church of Marcella Hazan, orthodox sect.
What the exacting doyenne of Italian food tells me to do in her Essentials of Classic Italian Cooking, I do. No questions asked. In her celebrated chapter on pasta -- which I revere like Christians revere the Gospels -- Hazan had this to say about the role of water:
Pasta needs lots of water to move around in, or it becomes gummy. Four quarts of water are required for a pound of pasta. Never use less than three quarts, even for a small amount of pasta.
She also laid down the law on salt in pasta cookery.
For every pound of pasta, put in no less than 1 1/2 tablespoons of salt... Add the salt when the water comes to a boil.
For about 15 years, through literally hundreds of pounds of pasta (I conservatively estimate 650 pounds), I followed these instructions. The great results I got were like worldly riches to a Calvinist -- proof that I had chosen the right path.
Now everything has changed. Reality has been overturned. In a recent New York Times article, the eminent food-science writer Harold McGee issued a decree tantamount to a papal renunciation of the Immaculate Conception.
Turns out, you don't need "lots of water" for pasta -- two quarts will do. As for salt, two teaspoons is enough. (Although, in terms of salt-per-water, McGee's suggestion is only a little less than Hazan's.) Moreover -- this is the part that really sent a cold chill of apostasy down my spine -- you can put the pasta in the water before it boils; while it's cold, in fact.
For the non-food-obsessed, there is a green angle here.