Rabbis Allow Leavening For Passover?

Evidently some rabbis are now allowing baking soda and baking powder as kosher for Passover! (Link via Chequer-Board)

Actually, it makes some sort of sense. Yeast (an organism) is a very different sort of leavening agent from baking soda and baking powder (which make use of a chemical reaction between acids and bases). One of the main differences between yeast and baking soda/powder is that yeast improves its leavening ability with time, while once you mix a baking soda/powder batter the clock is rapidly ticking on the efficacy of the leavening. The whole point of the unleavened bread is that the Children of Israel didn't have time to wait for the leavening and had to leave quickly, so that would indicate a yeast leavening. If the Children of Israel lived now, they probably would have made quick breads instead of yeast breads for a faster getaway.