so i pondered this earlier at work. Sidious is only 50-60 years old while Yoda is 900 years old. how could Sidious be more powerful than Yoda? was it simply because the dark side allows a person to become much more powerful, or access this power at a much faster rate? it just doesn't make a lot of sense to me.
Well, how do you define "more powerful?" Are you referring to who won their fight in the Senate chamber? That's just physical power, the power to inflict violence. It stands to reason that Sidious would've focused all his efforts on developing that kind of power. Yoda, however, would've probably focused most of his 8-plus centuries of study to more ethereal, spiritual aspects of Force mastery. Yes, he's more than capable in a fight, but that's probably just a small portion of the total range of things he's devoted his studies to over the centuries.
Compare the climactic fight between Vader and Obi-Wan in
A New Hope. Vader won the fight (okay, Obi-Wan let him win), but Obi-Wan achieved something far more advanced by transcending the flesh -- and in his own words, becoming more powerful than Vader could possibly imagine. The true master of the Force would understand that physical might is the crudest kind of power.