This may sound like a strange question... I was walking away from my physics class today and I wondered if resonant vibrations were the reason my shoelaces become untied. I noticed that when I walk faster, and produce what I believe are more forced oscillations, they become untied more frequently. If I am thinking about this correctly, does this mean that resonance can overcome friction? In trying to understand physics better, I've been trying to relate new concepts to more simple ideas. If I am very off base, any recommendations would be welcome. Thanks!