# What's the difference between entrainment and resonance?

1. May 17, 2012

### quantum1234

This has been confusing me for a couple of days, maybe it's because I just started self teaching physics (which isn't going so well lol)

So entrainment is when one vibrating object begins resonating to the same rate as the more powerful, higher vibrating object. Resonance is when one vibrating object causes another vibrating object with the same resonant frequency, to vibrate.
Isn't is basically the same thing? or are the terms used interchangeably?

Oh and as an added question (i'm sorry) are the terms 'oscillating' and 'vibrating' used interchangeably?

2. May 17, 2012

### tiny-tim

welcome to pf!

hi quantum1234! welcome to pf!
i think entrainment is mutual resonance … each of two objects affects the other … while resonance is usually one-way
more or less

but i think in practice "oscillation" would only be used to describe a pretty regular vibration (like simple harmonic motion)

3. May 17, 2012

### quantum1234

Thank you, it makes better sense now, but I am still a little bit confused about resonance.
So resonance causes an object to transfer energy to another object if they both share the same natural frequency AND if the two objects are vibrating at different frequencies.

So what I don't understand is:
"Natural frequency is the frequency at which a system naturally vibrates once it has been set into motion."
- I read a while back that everything in the universe is in a constant state of vibration so how is something set into motion if it's supposed to be already vibrating? And so how can two objects be vibrating at different frequencies if they share the same natural frequency already?

I hope you understand my question, I have a feeling that I worded it oddly, if so please tell me and I'll rewrite it :)
Again, thank you!

4. May 18, 2012

### tiny-tim

(where did you read that? )

most of the vibrations are pretty random