Are vibrating strings in string theory perpetual motion?

Question

I have never learned string theory, so please forgive me if my question sounds naive or obvious, but I would like to know and I am most likely wrong.

As far as I know, strings vibrate in different modes and different modes correspond to different fields (electrons, photons etc) which is a fascinating idea. And to the best of my knowledge, these strings never stop vibrating as to continue being the fields that we know and love, i.e. my tasty fermionic coffee.

However, does that mean that these strings are perpetually in motion? I thought that violates the law of conservation of energy?

Taken from another perspective, since strings vibrate, i.e. fluctuate, would the Fluctuation-dissipation theorem apply here and eventually stop the vibration?

Answer 1

Regarding the dissipation, in string theory, different vibrational modes of a fundamental string are interpreted as different types of particles. The ground state refers to the lowest energy vibrational mode of the string. This would correspond to the most stable configuration of the particle.

For a particle to decay, it must transition to a lower energy state by releasing some energy (e.g., in the form of other particles). If the particle is at its ground state, there are no lower-energy states available. Hence, there's nothing it can decay into, making it stable. If the particle is isolated, then it cannot decay nor dissipate energy.

I don't understand though, why you think a vibration that keeps its energy violates energy conservation.