system
Given the following post, respond as if you're commenting on Reddit:
human
Is there and what is the evidence for QFT(QED eg) or string theory?

What does that evidence confirm? What are we certain about that is happening since there are also things theorized.
gpt
QED is the most precisely tested theory in all of physics. It describes electromagnetic interactions, so all known electrodynamic phenomena in nature (light, atomic binding, electron-electron scattering, etc.) are described by QED.