Plants and algae protect themselves from too much sunlight by a process called nonphotochemical quenching. Scientists studied this in spinach leaves and found that at low pH levels, a molecule called P680+ directly stops excess light from damaging the photosynthesis system. This happens by slowing down a specific process in the system, which helps prevent harm from too much light. The researchers used special tools to observe these changes and confirmed that P680+ plays a key role in protecting the plant from harm.