We don't fully understand the physical world. Our own models don't yet properly describe what we observe (ex. the Two Slit Experiment). Imagine how advanced we look technicaly to someone from say 500 years ago. Now imagine there are civilizations out there 500 or 5,000 years more advanced than us. I would speculate they may have uncovered a few things we've let to learn.
Our intelligence is not even 1% of what the ets know some with IQ’s of 450 accd. to Steven Greer. The speed of light a good example.Speed of light was eclipsed by “the speed of thought” centuries ago.