Questions set the scientific method in motion. Without that initial curiosity, that “I wonder…”, that “What if…”, we would not have the technology, the medicine, nor the knowledge that we have today.

But not all questions have readily attainable answers. Despite our formidable advances in probing reality over the years, there are some things we are still incapable of concretely knowing. One day, that could change, but for these topics it’s currently hard to fathom how. Here are four questions that humans may never know the answers to:

Do You See Red Like I See Red?