[davidcuddeback]

Physical can be understood to mean "of or relating to matter and energy or the sciences dealing with them, especially physics." Light, temperature, and time are described by physics, so I would consider "physical" to be an accurate adjective for those units. You seem to be using a more limited definition of physical, closer to the word "spatial."

Also, btw, you might want to read the article you linked. The article is discussing a fringe idea that some scientists have. Scientists are free to explore new ideas, and they make for good click bait for science journalists. Until those ideas gain traction, they don't provide for compelling arguments, though.