Really interesting thoughts!

My point being not that these things don't exist. Instead, I'm thinking about how our everyday understanding, and the definitions most people agree upon (or the words we use to communicate ideas), are more often defined by our shared subjective experiences. In other words, the usefulness of so-called 'objective' truths is often less than the socially-constructed truths, which are influenced by time, place, and other contextual factors.

Like heat: Scientists and many people have a deep and 'scientific' (by Western standards) understanding of thermal energy, thermal conductance, etc., but in most situations people encounter, I would argue that "hot" or "cold" is more practically defined by the subjective experience. For example, scientists can agree what a 10C air temperature means, but whether that is "hot" or "cold" will vary depending on who you ask and when. 10C on a summer morning could feel bone chillingly cold to many people, but that first 10C afternoon in Spring can feel like a warm hug. I guess this is the 'defining' vs. 'explaining' thing you mentioned? If I think about how this applies to TERFy types or transphobes, I guess they're the equivalent of someone getting hung up fixating on a rough understanding of Joules or Kelvin or some bullshit that does correspond to the air temperature outside, but says very little about what the actual experience of being outside is like?

Night and day are both diametrically opposed, and one could not exist without the other – day exists because the Earth revolves around the sun, and so there could not be life on Earth if there was no daytime or nighttime, our solar system would have to be arranged in such a way that makes no physical sense.

This one's interesting. It got me thinking about those communities who live too far north or too far south to experience a "night" or "day" for months at a time. Some of these towns go 100 days in a row before the sun dips below the horizon, or before it rises above the horizon. I'm not sure really what it means here in the discussion, it's just a thought that lit up my ADHD brain, lol.