I think there's a few ways we can interpret this connection. Mempool as dark energy seems appropriate. Sats as mass-energy is a natural fit due to the conservation laws in the physical world and the protocol. Boating accidents as black holes makes sense as it represents mass-energy lost to the outside world.

I think it makes sense to think of the genesis block as the big bang since it marks the start of "the universe" so to speak. All subsequent coinbase transactions could then be considered white holes?

The speed of light is the fastest a signal can travel in the physical world (quantum entanglement is faster but can't carry signal). Mass can only travel at less than speed of light. Maybe this correlates with 10-minute average block times? For example we can't have more than 2016 consecutive blocks significantly faster than 10 minutes on average due to the difficulty adjustment.

On that last point, ASICs are improving at an exponential pace but eventually they'll plateau. Who knows how long before then. Once they do, we can expect fairly consistent block times and little difficulty adjustment. Perhaps then the "speed of light" in bitcoin will be a firm 10 minutes?