Part 3/13:
Boltzmann proposed that even after the universe reaches maximum entropy—often referred to as the heat death of the universe—it might still experience random fluctuations that could lead to a more organized state. This, he suggested, could result in the emergence of a universe like the one we observe today. However, Boltzmann's ideas were met with skepticism, and the "Boltzmann brain" concept was introduced as a thought experiment to undermine his hypothesis.