Ludwig Boltzmann seemed to regard the entire universe, with or without a Bang, as unlikely. Does this help explain his deteriorating mental condition? Or vice versa?
In 1906, Boltzmann's deteriorating mental condition forced him to resign his position, and his symptoms indicate he experienced what would today be diagnosed as bipolar disorder. Four months later he died by suicide on 5 September 1906, by hanging himself while on vacation with his wife and daughter ... His tombstone bears the inscription of Boltzmann's entropy formula: S = k ⋅ log W
I'm not sure who first developed the concept of
Boltzmann brain. It may not have been the great Ludwig Boltzmann himself, but instead developed as a parody of his work.
The consensus amongst cosmologists is that some yet to be revealed error is hinted at by the surprising calculation that Boltzmann brains should vastly outnumber normal human brains. Sean Carroll states "We're not arguing that Boltzmann Brains exist—we're trying to avoid them." Carroll has stated that the hypothesis of being a Boltzmann brain results in "cognitive instability". Because, he argues, it would take longer than the current age of the universe for a brain to form, and yet it thinks that it observes that it exists in a younger universe, this shows that memories and reasoning processes would be untrustworthy if it were indeed a Boltzmann brain. Seth Lloyd has stated "They fail the Monty Python test: Stop that! That's too silly!" A New Scientist journalist summarizes that "The starting point for our understanding of the universe and its behavior is that humans, not disembodied brains, are typical observers."
Some argue that brains produced via quantum fluctuation, and maybe even brains produced via nucleation in the de Sitter vacuum, do not count as observers. Quantum fluctuations are easier to exclude than nucleated brains, as quantum fluctuations can more easily be targeted by straightforward criteria (such as their lack of interaction with the environment at infinity).
Some cosmologists believe that a better understanding of the degrees of freedom in the quantum vacuum of holographic string theory can solve the Boltzmann brain problem.
Brian Greene states: "I am confident that I am not a Boltzmann brain. However, we want our theories to similarly concur that we are not Boltzmann brains, but so far it has proved surprisingly difficult for them to do so."
I've been retired for some time, but try to keep my own (possibly Boltzmann) brain active so I've been doing sociological research on Floating Fortune Road. Among other interesting denizens,
I have discovered the original Boltzmann Brain herself; she's working in a cannabis dispensary in an alleyway just a few meters off F.F. Road. The music of Mozart, Bach and Elvis Presley are just figments of her imagination, along with the rise and fall of the Roman Empire, the very existence of
Homo sapiens, the Cambrian Revolution, the Big Bang,
my own life story and those of many or most of you —
all figments of her imagination.
This leaves me with an awesome responsibility. If I could somehow pound sense into her (or fill her brain with different psychoactives), the figment known as Donald Trump would cease to have any reality, along with the figments of Hitler, Atilla the Hun, Al Capone, and Kanye West.
But should I? We'd also lose millions of species of beautiful flowers and butterflies, Baudelaire's poetry, and the Holy Book of Mormon. There would never be another rainbow.
Faced with this dilemma I turn to the Infidels in this thread for advice and support.
