What Does It Cost to Be a Knower?
Details
Warm Greetings to All,
Join Plato's Cave philosophers and Orlando Stoics on Zoom this Sunday morning, Aug. 2 at 9:00. (Informal chat at 9:00, forum at 9:15)
NOTE: New Applications for Plato's Cave membership are currently closed. The Plato's Cave forum will soon be discontinued on this meetup platform for reasons stated in my message to members.
Links and program information may be accessed through our partner organization, the Orlando Stoics meetup, at https://www.meetup.com/orlando-stoics/
Active Plato's Cave members can temporarily reserve a place, receive zoom login information on this site, and receive e-mail confirmation, until September 2026.
Every Sunday, a new forum. Our meeting starts at 9:00 AM with friendly wakeup chat; then our select topic panel briefly introduces the subject at 9:15, followed by member discussion and Q&A.
Volunteer introduction panelists will meet following each forum to develop the next program;.
This Sunday:
# What Does It Cost to Be a Knower?
## Details
Last week we found that knowing costs. This week we ask what it costs in energy, and whether the universe could ever hand us a knower for free. Three thinkers answer.
We begin with Ludwig Boltzmann. Defending his account of the second law in Nature in 1895, he faced an awkward question. If disorder always increases, how did our tidy corner of the cosmos get here? He floated an answer: perhaps the universe as a whole is dead and uniform, and our ordered region is a fluke, the way a deck shuffled forever will eventually come out sorted. Later physicists found the trap. A far smaller fluke, and therefore a far likelier one, would produce no world at all, just a single brain hanging in the dark for a moment, complete with vivid memories of a past that never happened. That is the Boltzmann brain, a knower assembled for free out of noise. Contribution: given enough time, a mind can be an accident.
We then turn to Jacob Bekenstein, who asked what a mind costs to build. Studying black holes, he found a limit that binds everything. In "Universal Upper Bound on the Entropy-to-Energy Ratio for Bounded Systems" (1981), he showed that any region of a given size can hold only so much entropy, and the ceiling is set by the energy inside it. Read as information rather than heat, this says something startling: there is a maximum to what can be known inside any volume, and the currency is energy. So a mind is not a free lunch. It is a specific quantity of information, and physics names the minimum energy required to hold it. The fluctuation has to come up with the joules. Contribution: knowing has a floor price, and energy is what pays it.
We arrive finally at Sean Carroll, who shows the accountancy has a moral. Several respectable cosmological models predict that fluctuated observers eventually outnumber evolved ones. In "Why Boltzmann Brains Are Bad" (2017), Carroll asks what happens if you believe such a model. If most observers are flukes, then you are probably a fluke, your memories are noise, and the evidence that led you to the theory was assembled a moment ago out of nothing. The theory, once believed, eats the grounds for believing it. He calls this cognitive instability: such theories cannot be true and justifiably believed at the same time. What saves us is a real low entropy beginning, an enormous head start from which order was inherited rather than stumbled upon. Contribution: a theory that makes you an accident cannot ask you to believe it.
Links
Ludwig Boltzmann
- "On Certain Questions of the Theory of Gases" (1895, Nature 51, 413–415) — https://doi.org/10.1038/051413b0
- Lectures on Gas Theory (1896–98; trans. S. G. Brush, University of California Press, 1964)
- Boltzmann brain — Wikipedia — https://en.wikipedia.org/wiki/Boltzmann_brain
- Heat death of the universe — Wikipedia — https://en.wikipedia.org/wiki/Heat_death_of_the_universe
- Ludwig Boltzmann — Wikipedia — https://en.wikipedia.org/wiki/Ludwig_Boltzmann
Jacob Bekenstein
- "Universal Upper Bound on the Entropy-to-Energy Ratio for Bounded Systems" (1981, Physical Review D 23, 287–298) — https://doi.org/10.1103/PhysRevD.23.287
- "Black Holes and Entropy" (1973, Physical Review D 7, 2333–2346) — https://doi.org/10.1103/PhysRevD.7.2333
- "Information in the Holographic Universe" (2003, Scientific American 289(2), 58–65)
- Bekenstein bound — Wikipedia — https://en.wikipedia.org/wiki/Bekenstein_bound
- Jacob Bekenstein — Wikipedia — https://en.wikipedia.org/wiki/Jacob_Bekenstein
Sean Carroll
- "Why Boltzmann Brains Are Bad" (2017, in Current Controversies in Philosophy of Science, Routledge, 7–20) — https://arxiv.org/abs/1702.00850
- From Eternity to Here (2010, Dutton), chapters 10 and 13
- Arrow of time — Wikipedia — https://en.wikipedia.org/wiki/Arrow_of_time
- Sean M. Carroll — Wikipedia — https://en.wikipedia.org/wiki/Sean_M._Carroll
Hosted by:
Plato's Cave and Orlando Stoics
https://www.meetup.com/platoscave/
https://www.meetup.com/orlando-stoics/
=======================================================