Quantum Cyclic Cosmology with Sean Carroll

Comments · 243

• PH

  @PhilHalper1 · 4 weeks ago · pinned

  For more on possible solutions to the Big Bang, Boltzmann Brains and more do check out our book Battle of the Big Bang <a href="https://tinyurl.com/ypdaeuas">https://tinyurl.com/ypdaeuas</a>

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• JU

  @justatest90 · 4 weeks ago

  Sean Carroll is a great communicator, and you&apos;re a great interviewer as always Phil. So fascinating.

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• CA

  @callandaynes4095 · 4 weeks ago

  What a perfect moment for this youtube video to randomly fluctuate into existence.

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• FH

  @fhvisuals479 · 3 weeks ago

  A channel that has Sean as guest is an auto subscribe for me.

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• VO

  @Vorador666 · 4 weeks ago

  So cool that Sean Carroll joined this great youtube channel, will definitely listen to this today!

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• MC

  @mckenzie6593 · 2 weeks ago (edited)

  Sean Carroll is an absolutely superb communicator. <br><br>I&quot;m a light-year away from being a mathmatician or physicst but having listened to him over the last few years I can say he has single-handedly ignited my current fascination with both.<br><br>Grateful.

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• DO

  @dohpam1ne · 4 weeks ago

  Phil, you just made my work shift a lot easier (and more educational)!

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• OL

  @oliverjamito9902 · 3 weeks ago

  Gratitude and Honor

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• MA

  @marierausku9292 · 3 weeks ago

  I love it! Every time Sean is on it&apos;s a treat! 🤗

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• EM

  @EmergentMindworks · 4 weeks ago

  As a neuroscientist, it seems to me that comparing the probability of a low-entropy fluctuation giving rise to our universe with the probability of a low-entropy fluctuation directly producing a mind is considerably more nuanced than is often appreciated in these arguments.<br><br>The observable early state of our universe did not contain minds. It contained physical conditions from which stars, chemistry, planets, biological evolution, nervous systems, and eventually minds could arise through ordinary causal dynamics. That is a very different proposition from a functioning mind fluctuating directly into existence already possessing the physical organization necessary to instantiate cognition, however minimally we define it.<br><br>The relevant quantity therefore cannot simply be the entropy deficit associated with rearranging a certain amount of matter. It is the phase-space measure (and, where relevant, the dynamical accessibility) of the class of physical states sufficient to realize the proposed outcome. A Boltzmann brain is not merely a small, low-entropy lump of matter; it must fall within the highly constrained subset of physical states and trajectories that actually instantiate cognition. Conversely, a low-entropy early universe need not already contain the complexity of its eventual observers, because ordinary physical dynamics can generate that complexity later.<br><br>Accordingly, the relative spatial scale of the two fluctuations, or even a superficially estimated entropy deficit, does not by itself establish their relative probabilities. To make that comparison meaningful, one first has to specify what physical organization is actually sufficient to constitute an observer, and then ask what measure that set of states (and perhaps trajectories) has within the relevant statistical-mechanical framework.

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• AK

  @akirasthecat · 3 weeks ago

  I love to listen to Sean Carroll. &nbsp;Thank you, Phil!

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• WH

  @while_coyote · 13 days ago

  I’ve heard this so many times.

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