It From Bit, Round 2
In this installment, Wheeler kicks my ass. Again.
According to Langan and Wheeler, Quantum mechanics demands a new view of reality. Upon considering Quantum Physics, Information Theory, and the question “How come existence?”, Wheeler states, “the universe cannot be a giant machine ruled by pre-established continuum physical law”. This rebukes the current view of reality - at least in the implicit - and calls for a new one. Along with many others, Wheeler tried many, many different theories. The one that survived he calls “It from bit”. It from bit says that “every item in the physical world” ultimately has an immaterial source and explanation. We aren’t talking about God or ghosts here (though we’re not ruling them out), but bits. Binary yes-or-no registrations, 1s and 0s. Information is the immaterial source of every physical item and bits are the foundational units of information.
Wheeler gives three examples to argue in favor of “it from bit”: First the detection or not of a polarized photon, second the Aharanov-Bohm effect, finally the Bekenstein Bound. The first two we covered already. The third, the Bekenstein Bound, says that the amount of entropy contained in a physical space (so long as the space and energy therein are both finite), must be less than some upper bound. Wheeler is making a progression here. He first starts at a single one-bit effect with the polarized photon, then steps his way to large collections of bits with the Aharanov-Bohm effect, and finally steps to the upper limit on the number of bits that can be contained in some region of space. He thereby makes an argument for “it from bit” on the quantum, every day, and cosmic scales of reality, as well as on the object, systemic, and universal levels. Langan accepts “it from bit” as at least a hint toward a necessary view of reality, so by the foundational assumptions of this project so will we.
There is a further pattern to be noticed: Stoke’s theorem. In both the Aharanov-Bohm effect (see the video in the last entry) and the Bekenstein Bound, there is a theme of “containing the information on the boundary”. In the Aharanov-Bohm video we saw that the magnetic vector potential A could not be zero outside the shielding by integrating over a closed curve that contained a non-zero total magnetic field B. With the Bekenstein Bound we see similarly that all the information required to describe a system, e.g. a black whole, can fit on the surface. I suspect we’ll see this again in a later principle: The boundary of a boundary is zero.
