Discrete Space-Time-State Physics (Social Event Talk)

摘要

Consider that, perhaps, the most microscopic elements of space, time and all of the other basic measures in physics are discrete. We certainly have no evidence to the contrary. What this could mean is that there would be natural units of length and time. If so, every actual interval of time could be exactly represented by an integer.If we further suppose that, instead of true randomness at the level of quantum mechanics (QM), we substitute "Unknowable Determinism" or UD, where, at the level of QM, we replace the "random" by the continual influx of unknowable, microscopic information that pours into every QM event, from every direction. The unknowable information must, if this model is to correspond to reality, be essentially unaffected by any physical aspects that we can measure.The idea is to have a model of a microscopic system where physical events are actually deterministic, but that nevertheless, appear as random to observers from within the system. A given system could have unknowable determinism which could appear just as unpredictable, to those within that system, as does true randomness. There would be no way, in general, to reliably predict the exact future of the microscopic states of any actual region. There is a simple explanation for that impossibility. Aside from consequences of laws of physics, including conservation laws, there may be many detailed microscopic states that each correspond to what can be measured macroscopically. The nature of exact reversibility and exact conservation laws are such as to impose the laws of probabilistic QM on our higher-level observations despite the possibility that underlying the apparent randomness is strict determinsism at the most microscopic levels. Thus it may be that the QM process is actually deterministic, but a more appropriate description might be "Unknowable Determinism."It's not that microscopic physics requires a non-deterministic explanation; rather, it could be that our knowledge and understanding of exactly what is happening in the actual real microscopic world is what is necessarily uncertain.Imagine a model of the most microscopic state with space being a 3+1 dimensional regular Cartesian array of cells, where, at each instant of discrete time, each cell is in one of a small integer number of states (such as 3). If we assign integer coordinates (x, y, z, t) to the 2nd-order space-time coordinates of each of the most microscopic cells, then x + y + z + t can be thought of as always being an even number. Of course, the x, y and z coordinates must range over the size of the Universe, but the static range of the t coordinate is 2, the present time and the immediate prior time. This second-order array allows for the convenient static representation of dynamic information. Our hypothesis is that the process that is the most microscopic discrete physics (perhaps underlying QM) could correspond exactly to the temporal evolution of state of some such discrete, deterministic system. Instead of randomness, at the bottom we might have Unknowable Determinism. Every correct picture of the actual microscopic state cannot be calculated by us until after it has arrived, naturally.An advantage of such reversible systems to their creators is that after the detection of an extraordinary event, the process can be reversed to enable efficient study of the exact cause.