Apophenion
Page 6
Because our whole language and thought structure revolves around the idea of cause and effect we have difficulty in accepting the idea of random events, and prefer to think in terms of uncertainty instead. We tend to assume that apparently random events must have underlying causes even if we cannot work them out. However nature provides a simple example of uncaused events in radioactive decay.
Radioactive isotopes, (atoms which spontaneously decay), all exhibit a characteristic half life. Plutonium238 has a half-life of 88 years, Tritium (Hydrogen3) has a 12-year half-life, and these half-lives limit the lifespan of nuclear warheads. Many of the Uranium isotopes have half lives of hundreds of millions of years which means that we can still dig the stuff up because some still remains from the formation of this planet's material in an exploding star core billions of years ago. Now a half life denotes the time it takes for one half of a sample to decay, So after 12 years, half of a sample of Tritium will have decayed, after 24 years only a quarter will remain, and after 36 years only an eighth will remain and so on.
Thus the process seems predictable enough, however it seems impossible to explain how this happens except by assuming that each individual Tritium atom has an exactly 50:50 chance of decaying in a 12 year period. The behaviour of the individual atoms would appear to have to remain random, within limits, to produce the half-life effect. Random behaviour means no causal connection to previous behaviour. Just because a dice comes up with five twice in a row does not make it more likely to come up a third time. If a Tritium atom failed to decay in a 12 year period it does not affect the likelihood of it decaying in the next 12 year period; that chance remains 50:50. Dice may not actually exhibit truly random behaviour unless you bounce them around a lot, they may merely exhibit unpredictable behaviour because we cannot calculate all the micro-factors determining how they fall. Nevertheless with the internal behaviour of atoms it seems inconceivable that some sort of internal micro-factors generate the observed behaviour. Quantum physics depends on the idea that nature does not have unlimited divisibility, at some point something comprises the smallest possible piece of reality. It won't have any internal structure or smaller components within, and at that point the chain of cause and effect must presumably come to a halt.
The Double Slit experiment provides a second example of the weirdness of quantum behaviour. This seminal experiment demonstrates the whole mystery. Many variants on the original experiment exist but they merely serve to confirm the mystery a little.
If you fire light quanta or electrons or even moderately large molecules like Buckyballs (consisting of 60 carbon atoms), at a screen with a small hole in it, then they pass through the hole and land on a target the other side as you would expect particle like projectiles to behave. If you use a screen with two holes in it then they land on the target in a particular pattern as if as if they had passed through the holes as waves instead, even though they land on the target as particles. The wave like aspect of their behaviour suggests that they do not have a definite location in space and time whilst in flight, but that they somehow smear themselves out over a range of spacetime locations. When they encounter a target they somehow collapse back into definite particles, but their wavelike flight mode allows them to do seemingly impossible things.
All objects have wavelike characteristics, but things as large as bullets have a wave function much smaller than the size of a bullet, so bullets tend to go through only one of two closely spaced holes in a steel plate. However tiny objects like light 'particles', electrons, and moderately large molecules, seem to have the ability to pass through both holes simultaneously because their wave functions have a similar size to their particle sizes.
We should not however suppose that the wave like characteristics of quantum entities limits the weirdness to tiny areas of space much smaller than human scale events. With the progress of time, the wave functions can become spatially huge. Instead of using a screen with two closely spaced slits in it, you can use a half-silvered mirror to give a beam of light a choice of directions in which to proceed. Light quanta can either go through it or reflect off it, and with this you can achieve quantum weirdness on any scale you like. It seems that with such a 'beam splitting' apparatus we can force individual light particles (for this is how they manifest at the detectors) to fly 'both' ways round a system of mirrors that we can position yards or even miles apart. The wave function can become enormous by human standards. At this point it becomes imperative to take care about 'when' we speak of. Before a particle sets off, it may appear to have a choice of trajectories, when it lands it may appear to have exercised both choices simultaneously, we cannot however investigate its apparently wavelike manifestation whilst it flies, for in doing so we force it to collapse back into particle mode.
That a half-silvered mirror can apparently split a single light particle into two waves says something utterly strange in itself. Light registers on detectors by getting absorbed by single atoms in the detectors, yet a half silvered mirror consists of little clumps of silver atoms that reflect light particles instead of absorbing them, and spaces between the clumps where they can pass through. So although individual atoms can absorb light particles they appear to have a fairly huge wave size compared to an atom whilst in flight because even a fairly coarse grained half silvered mirror that looks patchy under a hand lens will do the trick.
The presentation of electrons that you get in elementary chemistry and physics classes as tiny little electrically charged balls orbiting the nuclei of atoms or travelling down wires to supply electrical current gives a model of very limited explanatory power. For chemistry to work as we observe it, the electrons need to act as though they have a sort of smeared out existence all over the outside of the nucleus. They don't function as tiny little balls whilst in orbit, they act like diffuse spherical clouds englobing the nucleus, but in other situations they act as point particles of zero size.
At the quantum level particles seem to behave as if they can 'be' in several different states at once or 'be' in several different locations at once. However we can never observe them in such a condition, we can only make observations that strongly suggest that they had occupied such states prior to our measurements. Here we see the double slit mystery re-appearing. Single particles appear to have passed through two different states simultaneously. This phenomenon has the name of superposition and it dominates the way the universe works. Most of the particles of mass and energy that make up the
universe seem to spend most of their time in superposed states. Only when they interact with each other do they seem to fall out of their superposed condition and momentarily manifest in a definite particle like state. The collapse of the superposed wave state occurs randomly, but because most human sized events involve billions of particles, such behaviour creates a more or less perfect illusion of cause and effect, at least in the short term. Thus whilst the water molecules in the glass on my desk vibrate and jiggle around quite violently and keep dropping into and out of superposed states, the water as a whole keeps fairly still and its behaviour remains fairly predictable. Yet some individual molecules may occasionally escape the surface of the liquid and evaporate away.
Under certain circumstances the collapse of the wave function of particles occurs in a not entirely random way, this happens if the wave functions of two or more particles become entangled. Quantum entanglement seems to contradict all the normal assumptions that we acquire about causality, space, and time. Many variations of the basic entanglement experiments exist, but a generalised account of what happens goes like this: Allow two particles which have come into contact to travel off in different directions, then force one of them to collapse its superposed state and assume a definite particle like property. You can choose what property to measure but randomness ensures that the answer will come out as either yes or no for that property. Now in doing this you ensure that the other particle will give a no if you got a yes, and a yes if you got a no, and this seems to work across any amount
of space and time you like. Thus not only do particles spend most of their lives in superposed states, but those superposed states remain entangled with those of the last thing they collided with. So if your eye caches sight of a distant star at night it establishes a quantum connection to an event billions of miles and perhaps thousands of years ago.
Conversely, and here it gets really bizarre, as you look out at that far star at night, light from you can in principle entangle you with an alien not yet born, thousands of years in the future, on a planet orbiting the faraway star.
With reality appearing to behave so differently at the quantum level than it appears to behave on the macroscopic level, many people have sought to interpret quantum physics in a way that makes some kind of sense in macroscopic terms. Often this has meant trying to add some kind of hidden variable to sneak causality back in, but none seems convincing. Macroscopic events do however differ from quantum scale events in one important respect; they exhibit a preference for increasing entropy. Processes involving huge numbers of particles do not usually exhibit time reversibility. Eggs break fairly easily but broken eggs never seem to unbreak, and a time-reversed film of an egg reassembling itself from broken pieces looks unrealistic.
On the quantum scale, events seem less limited by this apparent one way restriction in the direction of time, and the equations describing many quantum changes look fully reversible in their relativistic form, so nothing seems to prevent them happening in reverse.
So, in summary quantum physics presents us with two phenomena to reconcile with the rest of our understanding of the universe, namely superposition and entanglement. Both of these seem more comprehensible if we assume that what we observe as particles actually have a wave like behaviour that spreads out in both space and time into the past and future of the moment of observation. After all, superposition implies hyper-temporality, superimposed events happening at the same time, whilst entanglement implies hyper-locality, linked events happening at the same time in different places.
One particular interpretation of quantum physics, Cramer's Transactional Interpretation,14 explicitly describes the double slit experiment in terms of phenomena moving both forward and backward in time. In this model a forward wave goes through both slits and then makes the target emit a time-reversed wave, which travels back down one of the two paths at random, taken by the forward wave. The time-reversed wave meets the forward wave at every point of its trajectory and the two waves combine to make a particle. Thus in a sense, the particle reality arises out of an overlap between waves coming from the past and the future. This transactional scheme also makes some sense of the phenomena of superposition and entanglement. We can never observe superposition actually happening because any attempt to observe it forces it to collapse. Nevertheless it often seems that we observe behaviour that could only have arisen from a superposed state. Now if the past of a particle consists not of a discrete single state, but of two or more waves, then the moment of a particles interaction or measurement marks the point where these waves overlap and collapse to create a particle- like effect.
Similarly in entanglement we do not need to posit some incredible action at a distance that somehow finds its precise target across vast tracts of space and/or time. We just need time reversibility. When one of a pair of entangled particles falls out of superposition it sends a time reversed wave back down its trajectory back to the point where both particles had contact. This then modifies the starting conditions, which in turn ensures that the other particle in the entangled pair behaves appropriately.
Time reversibility thus solves the problem of how a single particle can 'know' that a screen has two slits, and how it can 'know' what it's entangled partner has done on the other side of the universe. However it does not explain the randomness or the apparent superposition of two states in the same 'place'.
For this I suspect that we need not merely reversible time but three-dimensional time as well, time which extends 'sideways' as well as just fore and aft. I propose that time may thus have the same dimensionality as space, three in each case. This may seem rather contra-intuitive on first analysis, after all a calendar shows a string of dates in a row but it never shows extra days stretching out sideways from any day, nor do we seem to experience such things. We do however generally accept that a number of possible tomorrows might follow today, although most people seem to assume that a singular yesterday led to today, despite that historians argue interminably about how and why we arrived at today. The assumption of a singular past will receive some re-examination in the following section.
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Part 2.
Three-dimensional time
If time does have a three-dimensional solidity we would not see it directly. We cannot even see a fraction of any length into the past or future by normal means anyway, so a thickness in time would generally go unnoticed as well. However a universe with sideways time would have one defining characteristic in particular; it would appear to run on probability rather than on strictly causal deterministic principles, and this one does.
Time appears linear and one-dimensional because we define and measure time as the direction in which entropy increases, but entropy only appears on the macroscopic scale, where large numbers of particles participate in a process. Although various macroscopic processes lead to increasing entropy at different rates we have tended to adopt the revolution of heavenly bodies as our standard entropy-meters as they dissipate their energy only extremely slowly and at a fairly constant rate.
Probability lies at right angles to time as we measure it, in sideways time, and it acts as a sort of pseudo-space or parallel universe space, but we should not suppose that any of the 3 dimensions of time has a special status, anymore than any of the spatial dimensions has. Now all objects have a limited spatial displacement in three dimensions, two and one dimensional objects exist only as theoretical idealisations; a piece of paper must have some thickness to exist. Similarly all objects have a displacement in 3 dimensions of time as well. Their temporal 'thickness' at any instant equates to their wave property, and it has enough room to accommodate superposed states which have slightly different orthogonal time coordinates. Thus at any instant of the present not much temporal room exists for parallel universes because particles displace only tiny amounts of time. Most of the particles in my body will exist in superposed states at any instant, but that does not imply that overall I exist in many parallel universes in any meaningful way. My overall wave property at any instant does not much exceed that of the size of a single particle. Thus it serves to locate me fairly precisely in time and space on the macroscopic level, even though most of the particles inside me have multiple orthogonal time coordinates in the pseudo-space of parallel universes.
Noether's theorem asserts that all conservation laws reflect symmetries in nature in which something remains constant. Thus for example the claim that 'matter can never get created or destroyed' implies that the amount of it remains constant under time translation. This claim proved inaccurate, and Einstein replaced it with the celebrated mass-energy equivalence where the energy equals the mass times lightspeed squared. This new conservation law asserts that the total mass-energy remains constant in time although one can change into the other. Heat an object and it becomes heavier, but only infinitesimally so at kitchen temperatures.
Einstein also uncovered a non-obvious space-time equivalence. All objects always move at exactly the same rate in spacetime, despite appearances to the contrary. The faster something moves through space the slower it moves through time. Onboard time actually slows down for objects moving very fast, months of jet travel can take a few fractions of a second off an accurate clock and theoretically add them to the life span of those travelling with it.
We measure time only by movement in space, even if that movement consists merely of parts moving within a clock or within the human body. A deep symmetry exists between space and time, so why do we ascribe different dimensionalities to them?
Can anything actually do this?
Yes, the wave aspects of particles of matter do it all the time, but usually on such a small scale that we do not notice it, in the same way that we do not usually notice the mass-energy equivalence or time dilation at speed. However waves sometimes have very big effects which show up as quantum entanglement over many kilometres or in the capricious phenomena of magic.
When it comes to the past and the future, objects can have as much orthogonal time as the period of 'ordinary' time under consideration, this equates to the idea that events become progressively less predictable or determinate the further you look in time. So a particle has many possible futures and its wave like behaviour allows it to spread out and 'try' all of them to some extent, but it only gets feedback across time from one possible future at random. This then creates positive interference and allows the particle to manifest in some definite form in the future.
Despite that we assume the past to exist in singular form because we experience our own past singularly, both magic and quantum physics suggest otherwise.
From the standpoint of the present, the past and the future do not exist in definite form. The present consists of the moment of interaction between waves from the past and the future as they collapse randomly into particle mode. The past and future consist entirely of wave modes spread out in orthogonal time in a progressively more diffuse fashion the further you consider them from the present. Thus time travel into the past remains a silly idea because the past merely consists of wave like echoes of what might have been. Time travel into the future remains possible, but only if you isolate yourself from the effects of entropy by slowing down your onboard time by travelling at, or accelerating towards, something close to light speed.