Quantum physics is a world where we’re told that probability and uncertainty rule and causality is thrown to the winds. However, I think it’s the observer that’s the real fly in the quantum physics ointment. Left to its own devices, the micro (quantum physics) would (certainly should) mirror the macro (classic physics) and thus causality rules both realms. Whatever applies to the micro must apply to the macro since the macro is made up of the micro (and thus I feel free to sometimes use more familiar macro examples in the following text). It’s the observer who is interpreting, albeit through no fault of her own, things as being in a state of uncertainty or as just probability.
Continued from yesterday’s blog…
To repeat, it is claimed by some that it is nonsense to talk about the existence and properties of anything in time and space until such time as an actual observation or measurement is made. (I assume here that previous observations/measurements recorded in some manner or other, by observers who no longer exist, is taken as valid.) Anyway, everything is just probability until that measurement/observation happens. The old quandary that revolves around that tree in a forest falling – if there is nobody around, is there any sound? Well, claimants of the no observation – no reality philosophy would have to conclude ‘no’ because the tree doesn’t exist in the first place (neither does the forest) because nobody is observing it!
Okay, lets say that’s true and say, as a thought experiment that nobody (human anyway) has even seen, measured, recorded, photographed, etc. the Moon (there was no Apollo program and no lunar landings). Some theorist speculating about a Moon could only say it existed with such and such probability. Mother Nature may, or may not have blessed us with a Moon. Since nobody has observed a Moon, the probability is probably close to zip and our theorist is headed towards a career meltdown!
What about indirect observations? Are they sufficient to prove the Moon exists and save the theorist’s bacon? I mean observers have observed such things as how the Earth is highly stable in its revolving about its axis. Observers have noted that sometimes at midnight it’s pretty bright outside (full Moon) yet two weeks later it’s pretty dark at midnight (new Moon). Observers have noted that sometimes when it’s very bright outside at midnight, for a few hours that brightness dims and turns a reddish colour (lunar eclipse). Observers have noted that sometimes it gets partially, sometimes totally dark during broad daylight (solar eclipse). Observers have noted lots of phenomena that have a 27 to 28 day cycle without any apparent reason(s). Observers have noted and measured the tides and tidal cycles. From all this indirect evidence, sceptics have concluded our theorist is right and that a Moon must be orbiting Earth with such and such properties. Those being the case, direct observations of the Moon are irrelevant in terms of proving its existence. The Moon exists without being stared at**.
In real life the existence of many unobserved objects has been proven to exist – indirectly – without any direct observation. Black Holes are a case in point. The nature of the Earth’s core is another. Now if something can exist with just indirect observation, then things can exist without any observation at all. A planet hasn’t just popped into existence around a distant star just because our technology has reached a certain degree of sophistication, sophistication now able to detect (observe/measure) it.
To take a more everyday example familiar to us all, throw a dice. Examine the five sides visible to you – you don’t have to be a rocket scientist to deduce the value of the unobserved (face down) side!
There’s another quantum category that suggests that observation is not always necessary. That’s the phenomena of quantum entanglement. Okay, it’s necessary to observe one thing, but in doing so you don’t have to observe something else in order to know something about it. Its phenomena where by two things are entangled and knowing the state of one thing tells you the properties (some of them at least) of the other.
Actually I quite love this idea of entanglement and to know the properties of something without ever having to actually observe or measure it. Let’s return to my favourite imaginary couple, Jane and Clive, who, as we all know, are a bit weird. So, I can imagine this hypothetical macro example from the Jane and Clive archives, where Jane and Clive agree that on any given day, whatever colours Clive wears, Jane won’t (or vice versa). So, if Clive is dressed in a blue suit, with white shirt and red tie, grey socks and hat, with black shoes, I can be sure, without observing, that Jane’s outfit will consist of nothing that is black, white, blue, red or grey. So, I know something about Jane’s properties without any observation because in this case Jane and Clive were entangled! In actual fact it is way weirder than that. If this were a real quantum entanglement example, then if Clive and Jane were on opposite sides of the Universe, and Jane had on a green outfit and Clive had on a red outfit, and Clive changed outfits to one of green, then Jane would have to also change – instantaneously. Now that’s really spooky!
Or, say Jane and Clive are expecting company, but don’t know when that company will arrive. Therefore, one or the other of them has to be home at all times – in case. So, if I see Jane shopping, I know, without observation, that Clive is home. Now let’s take a micro example. The vacuum energy spits out a matter-antimatter particle pair, but they separate and escape and head off in opposite directions. Jane captures one in her particle trap (box); Clive gets the other one in his particle trap (box). Jane peeks into the box and sees a positron. That alone spoils the surprise for Clive, for without any need to look; he now knows his box contains an electron.
So classical (macro) reality, as well as quantum (micro) reality (IMHO), is the same reality whether or not there is an observer around, so I repeat, it’s nonsense to say that they – observers – are the be all and end all of what’s real.
Still, when it comes to the nitty-gritty of trying to pin down the specifics of quantum activities, all is probability, and things can both be and not be (the technical phrase is superposition of state) at the same time with equal probability, only becoming either/or when the observer struts her stuff and observes. [The observer can be an instrument, but ultimately that instrument transmits the observation to the human that operates the instrument.] The case of Schrodinger’s Cat is the best known example. A Rube Goldberg device is constructed and operated by a probabilistic quantum process that will subject a cat to a life or death fate with a 50/50 probability of either life/or death after a fixed interval of time has passed (then the device turns off). The idea is that all remains probability until such time, and only until such time, as an observer actually looks and sees an animated cat, or a dead cat. Until that observation, the cat is in a limbo state of being both alive and dead simultaneously. But what if there is no observer? Would the cat remain in a limbo state for all eternity? Clearly that’s not, and can not be, the case. The cat is either alive, or it is dead, and the observer be damned! The observer is irrelevant.
When an electron is emitted (A) we know the details. When the electron hits its target (B), we know the details. Where is the electron in-between? Who knows? It’s all probability. But, does that mean that the electron has actually taken all possible pathways between A and B, or just one? The observer is hapless in such an experiment because observing the electron in mid-path not only changes that path, but says nothing about what path the electron took between A and the in-between observation.
This is weird. In one case, trying to observe an electron (which I’m certain had a precise set of coordinates at the time the observation was made) results in the observer only being able to conclude that the electron’s location is only just an observation of probability; while observing the cat changes probability to certainty.
Smite the observer! Off with her head! In Dalek-speak, “Exterminate!” At all times the electron is at certain fixed place and moving at a certain velocity and interacting with other things, like the little billiard ball it is, much like a real billiard ball that’s at a fixed set of coordinates, moving at a certain velocity as a result of interacting with other things, like the cue ball. From the electron’s point of view, there’s no probability or uncertainty. Screw the observer – she’s an uninteresting and unnecessary complication that has no bearing on reality, even at the quantum level. Ditto the cat. The cat is alive, or the cat is dead, and the cat ‘knows’ what state it is in even if the observer hasn’t a clue because she hasn’t yet made the relevant observation.
To be continued…
**In another way, quite a valid way I might add, you do constantly observe the Moon – just not with your eyes (or ears that hear, or a nose that smells, or mouth that tastes for that matter). You ‘feel’ the Moon (and the Moon ‘feels’ you too). You have mass and therefore gravity – ditto the Moon. So, you and the Moon are attracted gravitationally to each other, albeit it’s a very tiny attraction, but it is not zero, and tiny doesn’t negate the reality of that dual attraction. You have directly observed the Moon! Therefore the Moon exists. It’s observation via gravitations instead of photons. Since everything with mass has gravity and since gravity extends its influence out to infinity in theory (in theory because it travels at a finite velocity – the speed of light) and since gravity acts on all other masses, all objects with mass ‘observe’ all other masses. Now electrons, protons, neutrons, in fact all fundamental particles have mass, therefore gravity, and therefore participate in this universal ‘observation’ process because gravitational attraction is a universal ‘observer’! Therefore, to exterminate all observers means exterminating the entire Universe! Of course this use of the word ‘observer’ is probably somewhat outside the usual and traditional meaning of the word ‘observer’ and that’s why I’ve consigned it to this footnote. But, I suggest the argument isn’t trivial and is a valid one.
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