quantum mechanics

by

There’s a divinity that shapes our blogs, rough-hew them how we will

Hello and good morning.  It’s Thursday, and as I promised‒or threatened, depending on your point of view‒here I am, writing my weekly blog post as before, back when I was regularly writing and publishing my fiction.

I’m not sure what topic(s) I should cover here, today.  I rarely seem able to plan these posts in advance, and when I do plan them, I don’t think they often come out very well.  That’s from my point of view, of course; maybe other people have found my planned posts excellent and wish I would write them more often, but if so, they haven’t given any clear feedback.  So, I don’t really know what will happen from now until the end of this blog post.

Of course, if the universe is deterministic, then whether I or anyone else knows it or not, what I will write is already a certain thing, as is the fact that I don’t know it‒indeed one could legitimately claim that it “already” exists in a sense, particularly if one is invoking the picture of Special and General Relativity and the “block” spacetime concept.

However, the Copenhagen interpretation (if that’s the correct term) of quantum mechanics states that wave-function collapse is truly “random”, and so the future is not determined, at least at the smallest level.  But if the wave function truly collapses, then that would be the only fundamentally irreversible temporal process known in physics so far, and that seems suspicious to me.

I’ve been reading the original EPR paper and thinking about this subject at least a little bit lately.

Of course, in a way, the Everettian “many worlds” interpretation of quantum mechanics would say that the future really is determined, but that at every instance of decoherence, the wavefunction becomes subdivided into waves that no longer interact with each other directly.  People interpret this as if new universes were coming into existence each time, and that’s a decent way to conceptualize it, but to me it seems misleading.

To my mind, it’s just waves that are traveling along in “parallel” and not influencing each other.  But that’s not really any different from the sounds of two separate conversations happening in a crowded room‒maybe one involves a group of people discussing a recent sporting event and another gaggle is talking about some new show on Netflix.  Maybe the conversations are even in different languages.  The sound waves propagate from each conversation independently, and though there may be places where troughs and crests pass and add or subtract for an instant, locally, they are very much different processes.  But there is no mystical invocation of “new universes” such as what troubles some people about Everettian quantum mechanics because of a misunderstanding of Occam’s Razor.  There are just separate, “parallel” things happening within the same overall universe.

That’s not a perfect analogy, of course.  The “waves” of the quantum mechanics are more complex* than sound waves, and are more fundamental, and once they decohere, it seems they are far less likely to interact with their other “branches” than are even sound waves of parallel conversations in different languages.  But even those are more separable than we think.

We have an exquisitely evolved capacity to parse the information out of human conversation, decoding the waves without thought, and so we don’t think very often about how astonishing that process is.  If aliens who communicated only by light flashes were trying to interpret such a set of conversations, they would have a daunting task, indeed.

Just think about how hard it has been even to decode the communications of dolphins and whales‒highly intelligent and social creatures that clearly communicate with each other.  And these are our fellow mammals from the same planet, who also use sound for communication!  We vastly underestimate the complexity of what we’re doing when we understand conversation and other noises, because our auditory processing systems do it without our conscious intervention, and they have been honed over hundreds of millions of years by the brutal and pitiless sieve** of natural selection.

Likewise, we thoroughly underestimate the complexity involved in catching a pop-up fly ball, or a thrown football, or the process of walking, or of throwing a ball, or of finding a specific item on a cluttered desk.  It shouldn’t surprise us that even if the future “division” of the universal wave function seems random, it can be utterly deterministic, and in that sense each branch “already” exists.  But each “branch” that no longer interacts with others after an instance of decoherence will “feel” to given humans*** as if it were the one and only “universe” and that all others have collapsed out of existence somehow, when they’re really just there but not interacting anymore with the person in question.

Maybe I’m wrong, of course.  I mean, I’ve been right before, but not often enough to make it my default presumption.

Anyway, there you have it, the stuff about which I was “destined” to write, though I had no specific plans.  That’s fair enough.  “Life is what happens while you’re making other plans,” as the saying goes.

Speaking of plans, though, I plan to write tomorrow and Saturday**** on my fiction (probably just on Extra Body).  I may take my laptop with me to do it; the experiment with my smartphone seems to be working okay (see my reports from Monday, Tuesday, and Wednesday), but it doesn’t feel quite as “natural” to me, still.  Who knows, though?

Only Laplace’s Demon® (Quantum Version™) knows.  But of course, that entity would feel, if anything, less “free” than those of us who know not yet what is to be and know not fully what has been.  For an entity that can see every detail of the past and the future laid out deterministically and in full detail is utterly incapable of taking any action on such knowledge‒for its own actions are as determined as all others, and it “knows” this.  Indeed, it cannot but know it.

Ignorance is not bliss, but it does at least give you room to improve, and that can be ego syntonic.

Have a good week, if such is your destiny.

TTFN

*Ha ha, that’s a little physics joke there, when you think of how quantum wave functions involve complex numbers.

**Mixed metaphor alert!  How would a sieve hone anything?  Oh, well, I’m not going to change it; it works too well to communicate my meaning.

***And the very process of “feeling like something” is extraordinarily complex, and we only really understand the bare rudiments of how this happens.  This relative ignorance engenders the propagation of nonsensical, conceptually vacuous ideas like panpsychism and the like, and the pseudo-mystery of the “hard problem” of consciousness.  Well, it is a hard problem in a sense, but not the way philosophers of consciousness seem to express it, as far as I can see.

****I think I will be working Saturday, but I’m not certain, because of the highly atypical thing that happened last Saturday, with the office being closed.  This coming Saturday will be my son’s 24th birthday, and I will now literally have missed half of his life more or less completely.  That’s his preference, not mine, though it started as a consequence of my own misadventures‒our personal wavefunction decoherence if you will.  Still, when enough people repeatedly decide they don’t really like having you around or interacting with you too much, you have to think there must be some powerful causes for the consistency, especially when you don’t even really want to be around yourself.  So, I am profoundly sad about the state of things, and I miss my children terribly, but I have to conclude provisionally that they’re making a reasonable decision.  At least I “talk” to my daughter from time to time, and that’s not a small consolation.

by

Causality, relativity, uncertainty, and attractive versus repulsive gravity–these are worth celebrating

Okay, well, I’m writing this blog post from the office, because this is where I slept last night after the holiday party.  We did not have the party at the office, just to be clear.  We had it at a very decent restaurant called Maggiano’s, which may be part of a chain to some extent, I think.  It was a nice enough restaurant, food-wise, and the building and the outside lights were quite beautiful (see below).  However, inside, it was way too crowded and noisy, and we were seated at a very long, narrow table against a wall.

I felt incredibly stressed when we first arrived; I can hardly hear out of my right ear for one, and I have had tinnitus in it since about 2007 or so, and everything else was a tumult and commotion.  There was too much visual sensory overload also, and way too many people in too close quarters.  I miss the social mores of the pandemic, honestly.  I was barely able to endure long enough for our server to get me a drink so I could calm down a little.  I almost left and just walked back to the office.

My difficulties with such things have gotten worse over time, probably at least partly because I only ever used to go to restaurants and whatnot with people with whom I felt quite comfortable—my family, near and extended, then my wife, her family, our family, and so on—so there was always someone on whom I could focus, and with whom I could speak.

The drinks were rather weak, which may be good, since it was a work night, but I had to drink several to keep from tensing up.  Even so, at the end of the night, when they wanted to take a big group photo, I just walked away.  I had been dodging pictures all night already; there was a terribly annoying number of them, because everyone has their own little cameras in their smartphones, so instead of conversation—which was very difficult with anyone more than one seat away, and pretty hard even with those neighbors—people just took their little, instant, digital snaps, which I suspect will never really be used for recalling memories.

I’ve said it before, it’s not the case that things on the internet (or smartphones or whatever) are forever, as is sometimes claimed.  There is such a cacophony of data and images and whatnot, a good portion of it now not even being “real”, that most things will be swiftly lost like a drop of ink in a roiling, stormy ocean, or the quantum information of something that’s fallen in a black hole.  In principle it’s all there, but in practice it’s as lost as the echoes of Julius Caesar’s death rattle.

I guess it was a pretty nice evening, and the food was pretty good.  The salad was above average, and the broccoli I had on the side with my ziti dish was good.  It was all certainly well above the level of, for instance, the Olive Garden, but it was terribly noisy, literally and figuratively.  By the end, when we were the last party in the restaurant, it was still noisy, because our group was terribly noisy, and it was embarrassing and unpleasant.

I think I mostly at least prevented anyone from capturing my disgusting current face and form on camera in anything other than, perhaps, an oblique angle.  I really don’t like how I look, or how I feel, and certainly don’t want it memorialized, even if it’s evanescent and ephemeral*.

After the party, I was brought back to the office, which is only about four miles from the restaurant.  I could have walked, since the night was reasonably cool, but since I knew I wouldn’t be taking a shower, I decided not to do that.  I have washed up this morning and applied antiperspirant and aftershave (or whatever you call it when you haven’t actually shaved) and I brushed my teeth and everything.  I slept on the floor, with my backpack as my pillow, and it was about as comfortable as sleeping at the house, and I got about 3 hours of sleep.

This is the state in which my life is and has been for years now:  sleeping at the office and spending time here (by myself) is just as pleasant as being at the place where I nominally live.  That’s because I have no life, and I don’t expect one to occur again for me.  I’m really absolutely dismal and morose and unpleasant, even to myself.

I’ve hardly even read anything in over three weeks now, which is very weird and rare for me.  The single thing to which I’m now looking forward is the Doctor Who Christmas special, and that’s not a huge draw, just a pleasant one.  It’s not as though I’m actually watching it with anyone or can talk about it with a friend or anything.

I got out the hardcover books Spacetime and Geometry and Quantum Field Theory, As Simply as Possible at the office.  I have them resting on the desk, hoping to entice myself during any downtime I might have at work.  So far it hasn’t paid off, but I would like to master the mathematics of GR well enough that I can understand intuitively why a uniform energy field permeating space generates “repulsive gravity”.  I understand that it does, but I don’t have a good picture of it in my head, whereas I do have a much clearer intuitive sense of why the curvature of spacetime (especially the time part) leads to the apparent force of attractive gravity.

In a way, that’s my only remaining unaccomplished (and reasonably achievable) goal.  Quantum field theory is interesting and all, but the basic concepts of it seem fairly straightforward to me**.  Contrary to what people often say, quantum mechanics (et al) are only really counter-intuitive if you insist upon trying to apply macroscopic and mesoscopic intuitions to phenomena that happen at much smaller scales.  It’s a bit like expecting one of your bathroom tiles to behave just like the Burj Khalifa, only the scale is much more disparate between the quantum and the macroscopic.

People seem somehow puzzled by the notion of how complementary pairs of one’s measurements of quantum “particles” can never be more accurate than a certain level, as if this is truly different from measurements of macroscopic phenomena.  I’m quite sure that the errors when measuring, say, the mass or velocity of something as large as an elephant, or a car, or what have you, are waaaaaay huger than the absolute uncertainty in measurement of the position and/or momentum of a particle.  They’re just not as noticeable because the thing itself is big, and so the percentage of the error might be smaller and less consequential.

But we know things change with scale, like surface to volume ratios and whatnot.  An uncertainty of a millimeter when measuring a blue whale is hardly relevant, but if you’re measuring an ant, it could easily be crucial, and if you’re measuring a dust mite that error would be larger than the organism.

I also don’t get the objection to the possible “many worlds” description of quantum mechanics that derives from the fact that we only ever see and experience one world.  I don’t know why that puzzles people.  It’s not as if you can see both the outside and the inside of all the solid objects around you.  If you touch the near surface of a basketball with one finger, you can’t feel the opposite side of the ball with the same finger at the same time.

Yet, there’s no real doubt that the inside and the other side of physical objects really exist.  We just can’t sense the whole of any given thing at once.  Any part of space that will never enter our future light cones is something we will never, ever see at all***, but we don’t have any good reason to doubt that far distant regions of spacetime exist.  Internal consistency of reality and logical coherence of the world seem to demand many things existing with which we will not, and sometimes cannot, ever interact.

Okay, that was a weird tangent.  My apologies.  Anyway, I doubt that I’m going to achieve my “dream” of getting an intuitive, mathematical understanding, something I can feel, about why spacetime expands in the presence of a uniform energy.  After all, it’s something about which I honestly care, and my track record with such things is abysmal.  I don’t expect to achieve anything else of value, even to me, in my life.

I’m tired, I’m sad, I’m depressed, I’m alone; the only person in whose presence I always find myself is a person I despise (me).  My catharsis via this blog isn’t working.  I’m getting no help, though I wish for it, but I’m not sure how well I would respond if some were to come.  Maybe, like the wonderful simile Sting used in Be Still My Beating Heart, I would wriggle like a fish caught on dry land, unable to tell the difference between help and danger, between an offer of comfort and a warning of pain.

Whatever.  Sorry, that’s all pathetic, isn’t it?

In closing, I wonder if anyone listened to my little audio snippet yesterday, and if anyone thought it was worth it for me to try to do such a thing more often.  Let me know in the comments (on WordPress) if you have any feedback to offer.  Thanks.

maggianos

*Performing together live, for the first time.

**Straightforward for quantum field theory type things, anyway, to be fair.  I don’t mean that it’s not complex (ha ha! it uses complex numbers all the time, get it?) but I have a sort of picture of how the processes work, and it makes sense.  The rest would just be building details and specifics on top of the basic framework, which is a lot, of course, but there’s no real intellectual hurdle to be cleared.

***Assuming we do not discover any exceptions or workarounds to special relativity and the speed-of-causality limit.  There could in principle be workarounds, but it seems unlikely that there are local exceptions to the cosmic speed limit.  In any case, even such exceptions shouldn’t violate chains of causality.