relativity

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“The sun is the same in a relative way, but you’re older.”

Okay, well, here we are.  It’s Wednesday.  I don’t know what else there is to say about the day.  I guess…yeah, I don’t know.  It’s another day.  It’s a stretch of (roughly) 24 hours, the specifics depending on whether you’re using solar time or sidereal time or just the “self-contained” UTC time*.

UTC time is kept on a variety of clocks around the world and is based on the oscillations in the hyperfine transition frequency of the Caesium-133 atom.  That frequency has been defined as 9,192,631,770 Hz.  The international measuring community thing, whatever they call themselves, thereby agreed on defining the second as exactly 9,192,631,770 of those Caesium-133 oscillations.

Of course, oscillations of atoms, like all other processes that take time, slow down with increased spacetime curvature and with increasing speed relative to any given observer.  This is why the GPS satellites have to adjust their own time to account for both special and general relativity.  It’s pretty cool; you’re carrying proof of Einsteinian relativity in your smartphone.

You probably already knew that.

Then, of course, once they’ve decided on the precise value of a second‒knowing that the speed of light (or more precisely the speed of causality) is constant‒they then defined the meter as how far light travels (in a vacuum) in⁠ 1/299,792,458⁠ seconds (approximately 30 2/3 “vibrations” of a Caesium-133 atom).  Mind you, two observers moving relative to each other will see their meters as different each from the other, but c’est de la relativité.

It can be easy to imagine that definitions of units in science (and related fields) are not merely arbitrary but circular, almost tautological.  But really, given that these are attempts to codify specific attributes of reality itself, they would almost have to be self-referential with each other to be useful.

The length of a day is something that happens for real.  Thanks to the base 6 and 12 numbering system of the Babylonians, the day was long ago arbitrarily divided into 24 hours, each 60 minutes long, and each 60 seconds long, so a second was 1/(24 x 60 x 60) days or 1/86,400 of a day.

That worked well for a long time, especially since, before Galileo et al, humans couldn’t really measure time very precisely, anyway.  And then, until railroads allowed rapid travel between cities, it wasn’t necessary to worry too much about having the same time in different places.

But eventually that did become useful and necessary for many purposes, and eventually it was realized that a day wasn’t exactly what we were calling 24 hours, and indeed, that the length of a day varied slightly from day to day and year to year; also, a year isn’t a whole number of days long.  Also also, a day could be measured relative to the sun‒which is close enough that a day doesn’t end quite exactly after one full rotation since the Earth moves relative to the sun over the course of a day‒or with respect to distant stars, by which estimate a day comes closer to being exactly one complete rotation.

For most people most of the time, though, this precision, and that upon which it is based, are probably not merely irrelevant but unknown and unguessed.

Likewise, I don’t know how many people know about how Celsius made his temperature scale 100 degrees between the freezing and boiling of water at sea level pressure (a pretty reasonable choice, though I’m led to understand he initially had 100 assigned as the freezing point and 0 the boiling point!).

Then it was discovered that there existed a minimum possible temperature in principle, and they decided to set that scale, the Kelvin scale (named after William Thompson Scale**) using degrees of the same size as Celsius, but with zero defined as‒understandably enough‒absolute zero.

It’s all fairly interesting, if you’re in the right frame of mind.  But, alas, there’s every reason to suspect that all this information will be rendered moot and useless and perhaps even lost as the world winds down, or if life is replaced by artificial intelligence, or everything ends in some other way, as seems more than possible even in the relatively short term.

In any case, the laws of physics, as we know them, seem clearly to predict that the universe will tend toward ever-greater entropy and eventually all life, all structure will end.  Sometimes, I think it cannot happen soon enough for my taste.

Then again, there are cyclic universe proposals, such as Roger Penrose’s Conformal Cyclic Cosmology.  It bases its model on the fact that entropy, though always tending to increase, is not really an absolute quantity, not a substance, and that our universe’s “maximal” entropy may be the next universe’s low-entropy beginning, just on different scales; it doesn’t even require any “inflationary” burst of expansion to explain the uniformity of the CMB, I think.  I haven’t yet finished Penrose’s book about CCC, because though he is a stunningly brilliant mind, his writing can be a bit plodding and dry.

I guess it’s hard for any person to be good at everything, though Penrose has many strengths.  If memory serves, he invented a set of shapes which can be used to tile an infinite plane (in principle) with no gaps and no repeating patterns.  Supposedly this has been proven to the satisfaction of professional geometers, though I am not familiar with that proof.  Still, if it is a mathematical proof, then it is one of those rare things that we know to be certainly true, given its set of axioms.

It’s not necessarily useful in any practical sense, of course.  For instance, I think it’s probably true that any tiling system that can tile an infinite plane without repeating could not be used to tile a closed, finite, simple geometrically shaped portion of a plane‒such as a rectangular room.  I think you would always have to cut some of the tiles as they reach the wall, no matter how big the room is, as long as it is finite.  I do not know this for certain, that’s just my intuition.

Well, I guess I’ve wasted space and time enough here for now.  It’s no more wasteful than has been my entire existence, I guess, but also no less wasteful.  Or is it?  I don’t know.  In any case, for now I will stop wasting your time.

Please have a good day.

*Yes, it’s probably redundant to say “UTC time”, but the order of the acronym is sort of Yoda-esque‒it did not originate with an English term‒so I feel it’s tolerable to use it this way here.

**That’s a joke.  He was really William Thompson, the first Baron Scale***.

***I mean the 1st Baron Kelvin, of course, all joking aside.  A baron scale sounds like some long forgotten and unused (i.e., barren) bit of laboratory apparatus, left for eons, gathering dust in an abandoned world, like the broken statue of Ozymandius.  It’s very sad.

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Audio blog for Friday on anhedonia, fatigue, declining entertainment franchises and Newtonian and Einsteinian physics

This is an oddly meandering audio blog that I made this morning, having little desire to write much, and it goes from my troubles with depression and lessening interest in any former source of joy to the fact that even Star Wars and Marvel franchises are going downhill (with speculation about the causes) on to physics–first Newtonian then Special and General Relativity, and ponderings about the nature of near-light-speed travel and its potential effects when a spaceship passes the Schwarzschild radius in the direction of its motion (and even a tiny dabble into cosmic strings, which are not to be mistaken for the “superstrings” of string theory/M theory).  I find no firm conclusions, but maybe it’s mildly interesting somewhere.  It’s longer than I expected it to be, but hopefully not too long.

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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.