Friday Notes (Mar 24, 2023)

I don’t usually write two Friday Notes posts in one month, but I was dog-sitting my funny little “nephew” Bentley for a week, and every time I don’t post for a while it’s hard to get back into blogging mode. In fact, it’s harder each time. I increasingly find social media less and less interesting or rewarding.

Some of that is on me, but more of it is disappointment and disgust with social media and technology companies in general. A bit more on that below.

Mostly, though, I wanted to — at long last — post the last two notes that have been lingering on my Apple Notes app for years (in one case, since 2018).

I start with an even half-dozen Chinese martial arts movies Bentley and I enjoyed for our evening entertainment. I enjoyed them, at least. Bentley slept through all five. Yes, I know five isn’t an “even half-dozen” — I watched the sixth one last night without her. (She went home last Tuesday.)

That worked out fine, because the sixth movie isn’t related to the other five, so she didn’t miss anything. Which implies that the first five are related to each other, and indeed they are. Four of them comprise an original and three sequels, the fifth is a spin-off that follows a character introduced in the third movie.

I’m speaking of the Ip Man tetralogy starring the Hong Kong martial artist and superstar action film hero Donnie Yen (Yen Chi-tan).

Yen was born in 1963, the same year as another Chinese martial artist and action film superstar, Jet Li. In contrast, superstar Jackie Chan — perhaps more well-known to Western audiences — was born in 1954.

All three (and many others) are well-known to fans of the genre, but Chan is probably the most famous to Westerners due to co-starring in Rush Hour (1998) with Chris Tucker. Some may recall him from Rumble in the Bronx (1995), which made him a celebrity here and led to the Rush Hour trilogy of movies (as well as others made for Western audiences).

While Jackie Chan’s later movies frequently contain lots of humor (many of his films, especially the later ones, are comedies), movies with Jet Li and Donnie Yen tend to be more serious action films (much in the vein of Bruce Lee’s films). Some may remember Jet Li from his first international film, Lethal Weapon 4 (1998).

Donnie Yen is probably the least well-known to Western audiences, though he has appeared in Rogue One (2016), XXX: Return of Zander Cage (2017), the live-action Mulan (2020), and John Wick: Chapter 4 (2023). Sadly, these are not particularly notable films (I haven’t seen John Wick 4, yet, but I’m hoping it’s an exception).

If you like action films with lots of kung fu fighting, definitely check out the Chinese films of all three. There is a wonderful and vast world to discover!

The Ip Man tetralogy is (loosely) based on the real-life Wing Chun grandmaster, Ip Man (1893-1972) — whose student Bruce Lee (1940-1973) introduced martial arts to the world and is widely considered one of the most influential martial artists ever.

The fifth movie, the spin-off Master Z: Ip Man Legacy (2018), follows Cheung Tin-chi (Max Zhang), introduced in Ip Man 3, where he plays a rival Wing Chun master who challenges (and eventually loses to) Ip Man. In the spin-off, his loss has led him to give up martial arts and open a grocery store.

But he’s drawn into events and must use his skills against a crime syndicate (that includes another martial arts superstar, Michelle Yeoh, and — surprise — Dave Bautista). The film also has brief appearances by Thai martial artist and film star Tony Jaa. (Thai martial arts films, by the way, are a whole other level of awesome.)

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The four Ip Man movies differ in what nemesis Ip Man is drawn into fighting. In the first, Ip Man (2008), it’s primarily the Japanese — who occupied China during the Second Sino-Japanese War (1937-1945). Ip Man also deals with a gang of local bullies.

In Ip Man 2 (2010), Ip Man has escaped to Hong Kong (from the Japanese-occupied Foshan). He opens a martial arts school but must first prove himself by beating the local masters. He also must face local gang members, but the ultimate fight is a match against an arrogant British boxer and bully, Taylor “The Twister” Miller (Darren Shahlavi). In an earlier match, Miller had defeated — and killed — the head of the local martial arts society Hung Chun-nam (Sammo Hung — another martial artist star famous to genre fans).

In Ip Man 3 (2015), Ip Man once again faces local crime members and must rescue his son and other students kidnapped in an attempt to coerce him. The crime boss is — surprise — boxer Mike Tyson (playing “Frank”). In their confrontation, Frank promises to leave him (and his son’s school) alone if Ip Man can survive a three-minute fight. The final fight is between Ip Man and fellow Wing Chun master Cheung Tin-chi, who wants to be grandmaster.

Ip Man 4: The Finale (2019) takes Ip Man to San Francisco where he seeks study opportunities for his rebellious younger son (who’s been kicked out of school for fighting). Part of the conflict here is (once again) between Ip Man and the local masters who are upset that Ip Man’s student Bruce Lee has opened a martial arts school open to western students. The final conflict is between Ip Man and Barton Geddes (Scott Adkins), a corrupt and racist Karate expert staff sergeant in the US Marines.

I’ve left much out in these descriptions, both for length and to leave meat on the bone. Besides being excellent martial arts movies, they are, at times, profoundly dramatic and moving. All four were directed by Wilson Yip. The famous Yuen Woo-ping (check out his filmography!) did the fight choreography on the latter two (and directed Master Z). These are all must-see for genre fans. They all get a Wow! rating.

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The sixth film, Crouching Tiger, Hidden Dragon: Sword of Destiny (2016), as the title suggests, is a sequel to the very popular Crouching Tiger, Hidden Dragon (2000). For many Westerners, this was their first (and perhaps only) martial arts film.

Michelle Yeoh reprises her role as Yu Shu Lien, and the story once again turns around the fabled sword, the Green Destiny. Donnie Yen stars as the love interest Silent Wolf — AKA Meng Sizhao, who Yu Shu Lien was engaged to in the first film and the reason she could not follow her love for Li Mu Bai (Chow Yun-fat).

The film was directed by (the aforementioned) Yuen Woo-ping. Jason Scott Lee plays Hades Dai, the main Bad Guy. It’s available on Netflix. (So are all four Ip Man movies. Master Z is available on Amazon Prime.)

It was okay, I give it an Ah! rating.

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A quick note about social media platforms before I move on to the notes from my Apple App (and feel free to stop reading at that point; they’re technical).

While I do still love baseball, the greedy infighting that resulted in a loss of regional sports networks (such as Fox Sports North, which broadcast Twins games) meant I couldn’t watch baseball for the last two years (except for postseason games).

This season the MLB app, which let me at least follow scores and game results, raised their price from $19.99 to $29.99. Greedy bastards! That’s a 50% bump. So, I cancelled my subscription. With the recent changes made to game rules (to speed up games), and some other nonsense, I feel like the MLB has made baseball hard to enjoy anymore.

And based on Spring Training scores, my Twins aren’t looking good. Once again (and ever), they just can’t seem to get good pitching. And I really don’t care for the emphasis on the Three True Outcomes, so I guess I’ll go back to my pre-2010 mode of being vaguely aware of what the Twins are doing.

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I had a disappointing “discussion” with someone on YouTube. It was one of those “debates” where the other guy wasn’t willing to grant much validity to what I was saying (though I knew it to be valid). I was granting his validity, but I’m really sick and tired of the apparent inability of others to return same.

I’ve stopped engaging with many blogs due to that. With blogs, if I read a post, I want to comment. The whole point of taking the time to read someone’s posts is to engage with the topic. Otherwise, why bother? (The exception is science bloggers. For those, I shut up and learn from the experts.)

Over time, YouTube has trained me to do the same. Generally speaking, I only follow YouTubers who educate and don’t feel the need to comment. But this time I did, and the result was 12 rounds (24 comments) of back-and-forth that accomplished nothing and left me disgruntled.

I’m tempted to post the whole thing, but probably won’t bother. Between the ads, the content makers begging for contributions and their embedded sponsored ads, I’m close to being done with YouTube. I hate how everything eventually gets monetized. Pretty much every religion and spiritual approach disdains greed.

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Okay, you can stop reading, because the rest of the post is two long notes from my Apple Notes app. The content is technical and probably of interest only to me.

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Gravity

[Copied from a 2018 online discussion. The first part is by “Andrew”. Minor edits for grammar. They are answers to a question I asked about gravitons.]

True GR can operate just fine without gravitons. And, while massless spin-2 gravitons are equivalent to GR in a suitable classical limit, there are some distinct ways that theories that have massless spin-2 gravitons are different from GR:

1. In GR, gravitational potential energy is not localized, in a graviton theory it is.
2. In GR, energy is conserved locally but not globally, in a graviton theory, local energy conservation implies global energy conservation.
3. In GR, there is no quantum tunneling through singularities, in a graviton theory, there is.
4. In GR, gravitational field energy is not an input into the stress-energy tensor even though gravitational field energy does influence the predictions of GR by a more indirect route in the field equations; in a graviton theory, the strength with which a graviton couples to any other particle with mass-energy is universal and so gravitons self-interact with each other with a coupling strength proportionate to their mass-energy as an input on the same footing as any particle with mass-energy. In my view, the claim that these different mechanisms produce exactly equivalent phenomenology has not been rigorously proven (in part because of the extreme mathematical difficulties associated with doing calculations involving a massless spin-2 graviton for which the usual tricks of Standard Model quantum mechanical calculations don’t work).
5. GR is deterministic, a graviton theory is stochastic.
6. In GR, the cosmological constant is easily added as part of the field equations as an integration constant. The cosmological constant is not nearly so natural an addition to a graviton theory.

I’m sure that there are other technical distinctions as well, but the point is that there are basic, undeniable, qualitative differences between GR using the field equations, and a graviton theory.

For the most part, they are identical in phenomenology. For example, massless gravitons and gravitational effects in the GR field equations both propagate at the speed of light and both give rise to gravitational wave phenomena. But, they aren’t truly identical and the ways in which a graviton based quantum gravity differs from GR are critical to reconciling the Standard Model and GR, which is why developing a theory of quantum gravity is such a major objective.

[This part is by someone named “vmarko”.]

Just a short note — for a reference, I always recommend the MTW book to particle physicists who studied GR from the Feynman’s book. The latter just doesn’t do justice to GR, despite being written by Feynman.

Also, regarding Andrew’s points (1), (2) and (4), it is all a consequence that in the graviton theory the general metric of curved spacetime is being rewritten as a spin-two field on top of the flat Minkowski metric. The presence of the Minkowski metric gives rise to all those spurious things like localized gravitational energy, global conservation law and graviton stress-energy. All those things are undefinable in curved spacetime.

Regarding (3) and (5), GR is a classical theory, not quantized. OTOH, the graviton theory can be quantized, but is nonrenormalizable, and thus ill-defined.

Finally, (6) is also very interesting, since when you add a nonzero CC into GR, flat Minkowski spacetime fails to be a vacuum solution of the theory, so it doesn’t even make sense to rewrite the metric as a flat metric plus a spin-two field.

In general, forcing GR into the formalism of perturbative QFT in flat spacetime is a disastrous idea, and it doesn’t really work. The fact that Feynman pushed for that approach is responsible for much of misunderstanding of GR by particle physicists. Feynman even gave up on the idea eventually, but his “Feynman’s Lectures on Gravitation” is still doing the damage, IMO.

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Entropy, Information…

[This, from 2021, is (I think) is a comment I made somewhere and wanted to keep for future reference. It sounds and looks like my writing, but it may be from someone else. Again, minor grammar edits.]

You’re right, there’s a Maxwell’s Demon aspect to the idea of actually measuring the entropy of a system. So, yeah, our ability to quantify entropy in a real system is usually very limited and usually based on some simplified model of that system. What I like about the micro-state/macro-state view is that, even if we can’t precisely identify the macro-states, they do exist (identifiably in models), and entropy can be understood as the system migrating to more common (“larger”) ones.

An office with very little in it has a lower maximum entropy than an office with a lot of stuff. (Max entropy depends on the total number number of states a system allows.) Put in terms of uncertainty, with a sparse office, it’s easier to be certain a change has occurred, but in a busy office it’s much harder. (More specifically, it takes more memory and effort to remember the busy office.) FWIW, I see an office+index a low-entropy system in itself, but as you say, a large amount of entropy was generated creating it. That entropy has wandered off as unrecoverable waste heat.

I think there’s a difference between the reversibility of physics and the possibility that entropy can decrease. Usually the former implies a negative time signature — time literally going backward. Entropy can decrease while time still goes forward. It’s just hugely overwhelmingly we’re-talking-giant-numbers unlikely. (In fact, it happens all the time, tiny “violations” in entropy, but there’s a ratchet effect. Given equal probability of moving to a smaller configuration versus a larger configuration, larger always wins. It’s like a rock on the slope of a hill in an earthquake. It might jiggle upwards briefly, even for a few steps, but downhill always wins.)

I don’t think we can get away from the bond between information and the implicit or explicit map the informee uses to makes sense of that information. I suppose we could call the raw statistics that describe reality as “data” and the things we actually choose (or are able) to measure as “information” but that’s just semantics.

“Entropy measures the variety of configurations possible within a system, and recently the concept of brain entropy has been defined as the number of neural states a given brain can access.”

I agree with the first part of that, but I’m not so sure about the latter. There are indeed a huge number of possible states, but brains only occupy a single state at a time, and only a small subset of states in the right sequence creates consciousness. It’s because they maintain such a low-entropy state that they consume so much energy. As you mentioned about the messy office, it takes energy to either clean it or create a sorted index for it. (Refrigerators are another example of a system that burns a lot of energy maintaining a low-entropy state.)

We might say brains are systems with a very large maximum possible entropy, although they’re usually in low-entropy states functionally. In analogy to the canonical example of gas in a room, an even distribution is a max entropy state whereas all the gas in one corner is a low-entropy state because far fewer of the possible configurations of the room look like that. Functionally the brain seems like the gas in one corner — a state the brain works hard to maintain (as we would for gas in a corner).

As an aside, totally agree that information processing costs energy, but laptops are so hot because we want that processing done fast. The annoying heat comes from how CMOS transistors speed up switching by temporarily short-circuiting every time they switch states. Billions of short-circuits per second do create some heat! We waste a lot of electricity in the name of speed.

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Stay validated, my friends! Go forth and spread beauty and light.

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