Let's watch: Black Mirror, Hated in the nation

Black Mirror is a good hard sci-fi series with significantly less appeals to emotions than average sci-fi. We'll watch season 3, episode 6, Hated in the Nation (2016), by Charlie Brooker et al.

Also it's as long as a usual movie (90 min).

Cheatsheet

• Karin Parke: old detective, DCI, darker shorter hair than Blue. Traditional, thinks Blue is naive, not good at modern tech.
• Blue Colson: young detective, TDC, lighter longer hair than Karin, sometimes wears glasses. Digital forensics expert.
• TDC: Trainee Detective Constable
• DCI: Detective Chief Inspector
• 
  
• Jo Powers: first death, writer.
• Tusk: second death, rapper.
• Clara Meades: third death, took bad selfie at war monument.

Let's read: Sutton's RL, week 3, 4, chap 4

We'll first finish chapter 4.1 from week 3, and for week 4, we'll do:

• Sutton & Barto, rest of Chapter 4
• Sutton & Barto, Chapter 5

In this post we do chapter 4.

Dynamic Programming (DP)

Define: DP: a collection of algorithms to compute optimal policies for an MDP model of the environment. 

Classical DP algorithms are of limited utility in reinforcement learning both because of their assumption of a perfect model and because of their great computational expense, but they are still important theoretically. DP provides an essential foundation for the understanding of the methods presented in the rest of this book. In fact, all of these methods can be viewed as attempts to achieve much the same effect as DP, only with less computation and without assuming a perfect model of the environment.

Basically, can't solve Bellman, can't do classical DP, put them up as unachievable ideals and opt for more practical algorithms that can approximate them.

Summary of Elon Musk's projects

This post summarizes Elon Musk's projects: SpaceX, Hyperloop, Tesla, Neuralink, OpenAI. It summarizes from the series from Wait But Why.

SpaceX makes Mars spaceships and other space things, Tesla makes electric cars. Neuralink makes BMI (brain-machine interface).

Let's watch: ColdFusion videos

Today we'll just watch a bunch of videos.

The Strange Story of the Mp3 Player (begins at 1:50)
Portable music players were invented in 1979 by Kane Kramer and the way it distributes music without the internet was basically transmitting over the telephone-net at terminal vending machines in bars and music stores and such. It went bankrupt though.
Saehan made MPMan in 1998. RIAA sued Diamond Multimedia in 1998 over its MP3 player but lost, and this very publicized case made MP3 players popular. iPod, 2001, made it super popular.
Kramer got acknowledged as original inventor of iPod by Apple for some legal reasons.

Energy, the collapse of the Western Roman Empire, and of the modern society.

The collapse of Western Roman Empire is a very classic topic among scholars of history, politics, economy, etc. Joseph Tainter had a theory, based on complexity and energy management. 

If you have time, you can watch this lecture by Joseph, it's a fun and somber talk about the collapse of Western Roman Empire from his perspective. I also read the book The Collapse of Complex Societies, which elaborates his theory of social collapse with more examples than just the Western Roman Empire, including the Mayan Empire and Chacoan civilization.

The Collapse of Western Roman Empire

In the early days of Western Roman Empire/Roman Republic, it conquered a lot of new lands. Each conquest was easy, and brought great loots. The Romans used the loot to increase their wealth and power and social complexity. 

Some complexities were voluntary: they wanted to enjoy life. Some complexities were forced on them: they needed it to keep their growing republic/empire in order. These complexities were mostly in the forms of bureaucracies and law codes.

Eventually, the conquests ground to a halt: its borders reached the Germanic, Persian, Briton, and so on, countries that were either too powerful to conquer or too poor and distant to worth conquering. Rome went from conquest mode to farming mode. This placed a great burden on the empire: the economy and culture used to run on conquests, but now it has to run on farming.

Fermi estimate: eccentricity of earth's orbit around the sun

I was reading about Tesla's rocket when I noticed some numbers.

Someone asked about the orbit of the car launched by the rocket Falcon Heavy in February 2018, and it said that

After orbiting the Earth for 6 hours, a third-stage burn-to-depletion was completed at approximately 02:30 UTC Feb 7, placing the dummy payload in a heliocentric orbit having a perihelion of 0.99 au and aphelion ~1.7 au.

and I thought, wait a pony picking minute, 0.99 au? Isn't earth "exactly" 1 au away from sun? Surely, the car got launched by accelerating from LEO, so when it enters the heliocentric orbit, its perihelion must be almost exactly the same as earth-sun distance.

Well, it's not precisely 1 au, and earth's orbit around the sun has eccentricity... Fermi estimate time!!!

Philosophical sketch: Reducing a person to a will, with implications on morality

The Japanese religion of Shinto (神道) believes in Kegare (汚れ), meaning a religious state of pollution. It can be caused by many kinds of things, but usually those that are too... "bodily". Things like childbirth, touching dead bodies, etc.

In the West we have the saying that 'cleanliness is next to godliness' but the Japanese conception may be closer to 'cleanliness is not distinct from godliness'. ---- Brandon Toropov and Luke Buckles O.P.

As an example of how serious it is, after the Battle of Miyajima, which took place on a sacred island, the victorious army removed all the corpses, and then cleaned the entire battlefield of blood, to the point that buildings were scrubbed, and blood-soaked soil was removed from the island.