Electrodynamic Lagrange points and fusion reactors

In celestial mechanics, the Lagrangian points (/ləˈɡrɑːniən/ also Lagrange points,[1] L-points, or libration points) are the points near two large bodies in orbit where a smaller object will maintain its position relative to the large orbiting bodies. At other locations, a small object would go into its own orbit around one of the large bodies, but at the Lagrangian points the gravitational forces of the two large bodies, the centripetal force of orbital motion, and (for certain points) the Coriolis acceleration all match up in a way that cause the small object to maintain a stable or nearly stable position relative to the large bodies.

“Lagrangian point”, Wikipedia

I’ve only seen this concept in reference to gravitational fields. I suspect an equivalent may exist for electric fields, which may be useful for developing an improved electrically confined fusion reactor (AKA the sort that school students make every so often as science fair projects, which currently have so many flaws that almost nobody expects them to ever become useful power sources).

Why would it be useful? Let’s begin with the current problem: electrostatic fusion reactors have two grids, one a cathode and the other an anode, to create the electric fields which accelerate the ions enough for nuclear fusion to happen. Unfortunately, fusion is very unlikely compared to the ions simply bouncing off each other, which means even a very spacious grid — 99% empty — isn’t empty enough, and most of the power gets wasted by the few ions which hit the grid each time they fly past.

Some designs try to get around the grid problem. For example Robert Bussard (yes that one) has designed the Polywell reactor which uses a virtual cathode: a cloud of magnetically confined electrons. Another possibility I’ve never had time (and probably resources) to simulate was finding out if the so-called “star mode” of a Farnsworth Fusor, where the ions primarily flow through the gaps in the grids, might be caused by a magnetic field generated by the current flowing between the grids — if it is, you could enhance that field relatively easily, and boost the efficiency. This probably still won’t make it a net power producer (anything I can think of will have been thought of a hundred times already by the professionals), but it might still be interesting for other things.

This brings me to the idea of a Lagrange point as a virtual cathode, where the virtual cathode is the dynamic balance of the electric charges as they move.

It might not be possible at all (gravity is always attractive, unlike electric fields, and this may cause extra problems when you have a plasma field rather than claiming equivalence from a few point-like masses to a a few point-like charges); and even if it is possible at all, it might require a prohibitive power consumption (accelerating a charge produces electromagnetic radiation, slowing the charge down in the process).

Of course, the equivalence of moving electric fields and magnetic fields makes me wonder, again, if a hybrid electric- and magnetic-confinement fusion reactor could do better than either on their own.

Disclaimer: I’m a software engineer, not a doctor of physics. If a proper scientist disagrees with me, trust them.



Hover text: “Sitting here idly trying to figure out how the population of the Old West in the late 1800s compares to the number of Red Dead Redemption 2 players.” — — This work is licensed under a Creative Commons Attribution-NonCommercial 2.5 License.

Population of old (1900) American West: 4.277.402
Number of Red Dead Redemption 2 sales: >24 million.

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Dot product morality

The first time I felt confused about morality was as a child. I was about six, and saw a D&D-style role-playing magazine; On the cover, there were two groups preparing to fight, one dressed as barbarians, the other as soldiers or something1. I asked my brother “Which are the goodies and which are the baddies?”, and I couldn’t understand him when he told me neither of them were.


When I was 14 or so, in the middle of a Catholic secondary school, I discovered neopaganism; instead of the Bible and the Ten Commandments, I started following the Wiccan Rede (if it doesn’t hurt anyone, do what you like). Initially I still suffered from the hubris of black-and-white thinking, even though I’d witnessed others falling into that trap and thought poorly of them for it, but eventually my exposure to alternative religious and spiritual ideas made me recognise that morality is shades of grey.


Because of the nature of the UK education system, between school and university I spent 2 years doing A-levels, and one of the subjects I studied was philosophy. Between repeated failures to prove god exists, we covered ethics, specifically emotivism, AKA the hurrah/boo theory, which claims there are no objective morals, and that claims about them are merely emotional attitudes — the standard response at this point is to claim that “murder is wrong” is objective, at which point someone demonstrates plenty of people disagree with you about what counts as murder (abortion, execution, deaths in war, death by dangerous driving, meat, that sort of thing). I don’t think I understood it at that age, any more than I understood my brother saying “neither” when I was six; it’s hard to be sure after so much time.

Then I encountered complicated people. People who could be incredibly moral in one axis, and monsters in another. I can’t remember the exact example that showed it first, but I have plenty to choose from now — on a national scale, the British empire did a great deal to end slavery, yet acted in appalling ways to many of the people under it’s rule; on an individual scale, you can find scandals for Gandhi and Churchill, not just obvious modern examples of formerly-liked celebrities like Kevin Spacey and Rolf Harris. In all cases, saying someone is “evil” or “not evil”, or even “0.5 on the 0-1 evil axis” is misleading — you can trust Churchill 100% to run 1940 UK while simultaneously refusing to trust him (0% trust) to care about anyone who wasn’t a white Protestant, though obviously your percentages might be different.

I’ve been interested in artificial intelligence and artificial neural networks for longer than I’ve been able to follow the maths. When you, as a natural neural network, try to measure something, you do so with a high-dimensional vector-space of inputs (well, many such spaces, each layered on top of each other, with the outputs of one layer being the inputs of the next layer) and that includes morality.

When you ask how moral someone else is, how moral some behaviour is, what you’re doing is essentially a dot-product of your moral code with their moral code. You may or may not filter that down into a single “good/bad” boolean afterwards — that’s easy for a neural network, and makes no difference.

1 I can’t remember exactly, but it doesn’t matter.


The 1950s (ish) according to my mother


This list was created November 14th, 2015. In retrospect, mum was already starting to show early symptoms of Alzheimer’s even before this, but we only became sure of her condition in late 2016.

Mum was born in ’43, in the UK town of Horsham, and this is what she remembered of her childhood years:

  • “Poland” sounding like “coal-land”
  • Coronation day, “quite a lot of cars by then”, but not by today’s standard
    • Only 2 teachers had cars. At least one of them was a 2-income family.
  • If you had a car radio, the antenna was really visible. Coronation meant flags on the antenna.
  • TV was rare. Tiny, square, black and white screens.
  • Life was quiet. People didn’t get excited, being excited led to comments and funny looks.
  • Locked doors were very unusual
  • No health and safety
    • Very lax drug testing rules
  • School was quiet, but not boring.
    • Teachers were all female bar one, all single
    • Almost no men due to WW1
    • Women ran “everything” (all-girl school), general assumption was that they could
    • Games/gymnastic/country dancing every day; ball-room dancing once a week with boys school; dating done via dancing
      • Netball, tennis, relaxed about sports; could do this on weekends without staff because no locked doors
      • Discus, javelin, hurdles, high jump
      • Cross-country running
      • “Denn park” and “Denn hill” (what size are those places?)
    • Every morning was a bible reading and a hymn
    • School dinners. Everyone had them, they were “hearty”.
    • Normal to learn how to swim
      • Horsham had an open-air, unheated pool, school took everyone there to learn to swim
    • O-level courses:
      • [Needlework optional at O-level, mum didn’t do it]
      • Physics with chemistry
      • Biology
      • Latin
      • Geography
      • RE?
      • English
      • French
      • [Mum took German as an extra in the 6th form]
      • Art [mum didn’t do it]
      • Music [mum didn’t do it]
      • History [mum didn’t do it]
    • No national curriculum, every school was different, no teaching qualifications needed
  • Church attendance was almost universal; most had youth clubs
    • Self-segregation of which church, often on a class basis
  • Everyone was trusting and trustworthy
  • Ordered and orderly
  • Big events:
    • Old Vic theatre in London, organised by school
    • Local concerts
  • Clothing was sober, boring, dull. Plain colours, few or no patterns
    • Men and women both wore suits
    • Most people made their own clothes. Almost no clothes in the shops, but fabric and patterns.
    • Tweed very common due to the cold
    • You were not properly dressed without a hat and gloves (because it was so often so cold)
  • A lot of women went to the hairdressers every week
    • Straight hair was considered a great misfortune. Curly hair had a fuss made of it.
    • Curling done with chemicals, not tongs; clearly artificial, but most liked it
  • High-heels were smart, flat were a no-no
  • Fastidious neatness
  • Not respectable to talk about sex
    • Not much contraception
    • Babies before marriage was shameful, hushed up, mothers disappeared without discussion
  • Food boring, limited variety
  • Shops were all separate; no supermarkets combining them
    • Bucher
    • Greengrocer
    • Chemist
    • Clothes
    • Books
    • Jeweller
    • Ironmonger (kitchen utensils)
    • Fishmonger
  • Everyone cycled everywhere; shopping, church, school
  • Almost no obesity
  • Eating out was very rare
    • One or two cafes, no restaurants in Horsham
    • Nobody bought sandwiches, everyone made their own packed lunches
  • Most houses don’t have central heating, therefore very cold
    • Open fires very common
    • “Spring cleaning” was needed because of the dust from the open fires; called “Spring” because you waited until winter had finished and you no longer needed to burn fires
    • Chimney sweep needed to stop chimneys from catching light
  • Few houses being built. Council houses boring but very solid.
    • If you wanted a new house, you bought land and materials and hired a builder. When builders finished, they put a union jack (in UK, other symbols elsewhere) when they reached the chimney.
  • No spare money
    • Everyone put money into savings accounts
    • Shabby houses
    • Nobody bought stuff unless they had to; mend instead of replace
      • No built-in obsolescence; stuff bought new lasted
  • Rained a lot more. In any trip, people invariably packed raincoats in their bags
  • Men worked, women ran households
    • Running a house was much more time consuming than it is now
    • In the 1940s “laundries” was a service that took your clothes, returned them cleaned and ironed the next week.
    • By the 1950s people had washing machines in their homes
  • Cats and dogs very normal to have
    • Fed scraps; tins of dog/cat food not available until 50s
    • Mum saw dogs crossing roads on Zebra crossings
    • Lots had a budgerigar or two
    • Lots kept chickens. Couldn’t necessarily buy eggs, things in shops often sold out because the supply chain was no good
  • Battery farms had not been invented (invented in the 60s?)
  • Diets:
    • Vegetarianism was almost unheard of; archetypal meal was “meat and two veg”
    • Main meal at midday, light meal (bread and butter, perhaps a slice of ham) in evening
    • Home baking was the norm; if you want a cake you bake it, store bought cakes were rubbish
    • Tea was normal drink; coffee was instant not ground
    • Foreign food was unusual/unknown (no restaurants)
    • People might have their own fruit trees
    • No snack food available, apart from crisps
    • Helpings much smaller than modern days
  • Health:
    • Everyone caught measles, mumps, chicken pox; vaccination done by infection parties when as kids (as they are less serious when infecting kids)
    • Diphtheria was pretty much eradicated; smallpox vaccine was new, disease in the process of being eradicated; TB vaccination had started;
    • Appendicitis was serious
    • Eye testing rare, people did badly at school because nobody realised they couldn’t see the blackboard
  • Substances:
    • Smoking very common; seen as sophisticated and not as anti-social; cinemas stank of cigarette smoke so badly that watching films required one to change clothes afterwards because the clothes picked up the smell
    • People didn’t drink very much.
      • Pub once-or-twice a week for a glass of beer (but only men, it was a men’s drink not for ladies); larger hadn’t reached the UK
      • Smart people had gin, brandy, whiskey and offered small glasses of sherry (in particular) to guests
      • Rum was for drunken old sailors
      • Extremely drunk people was pre-WW2, 1920s-1930s ish?

Take all of this with a few pinches of salt. The thing about vegetarianism being “almost unheard of”? Although it might well have been extremely rare, she previously told me her brother was ‘officially’ vegetarian during WW2 because vegetarians got better rations.


Homeopathic solutions to the Fermi paradox

Homeopathy: for those who have never learned the details, claims that the potency of a treatment can be increased by repeatedly diluting it. There are many scales — the C-scale is “how many times has this been diluted by a factor of 100”, the X-scale “…by a factor of 10”. I’d say “clearly nonsense”, but I fell for it when I was a teenager.

Fermi paradox: there are so many stars in the observable universe — tens of sextillions (short scale) — that even fairly pessimistic assumptions imply we should be surrounded by noisy aliens… so why can’t we see any?

One of the most common resolutions to the Fermi paradox is that there are one or more “great filters” which make it entirely unlikely that any of those stars have produced intergalactic expansionist civilisations. There are good reasons to expect direct intergalactic expansion rather than starting with ‘mere’ interstellar expansion, and (rather more surprisingly) good reasons to think we’re within spitting distance of the technology required, but that only makes the non-technological problems all the more severe. There are a lot of unknowns here, obviously we’ve only got ourselves as an example, so the space between “where we are now” and “owning the universe” is filled entirely with underpants gnomes, and that’s where homeopathy fits in, in two separate ways.

First, as a categorical example. Homeopathy represents an archaic way of thinking, yet it’s very popular. It’s simple, it’s friendly, it is a viral meme. There are many of these, some of them are quite destructive, and while it’s nice to think nature is in a balance — especially when we’re thinking of something we’re really proud of such as our own minds — the truth is nature (including humans) often goes off the deep end and only sometimes recovers. It’s very easy for me to believe that an anti-rational meme such as homeopathy can either destroy a civilisation entirely, or prevent it developing into a proper space-faring civilisation.

Second, as an analogy. Dilution. It’s not the first dilution of a homeopathic preparation which removes all atoms of active ingredients from the result, but the repeated dilution. If there are, say, twenty things which have an independent 50% chance of holding back or wiping out a civilisation out before it can set up a colony — AI; bioweapons; cyber-warfare; global climate change (doesn’t matter if artificial warming or natural ice age); cascade agricultural collapse; mineral resource exhaustion; grey goo; global thermonuclear war; cosmic threats collectively from noisy stars whose CMEs make electricity impractical to asteroids and gamma ray bursts; anti-intellectualism movements, whether deliberate or not; feedback between cheap genetic engineering and genetically-defined super-stimulus making all the citizens a biologically vulnerable monoculture … — twenty items each with a 50% chance adds up to million-to-one odds (million-ish, but if you care about the difference you’re taking the wrong lesson from this).

Yes, one-million-to-one is almost irrelevant compared to ten sextillion. Odds of (100e9)^2-to-one would require 73 such events, not 20, but this combines with the previous Fermi estimates, it doesn’t replace them. 20 such events reduces the overall problem by a factor of a million, no matter what your previous estimate was, and both 20 events and 50% chances are just round numbers, not a real ones. Unfortunately, we don’t know how many small-filters we might face: as the Great Recession was starting, someone said that no two recessions are the same because we learn from all our mistakes and so each mistake has to be a new one. Sadly it’s worse even than that, as humanity as a whole does repeat even its economic mistakes, so even if we weren’t re-rolling some of our previously-successful dice because we keep thinking “we’re too big to fail“, humans don’t know all the ways we can fail to survive.

The Great Filter doesn’t have to be something that civilisations encounter exactly once and in much the same way a sentence encounters a full stop — it can be the death of a thousand paper-cuts.

If we do finally reach the stars, we may find the universe is much more interesting than it currently seems. Instead of Vulcans and warp drive, we might find hippy space-elves communing with their trees via mind-warping drugs… and if we don’t, instead of wiping ourselves out, we might become the hippy space-elves that some sentient octopus discovers while going boldly where no sentient octopus has gone before.

Philosophy, Psychology

A life’s work

There are 2.5 billion seconds in a lifetime and (as of December 2018) 7.7 billion humans on the planet.

If you fight evil one-on-one, if you refuse to pick your battles, if only 1% of humans are sociopaths, you’ve got 21 waking seconds per opponent — and you’ll be fighting your whole life, from infancy to your dying breath and from when you wake to when you sleep, with no holiday, no weekends, no retirement.

Conversely, if you are a product designer, and five million people use your stuff once per day, every second you save them saves a waking lifetime of waiting per year. If you can relieve a hundred thousand people of just 5 minutes anxiety each day (say, about social media notifications), you’re saving six and a half waking lifetimes of anxiety every year.

When people complained about the cost of the Apollo programs, someone said Americans spent more on haircuts in the same time. How many Apollo programs of joy are wasted tapping on small red dots or waiting for them?