Baryon asymmetry

One day, I might learn enough physics that my questions don’t sound like nonsense to physics graduates. Today is not that day — my working assumption is I sound like a freshman at best, and a homeopath at worst, and will remain so until I put numerical simulations of standard results in general relativity, quantum mechanics, and Navier-Stokes equations onto my GitHub page.

The baryon asymmetry problem is that matter and antimatter are always created and destroyed in equal quantity, yet the universe clearly has more of one than the other.

If you can make or destroy one without the other, in isolation, then you also get to violate charge conservation, which would mean that quantum field theory is wrong because something something Noether’s theorem. (Of course quantum field theory might be wrong; it’s known that general relativity and quantum physics can’t both be true because if they were both true the universe would’ve collapsed instantly at the very beginning).

The only way you can conserve charge but take antiparticles out of the system is if the process requires an equal number of antiprotons and positrons.

Both of these options — either violate charge conservation or take out multiple particles at once — have interesting consequences which can probably be tested, although not by me, given my degree is in a totally unrelated field.

If charge conservation is violated, then the universe should have a net electric charge. This charge should change over time, as there are still natural processes creating positron-electron pairs but not (at least to the same degree) proton-antiproton pairs. I don’t understand what this would do to the Einstein field equations (only that it would do something; given the effect on black holes I have to ask if it could be dark energy?), but I’m fairly sure lots of free electrons in the interstellar or intergalactic medium should be noticeable.

On the other hand, if antiprotons combine with positrons and that composite — possibly but not necessarily, given how conjectural this already is, an antineutron — either that composite is stable or it has a way of decaying into something other than an antiproton and a positron. The obvious question this raises is: could this be dark matter?

The obvious counter-point to the question “what if antineutrons are stable” is “surely someone would have noticed”, which is a fair question that I cannot answer — I genuinely do not know if anyone would have noticed yet, given how hard it is to make antimatter, how hard it is to trap antimatter, how hard it is to trap even normal neutrons, and the free-neutron half-life.

I can say other people have thought about neutron-antineutron oscillations, which might well solve the baryon asymmetry problem all by itself without any consequences for dark energy/dark matter:

(Another thing I definitely don’t know, and which my physics MOOC won’t teach me, is how to separate legit ArXiv papers from the bogus ones; that reflects badly on me, not on the authors of that paper).

AI, Futurology, Opinion, Philosophy

Memetic monocultures

Brief kernel of an idea:

  1. Societies deem certain ideas “dangerous”.
  2. If it possible to technologically eliminate perceived dangers, we can be tempted to do so, even when we perceived wrongly.
  3. Group-think has lead to catastrophic misjudgments.
  4. This represents a potential future “great filter” for the Fermi paradox. It does not apply to previous attempts at eliminating dissenting views, as they were social, not technological, in nature, and limited in geographical scope.
  5. This risk has not yet become practical, but we shouldn’t feel complacent just because brain-computer-interfaces are basic and indoctrinal viruses are fictional, as universal surveillance is sufficient and affordable, limited only by sufficiently advanced AI to assist human overseers (perfect AI not required).
history, Politics

History, according to the British

If you’ve ever wondered why the UK acts the way it does, consider that my formal history lessons at school went like this:

  • Boudica had a perfectly justified but ultimately futile fight with the Romans
  • Saxons exist
  • “William the Conqueror” came, saw, and conquered liberated and/or unified the country
  • “The” Manga Carta
  • Civil war War of the Roses
  • Henry VIII
  • Civil war Catholics or Protestants argue about which one is sent from God and which is the unholy spawn of Satan’s armpit hair
  • Witch hunts
  • “The civil war”
  • The Spanish Armada is defeated by Britain being awesome in a totally unspecified way
  • Britain decided to end the slave trade but only after profiting from it greatly and at around the same time as everyone else in Europe, probably because the industrial revolution had started and manual labour was becoming less important
  • The Industrial Revolution, which according to this version of events consists entirely of “Steam Engine → power loom (that it exists, no description given) → one specific picture of Isambard Kingdom Brunel
  • Queen Victoria, who never smiled, perfectly embodied the essence of what it means to be British by calling herself “Empress of India”, marrying her first cousin (Prince Albert of Saxe-Coburg and Gotha) and being the head of state when the Great Famine hit Ireland and a million people starved to death
  • World War 1
  • World War 2, where the UK stood alone against the Nazis with only the help of USA, the USSR, the British Empire, the French resistance, the Danish resistance…

In addition to my sarcastic strike-through comments, notice what is missing:


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.