For this particular story, it may be useful to look up "Feynman diagram" and have to hand some graph paper. And a rubber. But there's something interesting about Heinlein in general. In SF criticism, Heinlein has a verb named after him: "Heinleining", meaning to work necessary background information unobtrusively into a story's basic structure. This is to be contrasted with "info-dumping", which plops the information into the story in a vast expository lump. Quite often, this falls just after the chapter heading: in a fake quote from the Encyclopaedia Galactica; a newspaper article; or a news update from radio, TV, or Holovision. I seem to remember John Varley in one of his novels — possibly Steel Beach or The Ophiuchi Hotline — using interactive-newspaper excerpts, but niftily indicating the educational level of his society by following these with tabloid-style versions from news tapes "for people of literacy level 3 or lower". Like juxtaposing a Times story about Angela Merkel with one from an audio edition of the Sun, the latter's significant content being "Phwoaarrr, look at those tits".
Lewis Shiner and Bruce Sterling's Turkey City Lexicon explains that one pernicious form of info-dumping is "As You Know Bob" dialogue, where the characters stand around telling one another bits of recent history that they couldn't in fact possibly not already know, unless they'd been trekking in the Amazon jungle for the past ten years. As if, while talking about the summer's holiday plans in the pub with my mate Robert from Camden, I mention that because of safety, I shan't consider the overland trail to Afghanistan, or the Maghreb Loop; but I then spend the next four pints telling him about September 11th, al-Qaeda, Taliban rise to power in the 1980s and 1990s, the Bamiyan Buddhas, the London bombings, the Danish Mohammed cartoons, and that idiot pastor you have over in Florida who likes to burn Korans.
Robert Sheckley wrote a lovely parody of "As You Know Bob" dialogue in and just before Chapter 27 of his novel Mindswap. It starts with Milord Inglenook bar na Idrisi-san — first Lord of the Admiralty, Familiar to the Prime Minister, Advisor Extraordinary to the King, Bludgeon of the Church Rampant, and Invocateur of the Grand Council — justifying to protagonist Marvin Flynn the need to rescue the philosopher Sieur Lamprey Height d'Augustin The Enlightened from the fortress of Castelgatt, where he has been imprisoned in order to prevent his treatise The Ethics of Indecision bringing down the Church by initiating his universe's version of a Lutheran Reformation. (Though I'm not sure whether "universe" is the correct word, given the novel's surreal scene-shifting and the susceptibility of the mind-swapping Marvin to a perceptual disorder known as metaphoric deformation.)
"I fear that my political knowledge is but indifferent poor", Marvin replies when Inglenook asks whether he is conversant with recent political developments here and elsewhere in the Old Empire. So, as they sit in the coach and four on the way to Castelgatt, Inglenook begins to talk:
The Old King died less than a decade ago, at the full flood of the Suessian heresy, leaving no close successor to the throne of Mulvavia. Thus, the passions of a troubled continent came ominously to the boil. Three claimants jostled for the Butterfly Throne. Prince Moroway of Theme held the Patent Obvious ...
... These were the factors that exercised men's passion in that fateful year. The continent stood poised upon the brink of catastrophe. Peasants buried their crops underground and sharpened their scythes. Armies stood to attention and prepared to move in any direction. The turbulent mass of the West Monogoths, pressed from behind by the still more turbulent mass of hard-riding cannibal Allahuts, massed threateningly on the borders of the Old Empire.
Darkmouth hastened to reequip his galleys, and Hostratter paid the Vaskian troopers and trained them for a new kind of war. Romrugo cemented his new alliance with Puls, achieved a détente with Ericmouth, and took account of the new rivalry between Mortjoy and the epileptic but dourly able Murvey. And Moroway of Theme, unconscious ally of the Rullish pirates, unwilling champion of the Suessian heresy, and unwitting accomplice of Red Hand Ericmouth, looked to the grim eastern slopes of the Echilides and waited in trepidation. It was at this moment of supreme and universal tension that Milord d'Augustin all unwittingly chose to announce the imminent completion of his work of philosophy...
And, as Inglenook's voice fades slowly away, and no sound is heard but the heavy thrum of horses' hooves, Marvin says quietly, "I understand now".
You won't find expository lumps or "As You Know Bob" dialogue in All You Zombies. As Heinlein said in his 1957 University of Chicago lecture: You have a contract with the reader to place the reader in your universe, but if you have to stop the narrative in order to explain what the universe is, you've violated that contract.