Here's the latest updates to the timeline. I don't think I'll be adding anything else to December 2012, nor January or February 2013, but March is about half done.
Additions to earlier parts:
Dec. 23 (2012): Israel declares war on Nazi Germany. Hitler declares war on 'the Jewish State, and all puppets of the Jewish Conspiracy'. OTL-UK declares war on Nazi Germany, followed by OTL-US, OTL-France, OTL-Germany, OTL-Poland and OTL-Russia. Radio stations in the US celebrate by playing various renditions of
We Did It Before (and we can do it again), among others.
Dec. 24: OTL-China, Taiwan, the Philippines, and both Koreas declare war on Dp-Japan.
Dec. 28: In her Christmas Address (being about three days 'behind' OTL-Earth), Queen Victoria declares that 'An attack on any Britain is an attack on
every Britain!' Stp-UK Parliament declares war on Dp-Germany.
Feb. 16 (2013): A successful better-than-break-even
polywell is demonstrated in OTL-Switzerland, and the plans and methods involved are posted online. The device confirmably works as advertised, but according to experts, shouldn't (though no-one finds any clear evidence of cheating, beyond that fact that it shouldn't work this well). Most who try to reproduce the device get a normal polywell, unable to break even, but a few, always the more eccentric, are able to replicate or even improve on the device using the same or similar methods.
Feb. 19: A few people on OTL-Earth, mostly in the US and Europe, but not exclusive to those regions, begin visiting doctors due to odd skin conditions. Mostly, these relate to the skin changing colour, but not itching or otherwise causing discomfort. Blood samples taken, in some cases, also appear to be the wrong colour, but are chemically what they should be, and return to red when separated from the source by enough distance, time, and/or both (usually no more than two yards and/or five minutes). Some, with or without odd skin colours, have noticed minor physiological changes, such as eye or hair colours changing, ears becoming pointed, foreheads gaining ridges, fingers and/or toes becoming slightly webbed, and so forth. A very few appear to have small improvements to strength, reflexes, senses, and so forth. In nearly all cases, they note that the new features make them resemble their favorite science fiction or fantasy race, or a specific character or characters.
New parts:
March 1: Stp-US President Edward J. Phelps (Whig) offers a reward for the design of an orbital rocket with greater lift than any in use by the Great Powers, and an astronef able to cross the void to the other Earths swiftly, safely, and comfortably. This reversal of the usual Whig policy surprises many, but most of the smarter Stp-American politicians can see the way the wind is blowing. Stp-Earth's Russian Empire declares war on Nazi Germany. The fact that the Tsar's current favorite mistress is Jewish has nothing to do with that, of course.
March 7: The astronef carrying Stp-UK's ambassador to OTL-UK, along with various trade goods, scientists, and so forth, is launched from British Guiana, along with the first unmanned supply flight to the Stp-British space station. The crew, and some of the passengers, are veterans of both space and war. Stp-Russia announces plans to assemble a 'heavy' astronef at their space station, the first sections of which will be carried into orbit next month. Also announced is the launch of an embassy to OTL-Russia, next week.
March 12: On the 'forward' side of OTL-Earth's three light-second bubble, a small particle spray occurs, so faint as to be almost undetectable. Almost. While radar and infrared telescopes pointed at the area detect nothing, optical scopes observe something fantastic (once it slows down enough to be clearly seen): a gold and silver dragon larger than a C-130, flying through space, apparently by occasionally flapping its wings. Below the dragon is a bronze arch, with crossbars clutched in the great creature's front and rear talons. The arch carries a great bronze dish, upon which sits a magnificent
roundhouse of the finest woods, ivory, and well-polished stone and bronze, not gaudy, but likely far more beautiful than any such structure was in our history.
March 13: The dragon and dwelling enter OTL-Earth's atmosphere, heading toward Britain, and more specifically, London. As they approach
Hyde Park, a hill rises to meet the house (at a rate of about seven inches per second), in the clearing a little east of The Long Water. As the house touches down at the crest of the hill, the bronze dish and arch seem to collapse into themselves. A bronze fence grows three feet high at the base of the new hill, as the dragon seems to shrink to the size of an elephant, and gently dives into The Long Water, splashing around for a while. The people who exit the house are dressed quite finely, despite the over all look of their clothing being evocative of Ancient Britain. All are quite comely, and have pointed ears. The most beautiful woman among them approaches the fence, and attempts to speak to the British police and military personnel who by that point have arrived. After trying one incomprehensible language after another, the dragon sticks its head out, snickers, and says 'Lingua Latina.' Luckily, one of the officers remembers enough of his time at Oxford to establish a dialogue: The woman is named Brigith, and she is the daughter of Imperator Ambrosius Aurelianus Romanorum, known more properly as Arthur, High King of the Britons. Her mother is the High Elf Indeg, the eldest of the king's three principle concubines, and a daughter of the King of the High Elves of The Isles. Her father and maternal grandfather have empowered her to speak for them to the Queen of this Britannia, as her brother and sisters have been sent to the other Britanniae (the missions to Stp-Earth and Clp-Earth haven't arrived yet, but the one on Dp-Earth is on its way down, being escorted by a great flock of RAF fighters). The dragon, Dyfnallt, is only sticking around long enough to move the embassy, if requested, and then he needs to go back and get the embassy for the next Earth over (Clockpunk Earth).
March 15: The Russian ambassadorial astronef is launched, and is mated to it's long-range booster. The Russian ambassador is
Grand Duke Alexei Alexandrovich of Russia, who hopes, among other things, to meet and court whichever of Putin's daughters will find him most attractive, as it's clear to the Tsar that Vladimir Putin is Tsar Vladimir IV in all but title.
For those who are wondering, Brigith and her siblings are a non-standard type of half-elf, being the children of a spirit who was not possessing anyone at the time, and thus being spirits, themselves (which is how they can survive unprotected in the vacuum of space). They are 'half-elves' only socially, and in being more psychologically human than most elves are. The staff and guards of the embassy are mostly half-fey of various kinds. On another note, I sadly lack the skill to write the epic tale of how Arthur got the King of Elfland's daughter as his first concubine, but Brigith is perfectly willing to tell it, in the grand style of ancient British bards (save that she'll be speaking it in Latin).
EDIT for clarification: What crosses the dimensional barrier when a spirit travels from one universe to another is information on telepathic carrier waves, and it really shouldn't disturb the 'gate' nearly enough to produce a detectable particle spray. It looks like they're actually traveling physically because that's how they think of themselves (and transferring spirits so that they have sufficient, erm, administrative access to manifest apparently physical bodies on worlds other than their own is a fairly epic achievement for any wizard). Just another example of the Random Omnipotent Being messing with people, since it creates assumptions in-character that are contradicted by reality (though on the bright side, it does convey a warning that would otherwise have been absent).