Consider this. Tomorrow at 3pm. a 100 foot tall man walks onto the M5 motorway and begins kicking around cards and being a massive bastard to everybody. All of this is caught on CCTV and very quickly the police are informed and the giant is killed by armed forces. To describe the giant closer I'd say that he is proportional in shape to a regular human, is bald but has a groomed beard, and is wearing chain-mail like armour and leatherish boots. In the weeks after the incident experts determine that the giant is genetically a human, perhaps he only shows the same sort of variations to any human genome that two humans of different races would show to each other. Detectives scour the local countryside and there is no evidence of anywhere the giant came from or could have been living.

Now here's the question: how will this event be remembered in 100 years time, if at all? Maybe nobody died, or just a couple, so politically speaking it's a relatively minor event. In 100 years time we will definitely still be talking about events like 9/11, particular World Cups and Olympic Games, acts made by Parliament, the race between Obama and Clinton, and so on. (Will they remember Madeleine McCann I wonder, probably the most dominating news item of the last 2 years in the UK? I doubt they will).

Let's suppose that in the 100 years between the event and the future state we are contemplating, nobody has got any closer to explaining the event than the detectives who looked at all the evidence at the time.

I think the only explanation is that the giant is an alien or somehow walked through a wormhole somewhere in the universe and came out in the England countryside. The former explanation isn't that good really, as a coherent explanation. Why would an alien race that is sophisticated enough to transport a giant to Earth undetected be so easily dealt with, and why would they wear leather and chain mail? Why would they attack in the first place? Maybe some alien race invaded a world of primitive giants and for a laugh dumped one on Earth. Maybe they are watching from space somewhere as we wonder what the hell just happened? Maybe they had the technology to just teleport the giant here?

I suppose that the experts would test the materials found on the giant to see where they originated. Would the leather belong to a kind of animal that had never lived on Earth, for instance? And the same for the metal. Would this event only be significantly remembered in scientific journals and not in common knowledge of world history? Maybe this event would be so significant to count as proof for scientific theories. Any cosmologist who came forward and said that he had scrutinized the matter of space and determined that everywhere in the universe except for the Earth is made of some kind of natural kind that prohibits life in any form, would just be met with scepticism. It would become a scientific fact that life existed elsewhere in the universe. Maybe theories about wormholes would gain strength directly because of this isolated incident.

Maybe this event would be remembered most as a religious event? Perhaps it would gain backing as some kind of divine act, because it couldn't be explained any other way? Maybe a new religion would be formed as a result, and 100 years later that religion dominates the whole world.