Theories by FedericoF.

Space-time portals theory (doubtful)

Space-time portals theory
Theory history
Submitted 2012-12-16
Doubtful 2016-01-13

The portals don't only make you travel to different locations on the Subnet, but in time too. Each coordinate corresponds to a certain time and place. As we explore the Subnet we can see the differences of the architecture, but they are very well preserved, not all of them are in ruins. That makes me think that portals can make you travel to the past and the future, we can see examples in the altar (past) and the defense system (future). In fact, in the observatory's telescope, there's an image of the universe 590 million years after the Big Bang.

"Ancient people" absorbed in the Submachine (still alive)

"Ancient people" absorbed in the Submachine
Theory history
Submitted 2013-03-22
Still alive 2016-01-13
Location in Subnet
051 ↔ mlp

The people from the bamboo town raise many questions about the dynamics of the Subnet in the particular layer they inhabit, being the only native people who live in there.

One wonders if some particular oddity in the timeline allowed them to enter to the Submachine, or if they "wandered" in like so many other early submachine explorers. It's possible to assume that they were "absorbed" into the Submachine unintentionally, but this brings into question the Subnet's strange tolerance for these humans that apparently were not marked as part of the "infestation" like Mur and his teams.

A probably explanation would be that they were most likely the desendants of lost Subnet explorers that managed to settle in a less hostile layer of the Submachine, but there is no direct evidence of that.

Also their means of survival is unknown, although it's most likely that they were a culture of farmers (seeing as there are signs, albiet scarce, of plant life in the Subnet and (as far as we know) no animals).

As we can see in their note, they claim to have worshipped a woman for over 742 years, but as far as most notes state, the Submachines origins seem to be placed (but not proven to be) in the late 1700's to early 1800's. Perhaps they were the first people who entered to the Submachine world through a one-way "natural portal" that connected the outside world in the past to the Submachine and they got stuck in that location since then.

Many portals theory (confirmed)

many portals theory
Theory history
Submitted 2012-12-16
Likely 2014-04-06
Confirmed 2016-01-13

When you travel to other locations in the Subnet, you can see sometimes that the portals are quite different to the one you used before, for example, in SNEE if you travel from the portal in the radio lab, (which is very rusty) to the sanctuary (the grass and vines partially cover the portal) they have many differences between them, and there are a lot of examples of this. This means that the portal only teleports the Player (without the portal) to other ones, located in another places on the Subnet.

The beginning of the Defense Systems (likely)

The beginning of the Defense Systems
Theory history
Submitted 2013-03-25
Likely 2014-04-06

The Defense Systems started to be build in the first half of the 20th century. We can see an example in the armory location, which was part of it, there are an ancient turret (part of the old turret chain) with some amunitions around it. Then when the time passed, more sophisticated weapons were added and they replaced the material of the defense building as we can see in Submachine 6 or SNEE.

See also