Timeline

For a list of all mentioned timelines, see timelines.

The term timeline specifically refers to a 4D structure within certain multiverses, including the setting's one.

Noise
Timelines are constantly influenced by a phenomena known as noise, which is due to background paradox energy flowing into a timeline from 5D. Noise has the ability to modify timelines in random ways, such as changing the events of a timeline or causing a branch to occur, sometimes to the point it causes a timeline to split naturally. However, noise may also sometimes cause effects that deviate much more notably beyond a change to the events of the timeline itself. Some known effects include the birth of a time traveller, a special substance coming into existence that can't be found in other timelines, or something that violates otherwise established laws of physics - most commonly fuels that allow FTL capabilities.

Some timelines are exposed to more noise than others, which changes the amount of impacts and how much it changes. Nosie heavy timelines tend to be the birthplace place of many travellers

Noise may seem random in many ways, but the effects it causes always seem to have some amount of sense to them. It only produces results that make sense, never messing with linearity or internal logic through its changes, although sometimes it creates things that so happen to exist "just because" in the worldspace (though to be fair that can be said of a lot of things). It is sometimes said that noise is a manifestations of the whims of Weavers, but such a claim is unjustifiable.

Time Traveller Creation
There are multiple ways where noise can influence the creation of time travellers. One of the most notable is giving someone the potential to discover time travel - such as a scholar or researcher looking into similar matters being able to discover a breakthrough that turns what would otherwise be a normal person into a traveller. While lower tech individuals may have some amount of luck with gaining the ability, it isn't as common. In slightly more rare cases, it empowers an otherwise mundane object/machine to gain the ability to travel. However, while plenty of these cases are reported, this phenomena isn't as common as it may initially seem. Plenty of those time machines were left by time travellers either accidentally or intentionally.

It's theorized that those who actively try to research 4D and how to time travel attract more noise to themselves, drastically increasing the chances of them discovering a breakthrough to travel depending on their understanding of the topic. This merely weights the chances in their favour, but does not always guarantee success. This would explain how statistically, even if the chances are somewhat random, that advanced physicists and scholars actively looking into the subject make up the bulk of the population of time travellers, rather than a perfect spread of individuals across time and space. There may be other biases and actions by people that increase the likelihood of becoming time travellers, but until more data is collected on time traveller statistics such things are only in the realm of speculation.

Noise Abnormalities
Several strange things exist in timelines that aren't found can be the result of noise phenomena. What it can create can vary vastly in complexity and danger. It can be major as a reality warping substance or as minor as Mars horrifyingly being green instead of red for no discernible reason. The minor changes with minimal influence are the most common, and typically one can encounter at least one or two of these minor abnormalities in a single timeline. Meanwhile, major ones that have massive influence on a timeline are very rare, but they can happen. Most of these strange occurrences are a result of extradimensonal influence, however, and not purely at the fault of noise.

Timeline Disconnection
While a person will still stay synced with their timeline counterpart if they stay within the confines of their timelines, the moment a time traveller enters into 5D space and wanders into others they disconnect from their timeline version. Because of this, influencing the old version of their timeline version doesn't influence their time travelling counterpart. If a traveller does return to their home timeline they can become rescyched with that version of themselves, as they still maintain a connection with them.

Paradox
Paradoxes occur when someone from the same timeline interferes with the linearity of time, typically resulting in a nonsensical loop or some other nonsensical activity. When a paradox occurs, it generates a certain amount of paradox energy, which is measured in the unit of grandfather, aka the average energy released if one kills their grandfather.

A variety of different results can occur due to a paradox, but some specific paradoxes have rather documented results.