In 1905, the Earth scientist Albert Einstein proposed his theory of special relativity to explain motion between two different inertial frames of reference. That is to say, when two objects (people, places, etc.) are moving relative to each other, you treat neither as the absolute frame of reference. In fact, perhaps the only absolute to be considered would be the speed of light itself. That being true, Einstein realized that time and distance would differ for two relative observers.
While this is not easily observable in our day to day lives (and where we can therefore use the classical mechanics of Newton or Trel’kk’daneck), it becomes more relevant as we approach the speed of light. If you are traveling on a spaceship at near the speed of light for a week, everything on board will seem normal to you. But if someone outside were to observe you, they would perceive that you were moving slowly. When you touched down a week later (by your clock) a year might have passed for those left at home.
What does this have to do branes you ask? While time travel itself has never been observed, it is possible for messages to travel across time due to Einstein’s relativistic effects. This is because the branes of each ebullus are dynamically moving in relation to each other, in different directions at once. Although explanatory theories differ, two ebulli may be moving apart or towards each other along anywhere from ten to 24 dimensions.
Along one dimension, they may undergo the exact same time progression, while along another dimension, two branes may be speeding apart from each other at near the speed of light. But since the two bubbles are anchored to each other at least somewhat, a person could travel between two bubbles in the present time, yet receive messages from the distant past or the distant future.
While there has been much anecdotal evidence about this happening, there is a scarcity of good experimental data, but researchers hope to someday be able to make observations across time at will.