As we have stated, time is but a factor in our equations, which allow us to travel back in time, when permission is granted on rare occasions and for good cause, and travel forward on even rarer occasions. The motion and placement of objects, sub-atomic or otherwise, are predictable, given their placement and motion and composition at any given point. Likewise, just as you can back-engineer technology, just so we can reverse-engineer objects, their atomic structure, and their motion and placement a moment ago. Time travel involves reversing or accelerating activity that is predictable. This reversing or accelerating involves forcing the issue, as under normal circumstances objects proceed based on their surroundings, your familiar world.
Factors, ingredients that we are aware of but you are unaware of, are involved in the forward progression in time, and a lack of these ingredients results in a backsliding in time, as though falling into a vacuum. The forward press or falling backward is due to direction of flow, of what is just another element in your Universe. You are unaware of this element, as the steady forward progression is something you consider a given. Nothing is by chance, and no motion is without reason or cause. To you, in your perception, time is steady in its progression, but when the press of this ingredient is stopped, or diminished, what had occurred telescopes back in activity that is the reverse of what just occurred.
The grip points we refer to are places in the orderly arrangement of particles where we can, in essence, set our sights and target, and stop during a time travel, else the unraveling of what has occurred would continue unabated. One does not start on a journey without brakes! Grip points are predictable points where particles are structured in a particular pattern, and we aim for this pattern. This could be equated to so many ticks of the clock, or so many clangs of the hour bell, as the periodicy is predictable and reliable, like clockwork. All these matters are outside of the world you understand, but are as much a part of our science as working with solids and liquids and vapors are to you. Our young experiment briefly with these matters in school, in preparation for the day they may be required to use time travel, be called upon to set this in motion.