(draft location, not final) Speech of Dr. Gius Baltar, speaking to the Colonial Academy for Physics, at their 7th annual conference.
It helps to think of memory as stored in the environment, rather than in your head. Think of your head as merely storing the coordinates of the temporal environment where your memories reside. In this way the brain acts as an antenna to access memory from the external environment. It is much more complex, but viewed this way, helps you better understand the specific types of memory deterioration and amnesia that occurs with time travel.
The other component that is critical to understand is the simultaneous nature of the temporal plane. It by no means appears to us this way. With the limited processing power of the average human mind, we would not be able to function if we saw past and future as simultaneously occurring. There is a condition, temporal amotivational syndrome, or temporal catatonia in its worst manifestation, which proves this very point. Folks just sit and stare, watching it all, with no ability to come out of it.
Now I say that it is critical to understand the simultaneity of the temporal plane because we are so accustomed to thinking in terms of cause and effect, that you can actually come up with the wrong results in your analysis
Retrograde temporal amnesia is the result of traveling back in time, prior to the formation of certain memories. The memories still exist and can be accessed from anywhere in the time continuum, but there is a catch. If you travel back in time prior to the formation of certain memories, they can literally disappear, and become inaccessible. Now this is only in certain situations.
If you travel back in time and view your “ghost of temporal past”, and in the course of interaction somehow change the ghost’s future such that the memories for which you have coordinates — in your brain — never develop in his brain — well then, you lose your memories because your coordinates point somewhere that never developed. That’s called retrograde temporal amnesia.
Traveling forward in time is much safer in this respect. There are less complications. The significant degree to which forward time travel is less complicated than backward time travel is the reason why it was achieved first in our experimental explorations. Yes, write this down class, the first significant fact for our orientation to the history of the future is that time travel into the future was invented before time travel into the past. There are implications of this, of course, that are discussed in the next chapter (History of the Future, by Gius Baltar).
As we established earlier, time travel takes time. Now here is the second piece. It also takes a specific inertia to achieve the escape velocity required to reverse the direction of your temporal progression. One can not suddenly reverse the direction of their temporal progression. It takes time to build the inertia required to successfully turn around, per se. The third piece is that the inertia disrupts the temporal fabric, like a speed boat disrupts the surface of the water through which it travels. This is true with any travel through time, the material environment is changed by our presence, but much more so with travel against the temporal current. Using our wave analogy, it is like waves moving in two different directions colliding into each other, versus combining in the same direction. Clashing waves are more destructive to the fabric. The coordinates of memories can permanently change location, can cause what we refer to as retrograde temporal amnesia. A certain amount of temporary amnesia can occur due to any wave movement of the fabric. The reason this is significant is that we’ve found it best to do the actual time travel far away from the location we wish to visit, so as not to disrupt the fabric.
Minor wave disruption of the fabric does not noticeably effect the memory of those in a location hit by a temporal wave. Basically the relative coordinates of the respective memories bob up and down together with the human antenna. But while those “within” the sector of the minor wave disruption don’t notice any memory impairment, those further away on the temporal plane (e.g. those individuals who are time traveling) do experience intermittent memory loss until as the waves temporarily displace the coordinates of their memories.
More severe wave disruption, such as that due to the gravitational inertia of time travel taking place very close to a particular location can permanently dislodge the environmental memory of that location, creating a mismatch with the coordinates present in the head of any time travelers that had memories located there.
For this reason, pathways for time travel were designated far away from known habitats of time travelers. Eventually black holes were used as their gravitational pull naturally capture and buffer the severe temporal traveling waves created, and they are persistently old enough to reliably exist at the starting and ending point of one’s typical journey.