What is your question about divergence? It is possible he would be able to see this post in his future via archive. Zero divergence is mathematically possible, but many don't think it can be achieved after time traveling. Have not received an answer as to WHY, though. Math is math. They should figure out the technology eventually.
I think one of the biggest barriers to zero divergence comes down to the uncertainty principle. We can
either know an objects position, or its speed...but never both at the exact same time--which will always make uncertainty a factor. There are forces that have specified levels of uncertainty with each measurement we take (Alpha & Beta decay for example) that will cause the probability of measuring the exact same values more than once less likely.
If Alpha decay has an emission range of ~4Mev-9Mev, and averages at ~5.5Mev for most observations under normal conditions-->That can be thought of as the "central probability zone" where as low as <1-2% divergence is possible. Taking the same measurement at the same spot in time in a different universe can produce different results.
Lets imagine a divergence experiment with trains:
Objective: Measure the energy of a given Alpha or Beta emission to identify divergence.
Step 1) Measure the emission on Train A in Cart A, where Cart A represents the moment in time you take your measurement
Step 2) Write down the value of the emission to use as the benchmark (We'll call this D0)
Step 3) Hit a button on a box, which blows out confetti, before traveling "back in time" to take a new measurement
Step 4) Move from Cart A on Train A -> Cart A Train B to take a new measurement
Step 5) Take the same measurement on Train B, and write down the value for comparison to D0 (We'll call this D1)
Step 6) If D1 = D0 you will hit the button on the box, which bursts out some confetti.
If D1 <> D0 you will not hit the box on the button, but will instead do a backflip
Step 7) Repeat this process hundreds of times, moving from Cart A on each Train to each other Train
This is an oversimplified scenario, but you might be able to imagine already how the uncertain decay of some particles can in turn lead to divergence. Even if you found a way to minimize the probability variance of something like Alpha Decay--variance is going to happen eventually. When that happens and you do not hit the button, no confetti is blown. If confetti is not blown you've caused a divergent universe where you do a backflip.
Does the above make sense? It's never impossible...but it can be so mathematically improbable that the likelihood of 0.00% divergence is so unlikely that it can be considered impossible.
-Oz