I am a rank amateur, so please forgive me if the answer to this is well-known.
The following quote can in a weekly update for an EdX course I am following in astrophysics:
"And what a week it's been with the recent discovery of primordial gravitational waves from the epoch of inflation! This one observation has pushed back the earliest direct measurements of the Universe from about 1 second (the epoch of nucleosynthesis) to $10^{-35}$ seconds (the epoch of inflation)."
I would appreciate any comments as to what it will take to close the gap.
EDIT: Well, initially I asked this question with a few specific alternatives. Perhaps - respectfully and with moderators' approval -I should revert to that (as best as I can remember), in that any one of them could be answered with a "yes" or "no" and a few qualifying, suggestive sentences.
-- Would a viable GUT do the job.
-- Are there currently specifically directed experiments whose intended results will answer the question.
-- Can the gap be closed by correct extrapolation of know experimental and theoretical results.
If this is yet deemed unacceptable, I understand, and please feel free to restrict my question as deemed appropriate.