That's good, now I'm wondering about the others in the thread.

> 'Omics papers get away with a lot of hand waving

Making assumptions and interpreting results is part of any type of analysis, especially for unsupervised learning approaches like clustering. Or maybe I am missing something: how do you not-handwave the results of a clustering analysis if you don't have any supervision signal?

In any case, I agree that omics in particular take many more liberties than usual with their interpretations. And yet, sometimes they come up with useful and important finding. Yes, a broken clock...2x a day, but maybe after working in the same field for many years one can gain some insights and intuitions.

> but you are going to find peaks in a random walk

I would hope so since a random walk has pretty obvious peaks, and it's not hard to test if the peak is significantly beyond the level expected due to chance.

Do you have actual concerns about the data and the peaks they found, or are we back at wondering about all the fallacies that they may or may have not committed?

> They didn't test the theory that rapid aging occurs at those two specific time points in an independent hold out set.

This is a glaring omission, I agree.

> this paper does not prove they are biological. They could correspond to common socially driven changes in behavior.

True, but it dot make this paper worth any less. If anything, it's a great question for follow-up work.