To say that Physics is complete and that we fully understand how every bit of the universe operates is certainly inaccurate. Sure, physics has come a long way in the last 100 years, but we still don't yet have a universal model of reality that explains everything (ie an agreed upon Theory of Everything) and sometimes scientists discover things that simply do not make any sense using our current models and theories.
That's what this thread is for. Post anything that seems to defy the very laws or our current understanding of physics. And then of course, speculate wildly on what it could mean. 
I'll start this off.
This perplexing discovery is getting all kinds of headlines because scientists have discovered neutrinos in the depths of ice in Antarctica that are not behaving at all like the Standard Model in physics says they should. From my limited understanding, basically they found a certain type of neutrino, a high energy variant, that appears to have traveled all the way through the entire planet to get to where they are now. Only problem is, that shouldn't be possible given what we currently think we know about the way particles move and operate.
The most wild speculation from this question mark in physics comes from not the best source for science talk in the world, by a long shot, the New York Post. They ran a headline that reads - NASA scientists detect evidence of parallel universe where time runs backward. I personally can't think of a more salacious and click-baity way to report this story to the masses. And yet, its intriguing as hell to think about and consider that as a possibility, however unlikely.
A more reasoned approach to this finding comes from Ibrahim Safa, a lead author of a paper published in the Astrophyiscal Journal:
"We looked at these ANITA events and they can't be standard neutrinos. They were probably a result of our imperfect understanding of the Antarctic ice, but there's a chance some new physics phenomenon is responsible."
So we have something here that seems to defy the Standard Model in physics, calling into question our very understanding of particle physics in the first place. That means the Standard Model might very well be incomplete, somehow. It might either need to be expanded, or maybe this is evidence that it needs to be revamped completely.
Quantum Mechanics is (mostly) only good for explaining behaviors and attributes of very small things anyways. So we already know that its not a complete science. It directly contradicts General Relativity in many cases in physics, and we have yet to find a bridge science to connect these two sciences, otherwise known as Quantum Gravity. (Kinda talked about that in another thread already.)
Given that, I think physics is at its best when it stumbles upon something that its current models cannot explain, because it requires questioning the fundamental theories and models in the first place.
With this anomaly, perhaps its evidence we are at just the tip of the iceberg in understanding particle physics. Or maybe its evidence of a parallel universe. Or maybe the tools used are just picking up a misleading/somehow incomplete reading. Either way, it is a mystery that could lead to a major shake up in the world of physics. Or at the very least, a much more profound understanding of the way that.. Antarctic ice works.