Are Mirrored Universes With Opposing Directions of Time Theoretically possible? I found an article that talks about this here, entitled "Big Bang May Have Created a Mirror Universe Where Time Runs Backwards".
I know any notion of backwards time is probably a dead horse in this site, but given this is not a topic of time travel based on some theoretical non-linear time model, is a mirrored universe with backwards time even theoretically possible? 
Wouldn't backwards time violate the second law of thermodynamics? Wouldn't reverse time reverse rate of decay (e.g., reverse aging)? Wouldn't the reversal of time imply the future is predetermined (e.g., in order to reverse a falling person, the person falling in the first place is a fixed event), et cetera? I believe even determinism can be ruled out because there exists non-deterministic configurations in newtonian kinematics. 
I know that, perceptually, we would not notice a difference because our intuitions of past, present, and future remain intact. However, this is a question of the physics of it. 
 A: A little bit of digging allows one to find the original Scientific American article, which links (and I wish every science article did this) to a journal article from Physical Review Letters (preprint). PRL is very unlikely to publish "junk science."
I also think the case is bolstered by the fact that they did simulations, as the Scientific American article elaborates on a little more than your linked article, and that these simulations showed two universes always arising.
That being said, these articles were published four years ago, and the "two-universe theory" (I made up that term) hasn't caught on. The reason is that it is no more or less provable than any other theory that asserts the existence of multiple universes to try to explain some kind of physics.
I typically think of "junk science" referring to pseudoscience (think astrology, for example), faked science (think anti-vaccine movements) or things that look like but aren't science (think "human design"). Under that rough operational definition, this idea doesn't qualify as "junk science." But it does qualify as a largely unprovable theory about the nature of the universe.
A: What is "backwards" time?
From what I can see on the linked articles, the concept of "backwards time" is not particularly interesting. All they're saying is there are two separate timelines that both originate from the Big Bang, and, from a certain point of view, the timelines could be perceived as going "opposite" each other.
You could just as easily say the timelines are parallel and running in the same direction, and it wouldn't change anything. Whether the original article says something else is a different beast, but that's what I'm getting from the PBS article you linked to and the Scientific American article flevinBombastus linked to.
To the best I can tell, the entire point of the paper is that it's achieved further confirmation of the notion that "the arrow of time" isn't a physical property of reality, but rather an emergent perception of reality that naturally arises in a system with entropy. The notion of two timelines coming from the Big Bang is just a bonus point.
I don't think that word means what you think it means.
As an aside, I'd be rather skeptical of articles making the gross error of equating entropy with "disorder". Entropy is the amount of thermodynamically unusable energy in a system and has nothing to do with chaos or randomness. In fact, the universe has actually gone from a low entropy, highly chaotic place (just after the Big Bang), to a higher entropy, more ordered place (galaxies, stars, etc.), and is headed towards a maximum entropy, highly ordered place (when everything in the universe is sitting at the same energy potential). There will likely always be a little chaos in the mix, but, if anything, entropy leads to the opposite of disorder and certainly isn't defined as disorder.
Note that the quotes from the original paper acknowledge this.

Barbour adds. “And here we are, showing beyond any doubt really that this is in fact exactly what gravity does. It takes systems that look extraordinarily disordered and makes them wonderfully ordered. And this is what has happened in our universe. We are realizing the ancient Greek dream of order out of chaos.”

And

“This two-futures situation would exhibit a single, chaotic past in both directions...” Barbour says.

And when they talk about "low complexity" near the Big Bang, they're just talking about how spread out the particles are, not about any human-scale notions of organization of said particles.

They investigated the dynamic behavior of the system using a measure of its "complexity," which corresponds to the ratio of the distance between the system’s closest pair of particles and the distance between the most widely separated particle pair.

Like the definition of "complexity", it's possible certain quotes, taken in their original contexts, are using very specific definitions of "random" or "disorder" in a way that makes sense. But generally speaking, the broadly-cited connection between entropy and chaos doesn't exist, and I'm leery of "scientific" articles making this mistake.
Be careful ascribing current physics to outside-the-box thinking.
There are a number of "laws" you can read about in any physics textbook. They are called "laws" because they seem to be inviolate aspects of reality, but they are actually just theoretical constructs created by humans to help us understand physics.
In practice, any new theory that requires well-established laws of physics to be broken is highly suspect, but not impossible. At the end of the day, reality can do what it wants, and is unbound by silly human ideas. If it turns out that previously-established science isn't the whole picture, it's the science that changes, not reality.
Newtonian physics is an example of theory that works really well inside its original domain, but turns out to be incomplete at high speeds or under high gravity. Likewise, there's no particular reason thermodynamics can't be incomplete in some way.
The big thing to be highly skeptical of is "science" that implies everything we knew is wrong. Science only requiring modifications to existing theory so it works under non-standard circumstances is much more likely to be on firm ground.
(Conversely, just because something "is plausible" doesn't make it true. Even cool-sounding science needs verification.)
