Headscratchers / Upside Down

• Was it ever explained how they kept inverse matter and regular matter from burning when in contact for a few hours? There was the non-burny fabric that held the weights, and apparently (for no reason whatsoever other than an unexplored quirk of the pollen that the bees gathered) the pollen, but the "exceptions" are more of a rule. People who don't have the secret pollen drink all kinds of inverse fluids in the floor-to-ceiling club, and the air and possibly(?) snow can contact both regular matter and inverse matter. As far as I could tell, neutral matter was never mentioned, it was just a process involving the pollen, and only the pollen (oh, and ALL OTHER FOOD... apparently).
  • When the narration lays the three rules at the begining of the movie they say "matter in contact with inverse-matter burns after a few hours", but looking at the actual events in the movie I'd say this rule applies mainly to metals. Maybe the denser or heavier a material is, the faster it burns (and not in a linear progression), so with things like food and drinks you have days or weeks, and your body has time to digest and excrete all inverse-matter. With very light things like paper (as in the stamps) the process is so slow that you can keep them for years without worries. But with metals or other heavy things you'd normally use to ofset weights, you only have a few hours before it begins to heat up and burn.
    • While the introduction says that matter/inverse matter burn after a few hours, the evidence in the movie indicates it is not quite so simple. Rather, it seems as if contact between the two gradually increases the temperature of the items in contact . . . in fact, I would go so far as to suggest the narrator described it entirely incorrectly. It looks more like the phenomenon occurs when opposing matter types "push" against each other, like pressure that gradually builds up in the form of heat. If you look at examples in the movie, it shows that matter becomes "hotter" rather than just spontaneously igniting, and can be kept cool with things like water or a fridge. This would go a long way towards explaining the discrepancies . . . for instance, if you ingest inverse water, it would become fairly evenly distributed throughout your body (Bob even said, the body is 90% water!) which would then disperse that generated heat, allowing your body to eliminate it like normal waste heat. So yeah, despite the unreliable narrator's implication that "all opposing matter must combust", I would say it is ONLY if the temperature of the object could build faster than it could be dispersed . . . so little things like paper-thin stamps or snowflakes with lots of surface space would never reach that critical mass. In the case of the Transcorp headquarters, it is likely that the halves of the building are each supported by their own planet, and the exact meeting point in the middle was carefully calibrated to not have any "pressure" between the two sides. That would explain why the building doesn't burn.
• How come blood never rushes to Adam's head even though he spends about half of the film standing upside down?
• What kind of material is the TransWorld Building made out of? Because at some point there has to be Up Above bricks cemented directly to Down Below bricks, and according to the movie's rules, they will eventually catch fire...
  • It wouldn't be necessary. They are maybe just two buildings with a really tiny space between then where there's nothing but air.
• How do they have the same animals, plants and even humans on both planets? The ecosystem of them sould be completely different, right?
• The general manager of Transworld tells Adam that the policy of the company is to avoid as much as possible contact between people from Up Top and people from Down Below. So why Transworld building has a huge open-plan office where such contact is possible?
• I know it's a class thing, but isn't it weird that they choose "Up Top" and "Down Below" as the names of the cities when from each perspective, they should be the one down and the other the one up.