Well if people are really worried about the bathroom issue, they can just wear the specially designed, pneumatically sealed "HyperDiaper". Damned if I can't find the link to the appendix of Musk's document where he discussed those specs...
Anyway, what's likely more of an issue than either pod or bodily evacuation, is the possibility of motion sickness owing to the lack of a visible steady horizon from inside the capsule (no windows, no transparent aluminum pipes).
I suspect this is one of the reasons Musk mentions something about landscape images being displayed on the pod interiors. Some kind of projected artificial horizon, always steady no matter what the orientation of the pod, would likely keep people from getting too loopy.
Similarly, the very first subway in NYC (pneumatic, no less) [1] had cars without windows, but the line was only a few hundred feet long, so it's doubtful motion sickness was an issue.
Anyway, what's likely more of an issue than either pod or bodily evacuation, is the possibility of motion sickness owing to the lack of a visible steady horizon from inside the capsule (no windows, no transparent aluminum pipes).
I suspect this is one of the reasons Musk mentions something about landscape images being displayed on the pod interiors. Some kind of projected artificial horizon, always steady no matter what the orientation of the pod, would likely keep people from getting too loopy.
Similarly, the very first subway in NYC (pneumatic, no less) [1] had cars without windows, but the line was only a few hundred feet long, so it's doubtful motion sickness was an issue.
[1] http://freetoursbyfoot-nyc.blogspot.com/2013/02/today-in-187...