ETA: Well, I *did* embarrass myself, but not quite so bad; it was at least a somewhat more subtle error than it might have been.
The one character says "Feels like point eight Gee", implying that he feels lighter than standard gravity.
The other guy throws a ball and, it's implied, puts it into orbit (today's [Saturday] comic makes it explicit), returning to his hand eleven seconds later, saying "feels like fifteen meters per second".
This is wrong any way I look at it. Normal gravity is about 10m/s^2 (9.8 and change, actually), so point 8 g would be a bit less than 8m/s^2. 15m/s^2 would be approaching two gravities.
However, to achieve orbital velocity on Earth is more like 11 KILOMETERS per second. An orbital velocity of 15 m/sec would be a MINISCULE gravity, something you'd find on a not-terribly huge asteroid, and people would not be walking as you see, nor would the one guy think they were in a 0.8g gravity field.
Also, throwing something at 15 m/sec isn't very fast at all -- that's around 33mph -- but unless that really is orbital velocity, he'd have needed to throw it UP so it would arc, or it would have hit the ground LONG before 11 seconds elapsed. And he'd need to throw it FAR up, because that's 11 seconds of hang time, which means the equivalent of a 5.5 second fall time, or over 150 meters (more than 450 feet!) VERTICAL equivalent in Earth's gravity... which would require throwing it with a vertical component of 55 meters/sec.
I know it's SF, but it's set in a world putatively derived from ours and things like gravity and orbital/projectile mechanics have always seemed to work like ours.