The Pioneer thing, I should collect on some bets. I was on the side of "not a new force, it's some kind of radiation pressure that we're overlooking by treatin

The Pioneer thing, I should collect on some bets. I was on the side of "not a new force, it's some kind of radiation pressure that we're overlooking by treating this like a sphere." Not long after I mentioned that, I attended a lecture by a guy who spent a lot of time working over Casimir effects on strange topologies yielding equally unlikely results. He said something to the effect of "never underestimate the numerous small anomalies created by minuscule forces on complicated surfaces." I've been watching people look for a fifth force (and sixth) force in different flavors for decades. Maybe there's more out there but we have to work very hard to eliminate all of the numerous potential sources of error. If I had to lay a guess on it, it might take centuries of work find an additional force were it present.