Consider the vacuum solution to Einstein's equations with non-zero cosmological constant. Following Carroll, we can find the equation for the radial geodesic with the aid of killing vectors. It takes the standard form: E = T + V. But, with non-zero cosmological constant V(r) now has a term proportional to r^2. This obviously doesn't reduce to ordinary Newtonian gravity. If there were actually a term proportional to r^2 we would have experimentally detected it. What's going on?