[TowerTalk] dipole in space question

[Al Williams]

Why does a dipole in space have a radiation pattern shaped like a doughnut i.e. no or less radiation off the ends of the dipole?

Related to this question: Why is the radiation from a dipole over ground have its strongest radiation from the center of the dipole.
Yes the current is strongest at the center, but why?

I have tried to find the explanation in a dozen or more antenna books but to no avail.  I can speculate but perhaps some Towertalkians can explain it or offer their speculation?

k7puc