I have heard of Lemaitre - I am, afterall, studying at the university where he worked - but he is not quite so famous a figure as Einstein. I thought it was Hubble's observations of red-shift in distant galaxies that convinced Eistein the whole thing had been a bad idea.
Regardless of what Einstein thought of it, I don't have the impression that the cosmological constant is dead. I can't be effectively measured, and the major debate is whether or not it is zero. Weinberg wrote about it as late as the early 90's, which is roughly when I gave up trying to be a physicist.
The cosmological constant is not exactly a repulsive force, although it has similar effects. It is an attempt quantify vaccum energy, and in an expanding, closed universe, can't possibly be constant. The link between vaccuum energies and the cosmological constant is a post-Einsteinian thing.
> Papal endorsement soon followed, as the big bang does not allow any
> discussion of what happened before it - there is no "before". Leaves lots of
> room for the Almighty, needless to say. All this is also an interesting
> exception to Thomas Kuhn's rule that scientists cling to their paradigms
> until the bitter end.
I've always thought the big bang served Marxist philosophy better than Christian theology. The universe develops, it has a history, and it is rife with constraints that must be resolved dynamically. This is much closer to the world-view expressed in Engels' Dialectics of Nature than that of the Catholic Church.
Scott Martens