As Yogi Berra (and Niels Bohr) famously stated: “It is tough to make predictions, especially about the future”. The major argument of this essay on superclusters is based on the assumption that we can accurately predict what the actual cosmos will be doing in the future, and this assumption is based on the assumption that we have a very accurate models of what the cosmos has been doing, is doing, and will be doing in the future. These are dubious assumptions.
After all, it was not so long ago (~ 1998) that the “late” acceleration phase of the observable universe (note small u) was discovered. Are we sure this acceleration will continue? Could a period of non-acceleration, or a countervailing period of enhanced gravitational attraction, occur in part or all of our local observable universe in the future? We really do not know, and we need to admit that we are whistling in the wind when we claim to know more than we do.
I think it wise to to include appropriate caveats and qualifiers in our proclamations about the cosmos. For example, one could say that if our cosmological models are accurate, it appears that superclusters are temporary associations, and are not technically gravitationally bound. In this way we avoid misleading ourselves and readers. Scientists know, or should know, that absolute knowledge is not something science deals in. Science, and our understanding of the cosmos, evolves.
Robert L. Oldershaw