Media Reports on Cosmology Article

Salon, along with several other media outlets, has published a summary of a recent cosmology article published in PLB. The article claims to derive some quantum mechanical corrections to general relativity, yielding new equations that, among other things, force the age of the universe to be infinite. This has then been reported as something more or less like “Scientists disprove the Big Bang!!!” Phys.org is notorious for that kind of sensationalism, although the Salon article is not quite as accepting of what the paper says.

This kind of reaction always puzzles me. One of the main things many theorists do is to come of with new models that extend or alter what we currently think we know about physics in order to test how well we really understand things. While I can’t really judge the exact logic used in the linked paper, I would guess that the authors introduce some unsupported assumption or assumptions in order to make their claims. That’s not a bad thing either. In order to propose something different or new, one must often make some guesses in order to have something to compare to data besides the usual model.

One thing in the Salon article that I do object to is the characterization of this model as “simpler” than the current ΛCDM cosmology. While the laws of physics break down in the very early universe, having what is effectively a beginning at a finite point in time seems to me to be conceptually simpler than a non-static but infinitely old universe. Additionally, while there is no singularity in the theory proposed in the paper, the laws of physics will necessarily break down well before a singularity occurs (in fact, the singularity is likely one of the telltale signs that the laws of physics somehow don’t work during the early universe). Even if there is no singularity, it still doesn’t mean that we have a complete understanding of the history of the universe (Note that the authors do note that their theory avoids needing quantum gravity, so maybe they have determined that this point doesn’t matter here).  My guess would be that this theory is designed as to be virtually identical to the ΛCDM given current data but diverges at a very early point in time. Thus, it provides an alternative, but one that can’t really be measured unless more work is done to discover observable differences between the two cosmologies.

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