There are also other sets of discrepancies that are familiar to cosmologists: "horizon" problems, "flatness" problems, and "lambda" problems. They all have the same cause: systems proposed by "theoretical" cosmologists (mostly mathematicians) are ingenious, but they do not match up very well with what is observed by "experimental" cosmologists (often astronomers). The theoretical solutions can simplify ("solve") one set of problems but only at the expense of making others more difficult.
Now, a few brave theoreticians have dared to think the unthinkable. All the discrepancies can be solved simultaneously if cosmology's sacred cow, the speed of light, is acknowledged to be variable. Those who are inclined to question the holy-of-holies have not yet agreed on how and when light changed (or is changing), but they are working toward concordance. Then they will have to convince the other cosmologists, who are understandably antsy about chucking out everything they have worked on for the past several decades.
To read about where this is coming from and where it might lead, visit the following Internet sites:
Variable Light speed:
PS: A nominal, invariable light
speed has always been counter-intuitive, and it also does not appear to
be supported by classical observation. Light simply doesn't always arrive
when invariable light speed theory predicts. Cosmologists have explained
this inconsistency by proposing gravity induced curves and dimples in space/time
-- light takes a detour around some curve or into and out of some space/time
dimple but maintains its constant speed while doing so, and that's why
its late. Light, in effect, is bent by gravity just as it is by a magnifying
lens, and it arrives at its destination by circuitous routes. All this
may sound unlikely (counter-intuitive), but brand new Hubble telescope
observations support the hypothesis. See it at http://oposite.stsci.edu/pubinfo/pr/2000/08/index.html