Archive for the ‘Lambda-CDM’ Category

The last post

29Oct10

The dark energy controversy is unresolved, and will likely continue to be unresolved for a long while yet. While cosmologists do use the ΛCDM model to fit WMAP (cosmic microwave background probe) and SDSS/2dFGRS (galaxy redshift surveys) data, sometimes they vary the ‘cosmological equation of state’ parameter (w), which should be set at -1 for a cosmological constant; w=-1 […]


The third aspect of what makes dark energy a controversy is sort of a cumulation of some of the issues I’ve raised in past posts. There is a clear aversion to a dark universe and to a cosmological constant; some scientists are so unhappy with the situation that they actually hope that they’ve got it […]


But it was not the end of the controversy. There are three major problems with the cosmological constant that have caused the dark energy controversy to continue. The cosmological constant is controversial because: It’s often been used in the past as a fudge factor, only to be gotten rid of after more information has been gathered […]


In 1998, two separate teams, using different type Ia supernova data, went out to show that the universal expansion was slowing down due to gravity, but instead found just the opposite, that the universal expansion was accelerating. This was very controversial and very unexpected; in fact, it was so different to the accepted theory that […]


I find that I understand concepts much better when I use flow charts; I’ve had one for my controversy in the works for most of the semester, gradually evolving into this (hopefully) final flow chart: You can see, in blue, the three levels of controversy I noted in my previous post and, in white, the causes and […]


Before I discuss the controversies surrounding dark energy and its introduction into the big bang paradigm, I figure I should make some kind of mention of what it is. In my research I’ve come across, many times, the assertion that dark energy is the most famous and most embarrassing problem in physics. Maybe the most embarrassing, but the most […]


I’ve spent a lot of time on this blog writing about scientific controversy theory, how it relates to modern Big Bang cosmology in general, and small aspects of the overall cosmic controversy, without going into too much detail about the specific controversy. Cosmology is a huge subject, and as it’s based on observation, it has […]