Recently there was an article by Tim Reyes asking if the standard cosmological model is a Rube Goldberg machine. The idea is that so many ill-fitting ideas have been put together that it seems unreasonably complex. I’ve used a similar criticism against certain models through the phrase “tweak theories are weak theories.” Given the latest implications that the Higgs field may contradict inflation, and the BICEP2 results may not hold up, should we really think of standard cosmology more as a tweak theory than a robust model?
A Difficulty with Dwarfs
Most of the predictions of cold dark matter agree very well with observation, which is why it is a dominant part of modern cosmology. But there are aspects of the dark matter model that don’t agree well with observation. Take, for example, the clustering of dwarf galaxies around the Milky Way and Andromeda galaxies.
Not Like the Others
The nature of dark matter is one of the greatest mysteries in modern astrophysics. Actually that isn’t quite true. We do know of one type of dark matter, and we’ve even detected this dark matter in experiments on Earth. This particular type of dark matter is more commonly known as neutrinos.
Gravity Check
Newton’s law of gravity states that between any two masses there is a gravitational force. The strength of that force depends not only on the masses, but on the distance between those masses, following what is known as an inverse square relation. Newton felt that this inverse square relation was exact, but is it?
Mine Over Matter
Minnesota’s Soudan Underground Mine State Park is a former iron mine. Because of the orientation of the hematite, the mine had to go deep, and by the time of its close as an active mine in 1962 they were mining more than 2000 feet below ground level. Given its depth, and the geology of the region, the lower levels of the mine are well shielded from cosmic rays, which makes it a perfect location for sensitive experiments such as the search for dark matter. This is why it’s the location for the Cryogenic Dark Matter Search (CDMS).
Dark Star
So it is tempting to wonder what effect dark matter might have on the formation and evolution of stars themselves. The problem is we can’t be sure without an understanding of type of dark matter which exists. That hasn’t stopped some astronomers from speculating, however.
Dark Matters
You’ll notice the graph above is fit to the dark matter model, but not any alternative model. This was done intentionally, and it helps to feed the fires of sensationalism in science reporting. Unfortunately it makes it much harder to convey what’s really going on. These results were hyped, intentionally, and they shouldn’t have been.
On Dark Matter and Dinosaurs
There is no evidence that dark matter killed the dinosaurs. None whatsoever. It’s link-bait noise that makes the job of communicating real science all that more difficult.
When Dark Matter Collides
In the ongoing search for dark matter particles, the most popular are efforts to detect them directly here on Earth. Another way to look for dark matter particles is to look for the by-product of their collisions with each other. A recent paper posted on the arxiv has done just that, and they think they’ve found a signal.