Dark matter effect might be explained by modified way to calculate inertial mass
I've mentioned MOND theory from time to time as an alternative explanation for dark matter, but this MOND-ish proposal is possibly testable.
Furthermore, Mike McCulloch claims that his idea might explain the acceleration of the universe as well.
Who is he, though? Well, I would be a little surprised if stunning new understandings of physics come from some who works part time at the Plymouth University School of Marine Science and Engineering, and whose personal page features cartoons of dubious quality (yes, I know - I should talk!) and bad short stories, but I should retain an open mind, I suppose.