What's the Latest?
After decades of searching, still no evidence for dark matter has emerged, and some scientists are ready to abandon ship. The current technology meant to detect dark matter, via the presence of weakly interacting massive particles (WIMPs), can undergo a limited number of upgrades before it becomes too sensitive--a point at which background radiation would drown out the search for WIMPs. "Beyond a certain sensitivity limit, the signal would be swamped by neutrinos, nearly massless particles that are constantly streaming from the sun and from particle collisions in our atmosphere."
What's the Big Idea?
If we extend our knowledge of how gravity works among planets in our solar system to the level of galaxies, we would expect them to fly apart. According to our best calculations, there is not enough mass to actually hold galaxies together, and yet they do hold together. Alternative theories to dark matter--an invisible scaffold onto which normal matter is thought to have clustered in the opening moments of the universe--include pinning gravitational anomalies on axions or neutrinos. Failing that, some scientists say our understanding of gravity must be recalculated. It's an idea that may have Einstein rolling in his grave.