This really does not mean anything to me in everyday terms, but it is fun to stretch the mind to fathom some things....
According to Phys.org a new study examines "galaxy rotation curves without exotic dark matter and seeks to describe a modified Newtonian acceleration law derived from a relativistic modification of Einstein’s gravitational theory. Found in the Astrophysical Journal, the study, “Galaxy Rotation Curves Without Non-Baryonic Dark Matter,” may one day help to explain the Pioneer 10 - 11 spacecraft anomaly. The two space probes, launched in 1972 and 1973 respectively, are now at the edge of the solar system on trajectories that cannot yet be fully explained based on what is known about Newtonian and Einstein gravity.
Don't you find it amazing that a space probe launched in 1972 and in 1973 are still on their way somewhere?
Dig a little in and read the Space Today summary on Pioneer 10 - 11!
Comments from PhysOrg:
"I like the idea that maybe there is no dark matter. I always found objection to placing such importance on a unverifiable theory. If this matter emits absolutely no form of radiation, how can we ever find it? The equations claim that it is necessary, but it is entirely possible that the equations are wrong. However, there is one troublesome issue for me when considering that dark matter may not exist. Without such hidden matter, there is no way that the galaxy will ever collapse back upon itself. It seems that the cyclic nature of the universe, on all levels, demands that the universe collapse upon itself and blow up all over again. The idea that eventually there will be zero energy just doesn't seem right. As the Notorious B.I.G once said "Keep [big] Bangin'"
The Big Bang/Crunch, and zero energy universal "endings" are not the only theories out there that explain possibilities for the nature of the universe. They are the most well known, particularly the former which is taught to schoolchildren as "the way things are", but neither is necessarily true. Consider that with each new discovery in space science, our very timid and grasping understanding of our cosmic environment grows, and several new theories of planet, star and galactic formation spring up frequently....