Two of the greatest mysteries of the Universe are the nature of the invisible dark matter, whose gravitational effects we can detect, and dark energy that is accelerating the expansion of the Universe. Together they account for 95.1 percent of all the matter and energy in the Universe –the stuff that we can see, i.e. ordinary matter that makes up the stars, galaxies, planets and our own bodies, accounts for just 4.9 percent of the Universe!
As we can see, the vast majority of the Universe is a big unknown and if we can pin down what dark matter and dark energy are it would be a giant leap forward in our understanding of fundamental astrophysics and cosmology. However, what if there is another explanation? Imperial College’s Dr Ali Mozaffari will be speaking at AstroFest on the morning of Friday 7 February about MOND, short for MOdified Newtonian Dynamics or, in other words, a modified theory of gravity that, if correct, could go some way to replacing dark matter and possibly even dark energy. MOND is certainly controversial and many astronomers will point to evidence of dark matter really existing in the form of an unknown particle, but in his talk Mozaffari will suggest ways to test modified gravity in our own Solar System, the results of which could either rule out MOND or provide the answers we have been seeking.