My hope is that cosmic strings will be discovered. Strings are relics of the hot, high-energy epoch in the early universe. They are thin tubes of energy sweeping through space at close to the speed of light. Strings are extremely heavy; 1 metre of string can weigh as much as a thousand trillion tonnes.
Cosmic strings may or may not exist. They are predicted in many, but not all, particle physics models. If we are lucky and strings do exist, their discovery would allow us to test high-energy particle theories at energies far beyond what we can hope to reach in particle accelerators. A very exciting possibility is that superstrings - the hypothetical fundamental elements of matter - can have astronomical dimensions and play the role of cosmic strings. We would then be able to observe them in the sky and directly test superstring theory. The search for cosmic strings is under way, and their detection is very feasible within the next few decades
http://www.newscientist.com/channel/opinion/science-forecasts/mg19225780.101-alexander-vilenkin-forecasts-the-future.html
