Is it possible that the universe is just in a huge cycle of explosions?

The idea of everything coming back together into a singularity again (known as the Big Crunch) was a viable theory several decades ago, but not any more. Measurements of distant supernovas have shown that a mysterious force called dark energy is actually counteracting gravity over extremely large distances, causing the expansion of the Universe to accelerate and ensuring that no Big Crunch will ever happen. Instead, the Universe will probably continue expanding forever, becoming colder and more uniform, eventually undergoing something called the Heat Death as the last black holes evaporate and individual photons become permanently isolated by the expansion of space.