The current cosmological debate regarding the Universe includes theories that although it will continue to expand, it will slow over time, then begin to contract and come together in a "Big Crunch" that may trigger another Big Bang. This model is known as the "Oscillating Universe." The other theory is that the Big Bang was a one time event, and the Universe will expand outward forever, matter thinning out over space and time. That may be where the concept of a "Never Ending" Universe comes. However, with our current understanding of physics, eventually all stars will burn out and the Universe will cool down slowly over the eons (This is known as the "Heat Death" theory.) Astronomers have gotten glimpses via the Hubble Telescope to the "edge" of the Universe, 15 or so billion light years distant; nothing beyond that limit is seen because nothing beyond that distance exists, as we on Earth understand what existence means. Other theorists have maintained that at or near the edge the Laws of Physics as we understand them may not necessarily apply, and the terrestrial concept of a boundary between the "known" Universe and what lies beyond is moot.