The cosmological debates are endless like about the nature and magnitude of the cosmological constant as many ideas are not currently testable, as seen in past issues of the Scientific American. However, the most widely accepted viewpoint from cosmology, which is regarded as well supported but still debated, is that the universe had a finite beginning.
There is strong scientific evidence for this. The entropy increases as a system becomes less ordered and more random, and decreases as the system becomes more ordered and structured. The water at the top of the dam is stationary, but it has so-called potential energy because of its height. As it descends through the dam the potential energy is turned into kinetic energy, or motion, and this is used to turn turbines to create electrical energy that gets used by consumers.
Any moving water at the bottom of the dam will eventually lose most of its energy in one way or another as it flows away. The universe therefore must have a finite age otherwise if it had an infinite past our energy supply would have run out by now. This running down of the universe provides evidence of a finite beginning, otherwise the sun would have burnt out by now.