The law of conservation of energy states that energy cannot be created or destroyed, but changed into different forms, which I've never found entirely compelling. It's impossible to measure the energy that exists, since we are unsure of whether our universe is finite, or whether 'universe' is even a valid concept given multiverse theory.
Specifically, my understanding in regard to current validation of the law of conservation of energy within the known universe is as follows. The expansion of the universe shows that there is continually increasing kinetic energy of masses that are increasing in velocity despite a supposed initial fixed mass and energy in 'big bang' theory. Dark matter theory seeks to explain the gap between big bang theory and expansion of the universe
An alternative explanation to the increasing velocity of non-dark matter in the universe is that overall energy of a system can continually increase and is not finite. Is there any compelling evidence against this idea? The idea is that energy (and potentially mass) can actually somehow be spontaneously created from 'nothing'.
Is there anything compelling against this idea? Is there anything that I need to add to my understanding of energy measurement and overall energy theory in the universe that could weigh against the notion of spontaneous creation of additional energy?