Werner Heisenberg famously said, “Not only is the Universe stranger than we think, it is stranger than we can think.”
5.) Ancestor Simulation: The idea that we could be in a simulation isn’t only a staple of science fiction–e.g. The Matrix. It’s been given serious thought by thinkers who aren’t exactly on the lunatic fringe–most famously inventor /entrepreneur Elon Musk. The core of the argument goes like this. 1.) We are getting better and better at making simulations ourselves. 2.) At some point we will achieve a simulation indistinguishable from reality. 3.) If 2 is true, then it’s vastly more likely that we are already simulations because if it can be done, it probably already has been done many times over. (Thus, we’re more likely to be in one of the simulations than so-called “base reality.”)
4.) Mathematical Universe Hypothesis: Max Tegmark proposes that the universe may be–at its core–a mathematical structure, making us self-aware substructures. This may sound like a different way of stating the preceding hypothesis, but not necessarily. The simulation hypothesis suggests certain motivations of a simulation creator. MUH doesn’t require a creator or an objective. It could be the nature of reality at it’s most basic.
3.) A Holographic Universe: This idea sprang from thinking about what happens to the information when something falls into a black hole. The idea being that the information is trapped on the outside of the event horizon–i.e. information for a three dimensional entity stored in two dimensions. As physicists pondered this, some concluded that it might be that we are a projection of data, or–alternatively–much of what we see when we look out into space is.
2.) One of Myriad Universes: The idea that our universe is one of many (or an infinite number of) universes comes in several flavors and is a prediction of several theories widely given credence. In some versions, all the universes have different sets of laws and constants such that many flash in and out of existence and only a small proportion are capable of hosting life (but the math of infinity is weird and a small proportion of the infinite may also be infinite. I don’t know, I’m not a mathematician and the infinite never mattered in economics because ground zero is that everything is limited but desires.) This answers the Goldilocks zone issue nicely–i.e. we couldn’t exist if the equations and constants that govern our universe were very much different, but if there are many universes with many sets of laws then we just happen to be in one of the ones we can be in–hence, credulity remains unstrained. Other versions propose universes with the same laws such that there could be an infinite number of you living out lives that may be slightly different than yours (or–for that matter–in which you might be the Supreme Galactic Overlord.)
1.) Time is slowing: A couple Spanish physicists have suggested that the universe might not be expanding at an accelerating rate (as is the consensus view in physics,) but rather time may be slowing. This slowing would be anticipated to continue until one final moment is captured frozen in time–note: said point would be long after the Sun swallows the Earth.