Elon Musk thinks we probably live in a virtual universe. Meanwhile scientist have shown that wormholes can be traversed by spacecraft. Perhaps they’re used by nearly a trillion alien civilizations that live in our cosmos.
At its core, science focuses on evidence. Models are tested against the evidence we have, so that over time a confluence of evidence allows us to refine scientific theories into something that’s reliable and predictive. There’s always a chance that a newer, better theory will replace an older one, but our focus on evidence keeps us from straying into wild speculation.
That doesn’t mean we can’t sometimes speculate about what might or might not be. Exploring “what if” models can be a great way to push back against the assumptions of a model. Debates about metaphysics and the philosophy of science can help keep us honest about the limits of a theory’s power. While these speculations aren’t necessarily science, they play a role in the scientific process. Unfortunately there is often confusion in popular media about the difference between what might be and what is.
Take, for example, the idea that we live in a virtual universe. The basic argument is that if it’s likely that civilizations far more advanced than ours can arise in the universe, and they have a good chance of simulating aspects of their past, then odds are we are living in a simulated world. Statistically its more likely that we are a simulation of pre-singularity humans than actually living in that rare time period. The argument is a philosophical exploration about the limits of what we can know, and has a long history tracing back to descartes’ demon and Plato’s cave. The often-referenced work by Nick Bostrom doesn’t claim we are living in a virtual world, but rather argues we can’t simply discard the idea out of hand.
Then there’s the idea that wormholes might be traversable. Wormholes are a hypothetical idea that has been studied for decades, including how they might be traversed. The latest work on the idea focuses not on spaceship travel, but on how microscopic wormholes might allow elementary particles through. It’s a mathematical study of the limits of general relativity. It’s less about proving wormholes real and more about pushing an established model until it breaks to see how it works.
But what about alien civilizations? Have we finally proved they’re out there? No, the latest paper on alien civilizations is a study of the observational constraints on alien civilizations. We now have a good handle of just how many potentially habitable planets there are in the Universe, at least on a broad order of magnitude. They’re extraordinarily common, and that means there could be trillions of alien civilizations out there. There could also be no civilizations other than ours. It really comes down to how rare the formation of life on a world actually is. Even if civilizations are common, it’s quite likely that we simply won’t meet up with them.
While each of these ideas might be true, there currently isn’t evidence to support them. They may lead us to new ways of seeing the Universe, or they may just end up a false, but cool, story.
Paper: Nick Bostrom. Are You Living In A Computer Simulation? Philosophical Quarterly, Vol. 53, No. 211, pp. 243-255 (2003) DOI: 10.1111/1467-9213.00309
Paper: Gonzalo J Olmo, et al. Impact of curvature divergences on physical observers in a wormhole space–time with horizons. Classical and Quantum Gravity, Vol 33, No 11 (2016) DOI:10.1088/0264-9381/33/11/115007
Paper: A. Frank and W.T. Sullivan III. A New Empirical Constraint on the Prevalence of Technological Species in the Universe. Astrobiology, Vol 16, No 5 (2016) DOI: 10.1089/ast.2015.1418