| Nobody knows of any certain reasons to not scale, but there's plenty of speculation. Someone else posted about Gil Kalai in this subthread, so he's one high profile person that has documented his skepticism on quantum computing and explained his reasons. For my part, I don't think quantum foundations are on a firm footing. I think the measurement problem is still unresolved to a satisfactory degree, which means our understanding of decoherence is incomplete. Per the link I posted above, there's also a good chance that gravity is inherently decoherent, which means entanglement will naturally breakdown in various conditions around mass. I've also developed skepticism of quantum field theories. For one, the supposedly "most precise calculation in physics" has been marred by numerous mistakes and even fraud (electron magnetic moment). Renormalization is also sketchy business. A more fringe reason, but one I think will resolve some of those issues is a growing skepticism of continuity [1], even for classical mechanics; continuous formalisms just seem to lead to logical and physical absurdities, like Norton's Dome and singularities in GR. Discrete theories are only now getting a little attention, but they're promising [2] because they seem to eliminate some of the formal structure (gauges), and the infinities disappear. [1] https://arxiv.org/abs/1609.01421 [2] https://arxiv.org/abs/1902.08997 |