-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA512 > Which I also remarked in the original post. However, when (if?) > commercial interests grab a hold of quantum computing, huge leaps in > cost of production perhaps could be achieved, making memory-rich > quantum > computers abundant -- at least, from my chair, there's no > obstruction to > this future. (?)
Eh. I'm still unconvinced. It wasn't until last year that the final physics hurdle to large-scale QC was addressed (large systems have a strong tendency to near spontaneously decohere, turning your quantum computer into an expensive paperweight). We still have no idea how to apply this physics knowledge, however. Just knowing that something is possible doesn't mean the ability to do it is around the corner. We can teleport atoms in laboratories at the speed of light and we know how to do it for macro-scale items, but the engineering difficulties are so large that I doubt we'll see it in our lifetimes. While I agree that commercial development _may_ lead to developments in QC, I think it's equally likely that the engineering difficulties will be insurmountable. Which means that, from where I sit, we should just shrug and say "we really can't say with any confidence what the future will or will not hold". > found -- this pragmatism causes me to ponder the scenario in which > something like Rice' theorem could be established for quantum > computers' > ability (or traditional computers' inability): What do you mean? Rice's theorem applies to QC. Computational theory is computational theory. We've already got very robust mathematics to describe the computational properties of QC. We know that BQP is a superset of P, that it does not encompass NP- COMPLETE, that it has some overlap with NP, etc., etc. It's true that in mathematics there could always be a proof delivered tomorrow by some hungry graduate student which will utterly shatter our knowledge of math as we know it. But this is true for all of mathematics. It's not as if this risk is special to QC. You should be just as concerned about the prospect of P=NP. -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.7 (Darwin) iQEcBAEBCgAGBQJGKAhmAAoJELcA9IL+r4EJPM4H/3lBPfZa9Uo+86whHTtKX2Vi Y7tm/jXSdy0JVCXXjpOfl8tlb7vllX7OeG2PzCwjX8mbn20OaaEFccBLSRhKga00 YBKB6xdcaXtPDBHVq/bgFO2wFQyc77xdpdd6Uoem34OCx8H65XC/4N+pgvTC0LDj JkAGVaAABaCKwS4wIWrVNiFZRpVfuXDYx6QTaAWw789vDmVR3I06elbYVYHANnr4 R7KzTl+Y46qp2XMoKSLBore+xrvjqdailkMYP97D7rsYyCE5V3CtntoUYMerMiWy DgXjHR/kM06Ja1jaOTu4SKstE1zJjMGgHwj3qeCLgqvijiiuTmSYVdvhjMU4ROE= =wy/G -----END PGP SIGNATURE----- _______________________________________________ Gnupg-users mailing list Gnupg-users@gnupg.org http://lists.gnupg.org/mailman/listinfo/gnupg-users
