Several people have asked me to comment about a Financial Times opinion piece entitled The Quantum Computing Bubble (subtitle: “The industry has yet to demonstrate any real utility, despite the fanfare, billions of VC dollars and three Spacs”). The piece is purely deflationary — not a positive word in it — though it never goes so far as to suggest that QC is blocked by any Gil-Kalai-like fundamental principle, nor does it even evince curiosity about that question.The article is paywalled, so I don't know anything about it.
Aaronson always likes to draw a distinction between saying something is impossible, and saying something is impossible because it is blocked by a fundamental principle.
For example, saying that perpetual motion machines are impossible is not as satisfying as saying perpetual motion machines are impossible because the First Law of Thermodynamics says energy is conserved.
Okay, maybe, but it depends on how convincing the principle is.
Aarson concedes that the article is right that it is not yet known whether it is "possible to build a large-scale, fault-tolerant quantum computer."
As for applications, my position has always been that if there were zero applications, it would still be at least as scientifically important to try to build QCs as it was to build the LHC, LIGO, or the James Webb telescope. If there are real applications, such as simulating chemical dynamics, or certifiable randomness — and there very well might be — then those are icing on the cake.That is because he likes to study quantum complexity theory. But the practical applications may well be negative.
It is possible that the biggest practical application of QC will be to destroy the security of internet communications that everyone uses everyday.