Tenured professors who have been working in the field for decades before you ever heard about it in the news, and who have been consistently deeply critical of quantum computing hype despite negative professional and financial penalties from doing so, nonetheless still agree overwhelmingly that it will happen. You can't just believe the opposite of what swindlers are arguing and expect that to be right.
On one hand I can make a joke that you are defending the only job on Earth that not only gets paid but can't get fired past a certain point due to their 'tenure.'
On the other hand I can make a nod in the direction of the decades of expertise any one can build in a chamber of vapor ware with the hope that it will distill into something useful.
As critical as I am, I of course congratulate anyone on taking on such difficult innovation. Nonetheless, there is no physical evidence it will amount to anything thus far. It is purely hypothetical, and the only thing theoretical in justification is the fictitious proof of its use through mathematical modeling which is not physical reality and thus closer to building a virtualized computer in a MMO that mimics Earth saying you get to play as a martian using some weird technology while it runs on classical computing.
> On one hand I can make a joke that you are defending the only job on Earth that not only gets paid but can't get fired past a certain point due to their 'tenure.'
You could, but the premise is wildly false; tenured professors can get fired for cause (and tend to have some process protections alongside that), and tenured professors aren’t the only workers with contracts or legal protection that restrict firing to “for cause” (pretty much all high level employees with individual contracts like—but not limited to—executives have that, maybe with a high-priced buyout option, though without or with limited process protections), and most unionized workers and most (even if not unionized) public workers have both limitations to firing (or other adverse actions) for-cause and strong due process protections.
Yeah that's why most startups fail. Rarely do startups exist for over 40 years with no physical proof of the idea working and just a simulation of it that fundamentally undermines its reality and even more rarely are there people who don't work at those startups who defend them as if compelled by some strange force.
Quantum computing is not a startup, it's a technology. There are many technologies that took much longer than 40 years from initial conception to first useful application.
Nope. The analogy with the development of quantum sensing is actually very close: the idea of using squeezed or superposed measuring probes to increase measurement sensitivity goes all the way back to Braginsky in 1967. It took two or three decades for "demonstrations" of this effect to be realized in the lab. However, people correctly pointed out that in every case where these early demonstrations were done, it would have been much easier to carry out the same measurement using non-quantum techniques by simply scaling up the resources (usually, by increasing laser power). So these demonstrations were never actually useful for anything practical.
(Likewise, the earliest "demonstrations" of quantum computing where they factored two-digit numbers were ridiculous for several reasons, not least of which was that you could do it in a microsecond using a classical computer. Then later, when quantum supremacy calculations were done by Google, the mathematical problem chosen was completely useless for any practical application.)
It was not until 2013, 46 years after Braginsky theorized the basic principles, that a squeezed probe was used for something other than a proof-of-concept: measuring gravitational waves at LIGO. This enabled LIGO to detect ultra weak gravitational waves that would otherwise be invisible to it: https://www.nature.com/articles/nphoton.2013.177
Needless to say, it will take even longer before these techniques are used for economically relevant applications.
I understand your point, jessriedel, but my contention remains that there's a marked distinction between quantum sensing and quantum computing. As we're discussing, quantum sensing has yielded tangible, applicable results, which is the physical manifestation I was alluding to earlier.
In terms of computing, we have seen many new paradigms materialize within decades, even centuries, of their conception. Babbage conceived of the Analytical Engine in the 1800s, but we saw programmable computers by the mid-1900s. The transition from electromechanical to electronic computing occurred within a few decades. Every instance of these examples are real physical examples that were able to be used and demonstrated as a physical device providing utility. We can even go back to the early computation devices of the loom or even analog computing calendar/clock systems.
Quantum computing is an ambitious concept, and while I respect the academic rigor that goes into its development, the lack of concrete, physical outcomes, even in a rudimentary sense, after four decades is notable. Theoretical advancements are important, but the inability to materialize them in some substantial form, especially when juxtaposed against the timeline of prior computing paradigms, can warrant skepticism.
Don't get me wrong, I value innovation and the pursuit of new technological frontiers, but I also believe in questioning, and when the physical evidence is wanting, I'll voice my concerns. This is not to discredit the work being done but rather to keep the discussion grounded and accountable.
Real physical quantum computers exist, they just can't do anything useful yet, and in particular they haven't achieved fault tolerance. Quantum sensing took 46 years before there was an application. The idea of quantum computers has only been around for 38 years (Deutch's paper was 1985). They seem highly analogous to me and I don't see what distinction you're trying to point to.
I see where you're coming from, jessriedel, but I must respectfully disagree with the assertion that "real physical quantum computers exist." In the common parlance, a "computer" is a device that can perform a set of operations or computations independently following programmed instructions.
For a "real physical quantum computer" to exist by this definition, it should be able to carry out such operations using quantum phenomena, without any reliance on classical computing architecture for function, error correction, or result verification.
What we currently have in the field of quantum computing doesn't fit this bill. The quantum systems we have today are not independent "computers" but rather more like "classical computers conducting quantum experiments." They're akin to people playing an MMO and running an imaginary computational architecture that only exists within the confines of the game rules. In this sense, they're creating and operating within an entirely simulated environment.
This isn't to diminish the value of the research being conducted or the strides that are being made. But I would argue that the statement "real physical quantum computers exist" is, at this stage, a significant overreach. We may have precursors or tools that can manipulate quantum phenomena in interesting ways, but we're still a considerable distance from having an operational, standalone quantum computer in the full sense of the term.
> For a "real physical quantum computer" to exist by this definition, it should be able to carry out such operations using quantum phenomena, without any reliance on classical computing architecture for function, error correction, or result verification.
Nope, wrong. Plans for quantum computers have always included assistance from classical computers. This is like saying for a nuclear weapon to exist, it must have no conventional explosives, but in fact all nuclear weapons contain conventional explosives to initiate the nuclear reactions.
You've made a number of incorrect claims here without admitting error, so I won't continue the conversation.
