Group blog from Caltech's Institute for Quantum Information and Matter, with physicists writing about quantum computing and physics research.
Commenters value it for informative pieces, such as John Preskill's, and the series on whether quantum advantage has been achieved.
> Physics has not changed much
What time frame are we talking here? We're constantly learning about how more stuff works. Physics has had plenty of changes[1] but perhaps you're only speaking to very specific theories that have not changed such as relativity? In which case yeah it hasn't changed much but there is also a disconnect between relativity and quantum mechanics and it seems a pretty large majority of scientists think there is a unified way to make them one theory so obviously our understand of both is not entirely accurate (though our observations with relativity are pretty spot on).
> Where do you go from there?
Hard to say since I'm not a physicist or hardware engineer but I've seen lots of interesting talks about scaling down more and more when we didn't think we could before. Ultimately there may be a size in which we can't get any smaller with conventional processor architecture but that doesn't mean we can't build new ones. Optical based processors, built in a 3D way, allows for far more overlap than transistors since light passing through each other doesn't interfere with one another[2] so that looks really interesting.
Quantum computing also promises great speed increases which perhaps could eventually be scaled down to closer to quantum sizes than traditional computing.
I think everything is getting much harder than the breakthrough before it but we seem to keep going and I would be surprised if we end up completely stopped due to hitting some physics…
Without getting into what Al Gore may have said or meant, let me quote the following lovely little tidbit from Paul Ginsparg (who created arxiv.org). It's about physicist Ken Wilson, but Al Gore and Newt Gingrich make a fascinating appearance:
"He [Wilson] was on the NSF taskforce that pushed for the implementation of the early NSFNet, and I was told by George Strawn (one of the people on the NSF side shepherding the process) that Ken was the key person who argued for using the TCP/IP (i.e., internet) protocol, rather than the DECnet protocol favored by many of the other physicists, and we know where that has led… (George also told me that the absolutely essential people who moved the NSFNet through the senate and house, respectively, were … Al Gore, Jr and Newt Gingrich)"
http://quantumfrontiers.com/2013/06/18/we-are-all-wilsonians-now/comment-page-1/#comment-3645
Can anyone with a background in quantum information theory tell me how QI models the distinction between a quantum system being measured or unitarily evolved? Nicole Yunger Halpern talks about these things as if the measurement process were a well-defined thing happening at a specific instant in time. How and what do quantum information theorists think about the measurement problem these days?
On another note, having read John Preskill's article (https://quantumfrontiers.com/2015/11/06/wouldnt-you-like-to-know-whats-going-on-in-my-mind/) on the whole topic, including his reference to the zebrafish (https://www.nature.com/news/flashing-fish-brains-filmed-in-action-1.12621): Assuming that quantum mechanics does influence cognition as proposed by Matthew Fisher, wouldn't mapping the (zebrafish's) brain then influence how it works?
We can model many "reality" with the classical methods good enough, using Deep Learning and Tensor Network based methods, see for instance
- https://quantumfrontiers.com/author/roundsphereblog/
- https://www.quantamagazine.org/key-chemistry-question-answered-no-quantum-computer-required-20260529/
When it comes to many of these systems relevant real world (e.g. quantum chemistry), classical heuristic-based approaches are already successful enough. For instance, you can run one of the simulations in Garnet Chan paper in a 10-15 minutes using some machine similar to DGX Spark to simulate FeMo-cofactor model within accepted quantum chemistry precisions.
I believe its biggest application will be to explore some areas in quantum information (e.g. quantum coherence), all the practical applications will be minor.
What do you mean? The original 2019 supremacy experiment was eventually simulated, as better classical methods were found, but the followups are still holding strong (for example [4] and [5]).
There was recently a series of blog posts by Dominik Hangleiter summarizing the situation: [1][2][3].
[1]: https://quantumfrontiers.com/2026/01/06/has-quantum-advantage-been-achieved/
[2]: https://quantumfrontiers.com/2026/01/25/has-quantum-advantage-been-achieved-part-2-considering-the-evidence/
[3]: https://quantumfrontiers.com/2026/02/28/what-is-next-in-quantum-advantage/
[4]: https://arxiv.org/abs/2303.04792
[5]: https://arxiv.org/abs/2406.02501
The piece[1] from John Preskill linked in the article has less fluff and is more informative, IMO.
Given Preskill is director of the IQIM, and Fisher is on its faculty, he may have a promotional agenda; but he has an impressive pedigree[2] - I don't have the knowledge to directly evaluate the hypothesis myself, but if Preskill considers it worth investigating, I'd refrain from betting that it's nonsense!
1: https://quantumfrontiers.com/2015/11/06/wouldnt-you-like-to-know-whats-going-on-in-my-mind/
2: https://en.m.wikipedia.org/wiki/John_Preskill