{"id":104728,"date":"2025-07-30T11:54:10","date_gmt":"2025-07-30T11:54:10","guid":{"rendered":"https:\/\/www.europesays.com\/us\/104728\/"},"modified":"2025-07-30T11:54:10","modified_gmt":"2025-07-30T11:54:10","slug":"after-100-years-of-quantum-mechanics-physicists-still-cant-agree-on-anything","status":"publish","type":"post","link":"https:\/\/www.europesays.com\/us\/104728\/","title":{"rendered":"After 100 Years of Quantum Mechanics, Physicists Still Can\u2019t Agree on Anything"},"content":{"rendered":"

In July 1925\u2014exactly a century ago\u2014famed physicist Werner Heisenberg wrote a letter <\/a>to his equally famous colleague, Wolfgang Pauli. In it, Heisenberg confesses that his \u201cviews on mechanics have become more radical with each passing day,\u201d requesting Pauli\u2019s prompt feedback on an attached manuscript he\u2019s considering whether to \u201ccomplete\u2026or to burn.\u201d<\/p>\n

That was the Umdeutung (reinterpretation) paper, which set the foundation for a more empirically verifiable version of quantum mechanics. For that reason, scientists consider Umdeutung\u2019s publication date as quantum mechanics\u2019s official birthday. To commemorate this 100th anniversary, Nature<\/a> asked 1,101 physicists for their take on the field\u2019s most fiercely debated questions, revealing that, as in the past, the field of quantum physics remains a hot mess.<\/p>\n

Published today, the survey shows that physicists rarely converge on their interpretations of quantum mechanics and are often unsure about their answers. They tend to see eye-to-eye on two points: that a more intuitive, physical interpretation of math in quantum mechanics is valuable (86%), and that, perhaps ironically, quantum theory itself will eventually be replaced by a more complete theory (75%). A total of 15,582 physicists were contacted, of which 1,101 responded, giving the survey a 7% response rate. Of the 1,101, more than 100 respondents sent additional written answers with their takes on the survey\u2019s questions.\u00a0<\/p>\n

\u2018Textbook\u2019 approach still tops, with a caveat <\/p>\n

Participants were asked to name their favored interpretation of the measurement problem, a long-standing conundrum in quantum theory regarding the uncertainty of quantum states in superposition. No clear majority emerged from the options given. The frontrunner, with 36%, was the Copenhagen interpretation, in which (very simply) quantum worlds are distinct from classical ones, and particles in quantum states only gain properties when they\u2019re measured by an observer in the classical realm.<\/p>\n

\"Quantum\u00a9 Nature <\/p>\n

It\u2019s worth noting that detractors of the Copenhagen interpretation scathingly refer to it as the \u201cshut up and calculate\u201d approach. That\u2019s because it often glosses over weedy details for more practical pursuits, which, to be fair, is really powerful for things like quantum computing. However, more than half of physicists who chose the Copenhagen interpretation admitted they weren\u2019t too confident in their answers, evading follow-up questions asking them to elaborate.\u00a0<\/p>\n

Still, more than half of the respondents, 64%, demonstrated a \u201chealthy following\u201d of several other, more radical viewpoints. These included information-based approaches (17%), many worlds<\/a> (15%), and the Bohm-de Broglie pilot wave theory<\/a> (7%). Meanwhile, 16% of respondents submitted written answers that either rejected all options, claimed we don\u2019t need any interpretations, or offered their personal takes on the best interpretation of quantum mechanics.\u00a0<\/p>\n

So, much like many other endeavors in quantum mechanics, we\u2019ll just have to see what sticks (or more likely, what doesn\u2019t).<\/p>\n

Divided results, equivocal reviews <\/p>\n

Physicists who discussed the results with Nature had mixed feelings about whether the lack of consensus is concerning. Elise Crull<\/a> at the City University of New York, for instance, told Nature that the ambiguity suggests \u201cpeople are taking the question of interpretations seriously.\u201d<\/p>\n

Experts at the cross-section of philosophy and physics were more critical. Tim Maudlin<\/a>, a philosopher of physics at New York University, told Gizmodo that the survey\u2019s categorization of certain concepts is misleading and conducive to contradictory answers\u2014a discrepancy that the respondents don\u2019t seem to have realized, he said.\u00a0\u201cI think the main takeaway from this is that physicists do not think clearly\u2014and have not formed strongly held views\u2014about foundational issues in quantum theory,\u201d commented Maudlin, my professor in graduate school.<\/p>\n

\u201cIt\u2019s just embarrassing that we don\u2019t have a story to tell people about what reality is.\u201d <\/p>\n

In an email to Gizmodo, Sean Carroll<\/a>, a theoretical physicist at Johns Hopkins who responded to the survey, expressed similar concerns. Several factors may be behind this lack of consensus, he said, but there\u2019s a prevalent view that it \u201cdoesn\u2019t matter as long as we can calculate experimental predictions,\u201d which he said is \u201cobviously wrong.\u201d<\/p>\n

\u201cIt would be reasonable if we thought we otherwise knew the final theory of physics and had no outstanding puzzles,\u201d added Carroll, who was part of an expert group consulted for the survey. \u201cBut nobody thinks that.\u201d<\/p>\n

\u201cIt\u2019s just embarrassing that we don\u2019t have a story to tell people about what reality is,\u201d admitted Carlton Caves<\/a>, a theoretical physicist at the University of New Mexico in Albuquerque who participated in the survey, in Nature\u2019s report.\u00a0<\/p>\n

However, the survey\u2019s results do seem to hint at a general belief in the importance of a solid theoretical groundwork, with almost half of the participants agreeing that physics departments don\u2019t give sufficient attention to quantum foundations. On the other hand, 58% of participants answered that experimental results will help inform which theory ends up being \u201cthe one.\u201d<\/p>\n

Schr\u00f6dinger\u2019s consensus, kind of <\/p>\n

For better or worse, the survey represents the lively, fast-developing field of quantum science\u2014which, if you\u2019ve been following<\/a> our coverage<\/a>, can get really,<\/a> really weird<\/a>. A lack of explanation or consensus isn\u2019t necessarily bad science\u2014it\u2019s just future science. After all, quantum mechanics, for all its complexity, remains one of the most experimentally verified theories<\/a> in the history of science.<\/p>\n

It\u2019s fascinating to see how these experts can disagree so wildly about quantum mechanics, yet still offer solid evidence to support their views. Sometimes, there\u2019s no right or bad answer\u2014just different ones.<\/p>\n

\"PauliWolfgang Pauli, Werner Heisenberg, and Enrico Fermi during the 1927 International Congress of Physicists, where the new quantum mechanics was discussed in depth. To the left are the first lines of Heisenberg\u2019s letter to Fermi on July 9, 1925. Credit: Heisenberg Society\/CERN, Wolfgang Pauli Archive <\/p>\n

For you fellow quantum enthusiasts, I highly recommend that you check out the full report<\/a> for the entire account of how and where physicists were split. You can also find the original survey, the methodology, and an anonymized version of all the answers at the end of the report.\u00a0<\/p>\n

And if you do take the survey, or at least part of it, feel free to share your answers. Oh, and let me know whether you believe Heisenberg should have burned Umdeutung after all.<\/p>\n","protected":false},"excerpt":{"rendered":"In July 1925\u2014exactly a century ago\u2014famed physicist Werner Heisenberg wrote a letter to his equally famous colleague, Wolfgang…\n","protected":false},"author":3,"featured_media":104729,"comment_status":"","ping_status":"","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[25],"tags":[492,836,159,6458,67,132,68],"class_list":{"0":"post-104728","1":"post","2":"type-post","3":"status-publish","4":"format-standard","5":"has-post-thumbnail","7":"category-physics","8":"tag-physics","9":"tag-quantum-physics","10":"tag-science","11":"tag-theoretical-physics","12":"tag-united-states","13":"tag-unitedstates","14":"tag-us"},"share_on_mastodon":{"url":"https:\/\/pubeurope.com\/@us\/114942054740984162","error":""},"_links":{"self":[{"href":"https:\/\/www.europesays.com\/us\/wp-json\/wp\/v2\/posts\/104728","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.europesays.com\/us\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.europesays.com\/us\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.europesays.com\/us\/wp-json\/wp\/v2\/users\/3"}],"replies":[{"embeddable":true,"href":"https:\/\/www.europesays.com\/us\/wp-json\/wp\/v2\/comments?post=104728"}],"version-history":[{"count":0,"href":"https:\/\/www.europesays.com\/us\/wp-json\/wp\/v2\/posts\/104728\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.europesays.com\/us\/wp-json\/wp\/v2\/media\/104729"}],"wp:attachment":[{"href":"https:\/\/www.europesays.com\/us\/wp-json\/wp\/v2\/media?parent=104728"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.europesays.com\/us\/wp-json\/wp\/v2\/categories?post=104728"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.europesays.com\/us\/wp-json\/wp\/v2\/tags?post=104728"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}