Science 1 publisher2 min readPublished September 13, 2026 at 2:43 PM PDT

A combination of explanations leads the dark matter answers in the largest physicist survey

A worldwide survey led from Waterloo and the Perimeter Institute records what working physicists believe about dark matter and quantum gravity, and the way its answer options were drawn shapes what those percentages can prove.

The Scientist · Science desk

What happened

The largest global survey of physicists ever conducted, released on September 13, 2026 by the University of Waterloo and Perimeter Institute, found the standard cosmological model ΛCDM short of majority support.
Only two of the survey's questions drew majority agreement: 68% said the Big Bang does not necessarily represent the beginning of time, and 51% agreed the early universe went through inflation.
On quantum gravity, string theory took the most support at 19%, 18% said gravity cannot be quantized at all, and loop quantum gravity took 12%.
Researchers reported similar spreads across black holes, dark matter, and the effort to reconcile Einstein's gravity with quantum mechanics.

Compiled by The ScientistSomething wrong?How this is made

Why it matters

constraint A single-choice question with many credible options holds every answer down, so these percentages bound how much the survey can say about agreement, separately from what physicists actually think.
exposure Coverage that leans on consensus language about particle dark matter now has a countable figure to answer to, and the figure sits below a fifth of respondents.
contradiction Afshordi cautions that truth is not settled by a vote, and also reads the absence of consensus as a signal about the evidence. A reader is left with two different weights to give the same poll.

The largest single answer on the dark matter question, at 21%, is the one that declines to name a mechanism: some combination of the many proposed explanations ^[9]. A respondent who picks that has not ruled out particle dark matter. So the 17% recorded for an undiscovered low-mass particle counts the physicists who picked particles on their own ^[7]^[9], not the share of physicists who think particles are involved ^[7].

The three dark matter options named in the release add to 50 of the 100 points available ^[1]. Half the responses went to answers the release does not list, and because 21% was the largest single group, none of those unlisted answers ran above it ^[9]^[1]. Quantum gravity divides the same way: the three options named there add to 49% ^[2].

The other 51% has to sit in at least three further options, since string theory's 19% was the most any single answer received and 51 divided by 19 is a little under 2.7 ^[10]^[3]. This is what a single-choice question with many live options does to majority thresholds.

The release leaves out the number of respondents, their subfields, the recruitment method, and the percentage that backed ΛCDM ^[16]. That last figure is the one it links to the Dark Energy Spectroscopic Instrument, whose results suggested dark energy could change over time, where the standard model assumes it stays constant ^[13].

Afshordi, who led the survey with coauthor Phil Harper and the American Physical Society's Physics Magazine, said: "The interesting point is not that physicists are confused. It is that the frontier is genuinely alive." ^[3]^[14]

Both of the answers that cleared a majority concern what a theory claims. The Big Bang theory describes how the universe developed from an extremely hot and dense state, and does not by itself explain whether time had an absolute beginning ^[17]. Agreement on that is agreement about the content of a model, which is a different thing from agreement about which model is right. Afshordi said: "Scientific truth is not decided by a vote. But consensus, or its absence, tells us where the evidence feels settled and where researchers still see room for radically different ideas." ^[15]

What to watch

Publication of the full survey with the sample size, subfield breakdown, and the exact wording and option lists for each question.
Further DESI data releases that either firm up or weaken time-varying dark energy, which is the evidence the release ties to the ΛCDM answers.
Whether Physics Magazine repeats the survey, giving a second time point to compare these percentages against.

Claim ledger

Ranked by verification strength, evidence, and original report placement.

[1]
The largest global survey of physicists ever conducted found surprisingly little agreement on questions including black holes, dark matter, and the effort to reconcile Einstein's theory of gravity with quantum mechanics.
ReportedSupportedView cited source
[2]
ScienceDaily dated the release September 13, 2026, and credited the University of Waterloo and Perimeter Institute as the source.
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[3]
Niayesh Afshordi, associate faculty member at Perimeter Institute and professor at the University of Waterloo, led the study with coauthor Phil Harper and the American Physical Society's Physics Magazine.
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[4]
The standard model of cosmology, ΛCDM (Lambda Cold Dark Matter), failed to win support from a majority of respondents.
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[5]
Across the questions included in the survey, only two received majority agreement.
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[6]
68% of the physicists surveyed said the Big Bang does not necessarily represent the beginning of time.
ReportedSupportedView cited source
[7]
On dark matter, only 17% favored the idea that dark matter is made of a yet undiscovered low-mass particle or particles.
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[8]
Another 12% supported modifications to the theory of gravity as the explanation for dark matter.
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[9]
The largest single group on the dark matter question, at 21%, favored some combination of the many proposed explanations.
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[10]
String theory received the most support on quantum gravity, but only 19% of respondents selected it as the most likely solution.
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[11]
Loop quantum gravity received 12% support.
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[12]
18% favored the possibility that gravity cannot be quantized at all.
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[13]
The release says the ΛCDM result may reflect recent findings from the Dark Energy Spectroscopic Instrument (DESI), which suggested dark energy could change over time, a possibility that would conflict with the standard model's assumption that dark energy remains constant.
ReportedSupportedView cited source
[14]
"The interesting point is not that physicists are confused. It is that the frontier is genuinely alive," Afshordi said.
ReportedSupportedView cited source
[15]
"Scientific truth is not decided by a vote. But consensus, or its absence, tells us where the evidence feels settled and where researchers still see room for radically different ideas," Afshordi said.
ReportedSupportedView cited source
[16]
The ScienceDaily release does not state the number of respondents, their subfields, the recruitment method, or the percentage of respondents who backed ΛCDM.
ReportedSupportedView cited source
[17]
The Big Bang theory describes how the universe developed from an extremely hot and dense state and does not, by itself, explain whether time had an absolute beginning.
ReportedSupportedView cited source
[18]
Just 51% agreed that the early universe experienced an extremely rapid period of expansion known as inflation, the second point to cross the majority threshold.
ReportedSupportedView cited source
[d2]
The three quantum gravity options named in the release account for 49% of responses, leaving 51% elsewhere.
DerivedSupported2 sources— sign in to open
[d3]
If responses were single-choice and no option exceeded string theory's 19%, the unlisted 51% must be spread over at least three further options.
DerivedSupported2 sources— sign in to open
[d1]
The three dark matter options named in the release account for 50% of responses, leaving 50% with options the release does not list.
DerivedSupported1 source— sign in to open

Sources

Publishers with included, body-backed reporting in this cluster.

sciencedaily.com
1 article · September 13, 2026
Physicists can’t agree on how the Universe works

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Clarity analysis

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Perspective Coverage

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For anyone working on these problems the usable content is the ranking. String theory leads quantum gravity at 19%, and on dark matter the biggest single answer, 21%, is "some combination" of the proposals. ScienceDaily's version of the release prints those numbers and nothing about how the answer options were written, so a reader cannot tell whether the combination option won because it is a position people hold or because it collects what the other choices left out. Half the dark matter responses, and 51% of the quantum gravity responses, sit in options the release never names.

Reality

Evidence, adoption, hype gap, incentives and confidence, each read independently from the current record on the scale shown beneath it. How these are measured.

Evidence45

0100

Precise figures, one route to them

The percentages are specific and they add up cleanly: 50% across the three dark matter options, 49% across the three quantum gravity options. The release does not say how many people answered, break the respondents into subfields, or explain how they were recruited, so 17% for a low-mass dark matter particle is a share of an unknown group. The Physics Magazine article and the dashboard that would settle this are cited in the release but not present in our coverage.

AdoptionInsufficient

Nothing to count

A survey of what researchers believe has no releases, deployments, or users behind it, and our coverage records none of those.

Hype gap+20

−100 understated0 aligned+100 overstated

Headline outruns the sample

The headline, "Physicists can't agree on how the Universe works," claims more than the percentages underneath it support. The results themselves are reported carefully and Afshordi is explicit that a vote settles nothing. But the release calls this the largest survey of its kind without stating its size, and on the two questions it treats as most divided it prints options covering only about half the answers.

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