Global Physicist Survey Finds Little Consensus on Dark Matter, Quantum Gravity

A global survey of physicists — billed by its authors as the largest ever conducted in the field — has found strikingly little agreement on some of physics' biggest open questions, including dark matter (the invisible material thought to make up most of the universe's mass), black holes, and quantum gravity (the unfinished effort to unite Einstein's gravity with quantum mechanics). Even the standard cosmological model — ΛCDM, or Lambda Cold Dark Matter (CDM), the leading picture of how the universe is composed and has expanded — failed to win majority support among respondents.

The survey was led by Niayesh Afshordi, associate faculty member at the Perimeter Institute and professor at the University of Waterloo, with coauthor Phil Halper and the American Physical Society's Physics Magazine. Only two questions drew majority agreement: 68% of physicists said the Big Bang does not necessarily mark the beginning of time, but only describes how the universe evolved from an extremely hot, dense state. A narrow 51% majority agreed the early universe went through a brief period of rapid expansion known as inflation.

On dark matter, the most common response (21%) favored a combination of several proposed explanations rather than a single one, while smaller groups backed undiscovered low-mass particles (17%) or a change to the theory of gravity itself (12%). For quantum gravity, string theory remained the most popular idea but was backed by only 19% of respondents; loop quantum gravity drew 12%, and 18% said gravity may not be quantizable at all.

One possible reason for the fading confidence in ΛCDM is that findings last year from the Dark Energy Spectroscopic Instrument (DESI) suggested dark energy — the force thought to drive the universe's accelerating expansion — might change over time, contradicting the standard model's assumption that it remains constant. The study was published on arXiv on May 10, 2026, by Afshordi, Halper, Matteo Rini and Michael Schirber.