Visitors gather at a new plaza at CERN on 28 September. Credit: Rachel Lavy, Julien Ordan, and Maximilien Brice/CERN

Hundreds of scientists who work in high-energy physics and related fields have signed on to a statement that denounces and refutes a physicist’s presentation at a CERN workshop last week on gender and equal opportunity in high-energy physics. University of Pisa theoretical physicist Alessandro Strumia has already been suspended from CERN, where he is an invited scientist, and is under investigation by his university.

“As particle physicists, we are appalled by Strumia’s actions and his stated views on women in high-energy physics,” says the 19-author statement, which was posted at particlesforjustice.org on 4 October. As of 4:00pm on 5 October, the document had more than 1600 signatures.

In his 28 September talk, Strumia presented suspect evidence and sweeping, inaccurate assumptions to attribute the relative shortage of women in physics to differences in interests and innate ability, before concluding that “physics is not sexist against women.” He argued that he had more citations than a woman who beat him out for a job and a woman on the hiring committee—and he named the two women.

On 30 September CERN removed Strumia’s slides from its website, citing a violation of the organization’s personal code of conduct. The next day it suspended Strumia from activity at CERN and promised to conduct an investigation. The University of Pisa announced that it has opened an ethics investigation, and European Research Council president Jean-Pierre Bourguignon said he would contact CERN to look into the matter. Strumia received a five-year grant from ERC in 2015.

The statements by CERN, the University of Pisa, and ERC highlighted the inappropriateness of Strumia’s presentation. The new letter from his peers goes further by refuting the theorist’s “fundamentally unsound” scientific case. Coauthor Chanda Prescod-Weinstein, a University of New Hampshire physicist who has extensively researched bias in science, says her fellow authors were already working to expose Strumia’s flawed arguments when she got involved.

The statement cites multiple studies, including a recent report by the National Academies of Sciences, Engineering, and Medicine, finding that factors such as discrimination and innate bias drive talented women out of academia. (For more on those biases and what physicists can do to combat them, see the article by Jennifer Blue, Adrienne Traxler, and Ximena Cid, Physics Today, March 2018, page 40.) The authors add that views like Strumia’s make the climate even more difficult for scientists of color, gender minorities, and other underrepresented groups.

The letter also criticizes Strumia for relying on questionable metrics such as citation counts as an indicator of research quality and, to compound the problem, for not taking into account external factors that skew those metrics. For example, past studies have found that men are more likely than women to cite themselves and that women physicists tend to have access to fewer resources, such as lab space and telescope time, than their male counterparts. “Ultimately, answering questions of cause and effect is subtle and requires carefully designed studies,” the authors write.

The letter does not address whether Strumia should be fired.

Other institutions and physics departments have responded to the incident. In one statement, the LIGO and Virgo gravitational-wave collaborations recognized “the challenges faced by scientists who belong to under-represented groups” and celebrated the staff members “who identify as women, transgender, intersex and/or gender-diverse.”

Prescod-Weinstein says that publishing the letter is a critical development in high-energy theoretical physics, which is “notoriously one of the least diverse areas of physics.” She adds, “This is a hint of the future, if we continue to work hard and recognize that ‘science’ isn’t just calculations but also who is in the room doing them.”