In late 2018, Google AI researchers Anna Goldie and Azalia Mirhoseini got the go-ahead to test an elegant idea. Google had invented powerful computer chips called tensor processing units, or TPUs, to run machine learning algorithms inside its data centers—but, the pair wondered, what if AI software could help improve that same AI hardware?
The project, later codenamed Morpheus, won support from Google’s AI boss Jeff Dean and attracted interest from the company’s chipmaking team. It focused on a step in chip design when engineers must decide how to physically arrange blocks of circuits on a chunk of silicon, a complex, months-long puzzle that helps determine a chip’s performance. In June 2021, Goldie and Mirhoseini were lead authors on a paper in the journal Nature that claimed a technique called reinforcement learning could perform that step better than Google’s own engineers, and do it in just a few hours.
The results won media coverage and notice in the world of semiconductors. In a commentary on the Nature paper, Andrew Kahng, a professor at UC San Diego, predicted the technique would be quickly adopted by chipmakers. “To long-time practitioners,” he wrote, “Mirhoseini and colleagues’ results can indeed seem magical.” Google’s data centers now contain TPU chips created with help from Morpheus. Samsung and Nvidia have independently said they also use reinforcement learning to optimize chip designs.
Yet in parallel to their success, according to five current and former Google employees, and documents seen by WIRED, Mirhoseini and Goldie spent years fending off a series of unproven claims that their results were wrong or even falsified.
Satrajit Chatterjee, a more senior researcher at Google, used the cover of scientific debate to undermine the women personally, the employees claim. They spoke anonymously because they were not authorized to discuss company matters. Multiple complaints about Chatterjee’s behavior toward the women were made to Google’s personnel department, and he received a written warning, some employees said, but he continued to criticize the women’s results.
The conflict came to a head in March of this year, after Chatterjee sought permission from research managers to publish a public rebuttal of Mirhoseini and Goldie’s Nature study. A committee of senior executives formed to review that paper denied his request, saying its results did not refute the earlier work. The same month, Chatterjee was fired.
On May 2, Goldie posted a document on an internal Google discussion list describing the committee’s rejection of Chatterjee’s paper and accusing him of a series of unproven attacks on the Morpheus coleads and their work. “Sat Chatterjee has waged a campaign of misinformation against me and Azalia for over two years now,” Goldie wrote. “He started a campaign to discredit our work [and] baselessly alleged that Azalia and I fabricated and falsified results.”
The document was posted in a thread where Googlers were reacting to a New York Times article that first reported Chatterjee’s firing, alongside complaints from his attorney that Google researchers were attacking him to shut down a scientific discussion. Most Googlers who joined the thread expressed support for the two women and their work; some current and former Google researchers did so publicly on social media.
Laurie M. Burgess, Chatterjee’s attorney, declined to make her client available for interview and denied he had acted inappropriately, saying he had evidence Google improperly suppressed his work. Burgess said she did not want to share that evidence and did not respond to an email asking detailed questions about Chatterjee’s behavior toward Goldie and Mirhoseini and their project.