Google's chief scientist is leaving after 27 years to build AI that can run its own research cycle with little human help.

Jeff Dean was employee 30, and he wrote the storage and computing systems that showed the rest of the industry how to serve a global audience.

He also started Google Brain in 2011 and drove the TPU units. His new firm is called Discovery Loop, after the cycle it wants to automate, which is hypothesis, then experiment, then evaluation of the result.

Dean says whole domains can be computerized that way, so you get more experiments and better ones out of the same year.

It begins by automating machine learning research itself, before moving toward hardware design, drug discovery and clean energy.

Joining him are Sanjay Ghemawat, his collaborator of two decades, plus Quoc Le and Oriol Vinyals from the Brain and Gemini years.

Radical Ventures and Khosla Ventures are co-leading a seed round that is not yet closed, and Alphabet came in as founding investor and cloud partner.

Alphabet will supply their computing power for at least a year, so the four keep frontier-scale hardware without paying to build it.

Google shares fell about 4% on the news.