Elon Musk is set to appear at the Google plex next month, not to talk electric cars or space exploration but to address a burgeoning movement of nerd altruists.

The Tesla and SpaceX founder will speak at Effective Altruism (EA) Global , a gathering of far-flung technologists, entrepreneurs, students and activists who use data and reason to determine the most effective ways to improve the world.

Effective altruists say theyre trying to do as much good as possible with each dollar and each hour that we have. Put another way recently in The Atlantic, the movement is injecting science into the sentimental issue of doing good in the world.

That means, for instance, figuring out precisely which causes will bring about the greatest positive impact (e.g. distributing bed nets to halt malaria or funding microloans in poor countries?). It means determining which charities to support to accomplish the maximum benefit per dollar spent. And, for a movement flush with millennials, it means deciding on a career path that will maximize ones lifetime social impact.

Groups devoted to each of these aspects of effective altruism (and a variety of others) have sprung up in recent years. Their efforts are increasingly well-funded by supporters from quantitative fields like tech and finance who care about social justice, have money to spend, and want hard evidence that theyre making a difference.

One prominent EA organization called GiveWell rigorously researches the most effective and low-cost strategies to reduce extreme poverty (turns out bed nets are a great investment, microloans not so much), then identifies nonprofits employing these strategies that are evidence-backed and underfunded. GiveWells largest donor is Facebook co-founder Dustin Moskovitz, and last year the group moved $28 million to its recommended charities. A related EA organization, Giving What We Can , has fostered a community of people who pledge to give 10% or more of their lifetime income to effective charities.

A newer effort called 80,000 Hours (named for the typical amount of time people spend working during their lives) offers guides and coaching to young people to help them maximize the social impact of their career choices. In some cases, the group encourages an unorthodox practice called earning-to-give that is, rather than working directly on a social cause, youd seek a high-income job specifically so you can donate a large portion of your salary to charity.

Another big focus of the EA movement is assessing catastrophic risks to humanityevents like global pandemics whose probability is low but whose results could devastate civilization. At the conference next month, Elon Musk will discuss his view that the biggest existential threat to humanity is advanced artificial intelligence.

Hes almost the perfect effective altruist.