Forget the Fountain of Youth.

Tech titans, crypto bosses, AI researchers, investors, and so-called “immortalists” are showing support for “longevity escape velocity,” the controversial theory that people could live indefinitely by extending their remaining life expectancy faster than time passes.

“Now that doesn’t guarantee you living forever,” computer scientist and futurist Ray Kurzweil explained in March. “You could have a 10-year-old and you could compute that he’s got many, many decades of longevity, but he could die tomorrow.”

Kurzweil, 76, argues that medical research — especially vaccine development — is progressing quick enough that you get back about four months of longevity a year. Technological advances — such as self-driving cars — will also help cut down on the number of accidents and deaths, he contends.

The former Google engineer predicts that by 2029, people will get back a full year of longevity.

“Past 2029, you’ll get back more than a year. Go backwards in time,” Kurzweil continued in his conversation with the venture capital and private equity firm Bessemer Venture Partners. “Once you can get back at least a year, you’ve reached longevity escape velocity.”

The term is not new, but it gained steam last year with the Dublin Longevity Declaration. As part of the pledge, leading longevity scientists called on world leaders to immediately expand research to improve health span and lifespan.

“We wanted to put this out there because everyone knows aging is bad, everyone says it’s bad, but nobody does anything about it,” gerontologist Aubrey de Grey — president and chief science officer of the Longevity Escape Velocity Foundation, which aims to prevent age-related disease — said in an October statement.

“Like bad weather,” de Grey added, “people are stuck in the assumption that nothing can be done, even if we try. We wanted to put that assumption to rest.”

Life expectancy in the US has slowly started to rebound from the COVID-19 pandemic. The overall US life expectancy at birth was 77.5 years in 2022, a rise from 76.4 years in 2021.

Still, the increase wasn’t enough to overcome the loss of 2.4 years between 2019 and 2021.

Heart disease, cancer, unintentional injuries and COVID-19 are the leading causes of death in the US.

It’s rare to see an American reach 110 years of age to become a supercentenarian. Houston woman Elizabeth Francis, 114, is the oldest living person in the US.

Dr. Thomas Perls — director and founder of the New England Centenarian Study, which explores the lifestyle and genetic factors that contribute to longevity — said the focus should be on battling age-related disorders like Alzheimer’s, not trying to live forever.

“We want to do what we can do to delay or even avoid aging-related diseases that may increase life expectancy or life span a little bit for people,” Perls told Insider last year.

“But in no way do I think that’s going to lead to the notion of living forever,” he added.