Longevity expert Stephen Cave explains to Guyon how living to 150 years old could soon be a reality, and why the consequences of immortality would be horrific for all aspects of our world.

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The ancient quest for human immortality has collided with ultra-modern developments in biology and AI. Billion-dollar start-ups, funded by tech moguls, seek to add decades to human life.

But philosopher and writer Stephen Cave, a researcher at Cambridge University in Britain, says life extension technology is fraught with ethical problems.

Guyon Espiner talked to Stephen about why we need to start taking the promise of extending our lifespans seriously.

"The claim that we're on the verge of defeating ageing or disease is an ancient one, as old as human history. Ancient Egyptian papyri were talking about the elixir of life. Mummification was just a backup plan for them. Throughout history we see these kinds of claims repeated, over and over again, and the one thing that all these people who claim to have found some kind of rejuvenation elixir have in common, is that they're now all six feet under pushing up daisies."

"So why should we think this time is different? Well, I think there are a number of reasons. One of them is the reality of scientific and technological breakthroughs. Life expectancy has doubled in the last 150 years from around 40 to around 80 or so in industrialised countries."

"Now, a lot of that has been from tackling infant mortality. If a lot of people die very young in their first few years, then that pushes down the averages. In industrialised countries, since the 1950s, life expectancy has continued to creep up at about two years per decade. And that's through treatments at the end of life - making cancer diagnoses that would have rapidly been terminal manageable and heart disease and so on."

"Life expectancies are genuinely creeping up to unprecedented levels. And right now, there are vast amounts of money and huge amounts of talent being poured into the anti-ageing research industry."

The modern quest for the Fountain of Youth is being driven by billionaires with money to spend

"They might make breakthroughs, but whether it's in time for them to achieve what they want, who knows? Because there is a very long history of the super-rich and powerful investing their resources into the pursuit of anti-ageing. It is the one thing that insults their power, the one thing that right now, money can't buy. They're still getting older. …

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