Gene genius

Lydia got out of bed full of excitement. It was 9 September 2171 - her 150^th birthday! She could hardly wait for tonight's party: all her 225 great-great-grandchildren would be there. Billie Eilish would be on stage, playing hits from her 73^rd album. And there would be a congratulatory hologram from the prime minister of England and Wales, Sir Boris Johnson. Amazing how the old boy kept going!

Humans have always been obsessed with the idea of living for ever. From the Epic of GilgameshA heroic saga written in ancient Mesopotamia, over 3,000 years ago. to Stephenie Meyer's Twilight series, it has inspired countless works of fiction. All sorts of techniques have been tried, from eating goldA fashion among the 16th-Century French aristocracy. to cryogenicsA technique for freezing a person's body in the hope of later bringing them back to life. and injecting old people with young blood. Now, thanks to Jeff Bezos, we might actually discover whether it is possible.

According to a report by Antonio Regaldo in MIT Technology Review, Bezos has invested millions of dollars in Altos Labs, a Silicon Valley company recruiting some of the world's best genetic scientists. "Altos is pursuing biological reprogramming technology, a way to rejuvenate cells in the lab that some scientists think could be extended to revitalise entire animal bodies, ultimately prolonging human life," Regaldo writes.  

A key figure is Shinya Yamanaka, a Japanese scientist who won the Nobel Prize in 2012. He discovered how to instruct mature cells to revert to an embryonic state by adding four proteins.

Altos Labs is also thought to have recruited Juan Carlos Izpisua Belmonte, a Spanish biochemist who applied this technique to living mice. After finding signs of age reversal, he hailed it as a potential "elixirA medicinal or magical potion.  of life".  

The technique, though, has worrying side effects: some of the mice developed tumours. And some commentators question whether people would actually benefit from having longer lifespans.

In Greek mythology, the goddess EosIn Latin mythology her name is Aurora. fell in love with Tithonus, a Trojan prince, and begged ZeusThe king of the gods, known to the Romans as Jupiter. to let him live for ever. But she failed to ask that he be granted eternal youth. As a result, he simply got older and more feeble, until he was finally turned into a cicadaAn insect similar to a grasshopper, known for the loud clicking sound it makes..  

Even if our bodies could remain young, there would be an ethical dilemma. In a world which is already overcrowded, should anyone be allowed to live beyond their natural span? And would it be acceptable to have a treatment only available to the rich?

Billionaires are certainly likely to be the first beneficiaries. Larry Page, the co-founder of Google, has also set up a company focused on gene reprogramming. Other entrepreneurs, including Elon Musk, favour an approach in which humans are fused with electronic devices. Russian media tycoon Dmitry Itskov is aiming to create an artificial brain which houses a human personality.

What experts agree, however, is that the science still has a long way to go. According to Felipe Sierra, a former director at the National Institute on Aging in the US, "The bottom line is I don't try any of these things. Why don't I? Because I'm not a mouse."

Would living for ever be a fate worse than death?

Some say, yes. You would live to see the world transformed into an utterly unfamiliar place, devoid of all the things you loved in your youth. You would inevitably be affected by natural disasters and live through repeated recessions and horrifying wars. Even if your friends' lives were also prolonged, you would lose many of them to accidents and disease.

Others argue that, unless you have a strong religious faith, there is nothing to expect after death except annihilation - and anything has to be better than that. Once science is sufficiently advanced to prolong human life, it will also be able to improve it in all kinds of ways. Disease would become largely a thing of the past, and a more prosperous, peaceful world would be created.