Physicist dismisses tech billionaires' quest for immortality as a waste of time

He noted that some individuals are turning to unregulated peptide injections, cold plunges, and supplements to defy aging, while the ultra-rich are aiming for immortality with more drastic interventions. Tech chief executive Bryan Johnson has even tried injecting plasma from his 17-year-old son, though he later stated he saw no benefit from it. Johnson is described as the world's most measured human.

Al-Khalili's fascination with time stems from childhood, and his physics training revealed that the common-sense view of time differs significantly from its conception in physics. He referenced Albert Einstein's theories, explaining that time does not run at the same rate for everyone, varying with speed and gravity. Einstein also theorized that all times—past, present, and future—coexist, similar to points in space, though we only experience the present moment.

The physicist plans to explore time travel in his Christmas lectures, noting that mathematically, it is possible to travel back in time through "closed time-like curves" in spacetime, though paradoxes make it unlikely. Traveling to the future, however, is theoretically easier by slowing down time through high speeds or strong gravitational fields, as depicted in the movie Interstellar.

Al-Khalili will also address the long-standing scientific conundrum of why time only seems to flow in one direction, despite fundamental equations suggesting no preferred direction. He claims to have found an answer to this problem, which he will reveal in the Christmas lectures, supported by CGI and broadcast on the BBC and iPlayer in late December.