Besides, even if anti-ageing techniques eventually proved successful, what would be the social and cultural consequences of literally pathologising old age? If we lived much longer, would we also be expected to work indefinitely? How would the planet cope with a hugely increased population, and who would be first in the queue? I think I know some of the answers to the last two questions. They resonate with the negotiations currently going on in Glasgow, and the lifestyles of some of the people gathered there. As my colleague George Monbiot recently pointed out, keeping the average rise in global temperatures to 1.5C demands that each of us is responsible for no more than two tonnes of CO2 a year, whereas the richest 1% of the world’s population are on track to produce an average of more than 70 tonnes a head. Imagine such people jetting around until they were 140, or 200, or even existing forever.

There is something about all this that feels analogous to the space travel efforts of Bezos and Elon Musk, and what those projects seem to say about a relative lack of attention to some urgent issues playing out on the planet that the two men apparently want to escape. In the same way, sizeable investments in attempts to eventually cheat death risk neglecting aspects of ageing that we all face right now. Some of these are about specific illnesses and conditions often linked to getting older. (Bezos, in fairness, has also contributed to dedicated work on cancer and dementia, though I dare say even more help would be welcome.) But there are equally urgent questions centred on people’s everyday lives – and potential answers that could certainly do with more help from self-styled philanthropists.