Letters archive

Falling birth rates will bring many social and economic problems, but are absolutely necessary for the environmental health of the planet. Loss of habitat, ocean pollution, carbon emissions and many other environmental problems have accelerated in step with population growth. With population decline, we must shift from an economic model that requires continual growth to …

Surely the problem of greater numbers of older people needing to be supported in every way by diminishing numbers of younger people will be a transient one. As more-populous older generations die off in the next few decades, they will be replaced by smaller, later generations and, in a relatively short time, a new equilibrium …

I can easily envisage a world of healthy, happy older people where everybody is active and works until they are 80 and old age is seen as being in your 80s and 90s. The hard physical work would, of course, have to be done by younger adults, with help from robots, but the less arduous …

Eco-anxiety is a new concept, but it is closely linked to another known as solastalgia , which The Lancet included in 2015 as a term related to the impact of climate change on human well-being. It defines the set of psychological conditions that occur in a population after destructive changes in their territory, whether as …

Could it be that parental overuse of smartphones, rather than their use by children, has something to do with the increase in anxiety in young people? There is a lot of evidence that attuned noticing by and interaction with attachment figures is crucial to child development and mental health. Parents matter more than school, peers …

You highlight the benefits of time alone. I have found that if you have a problem that requires thought and analysis, solitude is often your best friend. In my career, the best ideas and solutions occasionally arose in conversations with colleagues, but more frequently during a period of solitude, whether in an office, at home …

Focusing on the physical palaeo-anthropological record in the story of how human childhood and adolescence became so prolonged neglects what is perhaps the lengthiest task a child has: mastering language. It takes around 20 years for an acceptable competence to embed itself in the neuro-architecture of our brains and to acquire enough factual and conceptual …

I propose that, on some bizarre-but-possible meta-level, all the weird theories of quantum mechanics, panpsychism and simulated realities that Eric Schwitzgebel lists exist and are simultaneously useful. All are true, all are bizarre and all are dubious. We probably won't ever be able to "choose" between them anyway since they are, on a level we …

If we accept that our experience of reality is a simulation created by our brains, then the "self" must be part of the simulation. To ask whether we live "in" a simulation is a category error. We live as a simulation, not in one.

Quantum and wave mechanics, together with relativity, were developed to explain physical phenomena that had otherwise defied explanation. They have been spectacularly successful at describing particle/wave properties and behaviour, which is what they were intended to do. It really comes as no surprise that trying to extract sense from these mathematical constructs about more complex …

Sam Edge's correspondence and Alison Flood's insightful interview with Tali Sharot ( 2 March, p 40 ) both focus on habituation to negative signalling. But becoming inured to misleadingly optimistic scenarios can be just as dangerous ( Letters, 30 March ). To give just one example, the notion of interstellar travel is chimerical, and discussion …