Terraform Mars? That's a definite no
I noted that Alex Wilkins left the most important question to the final sentence of his piece on terraforming Mars: should we? Well, of course not. The urge to spread destructive humanity across the cosmos is merely the 21st-century equivalent of European explorers seeking to solve the problems of overexploited Europe by conquering new lands. We should be concentrating all our efforts on devising ways to exist on this one planet in total harmony and equilibrium for the entire foreseeable future (17 August, p 16).
Sedentary childhood: the problem is the parents
Good to see the hype about screen time deflated and the question of a more sedentary childhood dealt with. A missing factor is restrictive parenting. When I was a child under 10 (early 1950s), I was totally free to roam the streets or the countryside with my friends. Nobody questioned it and you can’t have a sedentary lifestyle if you are out there having fun (22 June, p 31).
The thought of today’s children going out in the streets without an adult seems inconceivable. Why? There are no more dangers than when I was young. Parents, not screen time, are the problem.
Roast dodo? It was revolting, apparently
Charles Joynson asks whether bringing back the dodo will put the bird on the menu. That isn’t very likely, I guess. In 1974, Dutch author Jan Wolkers published his novel De Walgvogel. The title refers to the dodo, which Dutch sailors found on Mauritius and hunted for food. They found the flesh not very tasty. “Walgvogel” translates to “disgusting bird”. So it is unlikely the dodo was eaten to extinction by humans (Letters, 3 August).
We lack knowledge to fully assess human family tree
Modern palaeoanthropology and archaeology can be misleading, I would suggest, and classification of “post-primates” like us and “prehistoric man” is confused (3 August, p 32).
As we devise post-primate species and genus from a scattering of bones and stones, we can’t see speech or family structures and dynamics that may be more significant in our classifications. Also, “primate” features among Homo of earlier varieties or species means we will put them at an earlier or more primitive phase in human development. The post-primates we are studying may well have had many different forms, hence confusion will be endemic.
We lack the knowledge to be able to offer a sound classification and understanding of human and putative post-primates.
A better measure of fairness in sport
The universe is abnormal, in that measurements of most things don’t fit a normal curve, where the mean (average) and the median (typical) are the same. So your editorial’s claim that it is “unfair” that bigger countries win more medals is irrelevant. Perhaps a metric such as medals per million people would be better (Leader, 3 August).
Get scrubbing to get your exercise
Scanning “The smarter way to a fitter you”, I discovered a comprehensive account of most aspects of exercise. However, apart from home-based game playing and pedometer measures, there was no mention of domestic work (27 July, p 32).
There seemed to be a theme of avoiding boredom in exercise pursuits, and maybe that is why domestic activity wasn’t featured. Getting out of sitting or prone positions to do cleaning, tidying up, attending to pets or plants regularly is good for health. In fact, a recent British Medical Council study of 4563 Northern Ireland adults found that many of them met or exceeded the UK standard of moderate to vigorous physical activity thanks to domestic work.
No real chance of time flowing backwards
Dave Johnson wonders if time can flow backwards in some small pockets of space, given increasing entropy equates with time’s arrow. This shows how intuition fails with huge and tiny numbers. When two atoms bounce off each other elastically, their energies tend to be more equal afterwards (increased entropy). When, by chance, they are less equal, it means there has been a tiny reduction in entropy. But the odds that the total entropy of many such atoms would detectably decrease grows rapidly smaller as the number of atoms increases, soon becoming unlikely in several universe lifetimes (Letters, 20 July).
In favour of weight-loss drugs for older children
When I read that the American Academy of Pediatrics was recommending weight-loss medication for children aged 12 and up, my moral stance on this initially made me cringe. However, after completing the article, I support this idea despite reading contradictory advice from the US Preventive Services Task Force, which cites insufficient evidence and suggests long-term studies. The covid-19 vaccines have proven that if the good of treatment outweighs the potential harm, use shouldn’t be precluded (6 July, p 8).
Let's call it what it is: so-called AI
As the article “Super AI is still sci-fi” noted, the term “artificial intelligence” is little more than a good branding exercise. This is much more attractive to investors than using facts about machine learning pattern recognition algorithms with more powerful graphics processing units. When it comes to “AI”, there is nothing approaching “intelligence”, so why not flag this as “so-called AI”(27 July, p 17)?
Try kangaroo to cut livestock methane
A vaccine to stop cows burping methane is very ingenious. But wouldn’t it be simpler to farm animals that eat grass and don’t burp or fart ? They are called kangaroos (10 August, p 16).