On the evolution of the menopause (1)
Historical life expectancies reflect infant and child mortalities much more than adult lifespan. In other words, a woman who had lived until menopause at 50 would probably live for 20 more years to the biblical three score and 10. So, while I am not denying the value of grandmothers (let’s be clear that we benefited from them and now so do our children), in ancient societies with no contraception, a woman was likely to have children up until menopause and therefore had to live 20 years longer just to support her own offspring. So, the surprising post-menopausal lifespan could be more to do with this (27 January, p 30).
On the evolution of the menopause (2)
“Mysterious you” presents a fascinating argument for the evolution of menopause in women. However, the question remains why evolution has permitted men to continue the possibility of procreation into older age. Perhaps it has done its best to hamper this with a shorter lifespan.
Menstrual labels might face resistance in the US
Jen Gunter’s comment on the reluctance to market menstrual products using that word is sensible, helpful and represents the world I want to live in. But I am in the US, where half the people believe that anything that appeals to liberals is wrong, unacceptable, literally taking dictation from the devil and to be fought against by any means. What are merchants to do, knowing that using the right word, “menstrual”, will result in demonstrations, boycotts and interfering laws? Maybe the UK can give it a try and let us know how it goes.
Long-term survival? No brain required (1)
In believing that humans will still exist in billions of years, several readers attribute differing degrees of faith in our mental agility to see us through the death of the sun. However, big-brained Homo sapiens has been around for less than a million years, whereas jellyfish have chalked up over 500 million with no brain at all. So, as in some corners of society, airheads may trump brains after all (Letters, 3 February).
Long-term survival? No brain required (2)
Assuming humans survive into the far future and continue to develop technologically, I reckon we will be able to construct and maintain a system of shields situated at a stable point between Earth and the sun that would reduce solar radiation reaching us and enable an ideal temperature, buying us at least some time before our star goes red giant.
Let the AIs help us in search for aliens
In NASA’s search for the biosignature of life on other worlds, could artificial intelligence help? When considering life’s chemical origins, two relatively simple structures that appear to have self-replicating properties are prion proteins and types of RNA. For life to get going, these would need suitable substrates on which to develop. We might be guided to even simpler self-replicators and substrates by AI (3 February, p 9).
Free buses may not reduce motor traffic on the roads
Merlin Reader advises free public transport as one way to have fewer cars on the roads. I advocated that for years, but then learned that it has been implemented in some French towns, and the result wasn’t less car use. The people who used the free transport were those who would normally walk or go by bike (which means they got less exercise!). I think we need more of a carbon tax (Letters, 30 December 2023).
Echoing your call to end neglect of women's health
As a menopausal woman of 54 and a mother, I was gratified to read your editorial on the unequal treatment of women’s health issues. Last year, I 鈥� and the many hundreds of thousands of women who have had to struggle to get an appropriate treatment for this “natural” phase of our lives 鈥� was met with the news that one of the most efficient and convenient options, dermal patches providing oestrogen, was going to be next to impossible to obtain for the foreseeable future (Leader, 6 January).
So, while the market sorts itself out, we women know that if this were an erectile dysfunction drug or got rid of wrinkles, there would be no end of money thrown at it. If that isn’t enough to spark menopausal rage, I don’t know what is.
Will moon gravity affect quantum consciousness?
Roger Penrose and Stuart Hameroff propose that consciousness arises when a gravitational field causes quantum wave functions in microtubules in our neurons to collapse, so-called orchestrated objective reduction. The gravity on the moon is a sixth of that on Earth. So, if the idea were correct, we would have expected to see consciousness changes in lunar astronauts. As far as I am aware, none was observed. Perhaps the Artemis programme could investigate this (20 January, p 32).
There are ways to solve hydrogen fuel problems
The shortcomings of using hydrogen as a fuel that were summarised in your article, relating to efficient and stable storage and transport, can be addressed by using chemicals that combine with the hydrogen, called liquid organic hydrogen carriers. These were successfully trialled during the recent European Union-funded HySTOC project. In addition, the technology relating to turquoise hydrogen, in which the gas is produced from methane without releasing carbon dioxide, has now reached what is known as technology readiness level 9 at the Olive Creek plant in Nebraska. That level indicates the most mature technologies (3 February, p 32).
For the record
Joachim Moortgat at the Ohio State University contributed to work to identify natural hydrogen deposits via soil circles (3 February, p 32).