Do other conditions share covid-19's immune effects?
You report three studies that indicate covid-19’s adverse impacts on the immune system 15 May, p 10. In particular, Verena Kaestele’s work highlights abnormalities of the innate immune system, with the suggestion that this may contribute to long covid.
Certain long covid symptoms are frequently likened to illnesses such as chronic fatigue syndrome (CFS). Whether people with these kinds of conditions also exhibit similar immune system signs remains largely unknown. It could be argued that these individuals, too, should receive early immune investigation. When I was told I had CFS, I asked for extra immune system tests. This bore fruit and showed abnormally high levels of IgM antibodies, which I was told not to worry about.
Just chill to make negative-calorie celery
James Wong reports that the calorific value of celery after chewing and digesting it is tiny, but not negative as some people believe 22 May, p 24. A few years ago, I read an article that came to the same conclusion, but expanded it by stating that if the celery was eaten when very cold 鈥� close to freezing, in fact 鈥� its calorific value did indeed become negative.
'Alien' plants are already among us (1)
There is much speculation about odd plants on other planets, but arguably such life is already found close to home, often in the garden centre 8 May, p 46. Black mondo grass (Ophiopogon planiscapus ‘Nigrescens’) has black leaves; a type of pore on the leaves of silver saxifrages secretes calcium bicarbonate, possibly as a sunscreen. Perhaps the big idea is that every type of plant that may be on other worlds already exists on our planet in some form today or in the fossil record.
'Alien' plants are already among us (2)
To say “astronomers are in little doubt that a plant-filled planet exists beyond our solar system” may be going too far. A few years ago, speaking of how views on life elsewhere have changed since the 1960s and 70s, physicist Paul Davies said the prevailing view was that its emergence here was a bizarre fluke, an aberration, something that happened in one corner of the universe and simply wouldn’t happen elsewhere. The pendulum, he said, has now swung too far the other way.
The reason to doubt is that we have no theory of the origin of life.
Nature is still better than a surrogate for nature
In her article on the importance of green spaces in urban areas, Kate Douglas paints a picture of accelerated urbanisation 27 March, p 36.
Much has been made of the advantages of urbanisation, but I would argue that this view is becoming outdated. Yes, connectivity and accessibility remain important, but in the 21st century they are no longer solely dependent on physical proximity.
Indeed, in a post-covid world, deurbanisation is possible thanks to the proven opportunities of digitalisation, coupled with clean transport services. This would enable the very real benefits of nature, rather than its urban surrogate, to be enjoyed by more of the population.
On the ancient origins of the alphabet
To say that mystery glyphs look like “early alphabetic letters” is to say that they look like crude versions of hieroglyphs 24 April, p 15. Finding such hieroglyphs in Syria 850 years before reliably dated samples of Levantine alphabetic writing might show not that the alphabet is older than previously thought, but that Egypt was exporting hieroglyphs of all sorts before it exported the monoliteral signs that became the alphabet.
Although less startling a claim than a radical redating of the birth of the alphabet, this would still emphasise the rich trade in abstract ideas that flourished in the eastern Mediterranean more than four millennia ago.
Why might some black holes survive as minnows?
From
You report suggestions that a primordial black hole roughly the size of a grapefruit and several times the mass of Earth is the hypothetical Planet Nine in our solar system, responsible for the orbital alignment of a group of small objects in the Kuiper belt.
This leaves me wondering how a black hole that formed in the first seconds of the cosmos could avoid accreting vast amounts of mass during the recombination epoch soon after the big bang, when this mass was in a universe just a few tens of millions of light years in diameter. I would expect all such black holes that survived to be the giant black hearts of galaxies.
Quantum determinism over the decades
I enjoyed Michael Brooks’s article on superdeterminism 15 May, p 36. Sabine Hossenfelder and Tim Palmer’s idea of a determinate quantum universe warrants comparison with thinking in the 1950s.
Back then, David Bohm argued for a that allows for probabilities to arise from certain “hidden” details, given a universe that began with the right quantum probabilities built in. In this respect, I can’t see how the Hossenfelder/Palmer model differs greatly from that of Bohm.
Other barriers on the road to eradicating malaria
Regarding the work to eradicate malaria 1 May, p 44. My husband was in Uganda a few years ago, and while talking to village elders in a lakeside area, they told him of their frustration with the bed net roll-out. They said that although families had been issued nets, many used them for fishing. It seems they had a choice between going hungry or avoiding malaria. Something else to be considered?
Get cold water's benefits with nice warm water
You reported the benefits of cold-water swimming 13 March, p 46. I shower daily in water as hot as I can stand and feel most of the benefits attributed to cold water. I wonder if this has been researched. In any event, hot water is much more pleasurable.