One reason why advanced life may be extremely rare
While discussing possible alien explanations for the insterstellar object ‘Oumuamua, astrophysicist Avi Loeb agrees that there is greater resistance to considering the existence of advanced life in the universe, as opposed to primitive life, though he thinks it is a “psychological barrier” (13 February, p 46). Surely it is a real barrier: one between chemistry and physics.
Beyond primitive life, complexity demands information; information demands power. The “mitochondrial event” on Earth 鈥� the symbiosis between two cells that led to much greater complexity 鈥� happened long after primitive life began. Each blossoming of life must cross this barrier to have a hope of sentience. With no mitochondria or similar, there can be no Dyson spheres.
This seems to be a more significant event than the emergence of life itself, and a barrier that is yet to be evaluated in the search for intelligent life elsewhere.
Native plants may be the enemy of climate efforts
James Wong is correct when he asks: “What’s so great about native [plants] anyway?” Here in New Zealand, there is a strong bias toward native species (30 January, p 24).
What is sad is that this emphasis could harm carbon capture efforts, which are trumpeted by politicians at all levels. Our native trees are very long-lived, lasting many hundreds of years, and grow very slowly when they are seedlings -exactly the opposite of what is needed for rapid carbon dioxide removal. There are much better alternatives, but they aren’t native species. More science and less politics are required on this issue.
Perhaps this virus variant isn't such a disaster
What are we to make of the small study in South Africa that found the Oxford/AstraZeneca covid-19 vaccine doesn’t prevent mild or moderate illness from the B.1.351 variant found there? The South African health minister’s decision, on 7 February, to put the vaccine’s roll-out in the country on hold seems to be based on the assumption that it isn’t very effective for this variant (13 February, p 7).
It seems unlikely, however, that the vaccine would only prevent severe infection. A more likely explanation is that it reduces the severity of nearly all cases, so that people who might otherwise have had a severe illness only get a moderate one and that people who might otherwise have had a moderate illness get a mild one. If so, then the sooner the vaccine is rolled out there, the better.
Herd immunity level may be location-specific
It doesn’t make sense to try to put a percentage figure on the achievement of herd immunity to covid-19 (23 January, p 12). Going to the extreme for illustration, in a sparsely populated country where you rarely interact with other people, your chance of getting covid-19 is slim, even if the incidence is somehow high.
On the other hand, in a country where you are shoehorned together on trains and in markets, you are more likely to catch the virus if even a small percentage of the population is infectious. We need some measure of how often you are likely to breathe in the air expelled by a fellow citizen multiplied by the incidence of the virus in the population.
Let's equip the world to produce vaccines
Rather than the industrialised West supplying vaccines to low-income countries, we should spend some money helping them build the facilities to self-supply, which would produce long-lasting economic and employment benefits at the same time (6 February, p 21).
If you can't hug a person, try hugging a tree instead
The article “How to give your vaccine a boost” mentions hugging, which is tricky right now (13 February, p 8).
Green hydrogen push could save us trillions
Your look at the pros and cons of using hydrogen as a fuel was great, but it failed to delve into the positive impact on the UK’s balance of payments (6 February, p 44). Investing billions into truly clean hydrogen could save trillions by reducing imports of oil and gas.
Free public transport: Let me tell you about subsidies
Roger Elwell writes that, as a non-city dweller, he would be unhappy to see his taxes pay for free travel in the likes of London (Letters, 13 February). He appears to be perfectly happy, however, to take advantage of cost-inefficient rural highways and services, all 鈥� inevitably 鈥� subsidised by those who live and pay taxes in high-density urban centres. If the UK is to work for all of us, sometimes it is necessary to think a little further than your own doorstep.
Please don't rely on an AI to raise Rover
Artificial intelligence may be great for specific tasks, but teaching your dog to sit isn’t one of them (23 January, p 17). Dogs, like humans, undergo brain maturation at specific time periods during development. If this doesn’t happen, they won’t be emotionally well-adjusted.
If you don’t have a bit of spare time each day to train your dog with some treats, you shouldn’t be allowed to own one.
A tasty solution to the Australian carp issue
The problem of carp in Australian rivers has one simple solution: eat them (13 February, p 20). Baked carp is an excellent dish. Your correspondent Sam Wong could provide a recipe.
Considered alongside the article on the fishing industry in the same issue (p 36), it seems cavalier to throw away a source of maybe 40,000 tonnes of fish per year whose production would produce no extra carbon dioxide.