Letters archive

James Wong's verdict on the poor efficacy of banana skins as plant fertiliser was spot on. However, it is likely that the widely reported benefits attributed to banana skins for gardeners are down to their polyphenol content ( 11 January, p 44 ). It has been shown that an application of polyphenols can act as …

If quantum computers are accessing the multiverse, as Hartmut Neven suggests, then we must assume that aliens in parallel universes could also have quantum computers. They must also be aware of their making use of other universes' quantum computers. Could this make us lab rats for their experiments( 4 January, p 40 )?

As an energy/carbon engineer for over 35 years, I fully support the "defossilisation" of production of goods. However, why the fixation on capturing carbon from the flue gas of blast furnaces or other hot and highly polluted sources( 4 January, p 22 )? In my career, I have encountered many manufacturing processes, including acid neutralisation …

Name/address withheld on request When it comes to optimism, I am a glass-half-empty person and know why. I now recognise that my mother experienced extreme anxiety, particularly in relation to travel. As a child, holidays and trips would be planned, only to be cancelled at the last moment. I learned to temper my excited anticipation. …

As I understand it, "Backwards computing" asserted that the bulk of heat emitted by computers arises from changes to information in the process of doing calculations. Does this apply to other media? How about a sheet of paper on which difficult sums had been written( 28 December 2024, p 38 )?

You ask if Santa's festive surveillance brings about an improvement in children's behaviour. A 6-year-old granddaughter was being encouraged to behave particularly well in the run-up to Christmas because Santa is all-seeing. When she encountered actual Santa in his grotto, he, not having been properly briefed, made the mistake of asking her whether or not …

Gremlins got into our bumper word search grid (14/21 December 2024, p 37), with Cetus, gray, Puppis, Crux, Lynx, lux, stratus and naledi affected. In computing, AND gates are logic gates that output the product of their inputs ( 28 December 2024, p 38 ).

As the world continues to react at a snail's pace to the threat of climate change, we need to at least start to experiment with geoengineering. The poles are nearing a runaway feedback loop that will forever change the Arctic and, in turn, world weather patterns. Does anyone truly believe our current governments can cut …

You indicate that we can expect more extreme weather with a wavier northern polar jet stream. I suspect this is even more likely when you consider the effects of an apparently weakening Gulf Stream and its interaction with the jet stream. One possible effect of a disrupted Gulf Stream is a cooling of Europe. Maybe …

I was fascinated by your piece on molluscs with distinctive "punk"-like hairstyles, but think you missed a trick by not headlining it: "Never mind the molluscs" ( 18 January, p 11 ).