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I broadly agree with Matt Strassler that the language we use to describe the basic stuff of the universe can obscure our understanding of reality, insofar as we truly can understand reality! I encountered this as a secondary school physics teacher. If not addressed early, conceptual misunderstandings can endure ( 21 September, p 32 ). …

Thank you for highlighting the huge imbalance between the carbon footprints of the wealthiest 1 per cent and those of the rest of us. I have also lost all respect for world leaders of every political shade who continue to fly around the globe to attend conferences that could easily be held on Zoom. While …

When it comes to common sense, it is worth noting that politicians and other public figures often use the phrase in a fairly specific way. In their usage, "it's just common sense" generally means, "I hope you will agree with me although I have no evidence to support my claim and experts in the field …

Your piece on "common sense" focuses on what is common, but the primary quantity is sense. Focusing on sense instead explains most of the conflicts reported, since what each person considers sensible depends on circumstance, experience and the level of risk that they accept. Professional associations recognise the roles of each of these factors in …

The conclusion appears to be that it would be common sense to agree there is no such thing as common sense. Very Douglas Adams.

There is no "brain microbiome" in the sense of a resident microbial community present in the brains of healthy individuals. Instead, microbes enter such sterile tissues through the process of infection. While the role of infections such as Lyme disease in eliciting neurological symptoms may be under-recognised, this is distinct from the idea of a …

James Wong was spot on regarding the poor economics of growing your own produce. But it is important to also consider other, non-economic, factors. These include convenience and flavour – closely linked to freshness. But perhaps most important is the availability of what you want ( 21 September, p 44 ).

There are further factors that could affect city atmospheres and feasibly increase rainfall in urban areas: water vapour released by burning fossil fuels and the use of evaporative cooling ( 21 September, p 15 ). Multi-megawatt quantities of heat and plumes of saturated air are probably being emitted into ambient air around the clock via …

Matt Strassler is right regarding words used in physics that can mislead. Changing them might go a long way to clarifying things ( 21 September, p 32 ). For example, instead of using a word like "particle", give it a new name – "omet" – and then list the characteristics of omets. They are atomic …

, Les Essarts-le-Roi, France The ideas suggested for keeping the International Space Station aloft aren't realistic, as they would require a lot of fuel and rockets. What might be possible is to set the ISS rotating in a way that when it is moving away from the sun (experiencing "sunset"), its solar panels would be …