Letters archive

Cedric Lynch writes that he would need planning permission to use his heat pump for cooling (Letters, 19 January ). Heat pumps are a central part of the UK government's plan, with predictions of 20 million being installed by 2050. Progress has been stalled by the introduction of the scientifically hard to grasp concept of …

Is it not a problem that only males were studied – hardly equates to all teenagers? Stella Collins spots a limitation of a study that found those who copy each other's risk-taking have more friends ( 9 February, p 14 )

Leah Crane suggests that if art generated by machine learning or artificial intelligences is deemed by the courts to be subject to copyright then AIs could flood national copyright offices with applications ( 5 January, p 18 ). Any work is protected by copyright from the moment it is created. Providing one can demonstrate provenance, …

Gisborne, New Zealand Paul Marks mentions suggestions for reducing emissions of carbon dioxide by aircraft, ranging from straighter flight paths to electrification ( 5 January, p 32 ). But he omits the elephantine obvious: reduce the traffic. A globally agreed carbon tax is essential for climate-change mitigation, along with increased consumer awareness.

You praise 10,000 Swedes who have forsworn air travel (Leader, 5 January ). Whether that is a good thing depends on what they do instead. If they go to the same destination by car, with only one or two people in the vehicle, they may be consuming more fuel than if they had taken a …

Discussion of cars becoming more autonomous extends to whether they benefit from back-seat drivers ( 2 February, p 16 ). But what of the additional electrical power the car needs to use to process this feedback? This load on a vehicle's battery is parasitical on its primary function as a means of transport. Could this …

• Before schoolchildren discovered Ediacaran fossils in the UK, geologist Reg Sprigg found some at Ediacara in the Flinders Ranges of South Australia in 1946. These weren't initially recognised as Ediacarans as we now understand them ( 12 January, p 28 ). • Not very heavy: the space rock that hit the moon during its …

Kelly Oakes describes suffering a hundred thousand kilometres of off-key lift music while riding a space elevator ( 12 January, p 42 ). At 100 kilometres per hour, that would take 42 days. This competes against a few minutes in a rocket.

Space elevators would pass through the upper atmosphere, which is kept positively charged by lightning flashes all over the world. Since the only materials strong enough to build one are carbon nanotubes and graphene, which conduct, is there not a possibility of shorting the upper atmosphere to ground through the cable? Lightning flashes would easily …

Kelly Oakes explained that forming a fatberg involves oils being saponified ( 26 January, p 22 ). That is, they combine with calcium to create hard, water-insoluble, soap-like deposits. So are fatbergs found only in areas with calcium-rich "hard" water? The editor writes: • There are supplies of calcium even without hard water, such as …