Letters archive

Chris Eve wonders how much more heat burning a kilogram of petrol generates through the greenhouse effect than it does through the energy of combustion (Letters, 23 March ). He calls this a "gearing ratio", the name for the proportion of debt to capital used in finance. With colleagues, I estimated this , though we …

They'll be saying this about Earth in a few decades Lesley Wise expands on the news that Venus may have had a climate suitable for life billions of years ago ( 6 April, p 10 )

John van Someren asks for the match of colour and function in indicator lights to be standardised (Letters, 9 March ). On behalf of the many millions who are red-green colour blind, could we please never use red and green LEDs for off and on.

I would suggest getting rid of indicator lights . What is the point of wasting energy on an indicator to tell you that the TV is on?

I've grown up reading my father's copies of New Scientist , and as a student at the University of Texas at Austin, I have been learning about oceanography and the effects of climate change. I was delighted to read about the youth of the world coming together to combat the detrimental actions that have been …

I was most pleased to see my field of study – Corded Ware culture – featured on your cover. But the mention of genocide and "Stone Age conquerors" is, to my mind, overstating the evidence. Migration is no doubt a factor in the changes observed in the third millennium BC in Europe, but that doesn't …

Some questions sprang to mind about the spread of the livestock herders called the Yamnaya. Where does this name come from? Barras refers to some of the Yamnaya travelling to the Indian subcontinent. Is this perhaps the origin of the Indo-European family of languages? The editor writes: • The name is from "Yamnaya Kultura", a …

Terrance Chapman doesn't know the reason for his mother-in-law's total tooth removal in the 1930s (Letters, 16 March ) and Aroha Mahoney says a neighbour's were removed in the 1950s to save her husband money (Letters, 6 April ). My father, who suffered the same fate in the early 1900s, explained that this treatment was …

You draw the conclusion that alternative facts are real from a paradox, which arises from a thought experiment about the states of friends of observers of a quantum event ( 2 March, p 7 ). This would only be true if we accepted that an unambiguously quantum object such as a single photon can be …

Geoff Convery suggests that cystic fibrosis carriers might recognise each other through olfaction (Letters, 2 March ). But cystic fibrosis is caused by a mutation in a single gene. It seems extremely unlikely that one mutated gene among tens of thousands would be detectable by smell.