Restricting open-source software won’t stop misuse
From Sam Edge
Ringwood, Hampshire, UK
You seem to criticise open-source software on the grounds that it can give everyone access to potentially dangerous technology. However, there is a saying in cryptography that applies equally well here: “Security through obscurity is no security at all.” Just as trying to restrict access to books on chemistry and ballistics doesn’t stop rogue actors from killing people in large numbers, neither will trying to ban open-source control systems or large language models. In any case, closed-source software can also be reverse engineered, its source code stolen via industrial espionage or simply pirated and used for off-brand purposes (Leader, 25 July).
How to acclimatise to heat, courtesy of a Floridian
From Craig MacDougal
Tampa, Florida, US
The conditions Alec Luhn experienced inside a heat chamber are considered normal for summer afternoons where I live in Florida. Here’s a tip from a subtropical climate: to get a sense of how miserable it is going to be on a given day, focus on the dew point, not the relative humidity. The latter starts high in the morning and goes down as the temperature rises, possibly giving the impression that it will feel better in the afternoon (18 July, p 16). (It won’t.)
The dew point 鈥� the temperature where the relative humidity is 100 per cent 鈥� however, will stay relatively constant. Once it rises to about 21掳C (70掳F), it feels humid, regardless of the air temperature. I calculated the dew point for Alec’s test as about 23掳C (73掳F). A dew point of 25掳C (77掳F) or more, which happens around here, is miserable and can be dangerous.
I moved to Tampa from Jacksonville in north-east Florida in 1978. I am acclimated. At age 69, I play tennis twice a week, drink my sports drink and sweat a lot. Not everybody can do that, but I will for as long as I am able.
Shackleton photo hints at a forgotten injustice
From Margaret Cuthbert
Edinburgh, UK
You recently published a dramatic photo of the James Caird, the boat that carried Ernest Shackleton and five of his crew across the Antarctic waters to South Georgia in 1916. That image also highlights a long-standing injustice (18 July, p 18).
Following the loss of his ship, the Endurance, Shackleton had planned for the crew to haul their three lifeboats over the ice and snow until they reached open water. This was met with dismay by carpenter Harry McNish, who foresaw that serious damage to the boats from being pulled over rough terrain was likely to occur. The row ended with Shackleton reportedly levelling a gun at McNish and winning the argument, but within two days, he had to abandon his plans and return to their base.
Eventually, when the ice broke up, they sailed their three lifeboats to Elephant Island. It was there that McNish modified the largest of the three, the James Caird, and made it seaworthy for the journey to South Georgia. The photograph you published gives some indication of how extensive McNish’s modifications were. This work, carried out in freezing cold and with frostbitten fingers, was a vital contribution to the survival of the explorers, and only McNish had the skills to make it.
However, when Polar Medals were later handed out, McNish was deprived of his due, after Shackleton failed to recommend him for one. This is an injustice that it is not too late to rectify.
Intelligent life wouldn’t be power-hungry like us
From Dyane Sylvester
Arnside, Cumbria, UK
Brian Lacki shows a typically anthropomorphic bias in his search for extraterrestrial intelligence by assuming that any “advanced civilisation” will have developed computers and require huge amounts of power (4 July, p 41). Wouldn’t a truly intelligent species be using simple technology requiring minimal power and resources, to ensure that it could exist within the capacity of its home planet?
It’s hard to tally economics with the environment
From Tim Moulsley
Caterham, Surrey, UK
The expenditure by the Australian government to protect the Great Barrier Reef, as described in Keith Noble’s letter, is no doubt to be applauded. However, one should take care before concluding that this is a very good thing if that is based on the reef supporting 77,000 jobs and making an annual contribution of AUS$9 billion to the country’s economy, as Keith mentions (Letters, 18 July). Unless that economic activity is strictly net zero, it will be directly contributing to the climate change that is the primary factor necessitating protective measures in the first place!
I also wonder how much of this activity could actually be classed as the “useless overconsumption” Joel Millward-Hopkins mentions in the article “Living the good life” (18 July, p 32), and thus something to be curbed in our efforts to ensure everyone has a reasonable basic quality of life, while keeping within the planet’s safe operating space. I fully appreciate the great appeal of the reef for tourism, but it is hard to see that this will have a long-term future, unless, as part of the sum total of all other human activities, the proposed “Great Barrier Reef economic zone” becomes truly sustainable.
Don’t forget balance when it comes to brain health
From Wai Wong
Melbourne, Australia
An often neglected measure of brain health is balance. While exercise in general is good for brain health, a regime that targets balance, strength and movement, such as tai chi, improves cognitive function better than approaches focusing on just one area. Various forms of simple and free balance tests are available from trusted sites on the internet. So, it pays to include balance in your brain check-up and exercise routine (11 July, p 32).
Another option for geothermal in the UK
From Larry Stoter
The Narth, Monmouthshire, UK
Your article on new geothermal methods makes no mention of using abandoned mines. In the UK, there are many such ex-coal mines that could be used as a heat source. While temperatures may not be sufficiently high to generate electricity, they are high enough for district heating schemes. Such schemes are already in action at Gateshead (25 July, p 32).
For the record
Iceland’s Blue Lagoon is an artificial geothermal spa (25 July, p 32).
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