We can take lessons from these rodent drivers
Rats have been taught the complex skill of driving a tiny car to collect a food reward at their destination, Alice Klein tells us (2 November, p 12). Monitoring the rats’ levels of hormones associated with stress showed that they were relaxed: online you report that they were less stressed than rats that were driven around in remote-controlled cars. It seems to me that the rats may enjoy learning and mastering new skills such as driving 鈥� just as humans do.
This work was done to enable research on how brain conditions can affect cognitive function, for extrapolation to humans. But this brilliant piece of research may be as important in giving us pause for thought over autonomous vehicles. Will human drivers become stressed by going driverless?
The aether was a very productive idea on light
Brendan Foster describes renewed interest in the luminiferous aether (2 November, p 32). For all its shortcomings, the aether was one of the most productive scientific ideas of all time. Many conceived of it as being electromagnetic as well: it allowed to deduce that light was an electromagnetic phenomenon.
The hope that the forces of nature could be understood in strictly mechanical terms died before the aether did. Although the electron was seen as a knot or whirl in the aether, it was recognised as having fundamental electrodynamic properties. One of the discoverers of the electron, , made great use of the idea of an aether.
In the information age, many physicists treat the universe as a computer or a hologram. Those models will almost certainly lead to insights and even breakthroughs. But they will be no more literally true than the idea of the aether as a fundamental fluid filling space.
Hypnosis may be suffering from mentalist reputation
Reading Helen Thomson’s interesting and amusing article on hypnosis, I wondered if hypnotists aren’t taken seriously because, historically, they claimed to be using only their minds to do it (9 November, p 34). As Thomson reports, anaesthetist Aurore Marcou uses local anaesthetics and mild sedation in modern, medical-based hypnosis, making the hypnotist one part of the process rather than the whole process itself.
Thanks for bolstering my suspicion about measles
Debora MacKenzie reports that measles massively damages the immune system (9 November, p 15). In 1960, before vaccination was available, I had two weeks off school with measles. On the first day back, I came home covered in chickenpox. For decades I have suspected that there was some relationship.
Thanks to New 杏吧原创, I now know that this was probably the case. Given the information in the article, I count myself lucky to have got off so lightly.
Neglected concerns about the nutrient choline
With Clare Wilson’s article on the neglected nutrient choline, you present a diagram showing beef liver as an important source of it (26 October, p 20). As Wilson reports, some research suggests that women should have more choline when they are pregnant.
But pregnant women are advised to avoid liver of any kind, since too much vitamin A from animal sources poses for their unborn child.
The second-best source of choline that you show, hard-boiled eggs, is easily matched by soy and wheat germ flour, which you don’t show.
There is also a possibility that the relationship between the intake of meat, milk and eggs and advanced prostate cancer to the choline levels of these foods. In the public interest, it is worth mentioning that health concerns about dietary choline are being investigated.
Will nobody think of the poor Martian children?
Reviewing the exhibition, Simon Ings offers some welcome balance to dreams of long-term space exploration (26 October, p 30). I would add some ethical issues.
Adventurous adults may make informed, rational decisions about leaving Earth permanently. But if this isn’t to be temporary, there must be plans for them to have descendants, who will have made no such decision.
We have no long-term idea of how deeply the characteristics of Earth’s environment may be hardwired into us as necessary for our well-being. Earth-scented gloves and green wallpaper may be insufficient for their welfare.
Little figures on the ceiling explained by science
You mention the camera obscura as an example of unconventional imaging (9 November, p 42). I saw a camera obscura after moving into a house with high ceilings, tall windows and a short front garden. On a bright first morning, I saw tiny figures moving on the ceiling. The folds at the top of the curtains were acting as pinholes, projecting pedestrians on the street onto the ceiling.
Tackling the puzzle of low-carbon domestic energy (1)
As Adam Vaughan says, gas boilers are a UK election battleground, with three of the main parties wanting to phase them out, each at a different rate (9 November, p 18). But methane is a great biofuel that is relatively easy to make, store and transport. Sensibly, three times more UK domestic energy is supplied by gas than by electricity. So if we remove gas, we will need four times the electricity generation capacity. This is a large price to pay for a possible 12 per cent carbon saving. The next government should look at the low-carbon possibilities for domestic heating.
We need investment in insulation and heat recycling to avoid heat going down the drain, and into making gas from waste.
Tackling the puzzle of low-carbon domestic energy (2)
I am pleased by the progress in planning new homes that Vaughan outlines. But the suggestion that a space can be “airtight, but still well-ventilated” is confusing.
Should air trapped in an airtight home be recirculated? How would moisture escape? Dehumidifiers need electricity and moisture-absorptive materials have to be recharged (more electricity consumption) or replaced (recycled or landfilled).
The editor writes:
We mean only that houses should be built in a way that avoids unintentional draughts, not that no air can get in and out.
Recycling heat to save energy in our home
Matthew Allan proposes that we retrofit homes with integrated heat-handling equipment (Letters, 26 October). This is a great idea.
We already have a sealed house. Its controlled ventilation incorporates a heat exchanger working at 92 per cent efficiency. The only heat we waste is water from washing machines and showers. These use only 30 per cent of the normal water flow. Very few visitors notice the difference, and, of course, you don’t heat the 70 per cent you don’t use.
One spoonful of tea avoids plenty of plastic problems
You report the pollution and possible health risks of plastic particles from teabags (5 October, p 16). There is a simple way to avoid these: stop using teabags. For the price of a box of teabags that makes 25 cups, I buy loose tea to make 250 cups.