What if your mind's eye is an illusion?
Dustin Grinnell reports Adam Zeman's interesting suggestion that people who believe they have no “mind's eye” may nevertheless be using visual imagery at an unconscious level (23 April, p 34).
Surely the contrary is equally plausible – that some people who claim to possess a mind's eye may be mistaken? It is notoriously difficult to examine the workings of our own minds. For many people, the mind's eye provides a convenient theory of spatial thinking, but it may be no more than that. It is entirely possible to think spatially without forming any internal visual images at all.
Coal has not quite gone bust yet
I read with great interest your report linking the bankruptcy of Peabody Energy to China burning less coal and inroads of renewable energy (23 April, p 7). I suggest that the bankruptcy is rooted in a low coal price, related to an extended depression in oil and gas prices.
Thermal coal prices declined from US$142 to $43 per short ton from 2008 to 2015, leading to more than 42 US coal companies filing bankruptcy. Coal mines continue operations while the companies that own them restructure. For instance, in Powder River Basin in Wyoming, 5 of 14 mines owned by Peabody (the largest), Arch (second largest) and Alpha (fourth) produced 28 per cent of total US coal in 2015.
Weakened demand associated with cheap oil and gas together with a glut in coal, the federal clean power plan, coal-to-gas switching and financial factors are the proximal causes of the current coal crisis.
Wide-eyed and far away but focused
Tim Stevenson writes that at the distance of the Oort Cloud, the sun could not be obscured by a pinhead, since the dilated pupil of the eye would be bigger than a pinhead (Letters, 14 May). This is surely a misconception. The lens in the viewer's eye will focus the image of the sun and the pinhead onto their retina, and this image will contain the pin and the sun as their correct relative sizes, with the pin image larger than the sun image. This will be true whatever size the pupil is.
When did drones solve anything?
Do we want every foreign policy issue to be settled by sending in the drones, asks David Hambling (16 April, p 18). No foreign policy issue has been settled by sending in drones. In the future, as today, they are more likely to raise issues than settle them.
When a landmine is not a landmine
Reader R. T. Lewis notes that I say that “persistent drones could sit on buildings or trees and keep watch indefinitely” and asks: “When is a drone that sits in wait for its victim not a military mine?” (Letters, 28 May). If there is a human operator in the loop controlling the drone, it does not count as a mine. This is why the US is replacing anti-personnel mines with networked munitions, which are operator-controlled rather than activated by victims.
However, if communications fail, or the drone is designed to be autonomous and selects a target without human input, then it is legally a landmine. And of course not all nations have signed up to the Ottawa Treaty banning landmines: those not signing include the US, Russia and China.
The A to Z of your memories
You report that memory isn't arranged in alphabetical order, and indeed I am sure mine isn't (7 May, p 15). However, why is it that when I fruitlessly attempt to remember something, I often remember only the initial letter, which subsequently proves to have been correct?
Driverless cars and guardian angels
There has recently been a great deal of discussion about a coming revolution in self-driving vehicles. This often focuses on anticipated reductions in road deaths. Most of that will be in developed countries where many customers can afford the new autonomous vehicles – and which already have relatively very low levels of road death.
They will do nothing in the near future for developing countries like Nigeria and Bangladesh, where the most basic standards of vehicle maintenance, driver skill and highway condition are lacking and the casualty rate is orders of magnitude higher.
Driverless cars and guardian angels
I am still not certain what happens if a person stands in front of a driverless car and refuses to move. Can it back off and try to drive round the person?
Driverless cars and guardian angels
Like many others, I already drive a car that the manufacturers regard as a “guardian angel” (14 May, p 22). It has automatic emergency braking that allows it to stop itself if a collision is imminent. The designers seem to have an odd vision of the dangers posed by different collisions. A bird flew in front of me, was “perceived” as a collision, and the emergency brakes slammed on.
Certainly the bird must have thought it had a guardian angel. What if a truck, without guardian angel brakes, had been hurtling along behind me? Such systems may indeed limit collisions in the future, but until all cars are similarly equipped, I want to be the one who decides which of us dies, me or the bird.
Editor's pick: Free will or, rather, free choice?
John Hastings suggests that scientists who claim that we have no free will cannot be trusted because they themselves have no free will and were bound to come to that conclusion (Letters, 14 May). While I believe it is true that our thoughts and decisions are dependent on everything that makes us what we are, I think there is a difference between conclusions based wholly on belief and those based on demonstrable facts, such as the evidence for evolution.
From a deterministic view, scientists may have no choice but to come to the conclusions they do – but that does not mean that their conclusions are incorrect. I prefer to believe that, with our increased knowledge of the world and how it works, our predetermined conclusions are more likely to be correct than not.
All showy leaves and no seeds
Olive Hefferman indicates that plant growth is “increased with extra CO2 and temperature” and this is of course true (7 May, p 20).
More than 20 years ago, the Royal Agricultural Society ran tests in geodesic domes at Kenilworth with different temperatures and carbon dioxide levels. As expected, plant growth was enormous in the highest temperatures and CO2 concentrations. But the yield of seeds dropped to low levels or nil. That is not something we could live with.
What renewable energy needs
Le Page makes a valid point concerning the operation of the electricity market. It is clearly true that when solar, wind and nuclear generation reaches a certain level, further investment in any of these will bring a lesser return.
But he says “we can't keep subsidising [renewables] forever” – when that is exactly what we have been doing with fossil fuels for decades. The users of fossil fuels have not been paying for the damage they have been doing. In the not-so-distant future, major costs will strike home, which will make the present taxation deficit look like footling small change. We should compare the cost of renewables with the true cost of fossil fuels.
What renewable energy needs
Le Page is too pessimistic. Industries that use the excess cheap but intermittent energy will evolve – for example, the production of metals by electrolysis. There is a double benefit if the metal being won is now produced by means that emit carbon dioxide.
What renewable energy needs
Cheap renewable energy is not inherently the dangerous myth that Michael Le Page suggests (21 May, p 19). It may be, as long as its production remains subject to “free market” rules.
If you separate renewable energy production from economic forces, transforming it into a common good, the issue disappears. This comes at a price but perhaps it is a price worth paying when measured against the long-term effects of climate change.
Le Page ends with a message to politicians to take action, but it is the public mood that ultimately drives most political decisions. It is the rest of us that need to take a long hard look at what kind of future we want.
First class post
Thanks for ‘it's the first this has been seen in other animals‘ – yes, we're animals too
Elisa Drass of our online video on killer whale “culture” shaping their evolution ()
Truth standards in healthy debate
You suggest that health gurus should be held to higher standards (21 May, p 5). May I suggest that a law requiring all public figures and profit-seekers to tell the truth, and correct mistakes if they make them, would be a good start?
It is claimed that oil companies have known about climate change since 1977 and continue to spend millions each year blocking action on this issue. And what about Cardinal Alfonso LÓpez Trujillo ?
I see a problem in getting such legislation passed, though. The UK ensures that adverts are “legal, decent, honest and truthful”. But there is : adverts attempting to influence the outcome of elections.
Editor's pick: Free will or, rather, free choice?
The main problem with free will is terminology. The freedom to “will” things suggests a power over the universe to set the options – and that is not the same as choosing between them, which is the limited power we have. I suggest that freedom of will is a misleading term and what we actually have is the freedom to choose.