On the paradox of time flowing only one way
Paul Davies raises a critical point on the paradoxical arrow of time (25 September, p 34). Surely, the process of measurement at the quantum level defines a direction of time. Indeed, one could also extend this to note that the discussion about the (theoretical) reversibility of gas mixing is dependent upon perfect knowledge of state, which quantum mechanics also tells us isn’t possible.
Do these add to define both a direction of time and a link between the classical concept of entropy and the quantum world? As someone who is rooted in thermodynamics, it seems entropy gets short shrift in cosmological ponderings.
Solving the recycling issue requires more thought (1)
Any charges for removing rubbish just create fly-tipping and higher costs (25 September, p 18). A better way is legislating so those authorities not already using multi-bin sorting for recycling take it up. Supermarkets can also follow the example of a Canadian chain that has recycling bays to sort waste and repay deposits for returned bottles, tins and paper.
Solving the recycling issue requires more thought (2)
With the recent emphasis by the UK government on “nudge” techniques to modify behaviour, I wonder why there has been little research into the motivation behind recycling.
I live in Weymouth. Until 2011, we achieved 70 per cent recycling. Then our waste service merged with another authority, whose recycling rate was only about 30 per cent. Ten years later, the combined recycling rate is back up to 60 per cent. The question is, why was one area so keen to recycle while the other took years to convince? Surely, if the analysts could work this out, we could motivate the country to recycle.
Solving the recycling issue requires more thought (3)
A major problem in trying to recycle plastic is that it is often far from clear if it can be recycled. My local authority can’t recycle the large bags in which bird food is delivered, but if I go a few miles to the next local authority, it can be.
Then there is the problem of recyclable and non-recyclable packaging being mixed 鈥� for example, recyclable plastic bottles covered with a non-recyclable plastic wrap. Most people don’t have the time or inclination to carefully sort through all this packaging and pull it apart.
Legislation is required, not only to standardise recycling across the UK, but to ban mixed packaging and to get manufacturers to move towards 100 per cent recyclable packaging.
Why food waste might be an intractable problem
Of course we waste food (25 September, p 42). Since the green revolution in the mid-20th century, we have striven to ensure we have plenty of all kinds of food. We can’t have “just enough” because it is difficult to predict how much of each type of food we will need and even harder to know whether crops in a particular year will produce in abundance or if they will fail.
Given the only way to ensure we have plenty is to aim to produce too much, waste will inevitably follow from that. Buying lettuce in different-sized bags won’t make the slightest difference.
Orcas may have declared war on the fishing fleet
You wonder why orcas have started ramming boats off Gibraltar (18 September, p 17). Has any thought been given to the possibility that these animals may be perceiving the boats as competitors for the tuna they eat and are attempting to drive them away?
Mars life more likely to thrive in dark depths
You report work on the viability of life that relies on photosynthesis in the sheltered zone of caves on Mars (4 September, p 9). As life has evolved to process energy from chemosynthesis on Earth, surely life on Mars is more likely to exist without any need for photosynthesis, especially given the proportionate lessening of the sun’s power at that distance.
Nick Lane, in the book Oxygen: The molecule that made the world, makes a plausible case that photosynthesis was a process that evolved later, a mutation from an older, chemosynthetic life form.
Is it time to give the military robots a break?
David Hambling’s interesting article on firing weapons from autonomous warships mentioned that any strike from an uncrewed ship mandated human control (18 September, p 11).
Given that the last drone strike in Afghanistan was planned and executed by humans, resulting in the deaths of 10 civilians (seven of whom were children), maybe it is time to let the machines take control? The gods help us!
More thoughts on the shift to a net-zero way of life (1)
In one part of your illuminating article on a net-zero life, you mention the fictional Isla planning a holiday that avoids the “moral opprobrium” of long-haul flights in favour of a train tour in Norway (4 September, p 34). While I agree that travelling by train is preferable to flying within Europe, I can’t help but wonder about the future of nature reserves in Africa, South-East Asia or South America if tourists stopped visiting because of aviation emissions.
More thoughts on the shift to a net-zero way of life (2)
Your article missed a vital aspect of our transport future. A person on a pedal bike is the most efficient form of transport, as defined by distance travelled per unit of energy consumed. An extra bonus could be added to this equation if the person eats a plant-based diet. Plants fuelling bicycle transport is the ultimate in efficient travel.
More thoughts on the shift to a net-zero way of life (3)
Heat pumps probably are the way forward, especially in new-build homes. However, in existing housing, the payback time is long. And like many green technologies, the first things the user will notice are a rise in both installation and running costs over the status quo, an increase in noise and a decrease in convenience. Heat pumps’ advantages over direct electrical heating will also decrease as we decarbonise the electricity supply. We need to be upfront about this.