Editor's pick: Can't I be vaguely vegan and healthy too? (1)
Despite its clear benefits to self and planet, going vegan has its challenges (27 January, p 26). One of these is that, for reasons that are unclear to me, there is a philosophical attitude that you have to go either 100 per cent vegan or not at all. This probably dissuades many from making the effort, so we carry on eating beef and bacon unrestrained.
Why does it seem laughable to claim to be, say, 90 per cent vegan? The benefits would be significant, as you outline. Is there really a rational basis for adopting such an all-or-nothing approach? Would it not be just as ludicrous to adopt the position that you either generate zero waste, or don't bother cutting back at all? Is reducing fuel consumption also a binary option, in that you either sell your car and walk everywhere, or make no effort whatsoever to reduce fossil fuel use?
We should be able to cut back our ingestion of animal products and hold our heads up high, even if it isn't absolute. Let's wear our “90 per cent vegan” T-shirts with pride!
Editor's pick: Can't I be vaguely vegan and healthy too? (2)
It was great to see your leader on vegan eating (27 January, p 3) and the positive conclusion of Chelsea Whyte's article (p 26). But were the heavy-handed warnings consistent with the available evidence? They make it seem that it is only possible to be vegan if you are super-smart.
Evidence about the health benefits of plant-based diets comes from studies of normal people, not nutritional geniuses. Whatever challenges there are in finding a healthy diet, people on non-vegan diets are more likely to fail. New vegans should be warned that standard dietary advice about saturated fat, sugar and junk food all still applies. And yes, they should take vitamin B12.
The fate of civilisation is, in fact, in our hands (1)
I was concerned to read your leader on the possibility of civilisational collapse (20 January, p 5). You suggest that activists saw climate change as a “golden opportunity to further a political agenda: reining in corporations, regulating free markets and imposing environmental legislation”, and that these have prematurely politicised the science and caused “pushback” from the other side. That seems to me to turn the facts upon their head. Campaigners who call for regulation are reacting to evidence of environmental destruction, not causing corporate irresponsibility. You have articles almost every week calling for governments to act to prevent climate change and suggesting it may be too late.
I am astonished that you describe “inequality, population growth and resource depletion” as bugbears of the left. These are problems widely recognised by all those who make any sort of scientific analysis of climate change, and by all involved in helping people out of poverty.
Some activists may use more “isms” than I would like, but I wouldn't describe their agenda as being contentious or divisive.
The fate of civilisation is, in fact, in our hands (2)
You mention in calling for existential risk researchers to “concentrate on nailing the basic facts”. We quite agree.
Increasing scientific evidence indicates that there is a small but real probability of catastrophes that could lead to civilisational collapse or human extinction. Nuclear war, climate change and pandemics are familiar threats. Advances in areas such as artificial intelligence and biotechnologies promise great benefits, but also pose novel challenges.
Understanding these threats will inevitably involve analysis of issues that are unpopular with various parts of the political landscape. We must not ignore the science for the sake of the politics.
You are correct that we need policy responses based on solid scientific evidence and that this can achieve a consensus among policy-makers, industry leaders, academics and citizens. In the longer term, these global problems can only be managed through cooperation between governments of all political persuasions. Reducing existential risk isn't a partisan issue and must not become one – it is far too important for that.
First class post 鈥� 10 February 2018
Why did it take so long?
Paula Rose news of a drug that could, if approved, help prevent excessive menstrual bleeding (3 February, p 19)
Farming rhinos isn't the best possible proposal (1)
Fred Pearce reports on people breeding rhinos in South Africa for hunters to kill (13 January, p 42). This should remind us that the money paid goes to the farmer, not to conservation work. In addition, the farmed rhinos aren't wary of predators, nor are they able to handle the typical stresses of “wild” living.
Horn sold by rhino farmers within South Africa will no doubt be smuggled out of the country, which will make it harder to police sales. And the price of a “wild” rhino horn is far higher.
Farming rhinos isn't the best possible proposal (2)
I see there is now a documentary film on the idea that big-game hunting preserves African megafauna. In the spirit of the , I suggest that it could be more effective to cut out the middle species. Rich people could be charged a fortune for a licence to hunt poachers (with anaesthetic darts rather than live rounds). The money would mostly go to conservation, with a little to fund the police accompanying them.
For the record – 10 February 2018
鈥� Hot water bears: the highest temperature to which experimenters exposed Antarctic tardigrades was 41掳C (6 January, p 19).
鈥� Stratollite surveillance balloons fly only filled with helium (27 January, p 8).
鈥� The maximum thermal efficiency of a petrol or gasoline car engine is 35 per cent and that of a diesel car about 45 per cent (20 January, p 36).
鈥� Harris County in Texas is closer to Louisiana than to Mexico, and there have been no judicial executions in Iowa since 1965 (20 January, p 10).
[copy] If I were a sloth, where would I defecate?
I enjoyed Jason Bittel's article on sloths (23/30 December 2017, p 44). I was perplexed, however, by the statement that the reason sloths climb down to the forest floor to defecate, then bury the mess, “is still a mystery”.
If I were an extremely slow-moving animal with many predators I don't think I would drop my calling card from high in the forest canopy, allowing it to smear every leaf and twig as it fell and then lie at the foot of my tree.
Evolution has given the sloth the longest digestive process on record for a plant-eating mammal, so it doesn't have to make the descent too often.
The editor writes:
• This hypothesis is certainly appealing. Others include the idea that the excrement may contain something that allows sloths to communicate, which could explain why it is worth expending so much energy. We know of no one testing these ideas or others experimentally, which is what we would need to know for sure.
[copy] Shall I number the engines of your rocket?
Paul Marks asserts that Russia's workhorse spacecraft, Soyuz, has 20 engines (20 January, p 24). It depends what you mean by “engine”. Soyuz , but many describe these as parts of five rocket motors, each with one set of pumps feeding fuel to four combustion chambers. By this definition, the Falcon 9 first stage already has more engines than the Soyuz.
[copy] Biosimilar drugs may be better than the original
Alice Klein notes some clinicians' concerns about the safety and efficacy of biosimilar versions of biological drugs compared with the original product (6 January, p 22).
Writing , I found that many clinicians don't know that batches of biological drugs vary, and this is true for the original and the biosimilar versions. Clinical studies to support different uses of a drug are likely to have been conducted with different batches. It is possible that a biosimilar batch could more closely share critical attributes of the original than does the current batch. In this sense, a patient taking an original brand could also be considered to be using a “biosimilar”.
[copy] Borrowing from friends of friends is better
Ariel Procaccia and colleagues say that a society's overall wealth is maximised when people charge each other to borrow rarely used items such as tools (3 June 2017, p 7). This does seem interesting. reveals the assumptions on which it rests. Anyone considering whether or not to buy an expensive tool is presumed to base this decision on the number of people they will be able to charge. But the effect is much weaker when borrowing from friends of friends is allowed. It seems neighbourhood networks allowing borrowing from remote people are forbidden.
Once we accept this condition, the results are mathematically correct – but I fail to see how they relate to the real world, not least because in said reality a “popular” person who charges friends for every little favour won't be popular for very long.
[copy] When robots go out to play in arcade traffic
A robot that used machine learning to teach itself to safely cross roads dodges between the oncoming traffic by “shuffling back and forth to keep itself safe” (16 December 2017, p 20).
This is remarkably like creating an artificially intelligent player of the classic arcade game , which is commendable. But can it tell the difference between the floating logs and alligators seen in the game? And can a robot that is weaving back and forth amid traffic really be described as exhibiting “safe” behaviour?
Couldn't the robot just find a pedestrian crossing and wait for the signal to turn green? Are the police going to have to start ticketing robots for jaywalking?