Letters archive

Fred Pearce eloquently highlights that the UK's purported establishment of a "marine protected area" (MPA) around the Chagos Archipelago was a highly political decision, rushed through against the advice of senior officials (27 September, p 26) . However, Pearce has proceeded on the erroneous assumption that the UK has sovereignty over the Chagos Archipelago. It …

Designating the Chagos Archipelago a no-take marine protected area (MPA) was based on the best available science. The precautionary principle was rightly applied to ensure that lengthy deliberation did not allow further destruction of the world's most pristine coral reefs. Policies should, of course, be reviewed as further scientific evidence comes to light. In the …

How strange that supporters of the many-worlds interpretation of quantum mechanics fail to grasp the bleak moral implications of this view (27 September, p 32) . If it's true, it is surely absurd to worry about the consequences of "decisions", since we all make every possible choice and enjoy or suffer every consequence. Since everything …

In your fascinating article on the multiverse, much is made of the way that my decisions (in this universe) affect what happens to the other versions of me in other universes. However, isn't the situation symmetrical? Wouldn't the decisions of my clones in other universes have as much effect on me as I have on …

I was delighted with this article, but it left out a number of issues which make Hugh Everett's theory of the multiverse even more fascinating. Suppose I make a choice, and meanwhile an inhabitant of a planet 1 light year away makes an unrelated choice. Are there four universes immediately, or in a year's time? …

Surely if there are multiple universes, we are simply in one of them, with all those going before us and after us creating further universes of their own with every decision, giving more multiverses than I can shake a stick at. At least I know now who to blame for bad things in my life …

• It's a common criticism. One answer is that, since the parallel worlds are inaccessible, they cannot be sources or sinks of energy. Thus the energy "needed" to make splitting multiverses doesn't have to come from anywhere, because there is no extra energy.

In the multiverse interpretation of quantum computing, Rowan Hooper states that the necessary calculations are conducted in many universes at once. Does this mean that there must be communication between parallel universes in order to arrive at the final answer? Sidmouth, Devon, UK

Replying to my defence of televised investigations into the afterlife, Craig Gosling writes that "in the absence of evidence, David Silverman and the rest of us have every right to chuckle" (4 October, p 32) . He seems not to have read my letter closely enough. The BBC series that I referred to was very …

Dan Jones asks whether we would abandon our belief in free will if brain scans could predict our every action (27 September, p 11) . When did my brain stop being a part of me? My conscious self may be an executive in charge of hundreds of unconscious modules in my brain. These days I …

While it is true that losing belief in free will might affect how people feel about cheating or punishment, as Dan Jones asserts, the only scenario in which this matters in any way is if free will truly does exist, but people incorrectly believe that it doesn't. In any scenario where there is no free …

The protection of critical circuits from cosmic radiation may also be increased by reducing the cross section that is exposed to these high-energy particles (27 September, p 42) . During a recent coronal mass ejection – a burst of solar wind – I held a strip sensor so that it faced the sun, then changed …

As a keen microscopist I was delighted to see Arthur E. Smith's micrographs featured in your magazine (4 October, p 24) . However, I have to point out that the "sheep tick" is in fact a type of louse-fly, the sheep ked Melophagus ovinus . Having curated old microscope slides I quite often found slides …

I happened to be reading Catherine Brahic's article on the importance of imagination (20 September, p 32) in tandem with Donna Tartt's The Goldfinch , which contains a quotation from Friedrich Nietzsche: "We have art in order not to die from the truth." This seemed to resonate with Maurice Bloch's notion, as reported by Brahic, …

Further to previous letters on naming neutrons separated from their spin, how about "nontron" or "nontronspun"? Ballina, New South Wales, Australia

• Our article on quantum encryption incorrectly identified Shuang Wang as the leader of the research group (20 September, p 12) . The leader is Zheng-Fu Han. • Guilty as charged: our article on mitochondria contained two errors (20 September, p 42) . Hemes are not proteins but cofactors, and not all free radicals carry …