Letter
John D. Barrow’s article was intriguing, but his comparison of repairs to the physics of a simulated universe to a cell’s DNA repair mechanism is scary. If a cell has accumulated too many or dangerous errors in its genetic code it may undergo apoptosis 鈥� programmed cell death. Would the Earth pop out of existence just to prop up the simulation?
Evolution in chaos
Paul Rainey should study a little celestial mechanics (14 June, p 37). The interaction between two massive bodies is always simple and calculable. Introduce a third body, or more, and the behaviour can become chaotic.
Rainey has elegantly and convincingly shown that a single, simple organism will evolve in a morphologically repeatable way, even if the genetic implementation of the changes may vary. However, when other species 鈥� predators, prey and competitors 鈥� are introduced into a system, the situation becomes significantly more complex. To deduce that in this case evolution will stick to its tram rails seems to be an extrapolation too far.
No Mrs Nobel
Oh come on! The story of the lack of a Nobel prize for mathematics is very old, and has nothing whatsoever to do with a Mrs Nobel, mainly because there never was one (28 June, p 26).
See, for example,
End of innovations
Does Feedback live in a parallel universe to the rest of us? “How technophiles would miss the Innovations catalogue if anything untoward should happen to it” (28 June). Unfortunately something untoward has happened to it. It was announced in April that the Innovations catalogue is no longer to be produced.
For the record
鈥� In our article about the Tevatron accelerator’s search for the Higgs particle, we neglected to mention that the Tevatron does have a chance of disproving 115 gigaelectronvolts as the mass of the Higgs (28 June, p 13). However, the accelerator will almost certainly not be able to disprove the particle’s existence at higher masses, or prove its existence at any mass.
鈥� While a debate in the Norwegian parliament on the Nobel Foundation would undoubtedly be interesting (28 June, p 26), a debate in the Swedish parliament might be more productive, given the foundation’s residence in that country.
Forced to fish
In the case of cyanide fishing in the Philippines, Fred Pearce’s quoted argument that local communities should “work harder to police fishing” rests on a typical misapprehension (21 June, p 40). The average subsistence fishing community is utterly powerless to “police” its fishing. On the contrary, such villagers are at the mercy of political webs in which they all too easily become entangled and die.
No one who has fished their local reef for years likes using either cyanide or dynamite. They do not need lectures from Greenpeace to know the damage done by such methods. In the majority of cases, fishermen are driven to such extremes by forces utterly beyond their control, such as deals done by government ministers that allow factory ships from Thailand or Taiwan to trawl illegally close inshore, using equally illegal mesh sizes, decimating littoral fish stocks.
What are the poor and starving to do? I have seen the commander of a detachment of ill-fed soldiers supply villagers with blasting caps for their fertiliser bombs in order to get fish to feed his men for the next couple of days in the field.
Conservationists can redraw environmentalist policies until they are blue in the face, but it will make not a scrap of difference at local level until wider political forces 鈥� and the exigencies of poverty 鈥� change. For any fisherman it all comes down to feeding his family by fair means or foul.
Small is dangerous
My much-publicised call for regulation to catch up with innovation in the field of nanotechnology 鈥� and especially the use of nanoparticles of titanium dioxide in those sunscreens and other cosmetic products that are already commercially available 鈥� has been slightly overshadowed by discussions about my personal scientific credentials.
By quoting my assertion that “the laws of physics do not apply at the molecular level” outside the context of the words that followed it 鈥� “quantum physics kicks in” 鈥� your article misses the point of my argument (21 June, p 10). I had hoped it would be obvious that I meant to draw a distinction between classical or Newtonian and quantum physics to explain to a lay audience how different sized particles of an equivalent material can exhibit different properties.
I wish nothing more than to facilitate reasoned dialogue between scientists, industry, policy makers and the public on how to ensure the precautionary principle is applied in this area and to make sure that the full health, social and environmental impacts of nanotechnology are understood before the fruits of this research are made commercially available 鈥� and we have already let a genie out of a bottle.
The prospects for such a reasoned debate are, I fear, hindered by your article in the Feedback section of the same edition which dismisses the potential impact of nanoparticle use in cosmetics as “making my face go mushy”.
Click to confuse
You suggest that the ability of dolphins to adjust the volume of their clicks might do two things: prevent loud echoes from nearby objects and help them judge the size of the target (21 June, p 16).
I have a third suggestion. Fish have sophisticated “hearing” in the form of the lateral line running the length of their bodies. If the clicks made by a dolphin were audible to them and if these clicks appeared to get louder as the dolphin approached, it would allow the fish to assess the distance between themselves and their pursuer and so aid them in evading capture. Varying the volume of these clicks so that they seem to remain constant to the fish removes this advantage and so negates its effect.
Mouldy peanuts
The most common cause of an allergic reaction to peanuts is actually due to the mould that grows on the nuts. The curing methods you mention in your article on producing safer peanuts will also reduce the growth rate of mould (28 June, p 17).
Playing by the rule
Ever since John Conway’s game of Life showed how remarkable complexity could emerge out of extremely simple rules, it has been tempting to see the universe as a cellular automaton (CA) as Ed Fredkin does (21 June, p 32). And since the sole aim of physics is to reveal how nature’s patterns have emerged since the big bang, Fredkin may be right to claim that the universe behaves like a CA. But that hardly justifies the claim that the universe is a CA.
The problem is that all CAs are nothing more than patterns. For the patterns that emerge in the game of Life, it does not matter at all what kind of substrate supports them 鈥� it can be anything from a computer to a giant chequerboard. However, the game of Life (like all other CAs) does need this substrate, which must be in some sense separate from it. The universe is by definition everything that exists, so what is its separate substrate? For the universe to be a CA, it would have to include within itself its own substrate.
Some physicists recognise this. In his book A Brief History of Time, Stephen Hawking says: “Even if there is only one possible unified theory, it is just a set of rules and equations. What is it that breathes fire into the equations and makes a universe for them to describe? 鈥s the unified theory so compelling that it brings about its own existence?”
Letter
If the bits change in relation to rules based on neighbouring cells, how would the phenomenon of quantum entanglement work? In entanglement an exchange of information seems to occur between two elements that are not neighbours in space and yet affect each other within one “tick of the clock”.
The way I thought it might work is by thinking of space not as a regular 3D grid, as Fredkin seems to, but as a network that approximates the effects of 3D space over a large number of connections (on the scale we giants live our lives). On the much finer level which Fredkin talks about perhaps the local lack of uniformity of the connections is responsible for the quantum weirdness. If only his experiments were able to gauge this result.
Flying cars
I was pleased to read Mike May’s article on flying cars, not least because I have been following the development of these various vehicles and wondering why I didn’t see more articles about them (14 June, p 40).
However, cars are not the only vehicle on the road, and when it comes to the air, they almost certainly won’t be the only vehicles there either.
While the SoloTrek () has bitten the dust thanks to damage caused by a loose tether, Woody Norris’s AirScooter () is still the only vehicle that is a real prospect for both regular flight and purchase (although the price has risen to $50,000 at last reckoning).
Having ridden a motorcycle in the UK for 25 years I must admit the thought of being able to ride its airborne counterpart is very tempting. I wonder how long, though, before we are treated to the campaign: “Think Once, Think Twice, Think Airbike”?
Universe rewound
If there were a glitch in the simulation of our universe, then the species running it might rewind it a few seconds to incorporate their fix (7 June, p 44). Two frames forward, one frame back, and then two more frames forward would look like only three frames passed by from inside the simulation while five frames would have passed by in linear time outside of the simulation. But would passing through the same time frame inside the simulation spark a feeling of d茅j脿 vu? It would be interesting to do a national study in which people could log in the time and duration of their d茅j脿 vu experiences to see if clustering is taking place.
Also, is it possible that the species running the simulation might be doing it to see if the creatures within it could come up with a novel way to prove or disprove that the universe was a simulation? They could then apply that method to their own universe to see if it was a simulation鈥�
No change on whales
The International Whaling Commission’s move into conservation is less dramatic than it might seem (21 June, p 7). The IWC’s Scientific Committee has for many years been discussing other issues concerning whales and dolphins, such as climate change, by-catch, the growth of whale-watching, collisions with ships, and contamination by heavy metals and persistent organic pollutants. But the commission has paid scant attention to these threats, dealing with scientific recommendations in a perfunctory and unsystematic manner.
The new Conservation Committee should correct that without affecting the negotiations for bringing commercial whaling back under international control.
Possibly the most urgent task of the new committee is to examine the Japanese demand that whales must be “culled” because they are damaging fish stocks and contributing to the global decline of sea fisheries. This nonsensical claim rests on a grossly distorted interpretation of the widely debated concept of “ecosystem management”. Ecologists and fisheries managers beware! Hubris about our ability to “manage” large marine ecosystems may bring a sorry end to 50 years of efforts to manage fishing rationally and end the plague of overfishing.