Dream physics
The letters on physics in lucid dreams from Ray Pediani and Miranda Mowbray (23 February, p 21 and 1 March, p 25) merely hint at the possibilities. It should be clear that the subject under investigation is not physics as such, but the properties of a very complex simulation system.
Lucid dreaming is like being immersed in an advanced computer game. To play well requires an understanding of how the system responds to expectations, both habitual and deliberately cultivated.
When it goes well, the depth of reality is far superior to anything mediated by a video screen. There are innumerable options which would not be available in waking experience. Supposed physics experiments in dreams are fun 鈥� but are a small part of what one could be doing.
Time travail
Time gets a bad press: it causes wrinkles; it moves slowly when you need it to hurry up and quickly when you’d like it to slow down; and how many times have you cringed, toes curling, wishing you could wind it back? But there is also something profound about the fact that we can’t.
Yes, the possibility that if I’m late for work I could tell my boss to “hold on a sec” while I whip out my subtle knife, slice a hole in the fabric of the universe, jump into a wormhole and arrive 5 minutes before the start of my shift appeals to me.
So I’m as excited as the next physics geek about switching on the Large Hadron Collider and finding some dark matter to prop open a wormhole (9 February, p 32) while a future version of me hops through, rambling about all the mistakes I’m going to make with my life that I can stop myself making.
Yet I can’t help wondering who we are if not the products of time. Indeed, who would I be if I were always on time for work?
Oh good! Time travel! I’m looking forward to visiting my grandfather and presenting him with his pocket watch, which I inherited from my father and which he will still have in his waistcoat pocket.
Glengarriff, County Cork, Ireland
For the record
鈥� The silhouetted ape pictured in the feature on bipedalism (8 March, p 36) is a bonobo, not an orang-utan.
鈥� We said that the BTV8 strain of bluetongue appeared in Belgium in 2005 (8 March, p 12); in fact it made its appearance there in 2006.
Inflamed with Venus
I very much enjoyed J. Huw Davies’s “head-on impactor” explanation for the bizarre character of the planet Venus (23 February, p 14) 鈥� but his model cannot account for all the idiosyncrasies of Earth’s evil twin without raising troubling issues of plausibility.
The chaotic protoplanetary bombardment that characterised the formation of the rocky planets and our own extraordinary moon ended nearly 4.5 billion years ago. The radar survey of Venus by the Magellan craft imaged 98 per cent of the planet’s comparatively undented surface. Accurate counts of its strangely sparse craters determined the very oldest parts to be less than 750 million years old.
So if some catastrophic resurfacing event is responsible for Venus’s unblemished veneer, then it occurred when the solar system was about 85 per cent of its current age, when impactors of 0.4 Earth masses would have been just as rare in our neighbourhood as they mercifully are today. If Davies’s model is to explain such a recent crustal cataclysm, a rogue planet with four times the mass of Mars must have hurtled through the modern solar system, not only crossing the orbit of Venus, but also meeting it on precisely the right track for a head-on collision.
Venus is mysterious in many ways and no doubt requires an unusual explanation to fully fathom its many eccentric features, but the odds against such an energetic celestial wedding being the reason for its beguilingly smooth complexion are, well, astronomical.
ID theft made easy
You report proposals that computer operating systems should be modified to keep a copy of RAM on the hard disc, to aid forensic analysis when computers are found running at crime scenes (23 February, p 23).
This is a terrible idea. All sorts of confidential data is held in RAM, including the keys to any encrypted disc partitions. That would make all data on a stolen laptop available to the thief. The police already know how to grab the contents of RAM from a running computer. Let’s not make life easier for thieves.
A sick environment
David Nettle says that “for almost any personality profile, there is an optimum environment” (9 February, p 36). This has major implications for how we interpret and act on recent increases of so-called psychological “disorders”. Will we continue to medicate, or will we prove able to reconstruct a social and living environment that does not turn our natural personalities into disorders?
You have been warned
Matthew Killeya, offering suggestions for how to choose a PhD supervisor (23 February, p 54, UK edition), omitted one thing. I know of academic supervisors too inflexible to consider modifying the research programme they had originally mapped out 鈥� and PhD students who dropped out as a result. Supervising a PhD project calls for people-management skills which, sadly, not all academics have. If Professor X has more than one or two dropouts to his/her discredit, be warned.
An ear for music
There is no point in Christine Kenneally asking what kind of music monkeys like (23 February, p 29) unless we know what they have been exposed to during their formative years.
It is well known that teenagers dislike whatever music their parents like, and for the rest of their lives prefer the music that was in fashion when they were in their teens.
We need to get groups of “teenage” monkeys to listen to different styles of music, with father monkey coming in periodically to turn the volume down, to convince them that this is the “in generation” sound. Ten years later test them to find out whether they still like the music they thus learned to enjoy.
Christine Kenneally mentions birdsong, seal “music” and whale song: not whale speech and so on.
To speakers of Indo-European languages such as English, some other languages are as alien as Klingon, and their speakers’ musical traditions sound equally strange. Yet I have never had the slightest doubt whether somebody is singing or speaking. Barring evidence that other animals separate communication from “singing”, I’ll believe song is unique to us.
Findern, Derbyshire, UK
In 1956 musicologist Victor Zuckerkandl proposed in his book Sound and Symbol that the ear is the organ uniquely structured to perceive time. “No eye has ever seen time; no hand has touched time. But ears have heard time,” he wrote. As he observed, music played backwards is chaotic.
Point Pleasant, Pennsylvania, US
Apparently, amusia or inability to distinguish musical pitch is found in some 4 per cent of the population (23 February, p 37). I understand that Chinese languages are tonal, so meaning depends on pitch. So can 4 per cent of Chinese people not communicate properly?
Medical devices in court
Your report of the US Supreme Court’s decision in Riegel vs Medtronic may create the erroneous impression that the court has given manufacturers of medical devices a free pass to sell defective products (1 March, p 6).
While the court did hold that the Riegels’ negligence claim was pre-empted by Food and Drug Administration approval of the catheter used, the scope of the ruling is limited to those medical devices that have undergone the full rigours of pre-market approval.
The court’s 1996 decision in Lohr vs Medtronic stands: claims can be asserted against medical devices that were approved by the FDA as being “substantially equivalent” to a previously approved device. In 2005, 3148 devices were approved in this way and only 32 devices underwent full pre-market evaluation and approval.
Claims that address issues not considered by the FDA, such as post-approval misuse of a device, may still be brought.
Missile offence
Laura Grego is right to refer to the destruction by the US of its runaway satellite as a threat to the “fragile taboo against interfering with satellites” and to “efforts to protect the future use of space” (1 March, p 23).
The whole business of anti-ballistic missiles is coming to a head, and a new arms race seems inevitable. The British government has agreed to the US making its base at Fylingdales, North Yorkshire, part of its global missile defence system. The US hopes to install other parts in the Czech Republic and Poland. In both countries public opinion is strongly opposed.
US missile defence plans already appear to embrace Israel and perhaps the Gulf states, evidently against Iran; and Japan and South Korea, against China. Just what the central Asian states are agreeing to is obscure.
The satellite destroyed on 20 February was shot down by an Aegis anti-missile missile launched from a US warship, after a few weeks’ fiddling with software. Such one-off shots may score a hit, but this is not good enough for a defensive system. For defence to be effective, every incoming missile has to be intercepted, and this is impossible to guarantee.
It is far easier to see an anti-missile system as part of an offensive strategy by a state that has adopted a “pre-emptive” strategic posture 鈥� as has President Bush. It would need to protect only against the depleted retaliatory forces of, say, Iran.
An anti-missile arms race would be astronomically expensive, as well as unrewarding to all except the arms industry. Russia and China both propose a treaty banning the militarisation of space. The US is against this, choosing instead to work for “full spectrum military dominance” of land, sea, air and space 鈥� and now of cyberspace (23 February, p 24).
Promoting inequality
In arguing that “social inequity is not an objection to genetically engineering children” (23 February, p 48) Arthur Caplan perpetuates a naive argument that is used to justify all sorts of inequities. Providing everyone with the same level of access as the wealthy will blatantly never be possible, in any field, from healthcare to education. So controls are needed to at least attempt to redress inequities.
More worrying, though, is the way this point seems to be so lightly dismissed. The idea of a dual society in which a genetically engineered “super race” coexists with a conventionally conceived underclass is troubling indeed.
Truth travels slowly
Robert Matthews makes some interesting points about animal experimentation (16 February, p 20) but seems more concerned with scoring points than promoting genuine debate. Those who are interested in the Royal Society’s actual views on this issue should look at , not just the single sentence that Matthews is keen to refer to.
In this we reaffirm our commitment to supporting the use of animals in research where there are no alternatives. We strongly endorse the “three Rs” principle: the refinement of processes to keep suffering to a minimum; the reduction of the number of animals used in research projects to the minimum required to achieve meaningful results; and the replacement of live animals with non-animal alternatives where possible.
The Royal Society was one of the first scientific organisations to speak out in support of the use of animals in research under strictly controlled conditions. Together with the great majority of the scientific community, we continue to believe that the benefit from the use of animals in research justifies their use.
From Caroline Herzenberg
I must disagree with the sentiment expressed in the headline “Nothing but the truth” on Robert Matthews’s article. After a lifetime in science and of wholehearted commitment to protecting intellectual integrity, I have come to the conclusion that in the world outside science, cold facts alone are not enough.
Truth travels slowly, and falsehood moves fast. Additional techniques must be used by scientists in struggling against propaganda, and I recommend ridicule. Here in the US we are contending with huge amounts of propaganda from very powerful institutions, including corporations and our own government, as Dan Hind has already set out (19 January, p 46).
This propaganda generates and publicises falsehoods at a greater rate than any well-intentioned individual or limited group of individuals could possibly research and examine on the timescale of an effective counter-argument. Of course we must present the evidence and the facts, but this response will be too little and too late when the propaganda is being churned out by well-funded political or corporate noise machines working around the clock.
I suggest an immediate response of publicly ridiculing the most obvious lies and propaganda, followed promptly by a detailed response that is as thorough, thoughtful and accurate as possible.