Life from outer space
In his review of two recent biographies on Fred Hoyle, David Hughes refers to Hoyle’s work on panspermia, the idea that life came from space, as one of his “hit and run interests” (7 May, p 49).
Presumably this is meant to give the impression that panspermia formed only a minor part of Hoyle’s work. In fact Hoyle and his colleague Chandra Wickramasinghe published widely on panspermia and, even at the end of his life, Hoyle remained convinced life arrived on a comet. Far from being a passing interest, the Hoyle-Wickramasinghe theory of panspermia may yet prove to be Hoyle’s most important contribution to science.
Newborn AI
Ah, more hype about Cyc, the artificial brain that will supposedly usher in the dawn of true AI (23 April, p 32). Forgive me if I’m sceptical, but “hoovering up new facts” is not the same as learning, as any college student could testify after spending all night cramming only to fail their exam. After it hoovers up all the various web pages about global warming, for example, and assimilates all the contradictory information about that topic that rains down upon its head, will it have an opinion on the subject that it will be able to lucidly defend? Somehow I doubt it. When we can’t make an AI that can converse for more than a few seconds without making a fool of itself, and we can’t make an AI that can drive itself a few kilometres across the desert, Cycorp founder Doug Lenat’s assertion that we are “less than 10 years” from a singularity is laughable. Cyc may well reach the point where it can regurgitate uncontroversial facts that are logically organied in simple ways. But it will still fail its exam resoundingly.
An interesting perspective on this is provided by the fact that Cyc currently contains 3 million assertions, and that this apparently comes from an attempt to minimise the amount of data it’s “born” with. Contrast this with a newborn baby; it’s hard to say just how many “assertions” a baby is born with, but it seems certain that, unlike Cyc, it is not born with “the entire Linnaean system of taxonomy of plants and animals” as Cyc apparently will be. To me, this illustrates that AI is still not only barking up the wrong tree, but is in the wrong forest. The first successful AI will be like a newborn baby: essentially completely naive, but designed to be so flexible as to be capable of learning any language, assimilating any fact, adapting to any environment. We need to think much harder about the simplicity of the human brain, and about how complexity emerges from that simplicity.
For the record
鈥� In our feature about euthanasia (“Last rights”, 23 April, p 46), we omitted to state that in 1997, Colombia’s Constitutional Court overturned a prohibition against assisted suicide and euthanasia for the terminally ill. However, Congress has not yet passed enabling legislation to carry it out, leaving the exact legal position in that country unclear.
鈥� We were guilty of some diabolical proof reading of the 14 May issue. In the illustration that started the “What the hell..?” feature (p 41), the figure we gave for the time since the Hadean was out by several orders of magnitude. It should have been “4,500,000,000”. In addition, there was an egregious apostrophe in “year’s”. What’s more, in our feature about the Milky Way (p 30), the figure we gave of 7.7. million kilometres for the radius of the dark region around the galaxy’s central black hole is correct 鈥� but that is about 20 times the distance from the Earth to the moon, not twice it.
鈥� In the article on the causes of autism (14 May, p 14) we said “Jill James published a study showing that people with autism have raised levels of glutathione, a compound that detoxifies mercury.” It should have read “lowered levels of glutathione”.
鈥� In “Instant messaging falls prey to worms” (14 May, p 26), we called an API “a piece of publicly available code”. In fact, APIs are not code themselves but a way for programmers to hook into another piece of code and get information from it via their own program.
鈥� Finally, Feedback’s item about punk scientists (14 May) gave a title from the wrong medium to the latest album by evolutionary biologist Greg Graffin’s band Bad Religion. This should be The Empire Strikes First not The Empire Strikes Back.
Bird-friendly turbines
If we build wind turbines, they kill birds which fly into them (7 May, p 10). If we don’t build wind turbines, global warming will kill them instead.
So what can we do? Putting lights on the turbines of marine wind farms would make then more visible to migrating birds, especially at night. Painting coloured bars or tips on the blades would make them more obvious when they are turning 鈥� and might even turn wind farms into art installations, which could improve their popularity.
Names of names
In response to Feedback’s penultimate paragraph on names of names (16 April), I suggest metanym or nymonym. You could ask readers for a better metanym, but you’d risk verse and adverse response.
For your penpenultimate paragraph on polyrepetitive words, (was that a deliberate placing of the paragraph?) I offer nymonym again (is that too close to be a Fishbein coincidence?
And the nonaming refuseniks? There’s antinymonymer and her rabid brother who is antinymonymiac. And monikerer’s oppo antimonikerer who is of course a polyrepetitive nymonym (not Fishbein 鈥� too adjacent). Which leads to a polyrepetitive word for a polyrepetitive category of names: polynymopolynym?
All from 2 paragraphs. Is that positive feedback?
I invented AI
The term “Artificial Intelligence” was not coined by John McCarthy as stated in your brief history of AI (23 April, p 35), though the conference at Dartmouth College in 1956 (which I did not attend) was probably the occasion of its first public use. In the first semester of that year, I was a visiting lecturer at Harvard when Marvin Minsky and Oliver Selfridge called at my office on the Van Vleck bridge. They said they were seeking a snappy title for intelligent behaviour by computers, as a need for such a term would soon be urgent.
We decided on “intelligence” before pausing to find a good adjective. I suggested “artificial”, they were happy, and left. Archivists have attempted to verify this with the other parties to no avail, so an event has become an anecdote, and I suffer a little tic whenever John McCarthy is credited with the etymology.
Human uric acid
Steve Benner’s group at the University of Florida, Gainesville, plans to reconstruct ancient versions of mammalian uricase in order to determine why humans retain high uric acid levels in their blood (23 April, p 44). They wonder if reducing uric acid levels by treatments for gout or hypertension might have adverse side-effects.
Lubert Stryer once proposed that our high blood uric acid levels replaced vitamin C’s antioxidant effect and protected our cellular DNA from oxidative damage 鈥� for unlike elephants and other long-lived mammals, primates long ago lost their ability to regenerate vitamin C. He pointed out that lower primates with far lower blood uric acid levels had comparatively short life spans and high cancer rates.
Furthermore, a recent Nature report suggests that the near-saturation levels of uric acid within human cells means significant leakage of intracellular fluid can promote uric acid crystal formation in tissue fluids. Thus uric acid crystallisation signals tissue damage in humans, and uric acid crystals (but not dissolved uric acid) serve to initiate inflammation and encourage immune cells to attack microbes whose proteins appear in synchrony with cell damage. Uric acid crystals may even underlie some cases of chronic inflammation and autoimmunity in genetically susceptible individuals.
United against spam
A collaborative spam filter along the lines described in your article has run quite well for a number of years (14 May, p 24). The Cloudmark SafetyBar has well over 1 million users who identify messages as legitimate or spam, ranking them in nine levels of trustworthiness (including negative levels). As anticipated by the team in the article, such a social network is extremely accurate at identifying spam while generating very low levels of false positives.
My experience with the system over about 18 months is that of the 49,252 emails I received, 2479 were spam. The software identified 2432 of these and left me to manually identify the remaining 47. Only 13 of these manual identifications happened in the last six months, so, as expected in the article, increased numbers of users are improving the effectiveness of the system. I now have to deal with only two spam messages per month myself.
From Eric Solomon
Filters of any type, networked or not, can never beat spammers. First, it is so easy to disguise key words in any of a billion ways. Second, the idea of a network sharing information implies that each user will be prepared to fill his hard disc with a myriad of sample spams, or extracts therefrom. And third, the system proposed in the article would be extremely vulnerable to sabotage.
The only complete solution to the spam problem is for email users to embrace the concept of passwords. I proposed such a system to the all party internet group at the House of Commons in September 2003, and to other interested parties. The idea is that email clients (programs handling email) will reject incoming messages not containing a password in the message body.
Each user selects, or changes, their password and may have different passwords for different purposes. Senders who need to contact a recipient whose password is unknown to them will simply send a message with a meaningful subject line, and the single word ‘password’ in the body of the message. The recipient can then decide whether to send his password, or not.
London, UK
From Chris Jack
The proposal to collaboratively look for spam by behind-the-scenes software sharing emails without user consent has two keys flaws. First, the ability to match emails automatically is no longer straightforward. Spammers add random text and variations to their email to make direct comparison harder.
Second, the idea that potentially confidential emails might be sent to other people’s computers is anathema to most people’s privacy requirements.
Opt-in schemes, where people voluntarily indicate particular emails are spam and this information gets centralised, avoid at least the second problem and make the first problem easier to analyse. These are already in widespread use.
St Albans, Hertfordshire, UK
From Morris Pearson
You say that filters would be a lot more effective if they pooled data. Further research would have led you to SPAM NET.
Owings, Maryland, US
From Rich Tietjens
Wonderful idea. It’s called the DCC, but instead of relying on hundreds of thousands of (frankly, bloody ignorant) end-users, it runs at the server level 鈥� which is where spam must be blocked, to be effective.
One hopes that the next development from your pundits is fire, or the wheel. We’ve never seen those before, either.
Newberg, Oregon, US
Too many rich people
Over the past 50 years, in less than a single human lifetime, the world’s population has grown from 2.5 billion to 6.5 billion. There are now 4 billion more people on the planet than there were half a century ago, and there will almost certainly be a further 3 billion in another 50 years. These facts are central to the world’s environmental crisis.
All countries concerned with environmental sustainability should be aiming to stabilise their populations as quickly as possible (7 May, p 5 and p 8). That is why the Sierra Club is trying to limit immigration 鈥� so that the US can show leadership. Developing nations will not accept that they should limit their population growth while wealthy nations continue to gallop ahead.
The urban sprawl of the US is probably the single greatest environmental threat to the world and needs to be stopped in its tracks. Artificially boosting US growth by encouraging huge numbers of immigrants is fine if you don’t give a damn about the kind of world future generations will inherit.
From Jenny Goldie, Sustainable Population Australia
Calls for cutting immigration carry no underlying message that it is OK to continue polluting. Environmental impact is the product of population, consumption and the technology required to deliver goods to the people. Thus, in order to lower Australia’s total ecological footprint, it is necessary to stabilise and then reduce population, lower consumption and develop technologies that minimise our impact on the Earth. One or two out of three won’t do, it has to be all three.
It is simply irresponsible to ignore population as an environmental issue. Of course, excessive consumption by the developed world is a major cause of pollution. Our per capita footprint needs to come down from over 7 hectares to around 2 if we are to have global equity. But in any country, total footprint is a product of per capita footprint times the number of “capits”, or people, and the more people there are, the bigger the footprint.
The high moral ground about increased immigration, assumes the whole programme is of intrinsic humanitarian worth. Yet in Australia the bulk of immigrants are skilled workers. Unfortunately, many come from poorer countries that can ill afford to lose them. By all means increase the humanitarian stream, especially as climate change bites and many people are displaced by rising sea levels, but only if decreasing the rest of the programme.
Michelago, New South Wales, Australia
Salt's deadly advance
Doug Cross describes salinisation of freshwater aquifers following over-abstraction near the sea and resulting in negative hydrostatic pressure (30 April, p 28).
In the Murray-Darling river basin in south-eastern Australia, exactly the opposite has occurred. Excessive irrigation with good-quality fresh water from the Snowy Mountains on productive farmland situated over extensive salty aquifers has resulted in a disastrous raising of the saline water through positive hydrostatic pressure. First trees, then vegetable crops die, to be replaced by unproductive salt pans when groundwater breaks the soil surface.
A toxic lungful
I was intrigued by your article on the prospects of inducing a state of hibernation by exposure to hydrogen sulphide (30 April, p 8). Many years ago I worked on a pilot plant making hydrogen sulphide. During that time I had many a lungful of the gas. I remember the symptoms well: depression, indigestion 鈥� and insomnia!
Climate blog
If New 杏吧原创 hasn’t already done so, global warming sceptics’ points, such as David Bellamy’s, are well rebutted at , a new blog set up by climate scientists.
Repeated reference to that site could save many trees being transmuted into copy in the magazine, thus shrinking its footprint. This would help the majority of readers who are doubtless aspiring to lower their carbon emissions.
Lightning strikes
The telephone line repair supervisor in my local area tells me he keeps a record of lightning strikes on a map and has noticed that they are much more frequent around quarries, especially those which use explosives to break out the rock (7 May, p 30). A mile downhill from my nearest quarry, the house jumps with the blasts. No doubt the surrounding granite has developed cracks and I wonder if perhaps escaping radon gas helps ionise the air?
Leaking oil and gas
Fred Pearce states: “Old oil and gas fields stored hydrocarbons for millions of years. The same could be done for carbon dioxide from power stations” (30 April, p 26). This is wrong. Some fields have lasted for many years but an unknown number leaked away in the past and are some are leaking today. Colonel Drake drilled his first oil well in eastern Pennsylvania at a place where oil was simply leaking out of the ground. California and Iraq have tar pits that resulted from the surface exposure of oil deposits. I suspect there are many others. The idea of sequestering CO2 is a dreadful notion.
Caring, not killing
Expert attention to detail, not therapeutic killing, should be society’s method of relieving suffering in those fearful of what the future holds (23 April, p 46). Morphine and other strong drugs against pain should be carefully titrated to meet the patient’s need. They then do not cause respiratory depression and death. Side effects of constipation and nausea are avoided by using adequate laxatives and anti-emetics, and over-sedation can be avoided with the newer synthetic opioids. Other drugs have dramatically decreased the pain of those who do not respond well to morphine.
Let me decide
I have problems with Google’s proposed method of ranking the articles it finds (30 April, p 24). The whole point of using a search engine is to find multiple related articles regardless of the source. It is not the engine’s job to make judgements, merely to report what is out there and enable readers to make up their own minds.
If I want to see BBC articles, I will add BBC to the search query. When I search on Google I don’t want filtering decisions to be made for me by a computerised AI.
Green little people
Rowan Hooper suggests that knocking out the growth hormone receptor to extend life is “unlikely to catch on in people” due to the dwarf nature of the similarly modified GHR-KO mouse (14 May, p 8).
Surely, however, a dwarf race is one of the few ways in which to offset the more obvious negative effects that might be experienced by a society of ever longer-living humans. Assuming they were shrunken proportionately, our future half-height descendants could have twice as many road carriageways, four times as many sports pitches, and eight times as many apartments in the same space that we giants occupy on our already crowded planet.
More than a magazine
The main criterion my children use in choosing a magazine is “what’s it got free with it?” After New 杏吧原创 has provided us with a DVD and a map of the galaxy, are we seeing the same trend coming to science magazines?
Will we soon be deciding between Nature‘s free poster of the complete muskrat genome and New 杏吧原创‘s DIY cold fusion kit? I can’t wait.