Artificial colonists
Richard Gott’s article (8 September, p 51) certainly made some good arguments for manned space exploration, as did many other theme pieces in that Conquest of Space issue.
We run smack into a nasty wall, however, when the logistics are considered. Flesh-and-blood humans confront the horrible realities of a hostile space and want for the protection, biological resources and time to let spacefaring be an easy reality.
It strange to think that one solution to all this may be an idea touted in both the best and the worst of sci-fi 鈥� the cyberman. If we can create the hardware that can make full-blown artificial intelligence possible, infuse that with a full human personality and intellect, and then jettison organic prejudice so that we can consider them progeny, the stage is set.
The silicon tribe of Homo sapiens could easily handle the physical rigours and demands of space, including the need to say alive for centuries to reach a destination. A Columbus of metal and plastic may be the hero of 2492. If you don’t like that, you’ll have to find out how to get the damn “wormholes in space” dream to work.
Mathematical reality
Max Tegmark postulates that the ultimate theory of everything is inherent in our universe that is, in and of itself, pure mathematics.
Now I wonder, are we yearning for such a theory for the benefit of us human beings here on Earth now, or are we going to bequeath it to the Boltzmann brains that will outnumber us in the aeons to come (18 August, p 26)?
Mathematical reality
Max Tegmark proposes that the universe is made of maths (15 September, p 38).
The common-sense view is that mathematics is a human invention based on sense experience, one which has enabled us to explore and to some extent master the world in which we find ourselves. It by no means follows that this external reality, which I believe in some sense really exists, is “essentially mathematical”, supposing this statement has any sort of sense.
Philosophically Tegmark is accepting Platonic realism: the view that we discover mathematical structures because they already exist in some higher realm or dimension. His argument appears to be that if all mathematics really exists, then if some mathematical structure does not have a physical counterpart in our universe then it must have such a counterpart in some other parallel universe that we have no connection with. The question is: how do we become aware of this extra-universal mathematical structure if it has no physical counterpart in our universe?
Mathematical reality
Jorge Luis Borges wrote in On Exactitude in Science of an empire that created a map that was as large as the empire itself. It seems that Max Tegmark is replicating this with his extrapolation of the mathematical models that have been designed to simulate the universe. It is important to keep in mind that the map is not the terrain. Models used by mathematicians and physicists often produce nonsensical answers that must be placed back into conceptual context before they can be useful. While I am willing to accept that the equations point to Tegmark’s level-IV multiverse, I would much rather see some kind of contextual evidence.
Mathematical reality
Max Tegmark’s hypothesis that mathematics is the ultimate physical reality seems to be a variant on the idea that anything which is logically possible must “exist”, in some sense of the word (15 September, p 38).
His argument appears to start from the notion that there is a dualism of logical and mathematical truth on the one hand and physical truth on the other; this dualism usually regards logical and mathematical truth as the more basic. He then seeks to abolish this dualism in the most difficult way: taking the logical/mathematical world as the real one, but without casting any light on what the nature of this entity is.
Some of us think the opposite far more likely: that logical/mathematical truth is subordinate to the physical facts of the universe.
Moreover, his hypothesis seems to require that logical/mathematical truth is a fixed thing, so that there can exist other universes in which any logically valid fact is physically true. Yet a mathematical proof depends on how symbols can be arranged along a line in our actual space, so mathematical facts might be different in a universe with different laws. This adds another difficulty to the notion that there must exist a universe in which any fact that we can mathematically derive is true.
Mathematical reality
Max Tegmark attempts to get past the objection that his hypothesis defies intuition with a deft Darwinian gambit: arguing that common sense is evolved only to grasp a fraction of the universe.
In fact, intuition is beside the point. The real challenge facing Tegmark is to overcome the same objections that defeat Cartesian dualism. That is, if there is something “out there” that is not material, where exactly could it be, and by what mechanism does it impinge on the material world?
I suppose Tegmark’s ultimate manoeuvre might be to posit that there is no material world at all, and that maths is all there is. But by explaining everything, that would explain nothing.
Carbon ban needed
The Montreal protocol on substances that deplete the ozone layer provides an instructive contrast with the Kyoto agreement on climate change (22 September, p 3). Montreal banned the guilty pollutants, and though industry initially issued shrieks of pain, it went on to develop alternatives. Unfortunately, Kyoto simply provides a hugely complex framework for buying and selling the right to carry on producing carbon dioxide.
Kyoto is not enough. While it has created an embryonic carbon market, it is open to fraud and inaction. We need a new international agreement modelled on Montreal to make actual cuts in carbon dioxide and other climate change gases, rather than providing a means for financial institutions to profit from ever more complex transactions.
Open access to what?
It is not clear whether Jim Giles is one of those who would like to see research publications in the humanities strangled, but that is a certain result of the “open access” publishing model he describes, under which authors will be charged $1000 or more to get into print (22 September, p 22).
The wealthiest 5 per cent of private US universities might subsidise publication beyond science and engineering. But no state-funded institution here would dare even to consider such a subsidy for the humanities.
As a supporter of the free software movement it pains me to cast doubt on any idea that might promote free access to publications. But such charges would silence all but the wealthiest who return to scholarly research after retirement.
It may be that private online publication (vanity publication, but cheaper) is the only feasible mechanism in the humanities. I have resorted to this after being repeatedly told: “We like the book. All you need to do is take out all the foreign language passages and find a $30,000 subsidy. We will, of course, require you to sign over all copyright.”
Parallel realities
You quote David Albert as saying “What we really want to know is why this branching [of the universe into many worlds] happens in the first place” (22 September, p 6). Max Tegmark supplied the answer by giving the most convincing reason I have seen to accept the many-worlds interpretation of quantum theory: “The mathematical universe hypothesis implies that such a simple theory must predict a multiverse… because this theory… lacks enough bits (of information) to completely specify our universe” (15 September, p 38).
In other words, if the ultimate laws of physics can be written on a T-shirt, where does the extra information that describes our particular universe come from? Tegmark’s answer is that this information specifies the location of our universe in the multiverse. But some 10100 random events have occurred since the big bang, so either the universe is incredibly random or there is more to it than meets the eye.
Man of renown
It was disappointing not to see mentioned as one of the top 10 influential space thinkers, given what he achieved and his legacy (8 September, p 48). This included the phenomenal success of the Redstone, Mercury, Gemini and Apollo missions, which incorporated his design for the rocket combustion chamber, fuel pump and injection systems developed in Germany in the 1930s and 1940s.
These design principles have since been used extensively by others, and this technology, with modern innovations, remains the mainstream of rocket propulsion systems in use today and for the foreseeable future.
Heart of the antimatter
Your special issue on the conquest of space contained a number of very good and interesting articles (8 September). A glaring exception was “Engage the antimatter drive” by Ben Crystall (p 62). which ignores the huge practical difficulties of storing and transporting significant amounts of antimatter.
Mathematical reality
Max Tegmark proposes that the universe is made of maths (15 September, p 38).
The common-sense view is that mathematics is a human invention based on sense experience, one which has enabled us to explore and to some extent master the world in which we find ourselves. It by no means follows that this external reality, which I believe in some sense really exists, is “essentially mathematical”, supposing this statement has any sort of sense.
For the record
鈥� In an article on Australian biotechnology (28 October 2006, p 60) we suggested that New South Wales has relatively few biotech firms compared with other Australian states. In fact, NSW hosts 25 per cent of Australia’s 421 core biotech companies, according to a 2006 report.
That time of month
The perhaps aptly named Randy Thornhill seems surprised that women “do have oestrus” (15 September, p 18). Perhaps he and his male colleagues should get out of the lab and talk to a few girls. Or they could read the health and problem pages of most women’s magazines to find out what’s going on.
I may not have the research to prove it, but I am pretty certain I know when I am most fertile. Apart from the changes in vaginal mucus and temperature that women are encouraged to monitor if using the “rhythm” method of contraception, there are mental signals too, such as heightened desire, sexual dreams, or simply that the idea of having a baby unexpectedly pops into your head. These feelings calm down again pretty quickly after the most fertile time of the month, and are sometimes replaced by mild feelings of sadness (perhaps corresponding to hormonal changes due to “lack of pregnancy”), which move on to a clear disinclination to have sex and the tetchiness that people often attribute to “the time of the month”.
As the end of the cycle approaches, women probably also notice changes in body odour, and an increase in greasy skin and hair 鈥� outward signs that we’re no longer “up for it”. And don’t forget that some women also experience mild “ovulation pain”, known as “mittelschmerz”, attributed to hormonal changes around ovulation, and increases in fluid in and around the uterus.
Lack-of-drug danger
Millie Kieve devotes a full page (15 September, p 24) to her view that serious adverse drug reactions are killing people, and you give a further quarter page to a news report that seems to support this (p 4). Then, in a space about the size of a postage stamp, you report that since young people have started to shun antidepressants following adverse publicity about them, suicide rates have increased by between 14 and 49 per cent (p 5).
This shows firstly that the drugs do work and secondly that hostile publicity has probably resulted in more deaths than have adverse drug reactions.
Mysterious morgellons
There may be simple explanations for the experience of “Morgellons disease” (15 September, p 46). Fungi, agrobacteria and other so-called plant pathogens are known to cause infections in people with immunodeficiencies and underlying illnesses, though they have not been associated with delusional parasitosis.
Readers should also have been alerted to the fact that Morgellons enthusiasts Ahmed Kilani and Robert Bransfield are advisers to the Morgellons Research Foundation.
Risk trap
In his review of a book about misunderstanding statistics, Mike Holderness seems to have fallen into a trap himself (15 September, p 57). “Roughly 9 per cent of women suffer breast cancer,” he writes. Then: “So, out of 1000 teetotal women, about 90 will suffer breast cancer.”
In fact what we have is a 9 per cent risk for a total adult female population. That includes unknown percentages of women who drink one glass of wine a day, or a bottle of gin a day, or are teetotal, or get pissed out of their minds only on Saturday nights, or used to but haven’t touched a drop since 1985…
The risk of breast cancer rises “6 per cent for every drink consumed on a daily basis”, we are told. Holderness appears to assume the baseline used is the (unspecified) rate for teetotal women, not the total female population rate, but I wouldn’t count on that without seeing the report.
Wording that personalises the statistic to a rise in “a woman’s” risk of breast cancer is misleading if not meaningless, because every woman, until she starts drinking daily, is somewhere else on the scale from zero drinking to daily drinking, so we don’t know what her risk level was before.
Mike Holderness writes:
鈥� Hoist by my own petard, and by the urge to simplify.