Letter
If there are multiple universes, it should be relatively simple to travel
from this one to another. All we need to do is wrap people in a protective
bubble and fire it at the speed of light towards two slits in a giant wall. They
then have about a 50/50 chance of passing into another universe, assuming that
they do not get interfered with by their alternative universe counterpart.
Flying fission fears
NASA’s belief that its nuclear-powered rocket project can piggyback on an
assumed softening in public attitudes to nuclear power is fatally flawed
(7 July, p 4).
If attitudes to nuclear power are changing, then the last thing the
nuclear power industry wants is for sensible public debate to be distorted by
worries about nuclear rockets exploding.
Anti-nuclear activists should speak out against this unnecessary project.
Pro-nuclear power environmentalists should protest even louder.
Letter
Your article failed to distinguish clearly between using nuclear rockets for
travelling to Low Earth Orbit (LEO), which includes the International Space
Station orbit at 380 kilometres, and from LEO to outer space.
The concerns expressed in the article apply only to the first. For LEO to
outer space missions, the nuclear rocket poses no safety or environmental
concerns. Because of its higher performance and unique features, we have been
advocating nuclear rockets for several missions that are either impractical or
impossible with chemical rockets (see “Fission Ships”, New 杏吧原创, 2
December 2000, p 32).
On a flap
I was interested to read of the efforts to make a person-carrying ornithopter
(7 July, p 34).
However, these may have more success if the aircraft is modelled
not so much on a bird as on a dragonfly. These insects, along with the related
damselflies (order Odonata), are unusual in that they flap their front
pair of wings downward as their rear wings flap upward, and vice versa.
So a dragonfly ornithopter (an odonathopter?) built with two wing pairs
flapping this way would be less likely to bounce up and down as the wings flap.
This would make it easier to take off and land and the pilot would be less
likely to feel sick. There would be a tendency to rock back and forwards in each
flapping cycle, but tail fins could reduce this. It could be further stabilised
by the gyroscopic effect of a flywheel in the drive mechanism.
Malaria matters
Your editorial states “A vaccine for malaria . . . should not be beyond the
wit of modern scientists”, and offers the useful insight “if only enough money
were invested in research”
(14 July, p 3).
Indeed. With the complete sequence of its genome already on file, the malaria
parasite turns out to have little more than five times the number of genes of
Escherichia coli, the gut bacterium beloved in laboratories. Much of the
“extra” genomic material in the parasite appears, however, to encode highly
variable proteins that give it a powerful capacity to evade the host’s immune
responses.
Around one million children die of malaria each year. Pregnant women are
another very vulnerable group鈥攁nd this has serious implications for mother
and infant health. Globally, 300 to 500 million people suffer from malaria, and
without the timely intervention of effective drugs it can be lethal. There is no
question that this level of disease is also a huge barrier to economic
development in Africa, Asia and South America. Resistance to anti-malarial drugs
is also an increasing problem.
The development of effective vaccines, not just for malaria but also for TB
and HIV, requires global development programmes on a scale unprecedented in the
history of biology. Malaria’s “Manhattan Project” will take wit, money and many
thousands of scientist-years. It would be a depressing comment on our species if
its governments and scientists could come together to build weapons of mass
destruction, but baulked at equivalent efforts to create medicines for the sick
and dying.
Eight legs better
Dog lovers will share my puzzlement that Susan Blackmore seemed to be
surprised to discover that animals other than humans could exhibit “consciousness”
(30 June, p 52).
However, I want to mention my experiences with quite another animal,
Octopus vulgaris.
In the early 1960s I was studying the balance organs (statocysts) of
octopuses for my PhD. We trained them to respond to visual or tactile cues,
rewarding them with a crab if they responded “correctly” or an electric shock if
not. Each of us trained about 20 octopuses, which were kept in separate
tanks.
Imagine my surprise when I discovered that the octopuses not only learned to
identify different cues, and give the “correct” response to them, but that they
also soon learned to identify different testers. Because of this, we did later
experiments remotely to remove the tester from the equation (the results were
similar). It may be unscientific to say that they had “consciousness”, but I
definitely got the impression that they related directly and differently to each
of us.
These animals are the only invertebrates protected by British law. They were
added to the 1986 Animals (Scientific Procedures) Act in 1993 in recognition of
their ability to feel pain. Consciousness, it seems, does form a continuum from
the “highest” invertebrates to us. It will be simpler, and much less complex in
non-human animals, but will nevertheless be there.
Bananas about GM
Contrary to the impression given by your story and editorial on the banana
genome project
(21 July, p 7 and
p 3),
genetic engineering is not the only
option for improving “sterile” banana cultivars which have three sets of
chromosomes (triploid) instead of two (diploid). Although triploid bananas don’t
breed well, if at all, they can be induced to produce seed if pollinated by
hand.
Honduras’s agricultural research foundation has had the most successful
conventional banana breeding programme to date. The Honduran Foundation of
Agricultural Research has bred disease-resistant bananas that are now grown
extensively in Cuba. One called Goldfinger is also grown in Australia, and
others are on trial in Africa and elsewhere. Conventional breeding can deliver
the goods, especially when it comes to bananas favoured by developing
countries.
It is true that it may be impossible to alter traits in the familiar
“Cavendish” banana with conventional breeding because of sterility problems. But
it may be possible to breed a commercially acceptable disease-resistant export
banana using a fertile dwarf variety of “Gros Michel”, an earlier export dessert
banana.
Many banana scientists, including me, believe that genetic engineering should
complement rather than replace conventional breeding strategies. Let’s not put
all our eggs in one basket.
Nonscience
What are we to make of postulates such as the multiverse, which make no novel
testable predictions, and therefore cannot be verified or disproved, even in
principle
(14 July, p 26)?
For centuries mathematicians have created marvellous mathematical worlds on
paper. But useful models should tell us, we hope, more than we already know.
What does it mean to say that the “. . . evidence that other universes exist is
at least as strong as the evidence for pterodactyls or quarks”.
How can a clever, but nonetheless only descriptive, abstract mathematical
model be seriously compared with a dinosaur bone you can hold in your hand?
Deutsch is critical of scientists who do not accept his viewpoint. He
believes they are sticking their heads in the sand. But with so many unresolved
problems in quantum mechanics, isn’t it premature to make such declarations?
There is nothing particularly wrong with a scientist engaging in
philosophical or religious speculation. If philosophers and religious leaders do
it, why not scientists? Yet it is worrying when scientists plead special
privilege for their opinions and speculations because they possess “scientific
authority” which, it seems, can make up for a lack of scientific proof.
Destroying other species could rebound on us
Unless one is omniscient, it is not possible to be sure that the demise of
any species will improve life for humans, whatever your correspondent Richard
Sears says
(14 July, p 52).
There are too many interconnections between species鈥攊nterconnections
misunderstood, not fully understood, or unimaginable until a catastrophe
happens. Therefore, it is reckless to believe that everything humanity does for
its own benefit will ultimately prove to be so. Enlightened self-interest would
suggest caution in all things, even if one takes Sears’s moral stance of “My own
species, right or wrong, to the exclusion of any other”.
There is also the difficulty that what benefits a white Anglo-Saxon living in
North America, say, might not benefit humanity as a whole. Every action has
unforseeable consequences as well as the intended results.