Letter
In Canada, a bluenose is a person of Nova Scotia. I think the name refers to
the traditional occupation of that province, fishing at sea under conditions
that are so cold that one’s nose turns blue.
During the 1930s, there was a fishing schooner named The Bluenose, that
worked out of Lunenburg, Novia Scotia. It became famous because, in addition to
being a working boat, it won a number of races. Its image has been on the
Canadian 10 cent coin for 50 years.
Beating the jams
In his article on traffic modelling, Philip Ball makes the highly dubious
claim that reducing congestion will also reduce pollution
(15 January, p 34).
Like many traffic engineers, he chooses to ignore the effects of induced
traffic. Many decisions such as how to get to work or where to locate a business
are based on the relative availability of different modes of transport. If
journey times are reduced by widening roads, building a new underpass, or
providing drivers with more up-to-date information, some people who previously
walked or took the train will switch to driving, and a number of businesses will
move to areas with better road access.
Any decrease in exhaust emissions caused by faster flowing traffic will be
negated by the overall increase in car use. If governments were serious about
reducing congestion, pollution and road accidents, they would not spend billions
increasing road capacity, or plan towns around the needs of cars. They would
instead invest in buses, trams and trains, and build communities where you could
get about easily on foot.
Let the sunshine in
Tam Dalyell accuses the government of “pessimism” over its lack of support
for solar electricity in Britain
(22 January, p 49).
The main arguments against solar photovoltaics are well known: they cost a lot to install and do not
produce much energy (well under 20 per cent efficiency), which yields very
expensive power.
An additional and conclusive argument, however, is that in “on grid”
applications, solar photovoltaic panels are not the cheapest way to create
electric power from solar energy. Solar heating panels, which are significantly
less expensive, can replace another heat source, either electricity or gas
(which can be easily converted to electricity) and hence have the same effect at
lower cost.
This capability is shown most clearly where solar heat replaces heat produced
directly from electricity, which has the same net effect as making expensive
solar photovoltaic electricity and then using it to create heat. The difference
is that solar heating panels are a much less expensive way of turning heat into
power, while achieving 100 per cent efficiency.
In the case of gas-fired heating, solar heat reduces gas
consumption鈥攁nd the displaced gas can be burnt in an efficient (say 56 per
cent) combined-cycle gas turbine (CCGT) power plant.
It still makes sense to do R&D on solar photovoltaics鈥攖here may be
a cost-effective technology waiting to be discovered, many “off grid”
applications already make sense, and photovoltaics may be effective in other
markets where there is little demand for heating. But spending huge sums to
implement the wrong technology is a misallocation of (relatively scarce)
renewables support. The government’s pessimism is entirely reasonable.
Faster and faster
Your correspondent F. Gwynplaine MacIntyre suggests that the inertial
“gravity” produced during space flight would be enough to overcome the problems
associated with physical development in space
(22 January, p 50).
But MacIntyre has obviously forgotten some elementary physics. The effect would only be
produced during acceleration, which is unlikely to occur for the entire
journey.
Nonstick clay
In the article on killing algae with clay spray it is stated that the clay sticks to itself
(15 January, p 16).
This is in fact incorrect. The modified clay does not have the stickiness of the unmodified
clay and therefore does not form a cap on the bottom of the river.
A cap on the bottom is undesirable since bioturbation by benthic organisms is
important to move the PhosLock clay through the porewater zone of the sediments.
The clay does not act as a barrier but as an active phosphorus scavenging agent
in the sediment and will hold the bound phosphorus even under anoxic conditions
with no disruption to benthic organisms.
Best to bury it
I wanted to pick up on the point made by reader Fred Grisley regarding the
environmental consequences of biodegradable materials
(22 January, p 50).
Any material derived from fossil fuels that ends up in our atmosphere as a
gas is, generally speaking, bad news for the environment. Such products
that remain as stable solids鈥攁s many plastics do鈥攃an be
effectively disposed of by burying them.
What would be really useful is if a process could be developed to turn the
(used) liquid and gas products back into a more easily stored solid
form鈥攕uch as turning waste oils into solids for use in building and
landscaping materials.
An advanced solidifying technique may also be the best way to deal with crude
oil spillages at sea.
Letter
Could we not actively encourage the use of landfill sites for high-carbon
wastes, such as much household refuse? Can the scientific community work out
ways to stop groundwater contamination and the eventual return of the carbon to
the atmosphere?
If so, we could plant fast-growing trees with the intention of harvesting
them for burial鈥攅ffectively recreating the coal deposits we have spent the
last 200 years burning into the atmosphere. A possible use for that scourge of
English suburbia, the Leylandii, perhaps.
Third World countries could grow and bury such trees and receive carbon
payments from, say, the World Bank, who could organise carbon fees from
countries like Britain and the US who would be net carbon emitters.
If nature found a way to bury such trees and lock away their carbon, surely
we can do the same?
Peripatetic kidney
Your correspondent Linda Shields is puzzled that a kidney was removed in an
operation for an ovarian cyst
(22 January, p 51).
Sadly, although the kidney is retroperitoneal and thus strictly outside the
abdominal cavity, it can get in all sorts of difficult positions, and a
gynaecologist may inadvertently remove a pelvic kidney thinking it was an
ovarian cyst. As a practising gynaecological surgeon, I find these hazards haunt
my deepest dreams.
Nowt from nowt
Henry Bortman describes work by Jordan Maclay on measuring and possibly
extracting energy from the Casimir force
(22 January, p 32).
The implication of the article is that it may be possible to extract vast quantities of useful
energy from the zero-point energy of the vacuum.
If a device exists that operates cyclically and extracts any useful energy at
all from the vacuum, it will violate the first law of thermodynamics.
In principle, you can extract energy from the Casimir force in a one-way
process by allowing a cavity to change shape. By analogy, you can extract energy
from the gravitational force by dropping a weight. However, you cannot repeat
the process without restoring the system to its original state鈥攂y bringing
the cavity back to its original shape or lifting the weight back to its original
height.
Restoring the system to its original state requires exactly as much energy as
was originally extracted so there is no net gain.
Measurements of the Casimir force would be scientifically interesting, but
don’t hold your breath waiting for a breakthrough power source.
Horrible humps
So engineers have invented a friendly sleeping policeman for the slower motorist
(8 January, p 7).
What I would like to see is a cycle-friendly hump.
The designers of these fiendish things just do not realise that the abrupt
changes of slope at the start and end of humps give a painful jolt to cyclists
because cycles, while travelling much slower than cars, do not have
suspension.
Another common type of traffic calming features roughly textured strips
extending from the gutter to the centre of the road.
To cars these are nothing more than a minor irritant (in fact, the noise they
create inside a car is their major nuisance value), but to a cyclist they are
sheer hell.
Nature's bar codes
In suggesting that we should all have bar codes in our foreheads, your
correspondent Brian Moss is millions of years too late
(22 January, p 50).
Nature has already marked us with unique patterns of lines, on our fingertips
and retinas amongst other places. Those on our fingers mark every manual
transaction we make, while those in our retinas will, if current predictions
come true, soon be read automatically without our knowledge. Nature has prepared
the way for Big Brother.
Rudolph's rear
The difficulty with Michael Hill’s theory about the reason for Rudolph’s red nose
(29 January, p 52)
is that it would be impossible to see Rudolph’s nose when the Doppler
effect is causing it to appear red, because you would only be able to see his
rear end. I don’t think the song would sound the same, do you?
Living impaired
In the
22 January Feedback
you say “According to the `Scole Report’ in Proceedings of the Society
for Psychical Research, no one was allowed to take an infrared or
light-intensifying camera into the seance room, in case they harmed the
spirits.”
I wonder what kind of harm might have been caused. Nothing life-threatening,
I hope.