• New book reveals the many forms of the snow crystal

Leading snow crystal scientist publishes book in bid to persuade the world that no two flakes are exactly alike

  • Obituary: Tim Miles

Obituary: Researcher with a radical approach to the understanding and remedying of dyslexia

  • Spacewatch: 7 January 2009

The planet Venus blazes in the SSW at nightfall, stands at its greatest angular distance from the Sun (47°) on the 14th and remains conspicuous as an evening star until it plunges into our evening twilight in late March. Viewed through a telescope, its dazzling cloud covered disc grows from a small almost-first-quarter phase tonight, to a large slender crescent as it moves towards the Sun's near side. Indeed, by February it should be possible to make out the crescent through binoculars.

The changing phases of Venus were first observed by Galileo in the autumn of 1610, providing key evidence in his championing of the Copernican (Sun-centred) cosmology. In fact, his first use of a telescope for astronomy came in the previous year and in 2009 we celebrate its 400th anniversary as the International Year of Astronomy.

Until the first Venus flyby by Mariner 2 in 1962, there was speculation that the Earth-sized planet might harbour primeval forests below its opaque clouds. This and succeeding probes, culminating in ESA's Venus Express which began to orbit Venus in 2006 and is due to conclude its mission this year, have told a very different story. The clouds are of sulphuric acid and float in an atmosphere largely of carbon dioxide. This crushes the surface at a pressure some 92 times that of the Earth's atmosphere and keeps it at a roasting 462C. Not what we might expect for a planet named for the goddess of love and beauty.

  • Snowflakes under the microscope

Snowflakes photographed using a designed photo-microscope

  • Atheist bus campaign spreads the word of no God nationwide

Anyone who has spent a chilly half-hour waiting for a double-decker may already have doubted the existence of a deity. But for those who need further proof, a nationwide advertising campaign aimed at persuading more people to "come out" as atheists was launched today with the backing of some of Britain's most famous non-believers.

The principal slogan ? "There's probably no God. Now stop worrying and enjoy your life" ? can already be seen on four London bus routes, and now 200 bendy buses in London and 600 across the country are to carry the advert after a fundraising drive raised more than £140,000, exceeding the original target of £5,500.

The money will also pay for 1,000 advertisements on London Underground from next Monday and on a pair of giant LCD screens opposite Bond Street tube station, in Oxford Street. Organisers unveiled a set of quotes from public figures ? including Albert Einstein, Douglas Adams and Katharine Hepburn ? who have endorsed atheism, or at least expressed scepticism about a Creator. The words "That it will never come again is what makes life so sweet" are quoted from the poet Emily Dickinson.

At the launch in a heated marquee next to the Albert Memorial, the television comedy writer Ariane Sherine, creator of the campaign, said: "You wait ages for an atheist bus and then 800 come along at once. I hope they'll brighten people's days and make them smile on their way to work."

She suggested the campaign in a Guardian Comment is free blogpost last June, saying it would be a reassuring alternative to religious slogans threatening non-Christians with hell and damnation. At today's launch she said the sheer number of donations, which were still coming in, demonstrated the strength of feeling. "This is a great day for freedom of speech in Britain. I am very glad that we live in a country where people have the freedom to believe in whatever they want."

Joining Sherine were Richard Dawkins, author of The God Delusion, Hanne Stinson, from the British Humanist Association (BHA), the philosopher AC Grayling and Graham Linehan, who wrote Father Ted, Black Books and The IT Crowd. There were messages of support from the actor Stephen Fry and the writer Charlie Brooker.

According to the BHA, "huge numbers" of people in Britain have non-religious beliefs ? between 30 and 40% of the population, with a higher figure, between 60 and 65%, in young people.

Hanne Stinson said: "We all, whether we have religious or non-religious beliefs, have a right to be heard, and no one particular set of beliefs has any more right to influence the public debate than any other. The message isn't aimed at people with religious beliefs ? it's aimed at atheists and agnostics."

Most commentators recognised the slogan as a simple statement of non-religious belief and appreciated that it was designed to reassure people there was no reason to worry about being non-religious, she said. "People can lead a happy, enjoyable and rewarding life without religion."

Prior to the launch, Sherine was concerned that the posters would be banned from buses operated by Stagecoach, the second largest public transport company in the UK. Its co-founder Brian Souter is a member of the Church of Nazarene, an international evangelical Christian denomination.

A Stagecoach spokesman said all adverts on its buses were vetted before being published. "This particular advert is being carried on a number of bus operators' vehicles across the UK. We took advice from the Advertising Standards Authority in advance of publication and we have been advised the advert complies with the relevant guidelines and legislation."

The theology thinktank Theos welcomed the campaign, saying it was a "great way" to get people thinking about God. "The posters will encourage people to consider the most important question we will ever face in our lives. The slogan itself is a great discussion starter. Telling someone 'there's probably no God' is a bit like telling them they've probably remembered to lock their door. It creates the doubt that they might not have."

A statement from the Methodist Church thanked Dawkins for encouraging a "continued interest in God".

The success of the British initiative has inspired atheists around the world. The American Humanist Association launched a bus advertising campaign last November with the slogan, "Why believe in a god? Just be good for goodness' sake", appearing on the sides, rear and insides of Washington DC's 230 buses.

The subsequent news coverage generated mostly negative phone calls and emails, with the largest number going directly to the organisers. Hundreds of complaints were sent to Metro, the government body responsible for the city's buses and subways. The poster provoked two counter-campaigns by devout Christians.

From Monday, buses in Barcelona bearing a Spanish translation of the British slogan will hit the streets, to the consternation of the city's Catholic hierarchy, while Italy's Union of Atheist, Agnostics and Rationalists plans to roll out atheist buses.

Atheists in Australia have fared badly with their campaign. Attempts to place slogans such as "Atheism ? sleep in on Sunday mornings" on buses were rejected by Australia's biggest outdoor advertising company, APN Outdoor.

  • Mini-turbines set to harness energy from pressure in UK gas pipelines

The enormous pressure inside the gas pipeline grid that supplies UK homes is set to be harnessed to generate clean electricity.

Work to place small turbines inside the gas network will start later this year at Beckton in east London. This first scheme will produce 20MW by 2010 from the natural gas that rushes through the pipes. Repeated across the country, the technology could generate up to 1GW ? equivalent to the output of a conventional coal or nuclear power station.

Andrew Mercer of company 2OC, which has developed the "geo-pressure" technology, said: "We're very lucky that somebody else has built this pipeline infrastructure. We can borrow it to produce renewable energy."

When natural gas is drilled from underground reservoirs it is at far too high a pressure to be used safely in homes. "It would just blow up your gas cooker," Mercer said. Instead, the pressure must be released at hundreds of sites across the supply network known as letdown stations.

Currently, the energy contained in this released pressure is wasted. The new technology aims to capture it to generate electricity.

2OC has teamed up with the National Grid, which owns most of the gas pipeline network in the UK, to build mini-power stations at eight letdown stations over the next few years. They will install devices called turbo expanders that generate electricity as the gas pressure is reduced. The turbines used are compact ? 20cm in diameter ? but can generate 1MW of electricity each.

The idea is not completely new. US companies experimented with turbo expanders in the 1980s and Mercer said a handful of similar efforts have already been set up in Europe. "But this isn't a cheap way to generate electricity. The reason it hasn't really taken off is that it's expensive."

Blue-NG, the joint venture developing the UK projects, aims to reduce costs by combining the turboexpander with a combined heat and power (CHP) engine, which generates both electricity and heat. Mercer says this boosts the efficiency of the CHP unit to over 70%. The CHP engine would run on vegetable oil squeezed from local rapeseed, though 2OC is experimenting with other fuels, such as synthetic oil made from wood.

Electricity may not be the only useful product of the turboexpander technology. Reducing the gas pressure also brings about a sudden drop in temperature, typically from 10C to -30C. Mercer calls this "free cold" and says it could be used as a cheap and green way to replace refrigeration units and air conditioning. He says 2OC is in talks with two companies that are interested in siting computer data centres, which require massive cooling, near UK letdown stations.

The technology could also cool the London Underground network he claimed, though Transport for London has balked at the likely cost.

Another use could be to provide cooling for giant concentrated solar power plants, which are gaining credibility as a future large-scale energy source. One plan is to site such plants in desert regions of north Africa, and to transport the electricity generated to Europe. Mercer says a lack of available cooling water could cripple such schemes. Siting solar plants near letdown stations, which are common in gas-rich North African countries and the Middle East, would halve the costs and double the electricity generated, he said.

  • What are the chances of a supervolcano in Yellowstone?

Bill McGuire assesses the likelihood of a cataclysmic eruption in Yellowstone National Park

  • New herbicide offers hope in battle against Japanese knotweed

Japanese knotweed, the bane of gardeners and train companies, might finally have met its match.

More than 120 sites across London are to be sprayed with a new chemical herbicide in a bid by one of the capital's Tube companies to become the first railway operator in Europe to eradicate the problem.

If the trial along 75 miles (120km) of lines is successful, it could be extended to other London Underground services and the national network.

Across the entire country, the Department for Environment, Food and Rural Affairs has estimated that the total cost of eradicating Japanese knotweed would be more than £1.5bn.

The mass spraying of chemicals is likely to prompt concern about the impact on other plants and insects and the birds that feed on them.

However the company, Tube Lines Group, says the move will drastically cut the quantity of chemicals used and help native plants and other wildlife, which struggle to push through the huge root network or survive under the dense canopy of the knotweed. It will also slash the cost stopping it from undermining bridges and buildings, and blocking sight of signals, the company says.

"Trackside land around London Underground network makes up 10% of all London's green space, so it is important to do everything we can to protect wildlife from this invasive plant," said Steve Judd, environment asset manager of Tube Lines Group.

Japanese knotweed was imported into the UK for ornamental gardens in the 19th century and has since proved one of the most damaging invasive species, and difficult to eradicate.

New plants can grow from roots weighing as little as 0.8g, and can spread their own roots up to 7m underground.

Spreading the plant is now a criminal offence and by law it has to be buried in deep hazardous waste sites. As a result Network Rail, the national railway operator, advises its workers not to strim or flail the plant.

Instead Network Rail, Tube Lines and other organisations traditionally relied on digging out the plant or spraying with a glyphosate herbicide ? like the more popularly known Roundup.

Now Tube Lines, which operates the Jubilee, Northern and Piccadilly lines, hopes instead of three sprays each year for seven years, the new chemical ? Tordon ? will eradicate the knotweed by spraying just once a year for two years.

Neighbouring properties will also be sprayed to help prevent the weed returning.

Suppliers warn Picloram, the active agent in Tordon, also kills other plants, and the US Environment Protection Agency says it is "slightly toxic" to aquatic plants and animals. However the Environmental Protection Agency also says the health risks to workers and the public are typically "negligible", and it is "practically non-toxic to birds, mammals and honeybees". Picloram also does not appear on the "sinlist" of the nearly 300 chemicals campaigners most want banned, a list compiled by several groups lobbying in the sector led by the International Chemical Secretariat.

  • Why creationism is not the biggest threat to schools

The world is full of terrible things and it may seem absurd to be shocked by the state of science teaching more than by war and famine or any of the more obvious candidates. But I was more shocked by the report showing that a significant minority of British science teachers can't see anything much wrong with creationism than by anything else last year.

You can twist it and fiddle it how you like. You can hope that teachers can't tell the difference between "teaching" and "discussing" something, though this is in itself a rather dispiriting hope. You can hope that by "creationism" they mean no more than holding open the possibility of theistic explanation (though the trouble with that is that it has increasingly come to mean more) But the facts of the survey remain. 37% of primary and secondary school science teachers think that creationism should be taught in classrooms and only 28% think it is unsupportable as a theory.

Riffling through the discussion of the paper's news story on this I came across an even more dispiriting comment, from "tegga":

Thought I might just add that when I mention evolution in any lesson at the secondary school I teach, I am bombarded with hysterical abuse and threats of violence. Intimidating mobs gather outside my classroom, boys mime shooting actions at my head, and one student has brought in a replica gun to threaten me.
seems to me the students see Darwinism as an argument for atheism, even if you don't.

It looks as if creationism has become a mark of some kinds of Muslim identity as well as of fundamentalist Christianity and this is a disaster.

It takes a peculiar combination of intelligence and a certain sort of imagination to find scientific explanations more attractive than religious ones. Almost anyone will abandon or adapt religious teachings for the benefits of technology, (I have yet to meet a creationist who doesn't believe in MRSA) but that doesn't help with the present problem. Not many people will give up religion for science if they are forced to choose.

I used to think that aggressive atheist propaganda was part of the problem here. If your primary purpose is to teach good science, it certainly doesn't help to insist that this entails atheism and to sneer at any believers who might be your allies. But it probably doesn't harm much either. Nothing said by intellectuals matters much in the face of the kind of classroom anarchy that Tegga describes.

Where pupils can form mobs or threaten their teachers with replica guns when it is suggested they learn something they don't want to, all real learning is threatened; not just the knowledge of evolution or even of science.

Science is at the very least one of the most glorious achievements of human civilisation. But it can't be learned, and it can't be practised, without first building a whole web of social knowledge about how to give and take instruction. This leads me to an unwelcome and apparently paradoxical conclusion. The spread of creationism may very well lead to a spread in faith schools to combat it.

Some years ago, when a creationist was discovered to be head of science at an Academy in Gateshead, and a campaign was mounted to stop the same organisation taking over a school outside Doncaster, I went up and talked to the teachers, the parents, and some of the government figures responsible for the policy. One of the things I then learned was that the government is much more worried about the breakdown of discipline, and of social mechanisms for the transmission of knowledge, than it is about the kinds of knowledge being taught.

In many ways the consequences of this government indifference have been terrible and have further demoralised teachers. But although their solutions (and especially the crazed reliance on testing) have been wrong, their diagnosis of the problem has to be right. That is one reason why they believe in faith schools.

Religions have historically been systems for the transmission not just of doctrines or beliefs or customs, but of the underlying cultural rules which are necessary for anything else to be learned. They have been sources of discipline, and of compulsion, which is of course one reason why many people loathe them. But it turns out that without discipline, without some compulsion, nothing complicated gets learned at all, whether it's true or false. And if the teachers aren't respected the big boys will be – and they're worse. It is more important to learn that you do not threaten the teacher than to learn that Darwin was right. For one thing, it's much easier to unlearn creationism than to unlearn the lesson that the mob rules.

This is not an argument for teaching that evolution might be false either in theory or in practice (would this be the time to repeat that both the Church of England and the Roman Catholic church teach and believe in evolution?). It's an argument that before you can even teach creationism, or science, or for that matter French, English, history and even cooking, you have to teach children how to learn and not let them forget it. To use a computer analogy; it's no use trying to run a stable program on a broken operating system. That is why, I think, the government will increasingly turn towards churches and other religious bodies to run schools. They have an operating system that works.

This is of course an extremely risky strategy. It could very well lead to further social segregation; to further oppression of young girls and to all sorts of other undesirable consequences. But the alternatives are every bit as risky and governments, whatever else they do, must choose.

  • Professor Gerry Gilmore on the Milky Way's collision course

Our home galaxy is set to collide with neighbouring Andromeda. Professor Gerry Gilmore explains