24 April 2010 | NewScientist | 5

trip to an asteroid, he said. Travelling to an asteroid will not

be easy. Astronauts will be exposed to higher levels of radiation, and will have to find a way to attach themselves to the asteroid’s surface to cope with its weak gravity.

But the pay-off for planetary defence could be big. One future mission might be to nudge an asteroid from its original orbit. That “would demonstrate once and for all that we’re smarter than the dinosaurs and could therefore avoid what they didn’t”, White House science adviser John Holdren said in a discussion after the speech.

Dam war rages onA TUG of war that has raged for decades over the construction of what would be the world’s third-largest dam is becoming frantic.

The Belo Monte dam on the Xingu river in the Brazilian Amazon could power as many as 23 million homes. But since its proposal 20 years ago, it has been the subject of a vitriolic dispute with the government on one side and indigenous people and green groups on the other.

The latter say it would flood 500 square kilometres of farms and rainforest and prevent the migration of fish that are a major food source for 800 indigenous communities. It would also function at full capacity for a mere three months of the year – the dry season means its overall efficiency would be just 39 per cent.

Contractors were due to bid for the project at noon on Tuesday but the auction was suspended by an injunction late on Monday. A similar injunction was issued, then lifted, last week.

The latest one calls for Brazil’s environment agency to revoke a go-ahead it gave the project earlier this year. It claims some evidence was ignored during the environmental impact assessment. As New Scientist went to press, this injunction was still in place.

Paper wastageNEXT time you reach for the toilet roll, consider this: 60 million rolls of toilet paper are flushed away in Europe every day. And the average American gets though 57 sheets a day, six times the global average.

In a report last week, the Worldwatch Institute in Washington DC highlighted the wastage of paper in rich and rapidly developing nations. In the US, 14.5 million tonnes of office paper and newspaper will be dumped this decade, despite being ideal for recycling as toilet paper.

The potential savings are huge:

recycled paper consumes 64 per cent less energy and 50 per cent less water, and creates 74 per cent less air pollution, compared with paper made from virgin wood pulp. The biggest obstacle to recycling, says Worldwatch, is a

preference for luxury, multi-ply tissues. The problem is growing: western nations are the biggest users of toilet paper, but its use is increasing in China and Africa.

“Millions of tonnes of office paper and newspaper are dumped, despite being recyclable as toilet paper”

CAN fetuses feel pain – and if so, when? The questions have long been debated by scientists and are key for opponents of abortion. But this week Nebraska became the first US state to restrict abortion on that basis.

The Nebraska law, passed on 13 April, lays out several arguments about fetal pain. Each was contradicted last month in a letter to the Nebraska legislature by Mark Rosen of the University of California, San Francisco, co-author of a 2005 review on the subject.

The law states that at 20 weeks a fetus “has the physical structures necessary to experience pain”. But Rosen argues that fetuses don’t have the brain connections needed to feel pain until about 29 weeks.

The law also claims that after 20 weeks fetuses have reflex responses to evade painful stimuli. Rosen counters that these responses are involuntary, and, like “knee-jerk” reflexes, don’t correspond to pain.

Vivette Glover of Imperial College London says that fetuses may feel pain at 20 weeks, but they can be given anaesthetics in any case.

Rosen and others believe the law is designed to provoke a legal challenge from LeRoy Carhart, a surgeon who performs late-term abortions in Nebraska. This could take the claims of fetal pain to the US Supreme Court, which has the power to overturn the Roe vs Wade ruling of 1973 that gave US women almost unrestricted access to abortion.

New law claims fetuses feel pain

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Tibetan tollChina’s Qinghai province is recovering from a magnitude 6.9 earthquake that hit on 13 April, killing around 2000 people. The United States Geological Survey says the quake occurred because the Indian plate is colliding with Asia, causing this part of the Tibetan Plateau to move eastwards.

Halting hepatitis CHepatitis C virus – which causes liver cancer and cirrhosis and infects nearly 200 million people worldwide – may have met its match. An experimental drug stopped it replicating in test tubes and reduced the levels of virus in eight people with hepatitis C by a factor of more than 1000 (Nature, DOI: 10.1038/nature08960).

Sunbed worshipSurveys normally used to identify alcoholism have found that of 229 users of tanning beds, the behaviour of 50 indicated addiction. The study authors suggest that interventions to reduce skin cancer must address addiction and anxiety in order to be effective (Archives of Dermatology, vol 146, p 412).

Salt lickedThe US government should curb salt levels in prepared and processed foods, according to a National Academy of Sciences report. The Food and Drug Administration has the authority to force manufacturers and restaurants to reduce salt levels. Companies should also cut them voluntarily, the report says.

Tree data releasedA UK university has been told to release tree ring data going back about 7000 years. The ruling follows a three-year Freedom of Information (FOI) dispute. In January, the Information Commissioner’s office criticised the University of East Anglia for its handling of FOI requests from climate change sceptics.

For daily news stories, visit www.NewScientist.com/news

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