UK Science Minister Lord Sainsbury has played down fears that the human race might be wiped out by a self-replicating "grey goo" as a result of emerging developments in nanotechnology.
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His remarks, on BBC Radio 4's Today programme, came after Prince Charles expressed concerns about the emerging science, an umbrella discipline which concerns itself with the engineering of objects from individual atoms and molecules.
It promises to radically reduce the size of computers and produce materials that strengthen and lighten bridges and planes.
But environmentalists have expressed the concern that self-replicating nano-machines might escape from a laboratory to infect and destroy all life on the planet.
"There are things that could be worrying but basically they are things very much in the future," the minister said.
"Those still are basically at the speculative science fiction stage," Lord Sainsbury added.
The minister said that many of the advances hoped for by nanotechnologists would fall under existing regulation.
"We already have regulations about the release of organisms into the environment. We have health and safety regulations. We have medical devices regulations.
"It is not clear to me that nanotechnology raises issues that would not be covered by these regulations already."
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"This is something we are going to look at," he told the BBC.
Prince Charles is said by his office to have read a report on the potential environmental and social risks of nanotechnology.
He is meeting experts at his Highgrove residence to hear more about the subject.
A grey goo catastrophe is the subject of a recent fiction book by the best-selling author Michael Crichton.
It is also one of the scenarios referred to in another new book from the English Astronomer Royal in which he gives humanity a 50-50 chance of surviving the century.
Jim Thomas of the ETC Group, an environmental organisation, has told the BBC: "There needs to be a moratorium, so that we are not always running after these powerful and potentially dangerous technologies.
"We're saying there are going to be big societal questions here; there are potential environmental problems. Let's put a hold on and see if this is a technology for the common good and can be properly controlled."
The Joint Centre for Bioethics (JCB) at the University of Toronto, Canada, recently published a study in the UK journal Nanotechnology, in which it assessed the current state of nano-science.
It said research and development spending was growing fast - in the US up from $432m in 1997 to $604m by 2002; in Japan from $120m to $750m over the same period.
However, the report's authors warned that many of the advances were running ahead of the public's ability to comprehend their implications.
"There is a danger of derailing nanotechnology if serious study of its ethical, environmental, economic, legal and social implications does not reach the speed of progress in the science," the authors said.
"A showdown of the type we saw with genetically modified crops" was a real possibility if these issues were not addressed early, they added.
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Nanotechnology is the science of building working devices, systems and materials molecule by molecule, by controlling matter.
Materials fabricated on the nano scale (measured in billionths of a metre) have novel properties not displayed in normal, large-scale crystalline solids or glasses of the same chemical composition.
Nanophase materials, as they are often called, have unusual electrical and optical properties because of the very precise way in which their atoms are arranged.
By carefully controlling particle sizes, it is possible, for example, to make "superplastic" ceramics that stretch like chewing gum and liquids that are magnetic.
Scientists say they have only just begun to consider how they might exploit these amazing properties.