Jodrell Bank work threatened by housing plans, say scientists

http://www.theguardian.com/science/2015/feb/13/jodrell-bank-new-homes-threaten-gravity-waves-project

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One of Britain’s most ambitious astronomy projects is under threat due to a large housing development being planned nearby, scientists have warned.

Prof Simon Garrington, director of Jodrell Bank observatory, said proposals to build 119 houses just over a mile from the Lovell telescope in Cheshire would seriously compromise observations of deep space.

Among the projects at risk would be an attempt to make the first experimental observations of gravity waves, ripples in space-time predicted by Einstein’s general theory of relativity.

The astronomers estimate that, if approved, the development would increase background interference levels by about 10% to a level exceeding an internationally agreed threshold for “detrimental interference” to radio astronomy observations.

“Many housing proposals don’t cause problems,” said Garrington. “It’s the ones that are largest and closest that are the most dangerous.”

The electromagnetic signals astronomers are looking for are barely distinguishable from background noise coming from sources such as electricity lines and mobile phones.

The latest development site, in the village of Goostrey, is particularly problematic because it would fall in the line of sight of the telescope’s observations of distant pulsars – incredibly dense neutron stars that send out rotating beams of radio waves.

The signals from a pulsar are picked up as regular “blips” as the star spins on its axis – sometimes as quickly as hundreds of times a second. Astronomers believe that irregularities in the blips could indicate that space-time is being stretched or compressed in gravity waves, but spotting such tiny differences would require incredibly precise observations.

Measuring gravitational waves directly would be widely viewed as a signifcant scientific advance, and teams around the world are racing to be the first to claim the discovery.

“Jodrell Bank is still the third largest single telescope on Earth and the fact that it’s been making continuous observations of pulsars for 40 years is a huge advantage,” said Garrington.

Last year, cosmologists from Harvard’s Bicep2 (Background Imaging of Cosmic Extragalactic Polarisation) telescope at the south pole announced they had observed patterns of light consistent with gravity waves, but it later emerged that the data was probably explained by space dust instead.

Martin Barstow, president of the Royal Astronomical Society, said that there was sometimes a misconception that Jodrell Bank was now largely simply of heritage value. “It’s not just something to look at,” he said. “It’s still doing high-quality science. You’re looking for a signal above a background of noise and if that background gets bigger, the less you can see.”

Garrington said that the increased number of houses in nearby villages had already seriously degraded the centre’s ability to carry out new science. Despite discovering many of the first pulsars in the 1970s, Jodrell Bank is no longer capable of searching for new ones due to increased radio interference. “In many observations it is the main factor which limits the quality of the data,” said Garrington.

In principle, Jodrell Bank is protected by a statutory consultation zone, within which the new developments fall. However, in the past developers have successfully appealed against objections submitted by the observatory.

The science minister, Greg Clark, said: “Cheshire East council must ensure that, in line with protections set out in the national planning policy framework, any new housing developments do not adversely impact on the important scientific mission of Jodrell Bank.”

In a detailed mapping exercise, Jodrell Bank scientists have shown that the majority of radio interference, from sources including electricity cables and mobile phones, comes from neighbouring villages, such as Goostrey, rather than more densely populated but more distant locations in central Manchester.

Councillor Michael Jones, leader of Cheshire East council, said that the scientists’ concerns would be carefully considered. “Cheshire East is keen to promote the tremendous scientific potential of Jodrell Bank and to ensure that an appropriate balance is struck between providing the homes that the country needs and the economic and educational benefits that the telescope provides,” he said.

Martyn Twigg, managing director of Gladman Developments, said the company had sought discussions with scientists before formalising the proposals, but had no response. “We have made several requests for the detailed technical evidence which apparently substantiates their objection so that we can review it – but so far no information has been provided,” he said. “We have also provided Cheshire East council with an appropriately worded planning condition, which we feel would address the observatory’s concerns.”