Hubble's future
From Matt Mountain, director of the Space Telescope Science Institute (STScI)
Govert Schilling’s article on the Hubble Space Telescope implies that STScI senior management are looking for a way to boost Hubble’s orbit (9 August, p 38). It further implies that I have endorsed a Kickstarter campaign to save Hubble, and that such a campaign may be needed to prevent NASA from prematurely ending the mission in 2020. None of this is true.
NASA’s best estimates now place re-entry into the atmosphere due to atmospheric drag in the mid-2030s, nearly a decade later than the article suggests. No development work on a de-orbit mission is taking place because none is necessary.
We at STScI are looking forward to a new generation of space telescopes that will work synergistically. Hubble’s successor, the James Webb Space Telescope, will be launched in 2018. Larger and more efficient than Hubble, the new observatory will allow us to look further back in time and space, revealing the first galaxies.
In the 2020 to 2030 time frame we are looking forward to launching a “wide-angle” version of Hubble to be built from already manufactured Hubble-sized mirrors. That mission will provide wider-field imaging than a refurbished Hubble could, and will survey orders of magnitude more sky with the same superb resolution as Hubble.
Hubble is expected to operate and perform cutting-edge science until at least 2020, and could likely work in parallel with these other space observatories.
Baltimore, Maryland, US
Wheels of progress
From Roger Cook
David Boswell makes a good point when suggesting small-scale water power to supply the UK’s energy needs (2 August, p 30).
There are two water-powered generating plants near me, one at Grassington and the other in Burley in Wharfedale. The Grassington plant was installed in 1909 as a local initiative to supply home and street lighting to the village. It now uses a modern Archimedes screw to generate electricity, which it supplies to the National Grid. In Burley in Wharfedale, a more conventional water wheel system generates 300 kilowatts of electricity.
Both of these schemes use the facilities of old mills, with water siphoned from the Wharfe river. The Environment Agency estimates that there are at least 50 sites in Yorkshire where water power could be used to generate commercial quantities of electricity.
It’s easy to forget that the Industrial Revolution in the UK was water-powered to start with. That water is still here and could be tapped with ease.
Burley in Wharfedale, West Yorkshire, UK
Local power
From Matthew Davis
I am not convinced that a future of cheap solar panels is a bad thing for Africa as suggested in Fred Pearce’s comment article (2 August, p 26).
I recently purchased a cheap 10 watt solar panel and found it very effective at charging my smartphone as well as my tablet. Fortunately, the area where I live has 6 sunshine hours per day, which is high for the US.
If there is any piece of technology that would help to improve the life of the poor, and certainly the younger generation, it would have be to a smartphone and a way to power it without needing a grid.
Ridgecrest, California, US
Keep it buried
From Bryn Glover
In your article on fracking for shale gas in the UK, Andrew Aplin is quoted as saying that the worst impacts from fracking would arise from heavy lorries and waste water (2 August, p 6).
I disagree. The very worst impact from an exploratory “frack” would be the discovery of vast reserves of methane, which profit-hungry petroleum companies, aided and abetted by power-hungry politicians, would fall over themselves to bring to the surface and burn.
To appropriate Fred Pearce’s comments 20 pages later in his discussion on electrifying Africa, what must be avoided at all costs is the UK stumbling into a future of cheap methane to use to power its cities.
Glasshouses, North Yorkshire, UK
Missing monopole
From Keith Davis
Richard Webb’s article about the search for magnetic monopoles (16 August, p 34) rang a bell, because I am old enough to remember a similar article written by Henry H. Kolm for Science Journal (which later merged with 快猫短视频), in September 1968.
Kolm bemoaned that fact that, despite three decades of effort, the particle predicted by Dirac remained “a source of embarrassment and irritation” and speculated whether this was due to an inadequacy of theory or a failure of experimental technique.
It is interesting to observe that despite the advances made in the intervening four-and-a-half decades, it would appear that the magnetic monopole remains as elusive as ever.
Kinver, Staffordshire, UK
Recipe for success
From Steve Hawkins
Your interview with legal high developer Dr Z (9 August, p 26) came two days after a colleague, who is a hospital consultant in acute medicine, told me that mephedrone 鈥� developed by Dr Z 鈥� is occupying more and more of their resources.
Dr Z says that he always tests a drug on himself, but I’m not sure this would constitute a proper measure of the number needed to harm 鈥� an indicator widely used in drug development to show how many people need to be exposed to a risk factor before someone is harmed.
It’s a shame that someone who clearly has talent as a developer of drugs doesn’t apply it in some other way.
Truro, Cornwall, UK
Left in a spin
From Ron Barnes
Anil Ananthaswamy’s excellent article on separating a neutron from its spin left me greatly puzzled (26 July, p 32).
Is a neutron without its spin still a neutron, I wonder, or is it something else?
Watlington, Norfolk, UK
The editor replies:
鈥� The question is a really good one. The honest answer is that this is so new nobody has a name for a neutron without a spin, or indeed a spin without a neutron.
Run a red light
From Jack Harrison
Hacking traffic lights isn’t new (9 August, p 20) 鈥� we were doing it over 60 years ago.
In those days, many traffic lights were activated by pneumatic strips across the road. The pressure as a vehicle passed over the strip would send a pulse of air to the controller. We youngsters had great fun jumping on the strips.
One particular road had so little traffic that children would play cricket in it. It wasn’t so much a case of “bad light stops play” but of “play stops lights”.
Tobermory, Isle of Mull, UK
Repeat prescription
From Chris Brooking
The idea of locally recycling wastewater seems very attractive (16 August, p 38).
However, one issue not addressed in your article is that of drug residues in the water. There have been many studies showing that drugs aren’t completely removed from conventionally treated sewage, including oestrogens from contraceptives, which have consequences for the development of fish.
An effective method of removing these chemicals will be needed in a closed loop system of local recycling, to prevent concentrations building up to potentially dangerous levels. In addition, toxic chemicals could be introduced into the loop from cleaning products, for example.
A lot of these issues wouldn’t apply to the proposals to develop partially treated water supplies, but 100 per cent recycling will need 100 per cent purification.
Queensbury, West Yorkshire, UK
Seed and soil
From John Harvey
It is not only in terrestrial systems that tomatoes can indicate the past presence of wastewater pollution (16 August, p 29).
I recall seeing pictures of tomato seeds on the seabed some kilometres off Liverpool. The density of seeds was being used as an indicator of the extent and intensity of sewage pollution.
This methodology seems to have been pioneered in the Thames Estuary by R. G. Shelton in the 1960s ().
Cheltenham, Gloucestershire, UK
For the record
鈥� Drug discovery isn’t all it’s cracked up to be. Dr Z isn’t the only person to have invented mephedrone (9 August, p 26). It was discovered in 1929, and a chemist known as “Kinetic” independently rediscovered it in recent years. Dr Z was the first to work out how to scale up production.
鈥� Something didn’t add up in our review of Dave Goldberg’s The Universe in the Rearview Mirror (27 July 2013, p 50). A quote attributed to David Hilbert was actually spoken by Hermann Weyl.