Original URL: http://www.theregister.co.uk/2013/03/25/geeks_guide_jodrell_bank/

Reg man goes time travelling at iconic observatory

Jodrell Bank: The visitors' centre at the start of the universe

By Joe Fay

Posted in Geek's Guide, 25th March 2013 11:03 GMT

Geek's Guide to Britain There are two ways to approach Jodrell Bank. From the north you fly through the WAGish end of Cheshire, with towns like Wilmslow and Alderley Edge housing Manchester and Liverpool’s finest and their harems. I prefer coming from the south, under the Twemlow Viaduct, a 105ft high, 500 yard long symphony of red brick, completed in 1842.

The road dips here, so that as you come under the bridge, you tend to hit the accelerator, before leveling out just in time to start catching glimpses of the Lovell Telescope across the fields as the road wobbles its way towards Macclesfield.

It’s still eerie, suddenly seeing the dish pop in and out of the lines of trees carving up the tweedily rough Northern Midlands countryside. It’s as if the credits for countless popular science shows were being projected around you. You’re on Jodrell Time.

If we all know what the iconic Lovell Telescope looks like, some of us might be a little fuzzy on what’s it’s for. To recap, its day job is to observe the Universe in the radio spectrum, and one of its early successes was in unlocking the secrets of quasars. But it also played a major role in the Cold War’s space and arms races, tracking the Russians’ first space shots, conveying instructions to US space probes, listening in to traffic from Russia’s probes and standing by to track incoming Russian ICBMs.

Radio Astronomy began at the site in the late 1940s, when the University of Manchester’s Bernard Lovell got sick of interference in the city, and hauled his collection of Army surplus radar kit to the Uni's out-of-town botanic gardens. He wheeled, dealed and otherwise pushed through the construction of the 76.2m Mark 1 dish which now bears his name. At the time it was the world’s largest steerable radio telescope. Six decades on, it’s still probing the universe, and is still the third-biggest steerable scope - on this planet, anyway.

Science not heritage

Two types of time in the Lovell control room

A few years back there were rumours that the site was up for the chop. Staffers at the site tell us that was never really on the cards, as any decision would have been based on peer review of the science it produced. And on a pure science basis, Jodrell had a pretty strong case to continue its work. Quite apart from collective affection for the iconic site, Jodrell Bank is ground zero for the UK’s eMerlin project, which links the Lovell telescope with six other UK-based radio telescopes, to give a unified dish array spanning 217km. It would have been difficult to argue it was not producing world class science

Arguably more important for the site’s future, it is also the project HQ of the Square Kilometre Array. This €1.5bn project will run a network of thousands of radio receptors across Australia and eight countries in Southern Africa, equating to a radio telescope dish one kilometre square. When it's up and running, it will be generating a bracing 960,000,000GB of data a day.

But these days it’s not just enough to be relevant. You have to demonstrate it. Scream it even.

And so things have changed a bit. The Jodrell Bank Centre for Astrophysics - to give it its full name - is not just a world class science site with a visitors' centre. The site has had a major makeover, and acts as the backdrop for the Beeb’s pop astronomy “Star Gazing Live” strand, runs a comprehensive programme of events to evangelise for astrophysics, and even hosts music festivals.

Some of us might have memories of just pitching up to the site, wandering in from the car park and having a couple of sandwiches under the dish, perhaps contemplating our role in the cosmos, or simply trying to remember what we were doing at the family wedding we’d attended in Wilmslow the night before.

Today, a tasteful wooden wall prevents access to the site from the car park. You can wander into the Planet Pavilion’s cafe and view the site from there. But if you want to enjoy the full visitor experience, or if you’re a groupie trying to get to Stargazing Live's Brian Cox and Dara O’Briain, you’re going to have to cough up £7 for an adult or a fiver for kid. A family ticket - two adults, two kids - will set you back £20. (The proceeds all go to the centre's education activities.)

Incidentally, the cafe is really rather good. Good enough that the designery ham sandwich and chips we had almost completely obliterated the disappointment we felt that we’d missed the full English by a matter of minutes. (11.30 local time if you’re wondering, but be warned each of the array of clocks on the wall shows the time on a different planet in the solar system.)

The Planet Pavillion packs in a quick intro to space, with lots of astral lighting. And a shop. That relief pattern across the front of the building is actually a radio map of the universe, created at Jodrell Bank, and the motif is repeated throughout the park, reinforcing Jodrell Bank’s pivotal role in mapping the cosmos.

Things get more detailed in the larger Space Pavillion, with plenty for kids to prod, listen to and grapple with. You can listen to the sound of the Big Bang, and then explain it to the kids. You can fondle a meteorite. Despite quite clearly being a lump of (mainly) iron this was strangely awesome, coming the week after the Russian meteorite shower.

You’ll want to get the kids into the Science Show, and the Ask an Expert Session, which gives them the chance to discover there are real astronomers who are not Brian Cox. Or even Dara O’Briain. With about 150 on-site, and more to come as the SKA project spins up, you’re unlikely to get the same expert twice, even if you buy the full year pass at £60 for the basic family version. The sessions can go with a bang, literally, but we won’t spoil the surprise here.

Attack of the foams

What you don’t get in either of the pavilions is a lot of history of the site or Bernard Lovell, the telescopes’ early successes in identifying quasars and pulsars, not to mention tracking the US and USSR’s jab-trading in the space race, and its role as part of the UK’s ICBM early warning system. This may seem unusual for something that is both grade one listed, and a candidate for World Heritage Status. This is a conscious effort on the part of the team running the site these days, with an urge to to carry out cutting edge science and act as a beacon for budding physicists trumping the temptation to lapse into the comforting arms of the UK heritage industry.

Still the history is covered reasonably comprehensively as you walk around the telescope itself. When we visited it was whizzing around like a cosmic taxi driver’s head. Older than most Reg readers, it’s still the world’s third-biggest moveable telescope. In fact, it’s moving all the time to compensate for the Earth’s rotation. Having 3,200 tonnes of metal and railway bogey noisily spark into life just as you’re contemplating your place in the universe can be disconcerting.

Almost as disconcerting is the ever-present threat of foam airpowered rockets. The site is riddled with them, part of the drive to give younger visitors a hands-on chance to play around with Newtonian physics.

If you want a break from the cosmos or the kids, you also get to walk around the University of Manchester botanical gardens - the botanists are still here. As part of the makeover, there’s a new Galaxy Garden. We didn’t get to see the garden though, as we were treated to a rare behind-the-scenes tour with Jodrell’s associate director Dr Tim O’Brien.

If the telescope itself takes us back through eons in space, a walk around the backrooms at the site will catapult you through a history of computing since the 1950s.

We had a walk through the control building for the Lovell telescope. If you were at college in the UK anytime before 1990, you’ll be familiar with the 50s style academic architecture. The control room itself felt similarly familiar. At first glance it looked like a set from a '50s scifi classic, or a particularly well-funded episode of Doctor Who. All steel-grey chassis and post-war municipal functionality.

One nuke or two

The control desk

All in all, it's a reassuringly familiar place to contemplate other worlds. Or to ponder the end of this one. Jodrell was the front line of the UK’s nuclear defences before Fylingdales, and O’Brien points out that received wisdom for staff joining in the '80s was that there were still two Russian nukes trained on the site - and an American one, just in case it looked like the Russians had a chance of taking the site intact.

Snap out of Cold War nostalgia, and a closer look at the control room reveals an eclectic mix of cutting edge and seriously vintage kit. On one side some seriously large flat screens were showing the dashboard for the eMerlin array. Everything was reassuringly green when we were there.

Across the room was a Compaq PC with some cannibalised HP CD drives which is used to monitor the onsite power generator. While the telescope sucks its juice from the national grid, if a power cut coincided with excessive wind at the site, the generator would kick in to allow the dish to be shifted into a position where it wasn’t likely to takeoff into orbit itself.

Another rack shows the time according to both GPS and the station's own atomic clock. Splitting these gives you Jodrell time. (This after already adjusting our watch for both Earth and Venus time in the cafe.) In the next rack was a wood and brass hygrometer. While the same info is available on a screen in the control desk, sometimes scientists just seem to prefer paper and wood, says O’Brien.

Walk up close to the veteran control desk itself and you see a much more up to date array of flat panels controlling the movements of the telescope, though an old Vax terminal on the far right shows that this is an academic institution with heritage, and the urge to recycle. The Vaxes are near the end of their useful life for the site, said, O’Brien, if only because of the scarcity of parts.

Talking of maintenance, a walk down the corridor - through numerous numberpad-sealed doors - took us to what looked like the ultimate garden shed. On one wall of the room is one of the most impressive arrays of wrenches we’ve seen outside of a KwikFit Centre. In the corner, you’re treated to the sight of one of the scope’s receivers hooked up to a life support system that uses helium to chill it down to the desired operating temperature of -260°C. Time almost slipped again here - the combination of the chemicals and the metronome regular pumping could easily have transported you back to the Madchester of the 1990s.

How cool is that?

A step further down the hall to the correlator would bring you sharply up to date. This is the two-rack machine that pulls together the feeds from the seven telescopes that make up the e-Merlin project, a task that keeps it ticking over at a brisk 1 peta ops per second. This would put it in the top 30 supercomputers in the world, but it isn’t strictly a general purpose supercomputer.

The correlator pulls in the feeds from all seven telescopes in the e-Merlin project.

Incidentally, if the pic on the right makes it look like it’s in an enormous biscuit tin, that’s 'cos it is. It’s situated a few hundred feet from the main dish, and so to ensure it doesn’t overwhelm the signals the dish is targeting, the correlator is enclosed in a box made of metal panels, with copper sealing the joints. Essentially it's a rather large, very noisy Faraday cage, throwing out around 1TB of data daily to be turned into astronomical images.

Feeding a beast like this requires huge amounts of data, drawn in from the optical network linking the stations that make up e-Merlin. The data used to be transmitted over radio links, but is now sucked into the site via a fibre-optic network, which includes 600km of pre-existing dark fiber and 90km of new fiber. This network allowed Jodrell to boost the sensitivity of the receivers by a factor of 20. This means it feeds the correlator at 210Gbps. Remember, that’s a G. The UK public internet current tops out at around 1Tbps, meaning eMerlin alone is running at around a fifth of the UK’s internet data. Put another way, O'Brien says on many projects the team can do in a day what used to take a year.

One further fact. The signals from the various telescopes have to be synced - this is done to an accuracy of 1-2 picoseconds.

If that sounds impressive, consider this. The site also includes two clusters - a pulsar research cluster running 1,440 CPU threads, and a modelling/simulation cluster running 328 CPU threads.

The Lovell Telescope, credit Mike Peel; Jodrell Bank Centre for Astrophysics, University of Manchester

With the site heading up the Square Kilometre Array project, the computing horsepower at Jodrell - and its sister site at Manchester - will be racking up its kit list as more physicists work their way up the M6 and settle onto the Cheshire Plain.

Sadly we didn’t have time to check out the SKA building, or to rummage around in the older buildings which house old labs, hand-tooled Ferranti era computers, and the site’s hydrogen maser.

Even so, we were still 40 minutes late getting to the car park to meet the family. But at least we had the excuse of not knowing which time it was. ®

GPS

53°14′13.2″N 2°18′25.74″W

Post code

SK11 9DL

Getting there

Around six miles from Jct 18 on the M6, just off the A535 between Holmes Chapel and Alderley Edge.

Entry

As of March 29, £7 for adults £5 for children. Family tickets from £20

Museum website

http://www.jodrellbank.net/visit/