Archive for Herschel

Science and Politics

Posted in Politics, Science Politics with tags , , , , on December 22, 2012 by telescoper

It’s a dark dreary December day with a downright deluge descending outside to add to the alliteration.  Fortunately, it being almost Christmas, this weekend is offering a glut of crosswords with which I’ve been occupying myself while waiting for a break in the rain.

Among the puzzles I’ve done was a moderately challenging one in the New Statesman.  I have a subscription to the New Statesman, which means that I get it delivered in the post approximately two days after everyone else has had a chance to read it. After finishing the crossword, which contain a number of hidden (unclued) famous pseudonyms, I had a look at the rest of the magazine and discovered that this issue, the Christmas one, was edited by Brian Cox (who needs no introduction) and Robin Ince (who I believe is a comedian of some sort). It’s nice to see science featured so strongly in a political magazine, of course, but I did raise an eyebrow when I read this (about the LHC) in a piece written by Professor Cox:

The machine itself is 27 kilometres in circumference and is constructed from 9,300 superconducting electromagnets operating at -271.3°C. There is no known place in the universe that cold outside laboratories on earth…

Not so. The cryogenic systems on ESA’s Planck mission achieved a stable operating temperature at the 0.1 K level. This experiment has now reached the end of its lifetime and is warming up, but  the Herschel Space Observatory with a temperature of 1.4 K is still cooler than the Large Hadron Collider. Moreover, there are natural phenomena involving very low temperatures. The Boomerang Nebula has a measured temperature of −272.15°C, also lower than the LHC.  How does this system manage to cool itself down below the temperature of the cosmic microwave background, I hear you asking.  A detailed model is presented here; it’s “supercooled” because it is expanding so quickly compared to the rate at which it is absorbing CMB photons.

Anyway, if this all seems a bit pedantic then I suppose it is, but if prominent science advocates can’t be bothered to check their facts on things they claim to be authorities about, one wonders why the public show pay them any attention in the broader sphere. Fame and influence bring with them difficult responsibilities.

That brings me to another piece in the same issue, this one co-authored by Cox and Ince, about Science and Society entitled Politicians must not elevate mere opinion over science. I’d realised that there was a bit of a Twitter storm brewing about this item, but had to wait until the horse and cart arrived with my snail mail copy before I could try figure out what it was about. I still haven’t because although it’s not a particularly focussed piece it doesn’t seem to say anything all that controversial. In fact it just struck me that it seems to be a bit self-contradictory, on the one hand arguing that politicians should understand science better and on the other calling for a separation of science and politics.   There are two more detailed rejoinders here and here.

For my part I’ll just say that I think it is neither possible nor desirable to separate science from politics.  That’s because, whether we like it or not, we need them both. Science may help us understand the world around us, and (to a greater or lesser degree of reliability) predict its behaviour, but it does not make decisions for us. Cox and Ince argue that

Science is the framework within which we reach conclusions about the natural world. These conclusions are always preliminary, always open to revision, but they are the best we can do.

I’d put it differently, in terms of probabilities and evidence rather than “conclusions”, but I basically agree. The problem is that at some point we have to make decision which may not depend solely on the interpretation of evidence but on a host of other factors that science can say nothing about. Definite choices have to be made, even when the evidence is ambiguous. In other words we have to bring closure, much as we do when a jury delivers a verdict in a court of law, which is something that science on its own can rarely do. Mere opinion certainly counts in that context, and so it should. The point is that science is done by people, not machines. People decide what questions to ask, and what assumptions to proceed from. Choices of starting point are political (in the widest sense of the word) and sometimes what you get out of a scientific investigation  is little more than what you put in.

It’s always going to a problem in a democratic society that scientific knowledge is confined to a relatively small number of experts. We can do our best to educate as many as possible about what we do, but we’re always going to struggle to explain ourselves adequately. There will always be conspiracy theories and crackpots of various kinds. The way to proceed is not to retreat into a bunker and say “Trust me, I’m a scientist” but to be more open about the doubts and uncertainties and to present a more realistic picture of the strengths and limitations of science. That means to engage with public debate, not by preaching the gospel of science as if it held all the answers, but by acknowledging that science is a people thing and that as such it belongs in politics as much as politics belongs in it.

Dust to Dust

Posted in The Universe and Stuff with tags , , , on April 27, 2011 by telescoper

Hey look! It’s our very own Haley Gomez (interviewed by Gemma Lavender) last week in Llandudno!

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The Travellers and the Rest

Posted in Biographical with tags , , , , , , , , , , on January 15, 2011 by telescoper

Yesterday’s journey to the Big Smoke wasn’t as bad as it might have been, although it was a bit frustrating at times. The train was diverted through Bath to avoid flooding near Bristol, which added about 20 minutes to the journey time. That was expected, so didn’t cause any major anxiety. After the rather scenic detour we found ourselves back in familiar territory on the Cardiff-London line, Swindon. I never thought I’d see the day when I was pleased to arrive at Swindon! However, my pleasure soon evaporated when we sat on the platform at Swindon without moving, and with no announcements or information or explanation, for another 15 minutes. Obviously 25 minutes late just wasn’t late enough for First Great Western, so they had to hold the train to enhance further their record of unpunctuality. In the end we arrived at Paddington 40 minutes late. Not good.

I still got to the meeting in time for a quick cup of tea before the afternoon’s proceedings. Straight away there was some great news. The President of the RAS, Prof. Roger Davies, announced the recipients of this year’s medals and awards and among them was Cardiff’s own Matt Griffin, who receives the Jackson-Gwilt Medal.  According to the RAS website

The Jackson-Gwilt Medal is available for award annually for the invention, improvement or development of astronomical instrumentation or techniques; for achievement in observational astronomy; or for achievement in research in the history of astronomy.

Matt Griffin’s citation reads as follows:

This year’s winner is Professor Matt Griffin of the University of Cardiff, for his work on instrumentation for astronomy in the submillimetre waveband, the region of the electromagnetic spectrum between the far-infrared and microwave wavebands.

Matt Griffin is one of a select group of scientists that helped establish a UK lead in the technical development of instrumentation for submillimetre astronomy. He has been involved in most submillimetre instrument projects over the last three decades, including the Spectral and Photometric Imaging Receiver (SPIRE) camera on Herschel. Matt led a diverse international team to bring this project to fruition, encompassing 18 institutions on three different continents.

SPIRE represents a step change in capability. With the ground-based SCUBA camera, 20 nights of observing led to the detection of 5 galaxies at submillimetre wavelengths. With SPIRE, 6000 galaxies can be detected in 8 hours.

Matt Griffin thus receives the Jackson-Gwilt Medal for in particular his outstandingly successful work on SPIRE, an instrument that is transforming submillimetre astronomy.

Heartiest congratulations to Matt and, of course, to the rest of this year’s awardees!

After the RAS meeting it was time for dinner. Owing to a muddle with bookings The Athenaeum wasn’t available for this month’s RAS Club dinner so we dined instead in the unfamiliar surroundings of The Travellers Club, which is actually next door at 106 Pall Mall.Given the trials and tribulations of travelling with First Great Western, perhaps I should apply for honorary membership?

The room we had was smaller than usual, but cosy, and the staff were very friendly. The dinner wasn’t marvellous but as always there was no shortage of interesting conversation, some of it even relating to astronomy! I got grilled by a few people about what’s going on with STFC new consolidated grants system. I told everyone who asked everything I know about it, which didn’t break any confidentiality because I don’t know anything at all.

The table service was a bit slower than at the Athenaeum so it was quite late by the time we got onto the club business. The January dinner is the “Parish” dinner at which new members and, if necessary, new officers are elected by an amusingly arcane process. A few members had to leave  to catch trains before the business was completed but I stayed to the end at about 10.00pm,  placing (perhaps unjustified) confidence in  the 10.45 train from Paddington actually existing and getting there in time to get it.

I did get to Paddington in good time, and the train hadn’t been cancelled, but it was a bit late leaving.  It then apparently developed an unspecified “mechanical fault” which made for slow running. I got into Cardiff about 25 minutes late. No diversions on the way back – presumably the floods had subsided. Perhaps there’s an excuse for the chaos ensuing from the floods, but poor maintenance is surely entirely the fault of the train company.  Not a good day for First Great Western, especially when they’ve raised their already exorbitant fares for the new year..

Oh, and one other thing that’s not at all connected with anything else. As I walked back through Sophia Gardens from the station to my house in Pontcanna about quarter to two in the morning, I saw a fox hurtling across the path in front of me then vanishing into the trees. When I lived in Beeston (a suburb of Nottingham) I saw foxes very regularly, often in my own garden. Likewise even when I lived in Bethnal Green, in the East End of London. I was  quite surprised when I moved to my house in Cardiff, right next to Pontcanna Fields and Bute Park, that no foxes were to be seen despite the apparently more promising surroundings. I’ve now lived here for two and a half years and this is the first one I’ve ever spotted. I wonder why there are so few foxes in this area?


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Flooding into London

Posted in Biographical with tags , , , , , , on January 14, 2011 by telescoper

A brave bunch of hardy Cardiff  University astronomers are heading into London today for a meeting of the Royal Astronimical Society in London which celebrates the first year of science from the Herschel Space Observatory. This wouldn’t normally constitute too arduous a trip, but it turns out after the last couple of days torrential rain in Wales and the South-West of England, there is flooding on the line at Sodding Chipbury Chipping Sodbury which has sent the railway network into one of its regular episodes of chaos. Half the trains from Cardiff to London are cancelled, and the other half diverted all round the houses so they will take at least an extra half-hour to reach their destination at Paddington.

There isn’t any flooding actually in Cardiff, but the River Taff, which hibernated peacefully through the recent snowy period, has now sprung back into life and seems to be in an angry mood. I took these snaps yesterday as I walked into work, so you can see the water level is high enough to submerge some of the riverside shrubs and trees, but not high enough (yet) to threaten the embankments.

At times like this the Taff is more than a little scary, not so much because of the way it looks but because of the sound of it growling along down to Cardiff Bay, carrying the occasional car tyre and traffic cone with it.

I suppose this is small potatoes compared to the terrible floods in Australia, Brazil and elsewhere in the world, but it is quite exasperating, especially since it happens so regularly yet still catches the train companies completely unawares.

Anyway, I don’t know if the first wave of Cardiff folk managed to get to London in time for the start of the meeting. I had a couple of things to do this morning so decided to go later, even though that meant missing some of the talks that are closer to my own interests. I did think about cancelling my trip entirely, but decided in the end to give it a go. I hope I make it there at least in time for dinner at the RAS Club.

But then there’s the question of what time I’ll get  home tonight…


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Herschel Views Andromeda (via The Herschel Space Observatory)

Posted in The Universe and Stuff with tags , , , , on January 6, 2011 by telescoper

An amazing composite image of M31 in Andromeda using both infra-red and X-rays was recently obtained using Herschel and XMM space observatories. It featured in the BBC Stargazing Live programme earlier this week and I’m told that, typically for astronomy, the inspiration behind it was … beer.

Herschel Views Andromeda We've been sitting on this image since just before Christmas so that it could be unveiled during the BBC Stargazing Live show last night, but I've been aching to get this onto the blog ever since I saw it. This is a Herschel image of our nearest neighbour galaxy, the Andromeda galaxy, also known as M31, along with comparison images at other wavelengths. [/captio … Read More

via The Herschel Space Observatory


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Cardiff inSPIREs Willetts

Posted in Politics, Science Politics, The Universe and Stuff with tags , , , , on July 9, 2010 by telescoper

The Minister for Universities and Science David Willetts’ important speech today at the Royal Institution in London has already attracted a considerable amount of comment and reaction. I haven’t really got time to comment on it in detail, but in between the expected warning of tough times ahead, it does contain a great deal of extremely interesting and thoughtful material, which I recommend you read if you’re interested in science policy.

Of particular interest to us here in the School of Physics & Astronomy at Cardiff University is that we get a specific mention for the wonderful work done by the Astronomical Instrumentation Group on the development of the SPIRE instrument on the Herschel Space Observatory.  Everyone’s chuffed about it, and delighted that the Minister chose to highlight this particular example of excellence.

In my speech at Birmingham University in May, I spoke of links between the academic and the vocational, the conceptual and the physical. We are not always good at this – we have world-class particle physicists at the Large Hadron Collider but sadly not many British engineers helped to build it. But there are other areas where these links between British science and technology are stronger. We not only have distinguished astronomers, but it was scientists and engineers at Cardiff University who produced the Spectral and Photometric Imaging Receiver for Herschel and Planck. This combination of scientific research and technological advance creates extraordinary dynamism, both intellectual and commercial. I see it as one of my tasks to strengthen these links.

OK, so I know SPIRE wasn’t for “Herschel and Planck” but the AIG was involved with instruments for both these missions so the point is well made anyway.

Space: The Final Frontier?

Posted in The Universe and Stuff with tags , , , , , , , on July 9, 2010 by telescoper

I found this on my laptop just now. Apparently I wrote it in 2003, but I can’t remember what it was for. Still, when you’ve got a hungry blog to feed, who cares about a little recycling?

It seems to be part of our nature for we humans to feel the urge  to understand our relationship to the Universe. In ancient times, attempts to cope with the vastness and complexity of the world were usually in terms of myth or legend, but even the most primitive civilizations knew the value of careful observation. Astronomy, the science of the heavens, began with attempts to understand the regular motions of the Sun, planets and stars across the sky. Astronomy also aided the first human explorations of own Earth, providing accurate clocks and navigation aids. But during this age the heavens remained remote and inaccessible, their nature far from understood, and the idea that they themselves could some day be explored was unthinkable. Difficult frontiers may have been crossed on Earth, but that of space seemed impassable.

The invention of the telescope ushered in a new era of cosmic discovery, during which we learned for the first time precisely how distant the heavenly bodies were and what they were made of.  Galileo saw that Jupiter had moons going around it, just like the Earth. Why, then, should the Earth be thought of as the centre of the Universe? The later discovery, made in the 19th Century using spectroscopy, that the Sun and planets were even made of the same type of material as commonly found on Earth made it entirely reasonable to speculate that there could be other worlds just like our own. Was there any theoretical reason why we might not be able to visit them?

No theoretical reason, perhaps, but certainly practical ones. For a start, there’s the small matter of getting “up there”. Powered flying machines came on the scene about one hundred years ago, but conventional aircraft simply can’t travel fast enough to escape the pull of Earth’s gravity. This problem was eventually solved by adapting technology developed during World War II to produce rockets of increasingly large size and thrusting power. Cold-war rivalry between the USA and the USSR led to the space race of the 1960s culminating in the Apollo missions to the Moon in the late 60s and early 70s. These missions were enormously expensive and have never been repeated, although both NASA and the European Space Agency are currently attempting to gather sufficient funds to (eventually) send manned missions to Mars.

But manned spaceflights have been responsible for only a small fraction of the scientific exploration of space. Robotic probes have been dispatched all over the Solar System. Some have failed, but at tiny fraction of the cost of manned missions. Landings have been made on the solid surfaces of Venus, Mars and Titan and probes have flown past the beautiful gas giants Jupiter, Saturn, Uranus and Neptune taking beautiful images of these bizarre frozen worlds.

Space is also a superb vantage point for astronomical observation. Above the Earth’s atmosphere there is no twinkling of star images, so even a relatively small telescope like the Hubble Space Telescope (HST) can resolve details that are blurred when seen from the ground. Telescopes in space can also view the entire sky, which is not possible from a point on the Earth’s surface. From space we can see different kinds of light that do not reach the ground: from gamma rays and X-rays produced by very energetic objects such as black holes, down to the microwave background which bathes the Universe in a faint afterglow of its creation in the Big Bang. Recently the Wilkinson Microwave Anisotropy Probe (WMAP) charted the properties of this cosmic radiation across the entire sky, yielding precise measurements of the size and age of the Universe. Planck and Herschel are pushing back the cosmic frontier as I write, and many more missions are planned for the future.

Over the last decade, the use of dedicated space observatories, such as HST and WMAP, in tandem with conventional terrestrial facilities, has led to a revolution in our understanding of how the Universe works. We are now convinced that the Universe began with a Big Bang, about 14 billion years ago. We know that our galaxy, the Milky Way, is just one of billions of similar objects that condensed out of the cosmic fireball as it expanded and cooled. We know that most galaxies have a black hole in their centre which gobbles up everything falling into it, even light. We know that the Universe contains a great deal of mysterious dark matter and that empty space is filled with a form of dark energy, known in the trade as the cosmological constant. We know that our own star the Sun is a few billion years old and that the planets formed from a disk of dusty debris that accompanied the infant star during its birth. We also know that planets are by no means rare: nearly two hundred exoplanets (that is, planets outside our Solar System) have so far been discovered. Most of these are giants, some even larger than Jupiter which is itself about 300 times more massive than Earth, but this may simply because big objects are easier to find than small ones.

But there is still a lot we still don’t know, especially about the details. The formation of stars and planets is a process so complicated that it makes weather forecasting look simple. We simply have no way of knowing what determines how many stars have solid planets, how many have gas giants, how many have both and how many have neither. In order to support life, a planet must be in an orbit which is neither too close to its parent star (where it would be too hot for life to exist) nor too far aware (where it would be too cold). We also know very little about how life evolves from simple molecules or how robust it is to the extreme environments that might be found elsewhere in our Universe. It is safe to say that we have no absolutely idea how common life is within our own Galaxy or the Universe at large.

Within the next century it seems likely that we will whether there is life elsewhere in our Solar System. We will probably also be able to figure out how many earth-like exoplanets there are “out there”. But the unimaginable distances between stars in our galaxy make it very unlikely that crude rocket technology will ever enable us to physically explore anything beyond our own backyard for the foreseeable future.

So will space forever remain the final frontier? Will we ever explore our Galaxy in person, rather than through remote observation? The answer to these questions is that we don’t know for sure, but the laws of nature may have legal loopholes (called “wormholes”) that just might allow us to travel faster than light if we ever figure out how to exploit them. If we can do it then we could travel across our Galaxy in hours rather than aeons. This will require a revolution in our understanding not just of space, but also of time. The scientific advances of the past few years would have been unimaginable only a century ago, so who is to say that it will never happen?

Ten Facts about Space Exploration

  1. The human exploration of space began on October 4th 1957 when the Soviet Union launched Sputnik the first man-made satellite. The first man in space was also a Russian, Yuri Gagarin, who completed one orbit of the Earth in the Vostok spacecraft in 1961. Apparently he was violently sick during the entire flight.
  2. The first man to set foot on the Moon was Neil Armstrong, on July 20th 1969. As he descended to the lunar surface, he said “That’s one small step for a man, one giant leap for mankind.”
  3. In all, six manned missions landed on the Moon (Apollo 11, 12, 14, 15, 16 and 17; Apollo 13 aborted its landing and returned to Earth after an explosion seriously damaged the spacecraft). Apollo 17 landed on December 14th 1972, since when no human has set foot on the lunar surface.
  4. The first reusable space vehicle was the Space Shuttle, four of which were originally built. Columbia was the first, launched in 1981, followed by Challenger in 1983, Discovery in 1984 and Atlantis in 1985.  Challenger was destroyed by an explosion shortly after takeoff in 1992, and was replaced by Endeavour. Columbia disintegrated over Texas while attempting to land in 2003.
  5. Viking 1 and Viking 2 missions landed on surface of Mars in 1976; they sent back detailed information about the Martian soil. Tests for the presence of life proved inconclusive, but there is strong evidence that Mars once had running water on its surface.
  6. The outer planets (Jupiter, Saturn, Uranus and Neptune) have been studied by numerous fly-by probes, starting with Pioneer 10 (1973) and Pioneer 11 (1974) . Voyager 1 and Voyager 2 flew past Jupiter in 1979;  Voyager 2 went on to visit Uranus (1986)  and Neptune (1989) after receiving a gravity assist from a close approach to Jupiter. These missions revealed, among other things, that all these planets have spectacular ring systems – not just Saturn. More recently, in 2004, the Cassini spacecraft launched the Huygens probe into the atmosphere of Titan. It survived the descent and sent back amazing images of the surface of Saturn’s largest moon.
  7. Sending a vehicle into deep space requires enough energy to escape the gravitational pull of the Earth. This means exceeding the escape velocity of our planet, which is about 11 kilometres per second (nearly 40,000 kilometres per hour). Even travelling at this speed, a spacecraft will take many months to reach Mars, and years to escape the Solar System.
  8. The nearest star to our Sun is Proxima Centauri, about 4.5 light years away. This means that, even travelling at the speed of light (300,000 kilometres per second) which is as fast as anything can do according to known physics, a spacecraft would take 4.5 years to get there. At the Earth’s escape velocity (11 kilometres per second), it would take over a hundred thousand years.
  9. Our Sun orbits within our own galaxy – the Milky Way – at a distance of about 30,000 light years from the centre at a speed of about 200 kilometres per second, taking about a billion years to go around. The Milky Way contains about a hundred billion stars.
  10. The observable Universe has a radius of about 14 billion light years, and it contains about as many galaxies as there are stars in the Milky Way. If every star in every galaxy has just one planet then there are approximately ten thousand million million million other places where life could exist.