Vigil for Charlotte Wilson

If you're popping in here on 28th December, please give me a miss this time and head out instead to Richard Wilson's blog - he's @dontgetfooled on twitter, responsible for the Banana Cake of Liberty. Or, please or look up his #titanicexpress tweets. He's holding a 24 hour vigil for his sister Charlotte, who 10 years ago today was murdered in Burundi, just south of Rwanda, in a massacre for which the perpetrators have never been punished.

Obviously I didn't know Charlotte, so I will say the minium; but I can see how much she was adored and appreciated by those who knew her. She was on a Voluntary Services Overseas program; having read biochemistry and gone on to do a doctorate in molecular biology - focussing on the cocksackie virus, related to polio, of course relevant to the region she went to - she was teaching science to pupils who were, she was shocked to learn, "always ill". She has just got engaged and was on a six hour journey on the bus named "Titanic Express", to meet her fiance's family in Rwanda.

But as Amnesty International says:

The Titanic Express was attacked on its way from the Rwandan capital, Kigali, to Burundi’s capital city ten years ago today. Those onboard were separated according to their ethnicity. Hutus were released, while Tutsi passengers and 27-year-old British aid worker Charlotte Wilson were killed. The Burundian authorities and other organisations have attributed responsibility to the armed opposition group Palipehutu-National Liberation Forces (Palipehutu-FNL). The FNL denies involvement. Ten years on, no one has been brought to justice.

Richard wrote a book about her and everything he found about the massacre. His family are still determined to get justice not just for their daughter but for the other victims, and also those who have tried to expose injustice in their country. As his blog says:

Tragically, while the war criminals remain free, one of the Burundian journalists who has done most to highlight the Titanic Express massacre, Jean-Claude Kavumbagu, has been languishing in prison since July. He is facing a criminal trial for “defamation” and “treason” after making critical comments about Burundi’s army.

You can read more at Amnesty International, the Justice for Charlotte Facebook group, a moving statement and subsequent interview at the Guardian, and an article about arms that Richard Wilson wrote five years later.

Richard was one of the first skeptics I encountered on Twitter and whose work I admired from the start. I only met him briefly once, but he struck me as incredibly friendly and cheerful. Until recently I had no idea this had happened. This is just a quick message from me, Richard, and a thoroughly ignorant one as I'm only just starting to catch up on this heartrending story - but just to let you know I'm thinking of you. And I admire the bravery and determination of the family, who are determined not to seek revenge, nor in any way to abandon Charlotte's belief that education and independence were the way forward, but to find out what happened, and why, and to let the world know, so that things need not always be like this.

Opening the doors of the heavens

It must have been the early 1920's. The Great War was over and Arthur Stanley Eddington had just come back from a voyage off West Africa which had made him "the man that proved Einstein right". He was in his office at Cambridge, perhaps working on relativity or on his next major project, the mass-luminosity relationship in stars, which ultimately led to his groundbreaking "The Internal Constitution of the Stars" - when in came the Second Assistant of the Observatory, a man named Henry Green, who said: "There's a woman out there asking questions."

Perhaps the telescope - or one of many? - at Cambridge. Courtesy Society for the History of Astronomy.

It was a public observing night at the Sheepshanks Telescope. Poor Henry Green had no idea why two stars of the same age should be different colours, or several other things she wanted to know, and had come to ask Eddington for help.

When Eddington arrived, the woman was standing near the eyepiece with a child in her arms. She was holding her up to look through the eyepiece and telling her what to look for, and the audience about the Andromeda Spiral, then not known as another galaxy but thought to be a nebula in our own.

She turned round when she heard Eddington "chuckle quietly". She was a large, tall woman with blue-grey eyes, a broad forehead, and slightly poking-out chin. Normally serious and shy to the point of being thought "comical" and "slow", her fascination with astronomy had just prompted her to talk enough to Henry Green that he "left her in charge" of the talk - and her to talk to Eddington now. She had recently attended a lecture he had given on relativity and its astronomical aspects, which had set her imagination afire to the extent that - as she put it decades later - "I knew again the thunderclap that had come from the realization that all motion is relative . . . For three nights, I think, I did not sleep . . . I experienced something very like a nervous breakdown." She had written the lecture down word for word, and decided to switch her studies (various sciences) to physics.

She told Eddington she wanted to be an astronomer. This was not a path open to women at the time (nor would it be for many years); but he did not attempt to dissuade her, and she asked him what she should read. Every book he suggested she had already read. So he invited her to use the Observatory's library, at which she would find the two journals Astrophysical Journal and the Monthly Notices of the Royal Astronomical Society.

Cecilia Payne-Gaposchkin recalls that it was that night that Eddington had "opened the doors of the heavens" to her. And she went on, against many odds, to be known in her lifetime as the greatest woman astronomer of all time.

It's wonderful how a small intervention, or series of interventions, can change the future. It was pretty well by chance that, following a series of disappointments during and after university and planning on switching from teaching English as a Foreign Language to chemistry, I had some free time and decided to indulge myself with a return to astronomy, my long-lost childhood love. It was through getting "BANG!" and finding their question and answer website that it really hit home that anyone could write to scientists with questions, not just the professors' favourite few at university. I'd heard talk of students who did that. I never could think of any questions, much less felt I had the right. As soon as I got back into astronomy, I was brimming with questions. And, as I discovered, Chris was happy to answer them. Not just about the book, but about a Sky at Night. Specifically, I asked how on earth painting an asteroid white would deflect its course. He explained radiation pressure to me and, having a handle, I now knew what to go and look up. He reassured me about bothering him. "It's genuinely great to get feedback," he e-mailed. "We often just cast something out into the ether with no idea whether it works or not."

It's that, really, that made me actively pursue astronomy the way I hadn't even figured out how to pursue environmental science, in four years of doing a degree in the stuff. In spring, by which time I was taking a pre-teaching course in chemistry at Sussex University, I did an afternoon practical alone over lunchtime so I could rush off to a lecture in Oxford. Why didn't I do this at university? I don't know. But in any case, that opened the Galaxy Zoo Forum to me (which in turn opened up She is an Astronomer, article writing, and Skeptics in the Pub!). I've felt that I can not only search for, and ask about, whatever I like in astronomy, but I can also make a contribution. Not to science - well, except my classifying. But to the astronomical community. To education. To, perhaps, setting other people on the path to be scientists. Not only do I love doing this, but I can repay.

In a world where sexism was quite respectable, and Cecilia was disregarded for countless positions at universities across England and America because a woman could not be in charge or would be thought unsafe or unseemly or what have you in an observatory, Eddington (and of course others) gave her little helping hands. Not of course with the work, for at that she excelled. But at getting somewhere. At having confidence. She set up public observing nights at that telescope in Cambridge - and placed a book there with instructions that everyone observing recorded what they saw. That's just the kind of co-operative, practical thing a good scientist does. But you need a certain confidence - a certain feeling of permission - before you can do that. If you feel invisible and ground down, these things are beyond your reach.

As you've probably guessed, I'm currently reading Cecilia Payne-Gaposchkin's autobiography. It's a slim volume, devoted largely to her school and undergraduate education and her early years in the States, with family history at the beginning and philosophical thoughts at the end, and several other essays by her colleagues and her daughter. The passage which contains the story I began this post with was an utter joy to read. I could feel her seizing the moment; I could feel that earthquake of a realisation scientific or personal that sheds light, understanding, and courage.

And I could sense that it might have been a little thing for Eddington. I'm finding there are a great many kind, helpful scientists out there like Chris (and I expect a great many not!), who take the trouble to answer someone's questions, to try and show them things in a new light; and, occasionally, to advise them or to exert influence to get them somewhere else. I can only do these things in the smallest of ways on the Galaxy Zoo Forum - encouraging and sometimes equipping people to write zooite Objects of the Day for example, or passing along their questions or findings to the team - yet I think it does occasionally make an immense difference. Scientists and communicators have an awesome potential nowadays, especially in the age of the Internet. I think it would be harder for some than others. But if you're reading this and you work in science, this is why it's so important to reach the public when you can. It'll get you more audience, more colleagues, and so very much more - joy and otherwise - will come out of your work.

Happy Christmas Blogosphere!

I hope everybody reading this has a lovely Christmas and New Year, whether you celebrate such things or not!

This is my nutpuss Izzy last year "helping" us with the present wrapping, and the border is globular clusters taken from Jules's Starcluster Index on the Galaxy Zoo Forum.

Thank you very much to all of you who've read and especially left me comments and feedback - I promise I'll try and write more in the New Year. Special thanks to Dean without whom I could never have started Wales's first Skeptics in the Pub, and to the zookeepers for endless enjoyable citizen science and a very funny Advent Calendar!

Have a great one!

Red Banana in the Milky Way

Look what a gorgeous project the Zooniverse has started!


Aren't they beautiful?





These are nebulae in our own galaxy, imaged with the Spitzer Space Telescope and now at the mercy of the zooites - so I have the feeling our entire galaxy will be mapped out in more bubbles than a bubble bath soon.

Remember the barred spirals lecture at Astrofest nearly two years ago? Johann Knapen mentioned then that Spitzer was an infra-red telescope (its webpage says it is designed as such; the lecture, from what I remember, seemed to imply that it could once do shorter wavelengths but its telescope has now warmed up too much to cope with that). I never heard more about the mapping of bars - mind you, we did our own bars project in the end. Anyway, this very same telescope is imaging nebulae in infra-red light - the kind of radiation that we sense as a feel of warmth on our skin.

Not nebulae all over the sky, I should point out. Mostly in towards the plane of our galaxy - the fuzzy pale band you'll see in dark clear skies. It's often impossible to pick out any stars in it because there are so many of them, including a general build-up of distant ones too far away to make out individually but whose collective light stains the sky. (Isn't it infuriating? I tried to find a remotely realistic, recognisable picture, but it's impossible - all of them are ridiculously fancy and long-exposure. Would any relatively normal photographers like to remedy that . . . ?) But that's where most of the nebulae are.

Not all matter is confined to stars. That which floats freely, within galaxies and outside, is not just dark matter, either. A lot is gas, which, if allowed to cool enough, provides fuel for star formation. Ironic that it needs to cool to form such hot things, isn't it? That's because heating gas up makes it fly all over the place - and in order to clump, the atoms and molecules need to be still, close together, and undisturbed. Where enough gas or dust is present to block or scatter light, or indeed to emit its own light, that's a nebula.

There are a great many types of nebula, which I think I'll leave to another blog post; you can check out Hubblesite for an overview. What the Milky Way Project is looking at is those involving star formation.

Stars initially form coccooned in dark gas; their births are therefore invisible to us, mysterious, though we are learning to see through their shrouds. The Pillars of Creation are a well-known example. Here they are as the world knows them:


. . . and here they are at the Milky Way Project:

But once they start shining, their solar wind blows off the remaining clouds, leaving a bubble like this:


This is the same thing as the solar wind that our Sun creates - a constant thin but powerful wafting of hot charged particles, which extents pretty much halfway to its neighbours (and which Voyager is leaving round about now). It's these charged particles that cause the aurora - and why, without a magnetic field to divert or otherwise channel them, planets such as Mars make biological life difficult on the surface.

(The Aurora over Noway. From, as ever, APOD.)

The Milky Way Project FAQ - a very informative page! - reports that the green and red parts of bubbles are different. In fact, you'll notice that the pictures are mostly red and green. The green light is 3 to 8 µm long - this is, on a logarithmic scale, only just longer than visible light, visible red light being about 0.7µm. The red light is a lot longer and therefore coming from weaker-energy (colder) sources - 24µm.

Different materials emit radiation in different, very specific wavelengths. That means, of course, that two different materials are being looked at. Zookeeper Rob (a.k.a. Orbiting Frog, and an exceptionally amiable person!) explains here that red is general warm dust, such as tiny silicon particles; and that green is polycyclic aromatic hydrocarbons. Do you remember those hexagonal carbon-based molecules from chemistry, where we were first taught to write two lines on alternate faces, and then not to? Polycyclic aromatic carbons are large structures of these, looking a little like strips of chicken wire. Actually if you click the link and scroll down you'll see a sight now getting familiar . . . These are effectively "soot" from stars - star formation bellows out as mixed a bag of by-products as cigarette smoke, but these complex carbon molecules fluoresce in ultra-violet light. Hot young stars of course will produce plenty of this (its wavelength is just a little shorter than visible light, just as the infra-red Spitzer is seeing with is a little longer). So they're an excellent general gas tracker. Zookeeper Chris's current non-Zooniverse research involves star formation and the use of sulphur compounds to track it - they are another good tracer.

I mentioned earlier that gas needs to cool in order for gravity to shrink it and start starforming, for heat and light and stellar wind from stars generally throw things around everywhere - that's why red spirals shut down, as we discovered two years ago. One mystery the Milky Way Project is hoping to solve is why the dust doesn't seem to be being blown around as much as it should be: why is it still there? But knowing what the Zoo projects are like, I bet a large host of unexpected and possibly even un-thought-of questions end up getting answered too!

For example, here's something I found as one of my first images: what is this red banana?


"Some warm gas I think," replies Rob. "A classic, if oddly shaped, fuzzy red object." Damn! Oh well. Only a few get lucky at once. Science is fruitful, but it usually takes a while . . .

Ooops! Once the bad jokes start it's time to get my coat. Please hop aboard, draw bubbles, and join the discussion!

Flabbergasted

I planned to have a nice, lazy Saturday today. Then I found out about this.

It's the stuff of complex political thrillers, possibly set in a fantasy world, such as George R R Martin's A Song of Ice and Fire. And it would probably sell pretty well, if it was a novel, and if it had a slightly less messy, drawn-out, utterly inhuman and unsatisfying ending.

Because he was unlucky enough to share a name with a suspected terrorist, Khalid El-Masri - a German citizen - was secretly seized by the CIA, held for many months, tortured, malnourished, and generally treated hideously. And this went on even after US authorities knew it was a mistake.

He was interrogated again and again. He began a hunger strike. One day before 4 weeks had elapsed he was granted an interview, at which he was basically told that they did not care if he was innocent; he was staying. All this time, nobody, not even his family, knew where he was or what had happened. It took an intervention from Condoleeza Rice to get him released. And when he was released, he was secretly dumped in rural Albania with no means of getting home. They, too - understandably given his condition - thought he must be a terrorist.

And even though everybody knows now that it was all a horrible mistake, he will never get any kind of compensation, or even an apology.

Apparently, an apology and compensation would require a lawsuit, which would break US secrets. And evidently, procedure and paranoia matter more to the powers that be than the most fundamental decency.

I cannot even begin to comment. I just have no words.

It all took place several years ago, but re-emerged on Wikileaks. Jack of Kent makes the reasonable point that Wikileaks itself, by making itself unaccountable, does not entirely fit the definition of liberal - but at this tearing-my-hair out point, I have to say: so what? It's at moments like these that I feel like I am transported into a nightmare world where everybody fights dirty. Wikileaks is not entirely what I would call honest; but I have more admiration for them than I do for those they expose. In a better world, Wikileaks could be open, as could more of politics . . .

The hideous thing is that while people can campaign admirably on so many issues, I fear that on this, our cries will fast turn to whispers. Largely, I suppose, because there's nothing we can do. We can't change how secret, powerful organisations work. I doubt they'd take much notice of protests or campaigns, other than perhaps to find ways of dealing with those who they think started them. We could try to elect governments who don't support them; but, again, the secrecy prevents us finding out who does - although, as I guess many of us suspected, both Tory and Labour are falling over each other to be first to kneel before the United States.

A friend once told me earnestly, "Countries are like people." I don't think that's true at all. Countries, even dictatorships, are run by many people; and while individuals can be brave and self-sacrificing, entire groups are less likely to do that. If all countries in the world were one person, enough of them would finally gang up together and turn on even the biggest and most frightening bully. But with countries? Catch any diplomat saying to several others, "Let's all tell X we've had enough", unless, of course, X would be a suitably small and weak victim, as Iraq was - and as human rights are.

And so all Germany needed to be silenced was this: "Our intention was not to threaten Germany, but rather to urge that the German government weigh carefully at every step of the way the implications for relations with the US".

It is unbearable to do nothing; if anybody has any ideas, I want to know about them.

(In the unlikely event that this blog ever gets important enough that I should conveninently vanish for typing these words, please could somebody save them?)

Celebrating Ice

I see that, just like last year, a bit of water in its solid form on the ground has, well, ground things to a halt again - apparently it's making even more news than the coming Royal Wedding. It's not stopping the students demonstrating in the open air, though! Oh and I hear we're out of grit? Come and sweep some off Haverfordwest's streets, there's so much I mistook a huge puddle of it for the results of an over-enthusiastic night out . . .

All right, sarcasm over (head over here for more from me if you like that sort of thing).

I have to say a personal thank you to the ice that froze on the inside of my car's windscreen, because it finally cleaned it. I'd dried off some condensation with a cloth bag weeks before, and it had been mucky ever since - despite umpteen cleans with tissue paper, towel, ice scraper, glass cleaner, and you name it - which made driving in the sunset a particular eye-watering nightmare. But every bit of that dirt fell off with the ice!

But look what came out of our bird bath a few days ago . . .



The leaves are actually less obvious to the naked eye than to my mobile's not-very-good camera. I think the ice actually expanded away from them, but retained their veiny patterns, so that it looked like a laser cutting into a piece of glass. Sadly, it's melting now . . .


I noticed that when I arrived home in the rain . . .

Off the topic of ice for a moment, I had one of those headache-inducing-ly annoying days at work today. It was supposed to be my day off, but of course certain people (who don't usually work in my office) decided to summon in me, and someone else who's disabled and doesn't come in on a Friday, all the same for our delightful monthly meeting. What happens in these is that we provide a lot of tea and biscuits, shove all our stuff off our information table for our guests, get yelled at for not doing it fast enough and generally criticised because our desks aren't empty (doh . . . believe it or not, we do do paperwork in my office), put the table somewhere stupid, arrange chairs for those who demand to be waited on hand and foot, apologise when the phone rings because somebody actually needs us, and take minutes while the same two people (neither of whom work at our office) go on and on and on about how sleepless they are about our future and how many idiotic irrelevant things they demand we must do instead of look after the people we're supposed to be serving. You get the picture. Pretty typical office meeting, I should imagine. To be fair, it isn't half as dishonest, unprincipled, bullying, or generally stressful and soul-destroying as the meetings I sat in on when I was teaching . . .

Anyway, today the person who generally takes the minutes and provides the records in my department hadn't turned up. So this task fell to me, as did taking the prolonged public kicking for not knowing the things this person knows, who has been here 15 years longer than me, and because somebody didn't know something that I thought they knew and that wasn't part of my plans so not my job to tell them . . . Again, you get the picture. I'll shut up now.

I then had an icy walk to the car and shopping to do, and my head was pounding. On the roads leading away from the town I work in are signs to one of our local beaches. They point right, while my home lies left (roughly speaking).

So today I thought . . . I will follow those signs.

As soon as I'd parked the car and got out to hear those waves between the still, silent cliffs, I felt better. The wind was painful around my un-scarfed face, it got in under my coat, and the clouds were dark; but the sea was a surprisingly bright blue-green.


This is Broad Haven according to the holiday websites . . .


This is it earlier today . . .


. . . yep . . . lots of water had frozen right there on the stones and sand. I walked on ice puddles which made wonderful noises but did not snap, merely created bubbles and pushed the sand around! (I'm actually really cheesed off - you see that blurry bit on the bottom right? That was an amazing ice puddle in which stones were nestled, but I somehow managed to delete that photo when I got home).

The ice had fascinating effects on the sand. It was wonderful to see where there was both solid and liquid water, and the alien landscapes it was managing to produce . . .





If someone had told you this was a satellite photo of Mars, would you have believed them? I'm afraid I might! But it's just ice and sand. Look at the effects . . .


. . . and just next to the image above:


It's a funny thing, ice. Most materials - as far as I know - contract when they cool. But the water molecule is a very special thing. It's sort of Mickey Mouse shaped, two hydrogen atoms and one oxygen atom. The oxygen atom is much greedier for electrons than the hydrogen atoms are, so they spend, on average, more time with the oxygen - or to put it in another way, their "probability cloud" or where they will be is somewhat skewed towards the oxygen. This means that the oxygen has a negative dipole, the hydrogen a positive one - so, like a magnet, they will be attracted to each other (this wonderful article mentions an old description of two hydrogen atoms desperately in unrequited love with an oxygen atom). But this affects other water molecules too: the oxygen will also be attracted to hydrogen atoms of other water molecules, and vice versa, which makes the general structure stick together very nicely. Most molecules so small, and made of such small atoms as hydrogen and oxygen, would be gas (think of nitrogen, methane, carbon dioxide . . .). But water's a liquid, because of this dipole. And although they slip under and over and around each other a lot, their strong bonding also causes capillary action - just watch rain falling on the window and notice how a new drop will leap into the track of an old one, rather than make a new trail.

But once water goes solid, the molecules form hexagonal lines. Russell Stannard, in his book "Ask Uncle Albert", describes ice molecules (water molecules below freezing point, if you will) as being like long, long lines of people all sitting on each other's laps. This rigidity leaves plenty of gaps between those lines, which is why it expands. That's why, when water trickles into rocks and soil and then expands, we get weathering. I believe that's probably what's happened in the last picture above.

It was also very satisfying scientifically to notice that the water that remained liquid seemed to be coming from under the stones or sand - since ice expands, it's lighter than liquid water, and so it rises. Again, this isn't true of most liquids. But it's made pondlife and icebergs possible. Without this characteristic of water, I bet a lot of Earthly life would be hugely different.

And meanwhile, something's a bit wrong with the cliff . . .


But after only a short time of tramping across the beach I was starving. So I went to the cafe by the road. It was closed, but another was open. I bought scampi and chips and a hot chocolate with whipped cream and marshmallows. While I waited, I chatted with a family already scoffing chips there. They had two utterly adorable and very well-behaved dogs, who let me stroke them like cats, one hand on each. I honestly cannot recommend a better remedy for awful meetings!

Anyway, yes, I took my scampi and chips and hot chocolate and two sachets of tomato ketchup straight out there to the beach again. I went closer to that cliff . . .


And mostly stayed away from the water; can you imagine how slippery it was there? I plonked myself down on a rock, found a little well-like bit to put my hot chocolate in, and gobbled scampi for a while. It was raining slightly but I decided I didn't care. Surprisingly it really wasn't that cold.

Nevertheless, although the huge icicles hanging from the cliff were shedding water and indeed a few chunks of ice onto the sand, clearly the ice wasn't going to melt very fast!


What a sight!






While a chap nearby did a crazy dance, I photographed and photographed, my hand over my mobile to shield it from the rain - also to put it in shadow, since the picture went especially dark whenever I tried to include a bit of sky. I wondered how long it had taken those icicles to form. I remembered a phrase I'd heard in my first year of university, describing Antarctica, which really tickled me: "thermal inertia". I think the gist was that an increased amount of water vapour in the atmosphere would increase the size of Antarctica to some extent, since the water molecules would be likely to stick to it. If the size of Antarctica increases, that will increase its albedo - in other words, it will reflect away more sunlight. Of course, it will also raise the average temperature of Antarctica, too, just the same as if you pour warm water into a bucket of ice.

Another beautiful characteristic of water is its high specific heat capacity or enthalpy of melting. Heat is basically molecules wriggling about frantically due to having plenty of energy. (Absolute zero is of course when they stop moving altogether.) Now, because of the strong attractions between water molecules, it takes quite a lot to make them separate, or wriggle away from each other. That means that you have to put an awful lot of heat in before it'll warm up. The converse is true, too: water will take a long time to freeze, because it's got so much spare energy you had to put in to warm it up in the first place.

And that is why the Earth's surface is (contrary to how it often feels) remarkably similar in temperature all over. OK, OK, so hot countries seem incredibly hot and cold ones seem incredibly cold, but that's because we're adapted to a narrow range of temperatures, and what cosmologically speaking is only a slight variation seems extreme to a biological entity. When water evaporates from the equatorial regions, it carries plenty of heat to the poles. And those cold deep currents that start at the poles and head towards the equator remain cold, which again is useful, because more oxygen can dissolve in cold water - so cold water upwellings are particularly useful for marine and coastal life in the equatorial regions.

In short, if the Earth's oceans were oil, the heat would be far less evenly distributed around the globe!

I love the water molecule. I actually fell in love with it during A level Chemistry, and kept up with it for my A level project and several of my university units. If you want more of what it can do, check out this site - I've linked to it before, but it has some desperately gorgeous close-ups of snowflakes!

I'll leave you with the most spectacular photos of that cliff . . . and by the way, it was very nice to get home!

A letter to the students

Dear students,

I am writing from a dark memory of a time when young people did not do what you do today. I was a teenager in the nineties when the mere mention of politics, or indeed anything that took place out of the classroom or the charts, was considered worse than discussing homework. In 1997 I was 14 and, I now regret to say, very excited about Labour's victory - my classmates could not tell the difference between this and "fancying Tony Blair". To speak up about things that happened outside one's life was "sad". It was just not done.

So I suppose, if we have one thing to thank the Labour government for, it was annoying people enough to make protest a do-able thing. Or, perhaps the introduction of the Internet. Or even better education. Who knows?

I don't know why you are doing things that my generation was too cowardly to do. But well done, and for God's sake don't stop. Democracy is precious, and easy to lose. (I later went on to live in Spain, but abstained from voting for student leaders because I didn't understand enough of the language to make a choice. I didn't feel I had the right to bias the voting with an uninformed opinion. To my fellow students, whose parents probably remembered Franco, my not voting was shocking and distasteful, letting down of a hard-won value.)

I notice you're having to put up with the usual remarks - "these kids are too young to be out of school", "they just wanted to bunk off and have a fun day out", "it's just £7.50 a week once you're rich anyway", and so on.

Why go to school other than to prepare yourselves for the world? Not just to be a consumer, not just to get a job: but to be part of society, to change the world for the better, for nobody else will if you do not. As well as to partake in the greatest joy I know - that of knowledge. As a professor of teaching pointed out to a group of trainee teachers, there are only three groups of people who we tell where to go: criminals; the insane; and children. But you are not in school simply to get you out of the way until you're a grown-up. I know if often feels that way, and that's what you've got to fight. Your education is for you, and for other people too. It is not only your right but your responsibility to fight for it. To those who did - I am so proud of you!

It may be true that the fees would not, in theory, prevent anyone from going to university (the BBC page has a good set of questions and answers you should check out). The MP Tom Watson, and those who agreed with him, got a lot of kicking for "misrepresenting" the situation by pointing out that, if he saved £100 a month for his 5-year-old son, that would still not pay his tuition fees, for they are not upfront. A loan hangs around your neck for many, many years; but it's still better than paying upfront. No, what's going on here is a subtler but pernicious ideology.

Even before it's time to apply, there'd be the worry whilst growing up about whether or not it's worth going anyway. "It won't help you earn back the money you'd spend on it. Such-and-such went into banking without a degree and is now earning so-and-so." It's an off-putter from the start, especially for poorer families. Incentives for poorer students (see that BBC link) sound good but might create a divide, turn it into a situation of charity, and also would not help students whose parents of higher incomes discourage or refuse to help their offspring who want to learn (yes, there are those).

And during, the thing itself: it's become a market. Introduce the market and what matters is money, not education itself. Education becomes a "product", your degree is something you've bought, no longer a labour of love. And it must be paid for in the end. So if you never earn that £21,000 a year, then what? Who does pay? Would your course leaders spend their time preparing you for jobs that do earn this figure, and perhaps throw you out if you're likely to end up on a job that pays less? And what about the marketplace atmosphere itself: as businesses compete, would universities have to work against each other rather than together? Would the corporate branding, the package, the adverts to try and "sell", become the focus rather than what's inside them? More simply: would people concentrate on what looks good rather than on what's to learn, and learning, as a result, suffer? It's hard for a non-economist like me to explain. Perhaps some of you economics students can tell me whether or not I'm right. My feeling is this. We have the National Health Service and I'm bloody proud of it. We do not treat people on the basis of whether or not they have money. A sick person is a human, and a normal human helps another person; end of story. Markets interfere with straight humanity from the heart. I wanted to be a teacher and give education as a gift - no, not even that, for child-rearing is not a gift but something a mother simply does, and that's how I saw learning.

Maybe this is a bad patch before we reach a very different future. Have you noticed those occasional articles about virtual schools and everyone learning online anyway? Maybe that's what'll happen; maybe university will one day no longer be about leaving home. The cost of accommodation and living has risen too. I lived in a cheap hall which I thought was part of the experience; but these were knocked down one by one and more and more students around me spoke snobbishly of their expensive quarters, expressing horror at the idea of sharing a bathroom. Well, these things do have to be paid for. That should be a choice; but what if the cheap choice is no longer available? Tuition fees aren't the only thing to worry about. Actually, going back to myself again (and I probably seem pretty ancient to many of you!), I noticed the lecturers mourning how their courses had to become easier and easier, and only an MSc would be taken seriously, and thought - for goodness sake, university just seems to be a pampered boarding school. That probably is a waste of your time.

But back to this week. Whether your worry is education cuts, or tuition fees, and whatever people think about those: well done. You have to do two things to really make a difference: one is to check the facts, and the other is to make your voice heard. If you only do the former, no amount of learning will make any difference. If you only do the latter, people will continue to get things wrong. (Actually, that'll happen even if you do both, but you know what I mean.)

I want to give some special well dones now, but please don't feel miffed if you simply didn't have the opportunity to do anything heroic; these things often come to you by accident.

I want to especially congratulate these brave girls. The Guardian shows the van being damaged, but the BBC caught this photo, and I do recommend a look through this entire photostream. I notice they've been insulted as much as anyone: "The van had already been smashed up, what are these silly little girls going to do ? Turn back time?" Sadly, the idiots in your classroom may remain idiots for life; believe me, grown-ups can be unutterably stupid too. This grown-up missed your point, I think. You were standing up for peace and responsibility at your own risk. You were being human shields; you made an inexpressably important gesture.

"If they smash it up, it just proves the point that teenagers are out here today for violence," said one of the girls amid the chaos, her eyes darting left and right looking for the next vandal. "If we let the government portray us as violent then there is no way they are going to listen to us."

Well said, young lady.

After watching videos like this, I guess many of you will, understandably, distrust the police for life. Wasn't there supposed to be a time when they wore tall funny-shaped helmets and were helpful, pulling boys' heads out form park railings? (No, I wasn't around then, but I've read about them in books.) I hope things like this won't lead to a complete collapse of any trust between those with authority and those without. That won't get the country or education anywhere. But this is largely for authority to decide. Yes, there certainly were from the sounds of things a few morons and violent people at the protests, who ruined your cause and did nobody any favours but the paranoid. Make it clear those were not the majority.

Young and old learners, students, school pupils, all those who want to learn - I've been reading article after article of what you've been doing. I'm smiling at the BBC's list of your activities around the country, and am intrigued at the UCL takeover (Update: They have a fantastic blog, do check them out!). Honestly, when I was your age I'd given up on my peers ever getting off their navy-blue-skirted bottoms and doing a thing - you have raised the profile of humanity. (Did you know that Paul Lockhart describes you as "the ones most often blamed and least often heard?") But most of all I'm moved by the words of Laurie Penny, who was in the kettle with you and wrote in the Guardian and the New Statesman. I was scared for your welfare, yes. I wish I'd been able to get to you all with food and drink and warmth, not to mention miraculous toilets and medication for those in need. It horrifies me to think of you being out there for so long, essentially deprived of things even a prisoner cannot legally be denied. The humiliation for some, as well as the cold and hunger and other discomfort, must have been terrible. But even then a lad told Laurie Penny not to add a book to the fire to keep you warm, because you're not Nazis. Let safety and comfort be secondary. You knew that, and I expect many of you would do it again.

As a last resort. If you can't go to university, don't stop learning. Something has happened which I hate, and that is the all-or-nothing situation all learners are in: you cannot leave school early, as some people want to do as much as others want to stay, but once you have, that's it. Adult education is very difficult to get into and often terribly expensive. But people have been doing something long before David Cameron came up with his "big society" ideas: they've been learning informally, alone, or together, online. I run Cardiff Skeptics in the Pub and the Galaxy Zoo Forum, both of which are essentially movements for people to discover things together. (Obviously what I say here is from me alone, not from either of these movements. We grown-ups have to clarify these things for each other's benefit.) You can be in on either of these - young Rhys Morgan is a 16-year-old skeptic, and we have young people who learn to classify galaxies and contribute to real science that goes in papers. There are many, many movements like this, peaceful organisations, cheerful groups of people whose brains are filling with beautiful things and who can do a great many things as a result. You'll be welcomed in. If they have to take over education for a time, that's not a good outcome, but it's better than nothing.

Let's all do what we can, our different things, to keep education going.

Much love and praise from Alice, who wanted to be a teacher, and hopes she can be a teacher in other ways.

How to Prove you're Inclusive: Be Slick

February 2018: Although I gave up this blog long ago, this post now worries me and I want to add some updates.

The central point - that what I witnessed from a schoolteacher, and what I was taught as a PGCE student, were stupendously crap lessons in inclusion, and seriously backfired - remains unchanged. What has changed is my knowledge, and I have a lot of people to thank for that.

What the people described in this post purportedly wanted to teach was about unconscious bias and how it feels to be isolated. What they ended up teaching was "don't trust your teacher. They'll have a go at you for doing exactly what they told you to do."

I wrote that I was a basically naive and straightforward person and liked myself that way. It never occurred to me that a person of colour might not be able to be that way, even if it was their nature, because they'd always have to be on the lookout for threats or duplicity. I wish I had thought of that.

I wrote that it wasn't good to always be worrying that what you say is construed as racist. I didn't realise that that is only the point when you're surrounded by white people looking to have a go at each other (as I was at the time). I didn't know that saying racist things can be done by the most innocent people with the best of intentions - that it's not about using bad, specific, well-known words but a whole power dynamic that affects people's employment, likelihood of going to prison, life expectancy and a hundred other things. And that intention doesn't equal impact. And that if you're accused of racism, that's not the worst thing in the world and defending yourself with the old platitudes about having friends of colour, etc, is not the way forward. Rather, knowing that you've grown up in a society and culture that systematically advantages white people means it can happen to anyone and a better response is, "Whoops, sorry! Thanks for letting me know. I'll try and learn more/think this over/do better next time," and even though such growth can initially hurt, it's very gladdening in the long run to know more. And trust me, people will respect you a lot better. I wish I had thought of that.

It is really valuable to know about unconscious biases, and not to waste your time getting angry, feeling guilty or scrabbling around for overused ways to defend yourself - but rather to find out what specific ways some people receive advantages or disadvantages, and press for your school or workplace to address these. When you see people of all genders, colours, sexualities, physical and mental disabilities and more all flourishing, then more inclusive thought is probably going to come much more naturally to you!

I also expect that in another ten years I'll look back at the kind of stuff I write today and be embarrassed or worried at having missed something really important, and therefore unknowingly leaving people to suffer. So I want to keep learning.

In the meantime, I recommend you follow some awesome people on Twitter, who've taught me a huge amount: Sunny Singh, Katelyn Burns, Chandra Prescod-Weinstein (who I hope is back on Twitter soon!), DN Lee, Ijeoma Oluo, "Elainovision", and many more who I can't remember offhand but who you'll see me retweeting a lot.

Anyway, I doubt this old post gets read any more but just in case, here it is, with the limitations as described above.

* * * 

A couple of years ago, as many of you know, I was doing the science PGCE - training to be a secondary school science teacher. As many of you also know, I didn't complete the course. But many things happened during it which I'd still like to share. Here's one of them.

A well known trick to get people thinking in science lessons is to give them a surprise. For example: Here are the four fundamental forces, which do you think is the strongest? Put them in order. Then, once everyone's claimed that gravity is the strongest, put a magnet on the table and use another magnet to make it jump up - demonstrating that magnetism is stronger than gravity.

(At least, that particular strength of magnetism is stronger than Earth's gravity. Do the same experiment on a neutron star or with a really pathetic little magnet and you might get a different result. *Update: how embarrassing. I'd missed the point of the experiment. The Earth has a much larger mass than the magnet and that is the important thing. If you put 1kg of magnetic stuff and 1kg of non magnetic stuff next to each other in space, the magnetism will - for this given weight - carry much more force than the gravity. Anyway, back to this post.)

I witnessed a similar method of teaching in a PHSE lesson (Personal, Health and Social Education) for a year 7 group (11-12 year olds). It made an excellent point. The task: get into pairs and draw what a bully looks like and what a victim looks like.

The pupils spent some considerable time at this task, getting the angle of the cigarettes and baseball caps exactly right, showing teeth and stubble, paying attention to the way people were standing. The pictures were detailed and graphic. They took a great deal of trouble over them.

The form tutor then went up to the board and drew two identical stick figures and said: "Exactly the same."

The point being that you can't tell that someone's a bully just from what they look like. And they went on to discuss what to do about bullies.

The problem with that was that those kids had really put a lot of effort into their work, only to have it universally rubbished. Next time they might be a lot more cautious about going to so much trouble. They might start fishing around for what the teacher's not saying. Get into the habit of that and lessons become a game of "Guess what is in the teacher's mind", as well as "Avoid taking any trouble, you'll only look stupid." Neither of these attitudes are conducive to learning. I don't recall there being any discussion about why bullies were perceived to be big and scary-looking, let alone the teacher acknowledging the work the pupils had done.

The very same week, I attended a day at college focussing on people whose English was not their native language. It was not taken by our regular professors, but two ladies from a public project dedicated to helping such people - I forget the exact details. Some of their demonstrations were excellent, such as one of them playing a gypsy lady who only spoke Spanish trying to get her kids enrolled in a local school, and the other playing an indifferent council worker who shoves a long complicated form at her, is embarrassed by her half-English-half-Spanish attempts at asking questions and keeps her head down hoping she'll go away. I enjoyed a lot of the day and felt even more determined to help the (very few) non-native pupils in the schools I worked in.

A complication was that this was an area with an almost exclusively white population. One of the demonstrators was brown-skinned and there was one Muslim girl in one of the classes I taught, and I think that was about it. We did have a lot of Eastern Europeans - I was living with three of them, and they were the nicest housemates I've ever had - but all of them were pretty fluent and generally I think doing fine. For me, a born Londoner, who'd spent the previous six months in Brighton, this was not my natural environment at all; and the acute, carefully-worded, self-conscious discussions about it made me extremely uncomfortable. It was like suddenly having to be incredibly conscious of the fact that the sky is blue, and that if for a moment your mind happened to drift into thinking of the sky any other way, that was morally wrong and everybody would know. And for the locals who did not venture far outside their area, this whole business was theory, not practice.

In fact, the area was so homogenous that in many schools, ESL (coded term for English as a second language) pupils often had to be protected from trainee teachers struggling to pass their course - you have to provide evidence that you have done specific work on these pupils in order to get your teaching certificate, but there were far fewer of them than of trainee teachers!

What also worried me was that the demonstrators did not seem to be offering realistic strategies to help non-native speakers. They seemed to be coming from an all-or-nothing perspective - these people need to be with full-time interpreters, for example. They also spoke at length about how gypsy children were legally entitled to a third of the year off school for "cultural reasons", but were unclear whether or not this level of absence would lead to the school being penalised for the effect this would have on the league tables. All in all, asking this much from people unused to anyone remotely different from them was, I could sense, engendering resentment and indeed jealousy, rather than being constructive.

But I may have been biased, for these people dealt me a humiliation that still stings today, two years on.

They set us an activity and sat us all down at tables of ten or so people. They kept us in strict silence, and then they went around with one of those sheets of star stickers. (I loved those when I was tiny.) Reminding us to keep absolutely silent, they put one onto each of our foreheads, not showing us what colour it would be. One guy whispered to his partner, "What colour am I?" and was told. Once they'd finished doing this, they cried out, "Now, still without talking, sort yourselves!"

"Into what?" somebody asked.

"No further instructions, just sort yourselves!"

Yes, it did dawn on me that these stars were supposed to represent skin colours. But I immediately dismissed the idea as too childish for a professional postgraduate course. For one thing, everyone knows their skin colour, but we didn't know what colours our stars were - presumably, we were supposed to find out. And they'd just done that wonderful demonstration about the poor lady unable to ask any questions. So I concluded this must be about non-verbal communication.

I waved my hands at two girls who both had green stickers on their foreheads and mimed them coming closer together. Immediately their eyes lit up, everybody else caught on and that was how most people did the experiment. I promptly found out this way I had a green sticker.

Yeah, you can guess what happened. Because I agreed to be sorted by colour, and because I had started it, I was shown up to be the racist, the enemy of everything they were trying to do. All right, not in so many words. "You started it, and that was good," they said in that uniquely ironic tone . . . and went on to ask two people how they'd felt - one had been the only silver sticker, and one hadn't got one at all. They played their parts beautifully, mourning how left out they'd felt.

The other science teachers to be (most of whom I didn't feel liked me very much, and who I generally avoided) had been at the back, and had seen exactly what was coming and simply all sat together. They claimed they'd sorted themselves "according to our subject" and were publicly praised and held up as an example to us all.

Ranting about this to a friend that evening, she nodded wisely and said, "Oh yes, there have been psychology experiments about that."

Can you imagine how I felt? Duped. Stupid. Mortified. Hopelessly, hopelessly guilty, as if I'd committed a crime against a sector of my fellow human beings who were already being victimised. I'd always hung around with the international students at university. I'd chatted with my Ghanian housemate in Brighton about Steve Biko and how unbelievably stupid some people could be; he'd always cheerfully told me what it was like to be black - no big deal except when people made it so. I'd lived in Spain for a year, and experienced not understanding a word of lectures, failing most of the exams through my bad Spanish, having chalk thrown at me presumably because I looked different, and having to correct hilarious assumptions about England such as that we all live like spoiled lords and have breakfast in bed (yes, really!) . . . and, on the other hand, much more importantly, I'd experienced people genuinely taking me under their wing, slowing down their talk, not minding my mistakes, lending me their notes and not expecting any major gratitude. How could I defend myself? Anyone who says "I'm not a racist" is usually about to add "but I wouldn't want my daughter to marry one."

And the main thing I learnt was: never believe what other people say. If they tell you to do something, they probably mean you to do something else.

And, even if the possible trap should be far too childish and basic to be the focus, that doesn't mean it isn't.

Hardly healthy.

Also, I learnt that theory and models that bear no relation to reality are still very prevalent. What has a suddenly and arbitrarily placed star sticker, whose colour you don't know, have to do with permanent skin colour? Nothing that I could see. What was the big deal with sorting ourselves into groups, when groups are how both pupils and trainee teachers did most work and how people congregate socially anyway? It would have made a lot more sense to say "Don't you dare talk to anyone with curly hair/blue eyes/who wears glasses" and then afterwards, if they must, "How did that make you FEEL?" Would I have wanted my fellow Spanish students to feel guilty that I didn't understand the lectures, that I was very pale in comparison to them? Don't be so ridiculous! Did I want a full-time interpreter? Splutter! What sort of person could possibly want that sort of thing?

Not at any point during the day did we ever get near discussing the classroom or realistic situations. Not once was the issue raised, for example, of "What do you do if some kid makes a racist remark?" or "How do you go about getting such-and-such some help with something you can't deal with alone?", let alone "What if someone's being bullied for the colour of their skin?" No, the day was about legalities, and an in-depth examination of ourselves, after which I felt unable to face the others - and which I'm still embarrassed to write about. I can hardly tell if I'm more embarrassed at being so publicly conned, or in case anyone really thinks that I would seriously split children into skin colour groups or something.

To be honest, while I've learnt to be very skeptical of claims, I'm a very straightforward and trusting person. That makes it easy to set traps for me. But it also makes other people feel safe when I'm there. They don't have to dig for extra meanings, or worry that I want something different from what I say. In the context of the classroom, I suppose that would mean it would be easy to lie to me about why you haven't done your homework - but it would also be setting a good example. As in: don't be slick, don't be devious, don't show off, there's no need. Just be curious and nice to others. That's how I try to run the Galaxy Zoo Forum, and that was how I tried to run the classroom, and it seemed to work all right. There are plenty of things I don't like about myself, but my trusting nature is not one of them. I like myself that way. Why should I become distrustful and suspicious and see tricks everywhere in order to avoid being labelled a racist? How does that make sense?

The more people start setting traps for each other, the less honest we can become with each other - and, frankly, the less we'll then be able to talk about real problems and what to do about them, for all energy will go to defence. And how can you enlist a group of people to help you deal with something when you're frightened of what they're going to publicly call you? That's how to get everyone to keep their head down and not draw attention to themselves - and when something needs sorting out, it wouldn't get done.

And is worrying and worrying about whether or not you're a racist really productive? Does guilt, self-consciousness and an avoidance of certain words really improve the situation for other people? (Update, May 2013: if said language is oppressive, of course yes.) Or does it just make you feel scared and them feel awkward? Here's an extreme example. For another, I've heard of people being condemned for saying "black coffee". That, dear friends, implies that there is something wrong with being black, but that you as a white or whatever else colour person are too sanctimoniously polite to say so. I cannot think of anything more isolating and humiliating than to be thought inferior, but for those around you to smugly think the better of themselves for using elaborate language to avoid saying so - and probably wanting a receipt, too. Get lost.

Myself, I like Allan Sandage's quote: "All humans are brothers. We came from the same supernova."

(From Hubblesite.)

Oh, and as a parting shot, that group of trainee teachers who were publicly praised for spotting the trap and therefore being non-racist? One of them, the very next morning, referred to one of the demonstrators in disgusted tones as "That Paki".

Whether you're black, white or bloody rainbow coloured - what do you think?

Book Review: "Big Questions - The Universe" by Stuart Clark

I'd better start this post by declaring an interest.

A few months ago I was contacted out of the blue by a friendly lady named Marta from Flint PR, inviting me to review a book, and asking me if I knew of any more bloggers who'd like to review it. I'm always up for getting a free book in exchange for writing a review, so I naturally said yes and alerted my astroblogging friends. I fear that by now she'll have put me on the blacklist as someone who nicks their books and doesn't carry out her promises, as I was probably supposed to do this in July - and you know what it's like, the guiltier you feel the worse it gets, like writing birthday thank you letters. Anyway, Marta, look, I've done it - though I'll understand if you don't want to bother with me again!

The book was from the "The Big Questions" series, subtitled "The Universe"; the others (so far) are Philosophy, Physics and Mathematics. I declare a subsidary interest: it's by Stuart Clark, who also wrote The Sun Kings and of whom I am a great fan. He's a very friendly and interactive Twitterer, happy to answer questions and generally a very encouraging sort of person.

He's divided up the topic into 20 questions, ranging from the obvious "What is the Universe?" to the basic "Why doesn't the Moon fall down?" to the contemporary "Why is 75% of the Universe a mystery?" to the uncertain "Do other intelligent beings exist?" to the downright brave "Is there evidence for God?" He chose the questions himself. You can see more of them in the link above.

Now, if you ask for my opinion, I'll give you my opinion - as some people have been rather shocked to find out. My opinion on the design and format of this book is that it is ghastly. The cover is made of that criss-cross stuff you get on nasty cheap folders. The pages are rounded at the edges, looking like a dreaded office diary, and smaller in the middle, so you can't riffle through them. There is no space between the heading of a subsection and the first paragraph, but there are spaces between the paragraphs. (This blog does that automatically too. I hate it.) The introduction paragraphs and the diagrams aren't aligned with the text and huge areas of paper are wasted, which does my eyes in. Stuart has inserted beautiful, illuminating, carefully chosen quotations to go here and there in chapters, and those appear in boxes with only the corners showing, as if the words are trying to burst out like parasites and escape.

Well, I did warn you. (Cumbrian Sky has more positive comments about the book's appearance if you want balance!) I suppose it would suit an ashamed closet astronomer who wants his or her colleagues to think they're reading something else. However, may I also add that this is a good moment to mention not judging a book by its cover?

Because it's a gorgeous book! It focusses heavily on the facts, the science, rather than trying to awe us with pictures. It presents the science that's been discovered so far, as well as what we don't yet know. Sometimes Stuart starts a chapter with a historical anecdote. Other chapters he starts by setting out the basics, or describing a method of measuring something to do with the question. You get a very gentle introduction to each issue, even when the issue itself (and the rest of the chapter) is enough to make your head spin.

The book is not afraid of uncharted territory (as scientists say, if you know what you're doing, it's not research). Kepler invented his laws of planetary motion before we knew what caused the planets to move. Pauli invented the neutrino, as Stuart writes, as "a desperate remedy" to account for lost mass in nuclear fusion - twenty-six years later, neutrinos were discovered. Stuart discusses dark matter and dark energy, but also modified Newtonian dynamics, "quintessence", and the idea of overturning the cosmological principle, as means to account for the 96% of mass that we cannot see and the expanding acceleration of the Universe. I can't pretend to have understood it all, but the nice thing with this book is that it's broken up into lots of little chunks you can go back to several times. Actually, that's one thing that kept me reading it for so long. I kept going back and looking at things again. Although each section is independent of the others (there's very little "see such-and-such a chapter" business), my mind got a lot clearer when I re-read and re-re-re-re-read, trying to take difficult concepts in.

There's a great variety of subject matter. In the chapter "Are we made from stardust?" we get taken into the world of biology, of the definition of life, of the intricate complexities of amino acids, of experiments and fireballs and meteorites and uncertainty. So taken in, in fact, that the "stardust" bit, of which we are reminded at the end, comes as a bit of a jolt.

One chapter really threw me and left me feeling very frustrated: "Can the laws of physics change?" We began with the story of cave in Gabon which is, as far as I know, the site of the only natural nuclear reaction that ever took place on Earth. I remembered a very pro-nuclear power lecturer at university telling us about that site, remarking that the products of the reaction haven't moved since (therefore, his point was, nuclear power is safe). How the uranium built up due to being carried along by water and deposited, and why it set off a chain reaction, was clear - until this bit:

The nature of the nuclear reaction appeared to have changed and that could only happen if the laws of physics had changed too. Research conducted in 2004 showed that the strength of the force governing the nuclear reaction in Oklo had been different by a tiny amount, less than five parts in 100 million, from what it is today.

That's all we learn - unless I've managed to miss the explanation every time I read the book (possible, I suppose). What aspect of the nature of the nuclear reaction had changed? What laws of physics had changed? What force governing the nuclear reaction? Different how? I'm hardly going to care what year the research took place in if I don't know that, or who did the research or what they were doing or what they found, am I?

And yet even from that paragraph you'll probably see how clear and easy Stuart's style is, how gently he takes us along - his text is not hideously condensed or full of jargon; he doesn't rush us; he explains exactly what he's talking about. Except in this one chapter, and one out of twenty isn't much to complain about. In any case, he's spurred me on to try and find out for myself, which if I was a bit less lazy I might have done by now.

I think some reviewers have wondered what the chapter "Is there evidence for God?" is doing in that book, but I found it very useful. It goes into the dilemma of exactly how fine-tuned the Universe is for life. There are a lot of terrifyingly exact coincidences that have allowed matter to exist, and carbon and oxygen to form readily in stars, and solids to form . . . But would slightly different conditions, perhaps, have been even more suitable for life, perhaps a different sort? Are there a lot of alternative universes which have these different conditions? As Stuart explains, the Universe keeps throwing surprises at us, and showing us systems (such as Jupiter-sized planets orbiting very close to their stars) which we thought were impossible - perhaps similar surprises will come on the subject of life. There is a lot we don't know yet. But Stuart clearly sets out what we do know, and there is definitely plenty to please both sides!

I'd recommend this book to anyone who knows a bit of physics and cosmology - and especially to those many people who know enough to start thinking up lots of fancy theories but have no way of testing them, other than to appear on the Internet and usually get refuted by scary mathematics they don't understand. Actually, I'd recommend it to anyone who likes reading astronomy but doesn't get much time, as it's perfect for dipping into and out of, or to anyone with lots of niggling questions and uncertainties. There's plenty I still feel I don't know after reading it, but that is of course always the way.

Cascades of Cassini's wonders

Saturn at equinox, found on APOD, imaged by Cassini.

I first fell in love with Cassini back in early 2007 when Mark Leese, who works on the project, came to give us a talk at Sussex University. At the time, Huygens had comparatively recently dropped onto Titan's soil. I remember three things most clearly from the talk. One was the video of Huygens spinning down on its parachutes, one of its instruments going thud-thud-thud like my heartbeat. Another was when he asked if we wanted a break, and Tim Metham, our course tutor, replied: "No, this is riveting!" - he wanted to hear it all, right now! And finally, he took us on a tour through Saturn's rings . . . those little blocks of ice, once thought to be dust and rocks, but made of frozen water, so they gleam . . . many of which looked like little dots - but one was blue. Was it an anomalous blob? No - it's the Earth.

And it wasn't for another couple of years that I encountered the traditional Pale Blue Dot, which you can see and listen to here. But the lump in the throat was exactly the same.

Here it is again, an insignificant point of light, a tiny flicker against this backlit Saturn:
Do read its caption on APOD. Imaged by Cassini.

I'm a poor substitute for Carl, but nevertheless I tried to give a little of that sense of hugeness in my Tea with the Stars lecture the other night. I described to the audience how the rings had scattered the sunlight to brighten up Saturn from behind - and then I zoomed in on the Earth. I don't know if it came across. It's often too personal to say.

Back to more practical terms, I was thrilled to be asked to write a piece for Astronomy Now's yearbook on what Cassini will be up to next year, and Keith, the editor, is happy for me to blog about what I found out.

I e-mailed various Cassini scientists and was answered by two, Carl Murray and Joe Burns, both of whom agreed to my ringing them up and taking up lots of their time with asking occasionally silly questions. Although I really must invest in a dictaphone or something else to record what people are saying (at the time I just scribbled it down; they were very sympathetic about waiting!), it's definitely easier to get information out of people by talking to them than by e-mail. I could ask very general questions and let what they said lead up to specifics; often the specifics came by themselves, rolling on waves of enthusiasm. I love talking to people who are exhiliarated by what they're doing! I hope it goes without saying that neither they nor Keith are responsible for any errors I have made . . .

Meanwhile, Keith had kindly pointed me to Cassini's 2011 timetable. That took some dissecting - mostly drawing up tables of types of event. To summarise, it'll make 16 orbits, usually using Titan's gravity for the slingshot effect but making 30 course corrections. It'll look at the Sun and our pale blue dot 11 times. Cassini has an elliptical orbit, allowing it to view moons at different distances from Saturn, and also goes "through the ring plane", from north to south, 29 times! This isn't through one of the actual rings, obviously; it picks fairly empty areas. But even so, it'll need to "employ protective mesaures" half a dozen times or so. I asked Carl Murray what these were and he said mostly turning the instruments inward, except obviously the cosmic dust analyser which loves that sort of thing.

And what about Cassini's main job - the moons? Well, as you'll see, it heads past lots of those. Most passes are only distant ones, though these can be useful, Joe Burns explained to me, as they show you the whole moon rather than just a "patch" of it; this allows them to check general brightness, which in turn tells us about their atmospheres, temperatures and so on. But the important, nearby passes will be Rhea, Enceladus, and Titan. Those will be checking the moons in great detail.

Rhea and Janus from Cassini. NB I'm finding all these on APOD but (update, Feb 2011) have just been told off by the legendary Carolyn Porco for not making it clearer that Cassini took them. All the originals can be found at that link. I'm now updating the links wherever possible - it's not easy! I will however keep the APOD links alongside as they are friendly and informative.

Here's where Huygens landed:
Tethys behind Titan from Cassini.

(A friend remarked that whenever he talks about Cassini he feels he should just shut up and show the pictures. I know how he feels! You can easily waste half a day going to APOD Search and typing in "Cassini" . . .)

Titan is the only moon in the Solar System with a thick atmosphere. This atmosphere is actually denser than the Earth's, and is mostly methane. However, this methane is split apart by sunlight, and if Earth is anything to go by this generates free radicals, which would then react with other methane and anything else around such as nitrogen to generate quite large molecules. This makes the famous haze which we can't see through. Cassini can see through to some extent with radar and IR. Radar doesn't bounce off liquid, so these dark patches were lakes:

Found on APOD; taken by Cassini Radar Mapper.

Herewith some beauties that Huygens found when it detached itself from Cassini and dropped down into Titan's atmosphere . . .

The landing site (having trouble finding the original one here) . . .

From eight kilometres high (JPL/Cassini) . . .

About five kilometres high, a fisheye view . . .

Rivers and lakes, as predicted (Cassini) . . .

And rocks and sandiness, just like Earth, or Mars. (Cassini)

And an artist's impression of what it looked like there.

So there we are. Titan is a solid world - but its surface is shaped like the Earth's, because of weather. That implies a cycle. Not a water cycle, for all water is frozen hard as rock there: it is, according to our best guesses, a methane cycle. It seems that those lakes and rivers are liquid methane, and methane rain falls from those hazy clouds. What we don't know is what drives the cycle: when does it evaporate or liquify? Is it the Sun - far less powerful out here, nearly ten times as far from Saturn as from the Earth (and those studying basic physics will know that means nearly 100 times less radiation, if I remember correctly) - or is it something else; volcanic activity perhaps? Can Titan hold onto its envelope of gas, or is it slowly losing it, as Mars probably lost most of anything it had lighter than carbon dioxide? The team may have found evidence of a changing coastline, but it's hard to tell, since these things take a long time to occur. There are still a few corners here and there of Titan unmapped (good old Huygens only lasted there an hour and a half), which is one of the tasks set for Cassini to do in its remaining estimated 7 years of life.

There is also some argument about wind on Titan. Dunes appear to point against the wind; this may be because only storms which occur rarely and go the opposite way from normal are strong enough to shift the sand. All in all, there are lots of delicious mysteries to go.

Besides its moons and rings, Saturn has a very complicated magnetosphere. Any planet with a molten core (that is, Earth plus the gas giants) has one of those. Do play around with it in this animation. Magnetic fields give off radio waves, which allows Cassini to study it, and it's got quite a few objectives on its (so to speak) hands. What's especially interesting about Saturn's magnetosphere is its interaction with its moons. Some moons have actually been found by local drops in the charged particles, which the moons take up - come to think of it I'm not sure if that's by gravity or by something else, sorry folks and anyone who can enlighten me and my readers, please do. (Good job this is a blog and not a news article. Of course, it may be that nobody yet knows why moons take up the charged particles . . .)

The effect of Saturn's aurora at its poles, from the VIMS probe, found at guess where. Sometimes these charged particle storms "punch through" Saturn's atmosphere, or indeed, drag it upwards. There are still a lot of mysteries and surprises - it was due to studying this magnetosphere that the moon Rhea has been hypothesised to have some kind of rings!

When I asked Carl Murray about this, he laughed wryly and said, "Well, that depends on who you believe!" He sent me a paper which describes their repeated efforts to go back to Rhea and find these rings again - which failed. Something is causing a local drop in charged particles; as yet, we know not what . . .

Rhea, the second-largest moon, whose surface is patchy and worn.

And, for me, the biggest surprise of all? Guess what's contributing not only to the very diffuse e-ring (the faint, outer one you see in that gorgeous backlit picture), but to the magnetosphere? The moon Enceladus.

Here it is, right in the middle.

These
These fountains are water. To be exact, they are salty water, indicating a rocky presence below, and they are ejected from the south pole by geyser activity. But why? Joe Burns remarked to me that something as small as Enceladus shouldn't still be hot; that it still is "calls into question our understanding of how things work" (always an exciting sort of sentence in science). It may be because it's in resonance with Dione, as Ganymede, Europa and Io are around Jupiter. This may be causing tidal shifts and heating.

Ultraviolet light from nearby stars is dimmed by these fountains, indicating that there's plenty of material there. Out in space, of course, with little or zero pressure but plenty of radiation flying around, much of it won't stay as water, but will break up into the charged particles that make up the magnetosphere.

Incidentally, the moons within the E-ring reflect more light than Saturn's other moons, indicating that they get blasted by these charged particles. I suppose to say that Enceladus "washes" them is going a little too far, but the thought made me smile. Actually, it's because such particles move pretty fast, and that melts their icy surfaces and keeps them smooth.

Another view of Enceladus's vents - if you click the first link, you'll see it's upside down! It makes for a terrific video too.

Enceladus looks, at first, like a pretty placid sort of world in comparison to all this trouble it's making - until you notice those tiger stripes. They indicate regions where the ice has melted. The stripes have a different temperature and composition to the rest of the moon, but as far as I know that's all we can say at the moment.

So, besides a very strange magnetosphere, unique rings, and the only moon in the Solar System with a dense atmosphere (Triton would have a similar one if it was warmer - on Triton, the methane is frozen, much as water is on Titan), Saturn has two moons where liquids are present. Could life exist in Titan's methane lakes, or under Enceladus's ice? Organic compounds and a liquid medium are present in both. I doubt it would be life like ours. I won't be personally disappointed if there isn't any. When people ask me if I believe in life on other worlds, I tell them that I accept my own ignorance on the matter and am simply waiting to see - which many people do not consider an acceptable answer! But life or no life, there's plenty for Cassini to do in its probably six remaining years.

Yes, it's due to last until about 2017. In fact, all flybys are planned until then. It may change, of course. But that's about how long the remaining rocket fuel should last. Once that time comes near, Cassini will head out a long way, 10,000km beyond the F-ring, to survey Saturn and all its moons from afar; then it will head in again - right into Saturn's atmosphere. While it's still transmitting, we might get our first glimpses of what it's like under that giant planet's visible surface. Further and further in it will head . . . until that's the end of the mission. And what an extraordinary mission it will have been.

Thanks to Keith at Astronomy Now, and Joe Burns and Carl Murray of the Cassini team for all their information, guidance and encouragement.

This was my last slide at my recent Cassini talk.