Wednesday 31 December 2008

Coincidentally . . .

. . . a few hours after I'd finally given up battling with Blogspot to upload the video for this entry, I realised that Astronomy Picture of the Day has posted another video.

This one is a four-minute sequence of scenes speeded up to show the movement of the stars, the Moon, the Sun, meteorites, and many other beautiful night-and-day sights. And clouds feature heavily too. An astronomer's opinion of clouds was summed up rather well by BunnyBB back in the early days of Galaxy Zoo:

Clouds!! I love 'em and hate 'em in equal measures.
Hate 'em when I want to observe the night sky - :(
Love 'em rest of the time :)

It looks as if the zookeepers are having a few problems with clouds at present (not as badly as Chris did last time he missed Astrofest by going to Hawaii though). So I'm hoping they go away from Granada for a while so we can find out more about our merging galaxies. But I'll never forget going home from Geneva, a few days into the launch of the Galaxy Zoo Forum, and noticing a cloud that looked so much like a spiral galaxy that I reached for the mouse to classify it!


"The H2O Galaxy".

Happy New Year and clear skies for 2009!

A Dance on New Year's Eve


Well, actually all this dancing took place over many months around the world, I'm not sure quite when. But with 2009 being the International Year of Astronomy, it seemed a good moment to post about a video I have loved for months.

(OK, I went to the recommended site, Stridegum, specially to download a video I could put here but attempts to upload it have merely managed to crash this computer and require a restart three times - thank goodness this blog saves automatically. Please click the Astronomy Picture of the Day link below, or the Stridegum link above, to watch the video. Sorry about that.)

The Astronomy Picture of the Day page where I found it remarked, "Few people are able to watch this video without smiling". My uncle commented, "Have you ever noticed, nobody can watch dolphins without laughing."

This video was created by Matt Harding and his girlfriend Melissa Nixon, travelling around the world and arranging dances by open invitation in advance of each stop. His website is well worth reading. If you're interested, you can check out the lyrics of the songs - and much more - in the FAQ section. Kudos to Matt for thinking up going to Nellis Airspace and for Astronomy Picture of the Day for (I assume) using that as an excuse to show the world such a marvellous video!

It's wonderful to watch people dancing all over the world. Forests and mountains and deserts and sea. Beautiful buildings and ugly ones; ridiculous fairgrounds and ancient monuments. The buildings in Yemen reminded me of Granada, Spain, my adored home town for 10 months and, coincidentally, where two Galaxy Zoo scientists are now. (I've walked right past that spot in Madrid too.) The dances are all different, and all the same. It shows how we are all neighbours. The scenery is often terrific, but to most of the happy people dancing, it is their scenery and they're used to it. And the dogs, crabs, lemurs, dolphins and camels felt like part of it too - I mean much more than that they were merely "there" - just as they and we are all part of the animal kingdom. All this on our little planet Earth.


(Credit: Astronomy Picture of the Day; NASA

Once you've watched it two, or twelve, or twenty or two hundred times, it then starts to become more thought-provoking. I started counting the political statements. The only people I saw in the video who looked unhappy with the thought of dancing (to say the least!) were those soldiers in the "demilitarised zone" . . . What was going on? What is it like there? Where were all the people? There were subtler points. Israel was directly followed by West Bank, Jerusalem. In some places, only males were dancing. And in South Africa - well, if you can't guess, just watch it and enjoy.

Half this lovely planet is in shadow at any one time, and I wonder how many people are dancing then, or looking up at the stars.

Saturday 27 December 2008

Staggering!

I love the Astronomy Picture of the Day website - indeed I thoroughly recommend typing in a random past date and scrolling forwards with the "tomorrow's picture" button for hours - but today's picture was absolutely mind-blowing!



I mentioned a while ago that, like sound, light (or, rather, the electromagnetic spectrum) works in many more wavelengths than our eyes can see - and this is what X-rays show of the Crab Nebula. 954 years after Chinese and possibly Native American observers saw the star explode, the force of the spinning pulsar creates jets and accelerates charged particles in a glowing cosmic wind 9 light years across. This was an impulse post, not a planned one, so I'm not going to go into X-rays for the time being - but I did want to show you the Chandra observatory's Crab Nebula photo gallery. Excuse me while I go and have a browse.

Friday 26 December 2008

Gravitokart?

Galaxy Zoo is often described as "like a game": not knowing what the next galaxy will be is one of its addictive features. Well, now Universe Today reports that scientific gaming has gone a step further.

The game is aimed to study mathematical models of gravitational waves. Albert Einstein described the Universe as being like a rubber sheet, which was bent by any object with mass. Imagine a marble being rolled along this rubber sheet. It dents the sheet itself, of course; but its path would be bent by the hollows made by other massive objects. If it comes too close to one, it will end up going round it in circles; any closer and they'll collide and end up in one hollow, all the deeper through both their masses.

Russell Stannard describes this as a much better model for the way gravity works than thinking of gravity as a force. A large object and a small object, such as the Moon and an astronaut, will end up circling the Earth in the same path at the same speed - which means the Earth's force, gravity, has to pull much harder on the Moon. How does it know how much harder to pull, and why would it choose to do that? Thinking of gravity as simply being the shape of space, and not a force at all, makes things far simpler.

Anyway, Einstein also predicted that, sometimes, ripples would travel through the fabric of spacetime, much as they do across the water - or across a sheet if you stretch it and start bouncing it around. A case of this would be two black holes colliding. I can't make out from the article exactly what the game involves, but it looks like lots of exciting simulations of this scenario which can be run and the data gathered gradually.


(Image from the BBC website.)

The book that changed my life, "BANG!", stated the following two years ago:

"to detect the effort . . . formidable precision is required - equivalent to measuring the length of a mile-long rod to an accuracy of less than the size of a single atomic nucleus. Perhaps the best hope lies in using satellites, and various projects are being planned. Detecting gravitational waves would enable us to probe a whole new set of situations and objects, including some of the rarest phenomena in the Universe.

. . . Although we have not yet detected gravitational waves, there is compelling evidence for their existence in the form of a system, unique in our experience and known as the double pulsar, in which two compact neutron stars orbit each other . . . these two pulsars are spiralling in towards each other, which means that energy must be being lost from the ssystem; the amount being lost corresponds quite well to the predicted energy that would go into gravitational waves - but until we detect the waves themsevlves, we cannot be sure that we have the answer."

People seem to have a fascination with black holes from an early age - as I discovered when I gave a talk to a class of year 6 pupils, intended to last 10 minutes, and ended up being nearly an hour, largely because they had so many excellent questions about these intriguing objects. Perhaps it's their mystery - that they give nothing up - that fascinates people. Or perhaps it's their terrifying power and invincibility. Whatever it is, they really spark people's imagination. "Black Holes and Uncle Albert" has a brilliant passage describing a girl's near-death when she allows her imaginary spacecraft to go too near one, and "Empire of the Stars" begins with a thrilling description of spaghettification. In any case, I wish I had a PlayStation 3 for the mere fun of the game, as well as the science, and I bet this will be a real hit even in the middle of this recession.

(Update: Some pretty amusing comments here!)

Monday 22 December 2008

Christmas Greetings at Galaxy Zoo

Sorry for the sudden absence after all those postings a couple of weeks ago. My immediate excuse is that one of my beloved new tortoiseshell kittens, Cassie, keeps sitting on the keyboard and trying to catch the mouse (the icon on the screen, not the piece of hardware itself). This was her trick a few days ago:



(I called her Cassie partly because I'm going to be learning how to use CasJobs, an SDSS application, soon - more about that in due course! The other is called Izzie and I am sure she will soon make an appearance here . . .)

Anyway. I might have said before, and I will doubtless say again, that it never ceases to move me how much effort the zooites put into Galaxy Zoo. In help, fun, protecting the site from unsavoury content, special pictures, and much more. I'd like to indulge in a sample of those that have been either magnificent or just touching.

Several days ago, Joseph K. H. Cheng started a carol-singing topic. A few days after that, I illustrated a well-known Christmas carol - and couldn't resist pointing out the title to the zookeepers when they got some good news as a Christmas present.

Then, Waveney began a Christmas card topic. Here are some of the cards from that:




[Removed one that got deleted]





I will be adding more soon, because I know of a very impressive Christmas card indeed on the way! In the meantime, here is a puzzle. What is odd about these two pictures, created by Half65?




Hint: He's done this before!

If you can't see - click on these links . . .

http://web.tiscali.it/half65/Image/Xmas.jpg
http://web.tiscali.it/half65/Image/Xmas1.jpg

Merry Christmas and eager awaiting of the International Year of Astronomy!

(P.S. And please wish my family luck for putting the tree up considering that we have two kittens in the house.)

Tuesday 9 December 2008

"The Front Fell Off"

A spoof, but I think truer than a lot of things you're going to see in real life!

Some rather "adult language" (an ironic term if ever there was one) in the comments, as is sadly usually the case on youtube.

Update: The user removed this video - thanks to Gumbosea at Galaxy Zoo for the tip-off! - but fortunately there are many more versions. I wonder why the user did that? Here's another one.


"The Front Fell Off"

Object of the Day: Inspecting Spectra



I thought you might enjoy this nice new angle to the blue ellipticals/red spirals discovery made by Galaxy Zoo: "Tuesday 9th December 2008", today's Object of the Day, written by me and Fluffyporcupine. I'm no expert on spectra - I know more about why we shouldn't use them as classification tools than about spectra themselves. I love the theory behind them, but as soon as I'm shown one and asked to apply it to a real-life situation I make a lot of mistakes.

I didn't think I'd be any good at collaborative writing, because I'm so bossy and inflexible - I can't resist wanting everything to be done my way. That didn't matter this time, because Fluffyporcupine is saintly as well as clever. She's the one who knows how to find great galaxies with telling spectra, and I'm the one who has had the practice of putting it into a story. If you write a lot, I'd actually recommend collaborating with someone to see what new things you learn. I certainly learnt a lot from Chris after he sent me his comments on my CERN article. And I learnt a lot this morning too - and was completely absorbed. In fact, I was more entranced writing something with someone, than I generally am when writing on my own.

I've been bowled over by the zooite contributions to Object of the Day - it's wonderful to give our hardworking, knowledgeable and very witty and imaginative zooites the stage for a day; and it's fascinating to see what they come up with. That's one of my favourite things about Galaxy Zoo - we're all students and teachers together, all at different levels. I think some Objects of the Day have been written jointly, and it's a great exercise. You can play to your strengths - and then perhaps later could try swapping over!

One advice I'd give anyone writing Object of the Day is not to try and tell an entire story. In astronomy, one story leads to another, which leads to another again. If you start talking about spectra, you could start talking about chemical elements. That might then go on to sizes of stars and nuclear reactions. That might go on to supernovae or quasars. Or maths. Or telescopes. Or . . . In any case, every year we'll have about 365 posts, so there is plenty of room for stories. That's one way you can have the stage, but you don't have to write a novel. I hope more zooites will volunteer to write an Object of the Day once the busy Christmas period is over. It's great fun, and hopefully useful and enthralling too.

Saturday 6 December 2008

What a sweet story.

This story was posted by Pat in "Just Chat . . .", the most dangerous thread in the Galaxy Zoo Forum.

It seems too lovely to be true. But Doubting Alice's voice got drowned in the music anyway. Besides, Sir Patrick Moore has played a duet with Einstein . . .

I won't write any more. Just read and enjoy!

Update: A knowledgeable friend isn't convinced it's true either. I would have liked some dates, other people there (he wouldn't have had to name The Hostess!), some details to boost the authenticity . . . What do you all think?

Friday 5 December 2008

CERN conCERNs

Sadly, CERN looks to be out of action until July 2009 now. I'll never forget how exciting it was, that morning in September when they switched it on. Knowing that I'm an astronomy fanatic, my boss kindly switched the radio on in the office so I could hear. I spent the rest of the day trying to explain the concept of black holes to people and why CERN won't produce one, and made a spectacular hash of it because I'm bewildered by this "mini black holes" idea anyway. (I thought you needed enough mass to reach the Chandrasekhar limit - 1.4 times the mass of the Sun - to make a black hole.) A 19-year-old at the office questioned me in detail about the possibility of life on other planets, but I fear she got scared off talking to me altogether after a while!

It saddens me that when I hear people mention CERN, or read a news article about it, I seem to detect a lot of disappointment and condemnation. "It shows the scientists aren't really in control," a columnist remarked in The Independent, to justify a child's fears. How many of CERN's critics have ever been there? I have, and I recommend a look. The size of the thing is mind-blowing. This area alone, down in the depths of ATLAS, is bigger than most buildings. You have to stretch your neck to look around properly. We were like ants on a mountain, on that flimsy little metal balcony. And it goes round in a 27km circuit! I'll take you on a quick tour.

Here we are on the balcony:


It's not possible to see from that that just how huge the place is. The balcony was about halfway up to the ceiling, a ledge on a mountain cliff. Looking down and across from it, if you narrow your eyes you might see people . . .

It was simply not possible to photograph the whole of that clock-face thing. It was interesting to get some neat shots of the back of it, though . . .


. . . of terrifying climbing operations . . .

. . . and up above the ATLAS detector . . .

. . . above which is a terrifyingly long chimney, the diameter of a swimming pool, with a length it made me dizzy to look down.

There was continuous noise and movement in there, forklift trucks needed to cart the equipment about, people running around all over the place, and the everlasting hum of machinery. I wonder if building the pyramids felt like this? It needed quite a lot of fuel to keep it cold, too - judge for yourself by the tiny figure next to these barrels of helium . . .


And that was just Atlas - one component. They had some neat posters showing the circumference of the tunnel under Swiss and French soil (and yes, I was forcibly dragged to stand under the bit of the drawing labelled "Alice" to pose . . .).

The BBC have a delicious animation of that working here.

In any case, given the size of that great monster, I would have expected at least one wire to be out of place somewhere. Or is that just because I can't operate machines to save my life? Strangely, it seemed to be something very straightforward that went wrong - a pressure build-up of helium which led to the failure of some valves, releasing a lot of helium gas. Apparently an official review proposes a warning system to alert scientists to such system failures early on in the future. That sounds half like health and safety stuff, and half like something back from the days of Chernobyl!

Perhaps I'm being unfair. According to The Book of Heroic Failures, the space shuttle Challenger crashed because somebody failed to type a "minus" sign into the computer. (There doesn't seem to be universal agreement about this, though.)

Main moral: never work for a health and safety consultancy. You will find all coverage of accidents exasperating and depressing.

In any case, it seems to me that an awful lot is being asked of CERN. Not only are they expected to find the God particle, they're also expected to be perfect - either that or to blow up the Earth, but I'll leave that story for another post. Before the leak happened, the experiment seemed to be going very well.

So, sadly, we have to wait a bit longer. I'll be waiting, though. In the meantime, if things just don't seem perfect enough, keep your spirits up by reading "But They Did Not Give Up". According to it,
Thomas Edison's teachers said he was "too stupid to learn anything." He was fired from his first two jobs for being "non-productive." As an inventor, Edison made 1,000 unsuccessful attempts at inventing the light bulb. When a reporter asked, "How did it feel to fail 1,000 times?" Edison replied, "I didn’t fail 1,000 times. The light bulb was an invention with 1,000 steps."

Thursday 4 December 2008

Stealth, eh? But you made stealth easy by not listening . . .

I haven't been reading The Independent so much since they had the cheek to have a column about how to live off £1 a week just as they raised their price to £1, but I think today is the first time they've actually taken a stand over ID cards.

They seem to have taken the safe measure of not kicking the government until they're down - now that the European Court have declared that it is illegal to hold someone's DNA if they're found innocent.

Since they're planning to hold all our DNA, the European Court have evidently made quite a wide implication. Good for them! I'm used to hearing that Europe is a nuisance, foisting all sorts of silly laws on us. On this occasion, they said something that needed saying.

What might be the consequences if everybody's DNA is held on a database? Hard to say. No other country has ever done such a thing. I think most people are hoping and assuming "nothing" - I wish I was that comfortable. I don't for a moment imagine they'll be able to organise it or prevent it from getting lost or corrupted (this is a database of 60 million we're talking about here). I'm sure it'll be extremely easy for civil servants to leave it on the train. And easy enough to bribe underpaid workers to hand over convenient details. "I'll tell the boss/the insurance people/your worst enemy that your genetic profile predicts you to be sensitive to cholesterol with risk of you dying young if you don't do/give me this." They'll be storing our medical information too. "Ooooh, so-and-so's had syphillis. I wonder if her boyfriend knows. That's some great gossip. Such-and-such would laugh . . ." Public body data? Could mean anything, and shops already "profile" their customers and might well join in . . . "That woman only spent this much on bread last week. I wonder if she's feeding her children the right stuff. Let's send the social workers round." "This person has some money sitting around and they spend a lot on cinema tickets. So 8pm is a good sort of time to burgle them." "Hey, he was accused of beating someone up when he was 12. He got off, but so what, they don't care about that any more. Let's let the boss know. He can't be allowed to work with anyone vulnerable even if it is 40 years later. Perhaps they'll give me the job instead."

Petty, but easily possible. The main point is that the government are having to account for what they do less and less, and we are expected to account to them more and more. In short, we must trust them with our most private information, while they don't trust or respect us even enough to tell the occasional truth.

I took a look on the BBC page where we can leave our comments and groaned to see the number of people repeating that exhausted mantra, "If you have nothing to hide, you have nothing to fear". Come on. You really believe that? You think that's not what dictators have said in the past? If they want all that information they're going to do something with it.

Would you agree to having a CCTV camera in your bedroom? The police assure you that it'll help catch terrorists, even if you can (don't ask me how) prove you don't sleep with any. They'll share all the footage with people they trust; you won't know who's looking at it. Is that natural? Is that comfortable? Is this a good use of their time? But you have nothing to hide of course. People do sleep together, get undressed, stare out of the window when they should be working, think private thoughts . . . So the police should watch it all, shouldn't they? Privacy is civilisation. People who are not ashamed of their bodies still generally wear clothes.

DNA does not establish intention. There might be a gene for having a long black beard, but as far as I know none for suicide bombing has been discovered yet. The government admit it won't catch terrorists, and that only 2% of benefit fraud is people lying about who they are - almost all is people lying about circumstance. And yet these are still the reasons being given for the cards' introduction.

They claim: "The power will be exercised only in circumstances where the sharing of the information is in the public interest and proportionate to the impact on any person adversely affected by it." Which is directly contradicted by random stop-and-demand-ID-for-no-reason-whatsoever powers given to the police! (Not to mention their old claim that we wouldn't have to carry these cards wherever we go.)

Distrust of the government, lack of logic and potential to abuse aside, the scheme is wrong in principle. "Innocent until proven guilty" is a law with a history spanning centuries, and not for no reason. I don't really fancy the idea of spending the rest of my life proving my innocence for this, that and the other. Saddam Hussein could not prove there weren't any weapons of mass destruction in Iraq. (A friend of mine actually said, "It really scares me that they haven't found anything yet, that only proves how clever Saddam must be".) Possibly I could be assumed guilty of all sorts of things I don't even know about. I might mistype a web address and they'll think I went to a dodgy website on purpose. Or they might wonder why I hang around space websites a lot - could it be because I have plans to thwart America's military interest in space? We'll start making ourselves late for things because we've forgotten our ID cards and have to run home for them; we'll avoid buying a bottle of wine or going to a country whose President has failed to flatter our Prime Minister enough lately because it might not look good and get us into trouble.

How soon before they start selling our details to their friends who run the most massive corporations and want to pile us with junk mail or pressure us to buy their products? How long before sick or injured people will be left to die in the street because they don't have any ID on them and may not have medical treatment? How soon before shops are forbidden to serve people without ID cards?
Oh, and they're expensive too. How soon before supermarkets buy ID cards off the government, so we spend the rest of our lives "with Tesco" or whoever, and these supermarkets start running protection rackets to make us pay more and more to be "kept on the register" and "maintain our entitlements"?

How soon before the computers keep getting an error whenever they try to log onto some people (just like some CDs and websites) and these people are written off as no longer existing? How soon two Britains form - those with ID cards and those without; two groups living in different worlds, trading on different currencies, surviving by different means? (I'm not just being hysterical here. My MP agreed with me on that one a few years ago! I won't publish his letter back to me unless he says it's OK, though . . . watch this space.)

Well, George Orwell warned us a long time ago. Mao warned us, by his government estimating that 5% of the country were against him, and therefore 5% of every workplace's employees - no matter of their guilt or innocence - had to be shipped off to the far north. (Source: "To the Edge of the Sky" by Anhua Gao.) I warned you. I demonstrated in Brighton, along with hundreds of others across the country. Videos such as "Taking Liberties" warned you. And they asked at the end: why? Is it the government? The police? Or is it us and our apathy?

Is it that news stories are sold for a profit, and editors and Rupert Murdoch decide what is and isn't "marketable" in a story, and ID cards just failed to look trendy on the packaging? I don't yet know whether a country loses its democracy because of its entire population or because of a few. Steve Biko said, "The most potent weapon in the hands of the oppressor is the mind of the oppressed". Perhaps in ten years' time we'll look back and it'll be clear.

In the meantime, there is a consultation, apparently. That was kind of you, Government! Thank you! Now, why was it NO2ID who told me about it, and not you? Anyway, you can download it here.

One last question. Am I still allowed to write things like this? Do let me know!

Tuesday 2 December 2008

Occultation of the Moon and Venus

One day I must actually learn to use the practical astronomy websites that generous people tell me about. But witnessing the occultation of the Moon and Venus was a great experience necessitating very little research!

Jules, on the Galaxy Zoo Forum, started a thread to let us know, which pointed me to SpaceWeather. Then, today, Paul from Skymania mentioned to me that the Moon was low in the south, and that Venus would disappear behind it, because they are lined up in the sky like overlapping galaxies. (Yes, that is a typical Alician take on it!) I couldn't find the Moon this afternoon, although I went up to the field at the top of our garden, the nearest I could get to a hill summit. There wasn't much cloud, but perhaps it was obscured by the ash trees. Those trees are splendid, and I wish they weren't in the south - if they weren't constantly lit up by the oil refineries at Milford Haven, the stars would come out behind them and they'd shine out like tiny pieces of magic fruit . . .

It was a pity it was the disappearance I missed, rather than the appearance. In layman's terms - and I bet there are professional terms for this - the Moon was lit up on the right this evening, and Venus was travelling from left to right. So this afternoon it would have appeared to just wink out in the sky. A split-second occurrence, but probably quite spooky. I saw it appear on the right of the moon at 5:10 p.m. this evening, when the sky was a very deep steely blue, with a watery pinkish-yellow sunset lingering a long way around the horizon.

It came out in a piercing burst of light, brighter than I had dreamed. It was as if a shard of splintered glass shone across the moon, giving the impression of being long and narrow - probably a trick of the light. I've heard that such astronomical events seem to be over in a heartbeat. Possibly because I was alone and extremely cold, this seemed to take forever. I kept waiting and waiting for Venus to detach from the Moon. I was lucky it wasn't over quickly, because at 5:15 p.m. I remembered that I own a telescope! A small blue skywatcher, which some good folks volunteering on a Telescope Amnesty night at Intech Planetarium told me has no mirror and is really for birdwatching - but it hugely improved things nonetheless. I ran inside to get it, trying to close my eyes to avoid losing their adaptation to the dark (the sky was quickly growing inky).

Too lazy to detach it from its tiny tripod, I dashed outside again, falling over a plant pot in the dark and hopping a few yards to avoid crashing to the wet muddy gravel. I struggled to hold it still, wishing it had a proper tripod my height. I went to try balancing it on the car roof, but from that angle I could only see the trees. Then I had a brainwave and propped it up on the gate:


It worked like a charm. The legs of the tripod held it in place, and I was able to adjust it to focus on the Moon and Venus! I was lucky the butterfly bush didn't obscure it. Venus still showed up as a white dot, like a star. But I did see some wonderful craters on the Moon. I'm used to seeing large detail, but these were tiny, and so very many! It was probably an ideal time to examine them, because the shadows from the Sun would be very long.

It's amazing how much things seem to move around in the telescope at random. Not the steady motion due to the Earth's rotation, but probably because I move without realising it, or jolt the telescope. I tried very hard to take a picture through my telescope and got a result so unimpressive I must share it with you here:

Without the flash it was pure black. I decline to bother uploading that one too.

You definitely need the right equipment for taking a good photograph - a tiny telescope and a mobile phone do not qualify! I did take a lovely one of the Sun last August with Jules's help - that story is here. Astronomy doesn't always favour the meticulous. I just dashed into this without doing any preparation; those who were probably more painstaking, and would have come away with a good photo, were in many places out of luck because of clouds in the way. But at least there'll be many next times. So let's all pay attention to the news snippets, even if we can't be bothered to read the websites. And if I can do this, folks, you definitely can!

Monday 1 December 2008

Well, I think it's a scale model of the Mary Celeste.

I see Episode Two of the funniest ever post on Chris's blog coming up.

"A plank of wood" is the latest miracle spied on Mars - now that is an interesting piece of wishful thinking. It was also seen in 2004. I think the total quota of annoyingness depends on what the reporters make of it - I can't find anything on the BBC website this time round, but Nancy Atkinson has provided an extremely sympathetic and understanding explanation in Universe Today. Perhaps I could learn from her.

Update! Thanks to Geoff on the Galaxy Zoo Forum for helping me find this picture:

This is from May 2004, at http://marsrovers.jpl.nasa.gov/gallery/panoramas/opportunity/2004.html.

I wonder why she says "don't think for a minute these scientists wouldn't be jumping for joy if they found something as amazing as a log on Mars"? I know they want to find life, but why can't we just accept that Mars is not Earth, and probably doesn't have Earth-like life, and we shouldn't need miracles to get excited? If we found wood on Mars, I'd be . . . scared.

In the meantime, I recommend geology. Trying to get a copy of the pictures I could reference properly [before Geoff found that one above], I instead stumbled upon this wonderful picture of what rocks are doing on Mars, from NASA Mars Picture of the Day.

If rocks are tilting on Mars, that demonstrates that something interesting geologically is happening on large scales. On the Earth, it might mean plate tectonics at work, or huge icecaps melting and taking their weight off the Earth's crust, or many other processes. Its largest volcano, Olympus Mons, is twice as large as any volcano on Earth. But its magnetic field is completely different from the Earth's, which suggests that it doesn't have a molten iron core like the Earth's (or at least not as large or hot), and Mars does not have tectonic plates. Isn't that enough mystery to be going on with?

For a simpler start to geology, may I recommend a visit to a beach very near me, Broad Haven. There are tilted, layered rocks sticking up all over it - I must go back there to photograph them. Credit to this page for this one: http://gallery.nen.gov.uk/image88659.html

Sunday 30 November 2008

The Story of the Red Spirals (part 1)

I'll be writing a lot about the colours of galaxies in several different posts; here's Chapter 1, as it were. Kind of hoping the scientists will pop in occasionally and point out any glaring errors, and anyone who'd like to will give me feedback on the clarity and style . . .

A few years ago, Kevin was a PhD student at Oxford examining a new breed of galaxy. It's well known that there are two basic galaxy types: spiral and elliptical. It has also long been well known that spirals are usually blue, and ellipticals are usually red. The beautiful arms in a spiral galaxy are really density waves, like a traffic jam on a motorway. And like the areas of congestion, they don't necessarily move along with the stars - a car might cruise along at 70 m.p.h. for a few hours, reach the traffic jam, get very cross, but eventually get to the other side of it and continue on its way. (The spiral arms do indicate a lot about the galaxy - which way it is spinning round [except in the exceptions], how big the black hole in the centre is, etc.) This means that the environment the stars and gas live in is continually changing and disrupted - which triggers off star formation.

When stars are young, they are hot - and blue. Blue light has the shortest wavelength, and the highest energy. The equivalent, in sound, is a high-pitched note. (Sound and light both have wavelengths way higher and lower than what we can hear and see, but that's another story.) In any case, a blue colour in galaxies is a good indicator of a lot of heat and star formation.

Elliptical galaxies, on the other hand, don't have star formation. There seem to be two reasons for this. One is that the orbits of the stars are "radial" - they all go their own way - so there are no large-scale disruptions to trigger clouds of gas to condense. Another is that they seem to have run out of gas anyway. Come to think of it, one thing I don't know for a fact is whether these two points are related.

Ellipticals appear dull at first, but they're incredibly peaceful, beautiful sights. SDSS pictures usually show them as a clear gold or vanilla colour. They sort of "fade out" towards the edge, and have a bright core. Of course, this bright core often contains a supermassive black hole, such as in the case of the giant elliptical galaxy M87, which won't be the pinnacle of serenity. Elliptical galaxies are thought to be remnants of past mergers. They're generally found in giant clusters of galaxies, where mergers would be more likely to take place, and they are often larger than spirals. Mergers create massive disruption and trigger off spectacular star formation, which might use up all the gas free to form stars.

So "blue galaxy" came to mean "spiral", and "red galaxy" came to mean "elliptical". It worked fine before SDSS. Then we found it wasn't that way at all.

(Is it just me or is most science based on "People have always said that things are this way. But we have found it might actually be this way!"? After you've heard that in every lecture at university for a year or so, it gets highly tedious and you wonder if all the academics want to do is prove each other wrong, rather than make new directions for themselves. On the other hand, "Eureka!" moments are . . . somewhat immature. Curiosity and research and painstaking surveys have gone on for centuries. [There are always exceptions - apparently there are no budding fungi taxonomists left in the UK, but not all British fungi have been classified yet! Who's up for filling this niche?] Most of science now seems to be refining, redefining, extending and building on what we already know. Perhaps it's irksome because you wonder what there is left to do, other than prove someone wrong and then get proved wrong by the next upstart next year. Or perhaps I'm the only one irk-able enough to be irked. Let me know.)

Kevin was studying a strange new breed of galaxy: the blue elliptical. In other words, an elliptical galaxy which was still undergoing plenty of star formation. Because these are rare, and studying a few probably wouldn't tell us the whole story of what was going on, Kevin was aiming to find as many as possible. He spent a week sorting through 50,000 galaxies, categorising them into spiral or elliptical. His office-mate, Tom Zlosnik, wrote in the Galaxy Zoo Forum that he was getting through about one per second! It must have been a trial, though, and he doesn't recommend it. "Your PhD student," Chris said in a lecture, "will classify 50,000 before telling you exactly what you can do with the other 850,000."

And so Galaxy Zoo was born. But that's definitely another story.

Many of our classifiers wrote to us to ask us, "I've been noticing that spirals are usually blue and ellipticals are usually red. Have you noticed that? Is it just me? Why is that?" I wonder if they knew what an exciting question they were asking? I didn't receive any of these myself, so I can't tell you what the team answered. The most important thing was to encourage people to classify by shape, not colour.

The blue ellipticals featured heavily on the forum, particularly in the autumn. "Here's a blue elliptical for Kevin!" we kept grinning, often posting dwarfs, irregulars and fuzzy spirals. In fact, the way they were really extracting the data wasn't using that thread but using the computer to check the colours, and extracting the ones that came out as "blue" from the computer and "elliptical" from us. (And that is why you shouldn't classify by colour, folks! If you'd followed convention you'd have clicked "spiral" and all these would have been missed!) Kevin nevertheless kept us up to date, and made us a special thread about his paper.

And that turned out to be only some of the story. Because then people started spotting the opposite: red spirals. Which I'll write about next time. One thing was getting clear - studying a few galaxies in depth won't tell you what's going on at all! Only by examining galaxies in vast quantities, on the scale of SDSS and Galaxy Zoo, can you get a whole picture. It's like studying a few animals for years until you think you know all about them - and then going and looking at the whole ecosystem. Suddenly everything we saw seemed to be introducing new exceptions.

Saturday 29 November 2008

A great start

Having written my first ever blog post, I've discovered two things . . .

1) Apparently it takes 7 hours to publish [some - not all] posts. I'm told that my last one is scheduled to appear at 00:33. Curiouser and curiouser . . .

2) There is a theme park somewhere called Galaxyland.

Oh well! :D

Update: 21:49 Aha! You click "post options", and it'll display the time it will be posted. You can change that. Now that worries me a little, because you could do quite a lot of time travel if you want it posted apparently a long way back in the past . . . Jurassic Park anyone?

An interesting primary school . . .

Welcome to my new blog, which I hope you'll find interesting. Thanks to my friends who persuaded me to set this up - blame lies particularly with Chris and Pat.

I was reminded today of a meeting I had with my mentor on my teaching course last year, shortly before they threw me off. "Now, Alice, in three weeks' time Bob [another PGCE student] has an interview, and part of that is to deliver a lesson for year 9s on their SAT papers. Now, be honest, I don't think you could do that, could you?" Too depressed to speak, I stared at the wall and shook my head. I wondered why I could explain any scientific concept to thirty-five children or one in a way that made their eyes light up; why they told me I was a good teacher and made earnest suggestions for other ways I could explain things and how I could improve the materials I gave them; how I could write posts about galaxies and astronomy and explain things to strangers over the Internet; but how I couldn't seem to do what the examiners wanted of me.

Things would have been different, I suspect, if I had trained at this school described today in The Independent. Two things leapt out at me about the article (besides the obvious happiness of the children and the parents). One was "no exams". None at all? Are exams the problem? According to the government, of course, they're the solution. "Testing children gives us a reliable indicator of where they are". (Unless they're having a bad day that day, not representative of what they can generally do. Unless the exam doesn't ask them the sort of questions they can answer well. Unless answering questions is not the only skill you need in life. Unless the examiner doesn't know what they're writing about. Unless the school is fed up with and contemptuous of this idiotic regime, and cheats.)

I've nothing against the idea of an occasional exam, as a challenge or as part of getting a qualification. What I am against is exams being the be all and end all. "They only take up a tiny proportion of the children's time in the classroom". Yes, but every single lesson has to be in preparation for them. Every lesson must have two learning objectives on the board (which must be measurable and achievable), and the more these relate to the exams the better. Why else do year 7 pupils arrive at secondary school with stories about having had to give up Art and Music and PE for year 6 to get ready for their SATs?

Do we need to get rid of exams altogether, or is it the general culture we need to change?

The other thing that struck me was the buzzwords around this school. "Its learning is child-led". "The Italian Reggio Emilia schools . . . put the learner at the centre of things". This might as easily have been said by OFSTED to promote personalised learning - a cringe-making fad state schools were caught up in when I began my PGCE, and which was a further box-ticking, time-consuming part of lesson planning. I really feel that the more talk there is around an organisation, the more false all these mission statements of theirs turn out to be, and the less gets done. Does the school buzz with these buzzwords? Or were they added to the article like a shiny paper bow stuck onto pretty wrapping paper, to make the article more marketable?

It's no good showing off how open-minded you are by saying "OK dears, the choice is yours, what do you want?" Otherwise, how will children learn anything? If you don't speak to them, how will they ever progress beyond baby-talk? What really mattered when the boy brought the rock in was that he brought in outside wisdom, luckily introduced by his grandmother. Sometimes the teacher could invent something to do; sometimes one - or more - or all - of the children will have something much better up their sleeve. Experiences like this will encourage them to keep their eyes open outside the classroom, rather than to learn the language the examiners want.

Because modern exams are largely focussed on getting children to write in the language required, rather than learning any facts (let alone expressing their own interpretations of such facts, or doing anything else with them). "It doesn't matter what they're learning, so long as they're learning something". The number of times I heard that. Not to mention, "He's got the answer exactly right, but we can't give him the mark because he's left out the key word".

To me, the truly special thing about Lewes New School is not their fancy phrases. To an extent, it's what the father says: "I wanted my children to love learning". But most of all, it can be summed up in one word: freedom.

A relative who works in a hospital spends far more time filling out forms for the government on how he will implement this policy or that, than actually seeing his patients. However, he's in their good books right now. He leads a project titled "A multi-disciplinary team-building exercise, open to all departments, with weekly reviews and performance indicators". What is it? Fantasy football.

You might want to try it.