The first, crucial question she must answer is, is the link real? The best way to deal with this to turn it around — is it not real? That is the question everyone else will be trying to answer.
So. If it’s not a real link between the galaxies then what is it? There are two types of possible answer. The first is related to the telescope. There could be an artefact in the image that mimics a genuine link between the galaxies, caused by the way the telescope works, or dust on the lens. That’s ok, she can quantify those possibilities because she has the necessary manuals and software to help her calibrate the image. To a large extent this work is routine.
Or the link could be caused by some real material being emitted by one galaxy, but not necessarily connected to the other one, and it’s only a coincidence because they’re looking at it from a certain angle. It’s just a trick of perspective. This is less palatable because it’s more difficult to quantify. It involves more conjecture. She doesn’t like handwaving arguments.
She sets about calibrating the data so she can eliminate the first possibility.
Then she zooms in on the link, blows it up until each individual pixel is visible. There are no sudden jumps in intensity from one pixel to another. Good. That means it’s unlikely the link is caused by a cosmic ray hitting the telescope.
She looks for evidence that the link is not actually joined to both galaxies, that it’s superimposed on one or the other. She makes a contour map to identify the pixels at the same intensity across the image. The smooth transition in intensity implies a coherent link.
It seems real. It’s unlikely not to be real. This is what she has concluded. She gets up and moves away from the screen and the sudden change in perspective takes her by surprise. Everything here seems far away, unlike the tiny chain of pixels she’s been staring at for the past hour.
Time to go and look at different types of images. She’s been invited to the end of year show at Paula’s art college. She’s keen to see what sort of art Paula has produced because she still can’t imagine Paula creating things, but perhaps she only knows one version of her, and there are many others folded up inside, like extra dimensions. Paula’s only been at art college for a year, and Jeanette isn’t used to the idea of her being interested in painting. She never seemed interested in it when they were both students.
At the show she discovers she doesn’t know anyone apart from Paula. Everyone else seems to know each other, or perhaps they’re just better at pretending than she is. Fortunately she finds one of Paula’s paintings and is able to stand in front of it, avoiding the need to talk to strangers. She’s just remembered that this is another of the things she finds difficult after observing trips.
But the painting’s good. She’s surprised at how good it is. It shows a woman who superficially looks like Paula, but there’s something different. It’s larger than life, the face is about three times its normal size. There’s a glowing intensity to the pale skin, it reminds her of the surface of the moon. Staring at the face makes Jeanette feel uncomfortable, so she works her way round the edges of the painting. Behind the face is a bed with a pile of white sheets on it. In another corner there’s a man’s suit on a hanger.
But when Jeanette looks closer at this dark suit she sees it’s painted to look like fur. It’s the skin of a large animal, maybe a bear. The title of the painting is ‘My Life as a Man’.
‘What do you think?’
Jeanette jolts round to find Paula grinning at her. ‘It’s amazing. I mean, I didn’t know you could paint like this. It’s so lifelike.’ She looks back at the painting. Now the face seems more serious and somehow more real than Paula’s own.
‘You haven’t asked about the title.’ Paula steers her away from the painting and towards the wine.
‘Well?’
‘I tried to imagine myself as a man. I dressed in a man’s suit when I was painting it. I wanted to be something different, the opposite of what I normally am. To see how it would affect the painting.’
Jeanette’s intrigued. ‘The opposite? Like anti-matter?’ She can imagine Paula meeting male anti-Paula and both of them exploding into pure energy.
Around them, other people swirl and laugh. It’s very hot in this room and Jeanette’s thirsty enough to keep sipping the awful wine. She asks ‘Where’s Becca? Isn’t she supposed to be here too?’
‘She’s not coming.’
‘Oh? Why not?’
But Paula has seen someone else she knows, and she darts off.
Jeanette finds another of Paula’s paintings. This one shows a woman lying on a bed, but only her legs can be seen, from the thighs down. Again, everything is meticulously depicted, the dark wooden floor, the white walls, the pale marble-like legs, even the crimson nail varnish on her toes. They’re nice legs, thinks Jeanette. She wonders who they belong to. Somehow she knows that the woman is naked, even though the rest of her body can’t be seen. There’s an elegiac quality to the painting. It feels as if someone has just left the room. Something in the way that the legs flop to one side implies that the woman is alone, and has been abandoned. The room seems old, whatever happened here was a long time ago.
The third of Paula’s paintings shows an ear, about two feet high, painted in shades of white and cream, with a few strands of dark hair. The title is ‘Omphalos’; the Greek for navel. Is this a little joke of Paula, to get her anatomy deliberately wrong? But as Jeanette studies the ear she sees the point. The earhole does appear to lead away to the centre of something, something dark and profound.
The Ancient Greeks used to call the oracle at Delphi the ‘Omphalos’, the navel or centre of the world. The oracle made utterances. But ears don’t speak, they listen.
She escapes outside, and bumps into Becca.
‘We thought you weren’t coming,’ she tells her.
Becca shrugs. ‘Is it crowded in there?’
‘Yeah, packed.’
‘Good.’ She walks inside, Jeanette following behind her. At one point Jeanette loses her, but then she sees her at the far side of the big room, looking at one of Paula’s paintings. It take Jeanette some time to work her way through the crowded room and get closer, but Becca hasn’t moved. She’s standing very close to the painting; the woman on the bed.
‘Do you like it?’ Jeanette asks her.
‘Like it?’ Becca turns to Jeanette, but her expression is odd. Jeanette gets the impression she’s not really looking at her, she’s still got the painting in her mind’s eye. Her eyes glance around the room. ‘Where’s Paula?’
Just then they both hear a trill of laughter and Paula is next to them. She is flushed, her cheeks pink with the success of her paintings, and her performance here tonight.
‘Darlings!’ She flings an arm around each of them. ‘Thank you so much for coming! For being here.’ She squeezes them to her so that there is a sudden muddle of soft bodies and perfume, and Jeanette gets a strand of someone’s hair across her mouth. Then Paula’s off again, greeting someone else, and Jeanette and Becca are left together in front of the painting.
‘Nice legs,’ says Jeanette, gesturing at the painting.
‘Thanks,’ says Becca.
‘That’s you?’
‘Yes. I had a short-lived career as an artist’s model.’
When? When did Becca model for Paula, and why didn’t they mention it? The label on the painting says it was painted last year. As usual, Jeanette feels like she doesn’t know what’s going on underneath the surface of things.
The next day at work and it’s Jeanette’s turn to lead a reading group for the students. This is an opportunity for the students to learn some new astronomy and demonstrate what they’ve learnt to their more senior colleagues. Most of the students tend not to see it as an opportunity, but as a threat.
Today’s reading group is based on a review paper about the standard Big Bang model, summarising the basic building blocks of this model, the assumptions needed to construct it, and the most recent work which both reinforces and modifies it.<
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The post-docs take it in turns to lead reading groups, sometimes watched over by more senior colleagues, keen to see how their students are getting on. Today, Jeanette must make sure that she challenges each of the students and gets them all to contribute to the discussion.
The reading group is always held in the canteen, to give the illusion of informality. All the first and second year post-graduate students are required to attend; it’s optional for the more senior ones, which means they never attend.
Today the students gather round one of the low tables near the white board, clutching their mugs of coffee and copies of the paper. The first year students look worried. The older ones just look resigned.
As they approach her, Jeanette remembers the incident in a reading group last year when a student started to quote poetry, something about the glory of heaven. Then he recited part of the Lord’s Prayer, ‘On earth as it is in heaven’. He left the Observatory shortly afterwards and was never seen again. There are always casualties.
She knows from experience how difficult it can be to get them all to participate. So she’s prepared a list of questions for them to respond to, and to get the conversation moving. She reads the first one to them as they’re still settling into their chairs. ‘What do we need to assume to build a basic model of the Universe?’
She wants to get them to think about what is known, and what isn’t known but can be reasonably assumed. They look down at their notes, shuffling through bits of paper. She tries not to sigh. This is such a basic question.
‘Something about everything being the same everywhere?’ says Clara. Clara doesn’t look like she really belongs inside here, she’s glowing with health, her hair is thick and butter-yellow, her cheeks rosy. She should be running through flowery meadows, surrounded by Alpine cows with long eyelashes. A black smudge of biro on her cheek only makes the rest of her look even cleaner and healthier.
‘Yes, but what. What properties are “the same”, and what do you mean by “the same”?’
Clara gives up and stares out the window. Her PhD is based in the lab with Jon, building part of the satellite instrument. The theory is not so relevant for her.
Silence. Part of the point of these seminars is to get the students to do the work, they shouldn’t be spoon-fed. So she can’t crack and reveal the answer, however much she’d like to. And perhaps a tiny part of her enjoys inflicting this pain on them, demonstrating how wide the gulf is between her and them, and how much she has achieved. Post-docs are the most junior level of the academic staff, but they are on the other side of the divide that separates her from this group. She has her PhD and they don’t.
‘Can you outline the two most basic, important assumptions?’ she prods them. Sometimes the silence just gets too much and she’s driven to speak. It can be horribly reminiscent of childhood dinners, sitting at the dining table wishing someone would talk to her. Answer her questions.
Clara tries again. ‘The same wherever you look?’
Finally. ‘Yes. We assume the Universe is isotropic, so it looks the same in all directions. This isn’t true on small scales, but is true on larger ones. Now, what’s the other assumption?’
She looks around. There are six of them present today; as well as Clara there is Giovanni, who hasn’t managed to button up his check shirt correctly, so there is mismatched fabric bunching around his neck and crotch, and Mark who is wearing a tee-shirt with Maxwell’s equations printed on it. She knows Mark knows this stuff and considers it faintly beneath him to be quizzed in this way. His silence has an air of disdain for the whole process. The others look more frankly baffled. She wishes they’d stop shuffling their papers around.
Mark finally decides to speak. ‘You also need the Cosmological Principle, which is just an extension of the Copernican Principle, namely that we’re not in a privileged position in the Universe. The view from the Earth, which is isotropic, is the same as the view from anywhere else. On this Weyl hypersurface anyway…’
She stops him. ‘Yes fine, Mark. But hang on. Let’s not go too quickly. Go back to the Cosmological Principle. What do you get if you combine isotropy with the Cosmological Principle?’
He looks at her as if she were stupid. ‘Homogeneity, of course.’
Of course. Bloody show off, she almost whispers under her breath. He’s left the others way behind, and their paper-shuffling has reached epidemic proportions.
Giovanni says, ‘Why do you have to assume anything?’ He finally realises his shirt is not buttoned correctly so he starts to adjust it, revealing expanses of hairy stomach.
‘Without any assumptions the problem’s intractable. The Universe is just random squiggles on the sky. But you can test your assumptions. The cosmic microwave background looks the same in all directions, so that backs up isotropy.’
Giovanni still looks worried. ‘So you must assume isotropy but you can derive homogeneity? What is the difference between them?’
Mark rolls his eyes.
An hour later the white board is covered in scribbles and they’ve managed to reach page two of the paper, so they pause to get more coffee. At this rate, it’ll take them the rest of the day to get through the paper so Jeanette decides to hurry things along.
‘Who can explain what redshift is, and its relationship to distance in the standard model?’
They get bogged down in discussions of Doppler shifts and speeding ambulances, and Bill does his impression of a siren, which seems to surprise some of the other people sitting in the canteen. Jeanette brings them back into line by reminding them that this is just an analogy. ‘Remember it’s space itself that is expanding, the objects are not actually travelling through space.’
‘No?’ Several puzzled faces turn to her.
‘No. Now, can anyone explain the evidence for dark matter?’
‘Umm, like, galaxies spin around too fast?’
‘Too fast for what.’
‘Too fast based on how many visible stars they have. So you need something else to stop them flying apart, something you can’t see?’ Bill looks relieved at being able to make the galaxies stable.
‘Well done.’
‘Hang on.’ Giovanni’s worried. ‘Where does the Cosmological Principle stop?’
‘Stop?’ She’s a bit annoyed that he’s gone back to this. They need to get on.
‘Yes. The Earth isn’t in a unique place and neither is the Milky Way, and now ordinary matter is only 4% of the mass so the Universe is mostly dark matter, and perhaps even the Universe may be just one of many. At what point does it all stop and something become special again?’
‘ “Special”?’ says Mark. ‘That’s not physics.’
But Jeanette feels almost sorry for Giovanni, still clutching his shirt as he’s being spun around on a cosmic wheel that has no centre. What else does he have to hold onto?
She’s sitting on a horse with rigid nostrils and a plaster mane moulded on one side of its bright painted neck. She’s paid her pennies and she can ride as long as she wants. But every seminar she attends and every equation she solves sends her looping and spiralling further beyond the wooden circumference of the merry-go-round.
Each new size and shape of darkness projects her further into the night, holding on to whatever she can find as she gallops through the universe.
The door to her office opens, and she’s caught resting her head on her desk.
‘Sorry to disturb you,’ says the Death Star and he waits while she removes the stacks of papers from the other chair to make space for him, before perching on the desk so that he’s looking down at her. He’s wearing a bow-tie. She realises she’s staring at the bow-tie; there are cartoon pictures of planets on it.
‘I’ve been interviewed for Radio 4, Melvyn’s programme. They’ve asked me to speak about the end of the universe,’ he says.
‘Ah.’ There’s a silence and she realises she’s required to say something, to offer some information in exchange for his. ‘I’ve been rewriting my pa
per, the one that needed a bit of work after the referee’s report.’
She tries to sound enthusiastic about this, although she first wrote the paper three years ago when she was a student, and the referee’s indictment of it has been lurking in her desk drawer for the past eighteen months. Only occasionally she has the strength to take it out and read it before hiding it again. Phrases from it regularly appear in her mind at night when she can’t sleep; phrases such as “the author clearly believes in the strength of her own argument without having to bother with the unnecessary, and clearly to her, irritating detail of testing it impartially and scientifically”.
‘Good. I imagine you’ve dealt with all of the comments? You’ll need to get it back to the journal soon, the editors’ll be wondering what’s taken you so long. At that journal, they’re daft enough to think that the referee might be right!’
Jeanette keeps an eye on him as he chuckles. She knows he likes criticising other people who attack his staff, but only because he thinks that activity is his sole privilege. Sure enough, he stops laughing and knots his hands together in front of him as a prelude to the inevitable lecture.
She fights back the impulse to mimic him and knot her own hands. She has observed plenty of post-docs who become their professors’ doppelgängers. This is how the scientific method is disseminated, and it’s a far more powerful way than simply studying textbooks. She has observed how a scientist speaks, how he (and it is nearly always a he) talks up his own work, rubbishes his critics, patronises his students and she knows that if she can replicate this behaviour she can become one of them, with a few minor modifications needed to allow for the fact that she’s a woman.
It’s necessary to jolt him off this topic of conversation. She doesn’t want to agree meekly to yet another rewrite of her boring paper. ‘I’ve got something interesting to show you,’ She displays the image of the connected galaxies.
He stares intently at the screen for some time before speaking. ‘What are the redshifts?’
She tells him.
‘So this… link is just apparent, it can’t be real.’
The Falling Sky Page 5