feminist blogs

Over on Scalzi’s blog, people are discussing the phrase white trash. Says commenter Lysana at 61:

It’s often easy to spot white trash. One Confederate battle standard or American flag item on the wardrobe and my antennae go up. Sorry you seem to think it matters that some of us know the signs while you don’t.

“Well, sure,” says Other Bill, at 63, “I know the signs. Just like we all know the signs for poor black trash and poor puerto rican trash, right?”

Over here on our own blog, we’ve got a tiff going on in comments about how poor people shouldn’t buy nice things, since they’ve got to save up their money so they can break out of poverty. RonF says at 12:

The desire for better material goods/healthcare/housing/food/etc. is what motivates people to get better education/training and work harder and longer in order to move up to the economic point where they can afford those things.

People who presumably aren’t poor, and certainly aren’t the poor people in question, feel free to comment on the responsibility of poor people’s economic decisions, as Sebastian H says at 14: “Isn’t it kind of a question of which nice things? A TV may or may not be a good example of acting irresponsibly, but a Cadillac almost certainly is.”

But these comments come from the same assumption: that we know what poor people want, and it’s to escape poverty. They come from another assumption, too: that it’s possible for the poor people to escape poverty if they make the right decisions.

But people in generational, grinding poverty, may not share these middle class assumptions and experiences.

I’ll let Dorothy Allison speak to both arguments, with excerpts from her short story collection Trash.

From the introduction:

My family’s lives were not on television, not in books, not even comic books. There was a myth of the poor in this country, but it did not include us, no matter how I tried to squeeze us in. There was this concept of the “good” poor, and that fantasy had little to do with the everyday lives my family had survived. The good poor were hardworking, ragged but clean, and intrinsically honorable. We were the bad poor. We were men who drank and couldn’t keep a job; women, invariably pregnant before marriage, who quickly became worn, fat, and old from working too many hours and bearing too many children; and children with runny noses, watery eyes, and the wrong attitudes. My cousins quit school, stole cars, used drugs, and took dead-end jobs pumping gas or waiting tables…. We were not noble,not grateful, not even hopeful. What was there to work for, to save money for, to fight for or struggle against? We had generations before us to teach us that nothing ever changed, and that those who did try to escape failed…

I had sweet-tempered cousins and I saw them get ground down. I had gentle aunts and it seemed they almost disappeared out of their own lives. Is it any wonder that when I set out to write stories, I made up women like my grandmother, like my great-grandmother? Troublesome, angry, complicated women with secretive, unpredictable natures… I wrote to release indignation and refuse humiliation, to admit fault and to glorify the people I loved who were never celebrated…

I originally claimed the label “trash” in self-defense. The phrase had been applied to me and to my family in crude and hateful ways. I took it on deliberately, as I had taken on “dyke”–though i have to acknowledge that what I heard as a child was more often the phrase “white trash.” As an adult, I saw all too clearly the look that would cross the face of any black woman in the room when that particular term was spoken. It was like a splash of cold water, and I saw the other side of the hatefulness in the words. It took me right back to being a girl and hearing the uncles I so admired spew racist bile and callous homophobic insults. Some phrases cannot be reclaimed.

I draw my comics at a shared space in Portland (Oregon), on SE Foster.

We’re currently looking for mild-mannered, friendly writers, cartoonists, visual artists, and anyone else who wants a affordable workplace share a usually quiet, air conditioned work space.

- Large desks (5 x 2.5 feet).
- High speed internet and utilities included.
- Open 24/7.
- Microwave, refrigerator and half bath.
- Close to food, comics shops and other awesomeness.
- On the 14 and 17 bus lines.
- $90/month — which is, frankly, incredibly affordable.

I can say from experience, being able to get out of the house to work is really, really nice, and boosts productivity. If you’d be interested, drop me an email.

The following is a response to Joanna Russ’s How to Suppress Women’s Writing, reposted with permission from Tansy Rayner Roberts. Roberts is a Tasmanian writer with a fantasy trilogy called The Creature Court coming out from HarperVoyager starting June 2010, featuring flappers, shape-changers and bloodthirsty court politics. The first book is called Power and Majesty, and tells the story of Velody, a dressmaker who discovers a hidden war being played out in the night sky of the city of Aufleur, and of Ashiol, the exiled Ducomte who would do anything to avoid ruling the people who cast him out.

Now here’s Tansy Roberts:

This is a book I should have read fifteen years ago. This is a book someone should have put in my hands the week before I started university, and locked me in a room until I had read it. I should have read it again before I started my Honours degree, and every year I worked on my PhD. When I walked out of my head of school’s office, numbed by his awful pronouncement that the work I had done over 5 years was not enough, that the thesis was simply not worthy of a doctorate because of its scope and subject matter, I should have gone home again and read this book from cover to cover before I began my campaign to prove him wrong.

(he was, as it turned out, wrong, but that is a story for another day)

I don’t believe in ’should’ when it comes to books. Who are you to decide how I should spend my limited reading time? But yeah. Someone should have told me about this book.

(except, of course, they did)

Part of the reason I did not read it for so long, even once I had heard that it existed, and even after I had bought it to put on my To Read shelf, is that I thought I knew what it had to say. I’ve spent my life training myself and being trained to see women’s work and art as valuable. It’s not like I need to be convinced that what this book has to say is true. But the experience of reading it was still important and I’m glad I finally found the time.

This is not an angry book. It is not a book that condemns men. It is a book that shows how our culture’s traditional (patriarchal) way of reading and studying and archiving literature has forced limitations upon all of us, preventing us from understanding the importance of a huge percentage of the work written in our language. Men and women both have been convinced that women’s writing (and indeed, art in general) is less valuable and less significant. And it’s really fascinating to read about some of the ways in which this has happened.

How to Suppress Women Writing isn’t a perfect piece of academic work. It has a definite unpolished feel about it in places. I was surprised at how little science fictional content it contained, tending instead towards examples from literature, poetry and the art world, though quite a few names relevant to the SF field jumped out at me from time to time, such as Vonda McIntyre and Samuel Delaney. Considering the generalist nature of the book, the odd framing narrative referring to aliens with funny names felt a touch out of place.

It is very powerful, though, packed with information and brain-expanding material. The arguments are elegantly divided by theme which makes the document very readable despite the academic content and tone. The message is very strong and succinct, and I found the historical references quite compelling, building up the story of the wealth of women’s writing and art that has been lost, erased from history, and merely forgotten, not because it wasn’t “good” enough, but because the very definition of what is “good” is skewed so heavily male that a female artist has to be turned into something akin to a mythological figure in order to be included – and that the price of being included in “canon” is often to have her work and personal history misrepresented, and her influences ignored.

While I knew already that a lot of work by women had been forgotten or quietly ‘disappeared’, I still have a tendency to say “yes, but” when people call up the argument that women simply write less. I don’t think I will ever agree with that argument again, after this book. While I have often voiced the idea that a lot of women’s work has been removed from history, and dismissed as unimportant, I had no idea quite how much we might be talking about. How have I not put this together before? I knew there was a huge history of novel writing by women in the 18th century, the year that the novel was invented, and yet it stunned me to learn here that three quarters of novels written in that century were by women. Where are they now? It’s a REALLY good question.

This book is full of really good questions. It challenges the reader to think beyond the culturally accepted definitions, and look at books in an entirely different way.

How to Suppress Women Writing was written in the early 80’s and obviously by its references is grounded in the twentieth century. Russ refers to her own university years in the 50’s, and other serious examples of sexism and misogyny in academia and the world of the arts of the 70’s. Sadly, while the book has most definitely dated, it has by no means become irrelevant. Many of the imbalances referenced in this book have been at least partly rectified, and I would love to show the Russ of 1983 how much progress has been made in the cultivation of women’s studies and women’s texts in the last 27 years. But this is still a very necessary work.

While Russ does provide information and arguments that can still be used today, in relation to current issues, I believe the greatest value of this particular text is as a tool to re-examine and interrogate the history of literary canon. History is important, and I think we forget what effect history has on the literature and art that is valued and remembered. Discussions of “canon” whether they be literary or genre-based, often give the impression that somehow the canon of Important Works just appeared, through the democratic process of people buying the books they liked best, and those books being reprinted over and over. It is important to remember that “canon” is an artificial construct, and by and large has been one decided upon by old white men who think they speak for everyone.

They do not speak for me.

Towards the end of the document you can feel Russ’s palpable impatience and frustration with what she is trying to say, and at the end of one of several afterwords piled upon each other like a tower of blocks, she says plaintively that she cannot finish it and charges the reader: “You finish it.” It’s an important statement, and one which establishes that the book is supposed to be the start of a conversation, not a complete text in itself. One of Russ’s other afterwords struck me as being particularly important: having spent the whole book telling us about the ways in which culture has marginalised women, she adds a coda about how her own preconceptions are part of the cultural marginalisation of race. She gives an anecdotes about how the work of Zora Neale Hurston seemed so very thin, uninteresting and lacking in substance to her upon first reading, and how she then set out to educate herself about the writing of black women by reading book after book after book, and upon re-reading the same book by Hurston, discovered that it in fact had a great deal to say, and that she was now capable of listening to it. I admire Russ’ ability to put herself out there and show her own flaws and failings as a reader, in support of her discussion of how our entire culture has limited itself in the appreciation of a particular kind of writing. It also shows her holding up her hands and saying – I am not just accusing those straight white male university professors over there of being the cause of this problem, I am saying that we are ALL the cause of this problem, and we need to stop and rethink the entire history of writers and literature.

The part I perhaps have not yet expressed well enough is just how good a read this slender volume is. I raved about it to my mother over coffee this afternoon and ended up giving her the book to take away with her – my mother, who I recall from my childhood once told me that she had read all the science fiction in the library and was bored with it now, had never heard of Joanna Russ. Russ is funny, and snarky, and bitchy, and clever. I particularly enjoy her smackdowns of Virginia Woolf, noting how A Room Of One’s Own (another of those vital feminist texts I’ve never read because I assumed I knew what it was going to say to me) has helped contribute to many of the damaging myths about women writers. I would happily read the expanded version of this book with half a million footnotes, so enjoyable is her writing style.

I have made a vow to stop saying that anyone SHOULD read anything, but I am making an exception with this one. If you have ever been interested in the history of books and literature, if you have ever started or finished a degree in the Arts, if you have ever voiced an opinion about a book or an author, or ever intend to do so in the future… then, yeah. Actually. You should read this book.

And then, every decade or so, you should read it again. It’s a book that must not be forgotten.

I’m asking for advice on cat dynamics. I’m gong to explain the cats and the situation involved in detail, and the specific question is below the cut.

Here’s the situation. Mike and I have two cats. One is a female, Athena, who is about four years old. We got her from the animal shelter last year. She seems to have been traumatized at some point in her past, probably via whatever landed her in the shelter as a three-year-old spayed cat who had obviously been someone’s pet. The shelter found her abandoned. She’s a dilute tortoiseshell, affectionate, sedentary, not super-bright, and kind of obnoxious–she pees when she’s stressed, or whenever she finds something she’d like to pee on, meaning our house has had to become an afghan/blanket/loose fabric free zone. If she’s really stressed, she’ll pee on our quilts or our clothes. We have to keep our bedroom door closed most of the time.

We also have a little, male grey tabby, Hermes, who is about a year old. He’s a cat we adopted from a stray litter someone took in. He has no trauma issues, is extremely affectionate and playful, and is one of the best cats I’ve ever had.

Hermes and Athena had their rough patches for the first few months when Hermes was a kitten who wanted Athena to play with him. Athena was like, “Um, no, and also get away.” They’ve worked it out, though, and are now good friends. Athena grooms Hermes, and they rub against each other whenever their paths intersect, and they sometimes sleep in a pile. Athena still hisses/growls/bats occasionally, but I don’t think this is so much a hostile maneuver as a “not now, kid, come on.”

Enter cat three.

Nine years ago, when I withdrew from Sarah Lawrence after my freshman year, I asked my parents to get another cat, and eventually they did. His name is Alexi and he’s part Maine Coon. He’s a gorgeous animal. He was six months old when we picked him up from the shelter, but already the same size as an average cat. As a grown cat, he’s enormous. He actually weighs about the same as Athena, but where she’s fat, he’s just very big. His huge, thick coat makes him look even bigger. He has the classic mane and tufted ears; he’s just very beautiful.

He’s also inquisitive, intelligent, and gentle, with the characteristic tiny mrrp voice of Maine Coons. He’s pretty independent and usually chooses to spend most of the day going about his own business, but he requires at least two intense bouts of petting a day. He’s a really nice cat, and I’ve always liked him a lot.

There were several years–when I was at Santa Cruz and Iowa–when I couldn’t have a cat with me, so Alexi stayed with my parents. My parents also had a second cat, a small and grouchy tuxedo cat–Natasha–who wanted nothing more than for people to sit and pet her all day. Even though they lived together for seven years, Alexi and Natasha never got along. This was primarily Natasha’s fault–she DESPISED Alexi from the moment she first saw him when he was a kitten. Every time she ever, ever saw him, she seemed to remember all of a sudden, “Oh my God, THERE’S ANOTHER CAT. I WILL NEVER HAVE PEACE AGAIN.” She hissed, growled, scratched, batted, and freaked the fuck out. She rarely did it with her claws out, although exceptions could be made.

Alexi, for his part, mostly just hung out. He rarely aggressed. He never made noise. He’d just kind of see her freaking out and then sit down, seemingly sadly.

Or, if you interpret it another way, he’d see her freaking out, and then sit at the very periphery of her freak-out range, as if asserting his right to be there.

She was dominant. She got to eat first and stuff. But periodically, Alexi would get sick of being yelled at all the time for the crime of existing and… retalliate. He’d wait around a corner, patiently for a long time, and then pounce when she walked by. (She took to looking nervously around corners, even when he was nowhere near.) He’d sit on the other side of the cat door, knowing she wouldn’t go through if she saw him. And every once in a while, he’d just chase her around–being so much bigger and faster than she was that he’d be running literally on top of her.

It sucked that they hated each other, but nothing we or my parents tried solved it.

Imagine everyone’s surprise when–after Natasha’s death–Alexi went into mourning. His behavior patterns changed. He lost weight. He started crying all the time. My parents go on long trips a couple times a year, and he completely freaked out while they were gone–he couldn’t handle being alone in the house for weeks at a time. Also, he was peeing and pooping in inappropriate places to demonstrate this, which was freaking my mom out.

So the next time my parents planned a trip, I couldn’t handle the idea of him being so miserable again, so when my mom started complaining over the phone about the inevitable gastric evidence of his displeasure, I said, “Okay, you know what? Let’s just move Alexi to our house.”

This was a solution which had been proposed before. When Mike and I moved to Bakersfield, we’d intended to take Alexi with us–but we initially moved into an apartment, and we knew he wouldn’t tolerate the lack of backyard. By the time we were in circumstances to take him, it just didn’t seem like a good idea–we knew Alexi would hate being relocated to a new range, and also my parents really love him when he’s not crapping underneath the piano. So everyone decided he’d stay with them, and we’d get our own cats, which of course we did.

Last time I posted about Alexi, people seemed unsure about whether or not he’d remember us from my parents’ house. He does, of course. Mike and I have both lived with him for large sections of his life. We know him well.

He’s adjusting pretty well to our house, in some ways. He spent a few days wandering about moaning and looking for my parents, but then he stopped. He no longer bangs on every closed door to see if it will open on his old house. We leave the back door open, and he traverses our yard, and goes out to play wherever the cats do, and then comes home and sleeps by our feet, or in our closet. He’s stopped the mourning behaviors–he doesn’t cry all the time anymore. He seems a lot less lonely.

But our cats HATE him.

On the surface, he seems to react to their hatred the same way he reacted to Natasha’s. He walks around, going about his business, and when another cat freaks out, he just kind of flops on the floor and sits there until they quiet down. Occasionally, he pads after the other cats, mrrping a hello noise, seeming for all the world like he’s saying, “Please? Be my friend?” And sometimes he and Hermes have a little, obnoxious standoff situation where they sit on opposite sides of the cat door and glower (I think Hermes is initiating these).

When Athena sees him, she growls and growls, like Natasha used to. Hermes is either indifferent, friendly (I’ve seen them rub on each other and sniff without clashing) or sometimes freaks the fuck out. He rolls around, growling and making a gargling sound, his ears go back, he bares his teeth, and unsheaths his claws. Twice, when the altercation happened on our bed, Alexi chased Hermes out of the room (with no violence afterward; we followed). But the rest of the time, when Hermes freaks out, Alexi just sits down in response. Alexi’s usual behavior SEEMS very pacifist.

Except, I don’t think it is.

Hermes is a rough-and-tumble cat. He wrestles with the strays outside; there’s a very young black cat in particular who always comes up to play with him. Hermes ends up with wounds, but I think it’s just from rough play. So I can’t tell whether Hermes is getting beat up these days, or whether he’s just doing the kitten equivalent of skinning his knee.

But someone’s pummeling Athena.

Last week, we noticed a puncture wound over her eye. This week, there are two more. She’s never been wounded before. Now suddenly Alexi moves in and she is.

Alexi never, ever hurt Natasha. But this is a new house and a new situation. Is he hurting Athena?

He’s not doing it when we’re around, and I’m actually around most of the time. But sometimes, we sleep. Is he doing it then?

We’ve taken some steps to try to calm all the cats. We have one of those plug-in, smell-generating things thats supposed to soothe cats. We have a bottle of spray that’s supposed to simulate cat-face pheromones and calm the cats down by making them think all the territory is already marked as theirs. We’ve stopped closing the back door at night (which we did because we would prefer the cats not be able to get into the street after dark) which has allowed Alexi and Hermes to go out to run around and blow off steam at night, instead of all piling on our bed to sleep with us and having enormous cat fights at 3 AM, which was not something we could live with long-term. (They seem to have settled for sleeping with us in shifts.)

But I’m not sure what else to do. Obviously, I don’t want Athena to get beat up on a regular, long term basis. If this is some kind of hierarchical cat issue that will work itself out once the new dominance is established in a month or two… well, I’m not in love with the idea, but I guess everyone can live with it for a short period of time. But if we’re subjecting her to long-term bullying and injury? No, absolutely not.

In that case, we’ll have to send Alexi back to my parents’ house–where he will be alone and where he will start crying all the time again. Obviously, Alexi doesn’t want to be left alone without humans. But equally obviously, he wants to be around other cats. But that’s not going to work if he injures them.

We’ve got the interests of all three cats to balance here, as well as our own need for some sort of household harmony, and–you know–occasional sleep.

Maybe there’s some magic bullet behavioral therapy, or technological assistance, that we can employ here. It would be a big relief if there were. I know many people manage much larger herds of cats than our discordant three. Is there a trick to it? What’s your advice?

–

Hmm! A new wrinkle! My friend Ann asks, “Are there any new cats who’ve showed up in the territory besides Alexi?” Why, yes, there is a new orange tabby. Perhaps he is the culprit who’s wounding Athena. Particularly since A) Alexi has no track record of hurting Natasha (though plenty of track record of coming home with wounds from fights with strays outside, which Natasha never did), and B) Athena’s first wound showed up last week, which coincides with new orange tabby’s appearance, but Alexi’s been here for about three.

I think we may try keeping all the cats indoors for a bit. This is antithetical to both peace of mind (the cats go a bit nuts when they can’t run around like they’re used to being able to) and sleeping (because of the kerfuffles on the bed), but maybe we can lock Alexi in the garage at night for the duration of the experiment. He’s used to it; my parents have always done that with their cats.

Lack of wounds on Athena during the experiment wouldn’t be *conclusive*, but it might be suggestive.

I admit I don’t spend much time thinking about Robert Heinlein, but when I do, I always have the same reaction, which is that shivery “Bleach! Get it off me!” response that the bug-phobic have to spiders and cockroaches.

There’s a reason for this, though.

I read Stranger in a Strange Land in high school, and liked it well enough. I no longer remember it that well, honestly. Then in college…

Well, see in college, there was this guy. He wanted me and my boyfriend to have a polyamorous relationship with him. Because he really wanted to have sex with my boyfriend, who he’d known for a long time, and he was interested in having sex with me. Okay, whatever. I knew I wasn’t suited to polyamory, but I was in my “I am a reed, bending in the wind, willing to do whatever I am told to do” phase, so I said, “I don’t know; let my boyfriend decide.”

That was an easy thing for me to say, on account of boyfriend was either A) really not bisexual at all, or B) chill with gay people, but really not chill with any gay feelings he may have felt. So he was not going to go for this polyamory proposal.

Indeed, he did not. This was conveyed to amorous guy. Who then decided that what was needed in this situation was more wheedling.

So he sent me a book.

The book was TIME ENOUGH FOR LOVE.

Let me start by praising this book, as I remember it from when I was 18. It was funny. It was a fast read. It was involving. It had at least one fantasy I was super down with–I wanna be immortal like Lazarus Long. It had one memorable scene which I still recall, wherein Lazarus Long sits down with his descendents and explains the dangers of incest by means of a metaphor involving a deck of cards.

And then there was the polyamory. Specifically, there was a wide-eyed, subjectivity-less, hot-hot-hot female character named Hamadryad who nurtured others with her healing sexuality…

And all of a sudden? I was no longer wishy-washy bend-like-a-reed on the subject of polyamory. In fact, I was no longer wishy-washy on the subject of Heinlein. I now had a distinct opinion of Heinlein: read Heinlein, said this opinion, and lose your lunch.

I am not particularly interested in reading more Heinlein. Yeah, yeah, I know, “read the classics.” Well, I tell you what, in the event I ever get through reading every other book I want to read and should read, I’ll then go back and start reading the books by the guy whose novels were used to try to seduce me by proxy. Also, at the same time, you have to go read all the things you think are boring or obnoxious.

However, my experience of TIME ENOUGH FOR LOVE may not really be representative of all of Heinlein’s work. I get that. A) He wrote lotsa books, and many may be less obnoxious, and B) When one is not being skeezily hit on, even the obnoxious portrayal in TIME ENOUGH may not be quite so “oh, please, godDAMN.”

I reserve the right to call the portrayal sexist, though. No matter how people argue to the contrary, this is actually an observation on par with noting structure and school–it’s a textual analysis. Was Heinlein himself sexist? No fucking clue, don’t really care.

Meanwhile, Heinlein? Brrrrrrrrrrrrrrrrrrrrr getitoffme.

–

*While writing this post, it occurred to me that I use Heinlein interchangeably to mean “the individual Robert Heinlein” and “the body of works by Robert Heinlein.” If I were to say “Heinlein is sexist,” I’d mean the latter. I wonder if this is the substance of some of the miscommunications b/w Heinlein-defenders and Heinlein-questioners; I don’t think I’m unusual in using the author’s last name to denote his body of work. By the same token, though, I wonder if people also react to observations/reactions to the body of work as if they are observations/reactions to the individual, so the potential for inappropriate condensation of writing and writer, as well as the potential for straight-up misunderstanding, abounds.

Renee at Womanist Musings has had a nephew die. My sympathies are with her and her family.

Womanist Musings is accepting contributions to pay for the burial; there’s a donor box on the upper-left corner of the blog, and any amount of money would help. They’ve currently raised a little over half of their $6626 goal.

Last month, Matt Cheney emailed me to let me know that he was putting together a celebration of Jeff VanderMeer’s new collection, Third Bear. He asked a number of writers and critics if we would each write about two stories from Jeff’s collection sometime in July. You can visit this site to see the rest of the carnival.

“Sure,” I said, “but my July is busy. It might be late in July.” Matt assured me that was okay, and here I am, as promised, at the very last minute.

Matt told us we could write however we wished about Jeff’s stories. In this case, I felt fan fiction would be the sincerest form of flattery.*

A Meta-Fictional Diptych Relating to the Stories “Appoggiatura” and “Fixing Hanover”

by Rachel Swirsky

I. Rebecca

Rebecca Salt, age fourteen, daughter of divorced middle class Jews from Long Island, was tired of being a Speller. She could still remember how things had felt before she got competitive, when Spelling was still a pleasure, when she had a sort of palpable sense of the l-u-x-u-r-i-a-n-c-e** of words and letters. She’d heard the symmetry between alphabet and language as a kind of ringing d-u-l-c-i-m-e-r, intricate and melodious. Sometimes the joy she took in words felt a-u-t-o-c-h-t-h-o-n-o-u-s, seeming to rise up in her from some ineffable, otherworldly source.

Six years into the rote of shuffling flash cards in every free moment, gasping out words as she ran out the door to school, eschewing the playground to snatch more time at recess and lunch, her evenings collapsing into a formless mass of homework seeping into study… well, six years into it she found herself waxing e-l-e-g-i-a-c about the days when words had seemed to sing and spin. It seemed almost s-a-c-r-i-l-e-g-i-o-u-s to admit it, but she regretted the k-n-a-c-k for words that had bound her to this labor.

Until she discovered s-m-a-r-a-g-d-i-n-e.

The word shattered the mundane expectations of her suburban m-i-l-i-e-u, rising in a flash of verdant foliage and lime feathers and sensuous snakeskin scales. It was fir trees and cat’s eyes and peridots and long silk gowns and malachite and moss. Wondrous shrapnel inundated her imagination. She could almost touch it: a land where everything shone like emeralds.

There was no reasonable explanation for why she had not run into the word before. It was a well-known spelling challenge, having decided the National Spelling Bee championship in 1961. She should have been spelling it in her sleep for years, as she spelled s-y-l-l-e-p-s-i-s and r-a-t-o-o-n and h-a-r-u-s-p-e-x. There was no reason for her persistent ignorance, none, unless—and here the a-u-t-o-c-h-t-h-o-n-o-u-s theory began to raise its head with whispers of mysticism and d-e-i-f-i-c-a-t-i-o-n—unless something had been waiting to show her the word until she was ready to receive it.

Day and night, no matter how laborious her studies, she was never again thinking about the words, not really, never again wondering if she had transposed the “i” and the “e” in a-n-t-e-d-i-l-u-v-i-a-n or used the right double letters in a-p-p-o-g-g-i-a-t-u-r-a. She was too busy contemplating her imaginary, emerald realm. Would it have green coins, she wondered? What would they eat there? Probably only things that were m-a-c-e-r-a-t-e-d; that would make her turn green. What were the people like? She imagined them with exotic, untenable names, like E-c-z-e-m-a and P-s-o-r-i-a-s-i-s.

Rebecca became so intent upon her fantasies that soon she forgot to rifle through her flash cards at all. Her parents became concerned. Her father tried to engage her with the kinds of intriguing words that had always lured her before—h-y-d-r-o-p-h-y-t-e and s-o-u-b-r-e-t-t-e and o-d-o-n-t-a-l-g-i-a—but these words did not fit into Rebecca’s imagined kingdom, and so she paid no heed. Rebecca’s mother became hysterical with worry, and brought the child into the s-a-n-i-t-a-r-i-u-m for a healing dose of Freudian t-h-e-r-a-p-y. A diagnosis of depression was applied, complete with prescription, but it made no difference.

The rapid decline began at P-u-r-i-m that year, when Rebecca looked down at the traditional celebratory meal and declared she would not eat anything that had not been m-a-c-e-r-a-t-e-d and was preferably green as well. Her parents, fearing anorexia, served their finicky offspring frog-in-chicken and chicken-in-duck, but Rebecca ate little, growing thinner and thinner. P-s-y-c-h-i-a-t-r-y had nothing more to offer, even when Rebecca tried to explain away her sudden onset of n-a-r-c-o-l-e-p-s-y by saying that her episodes coincided with the times that the ambassador of S-m-a-r-a-g-d-i-n-e was calling her for diplomatic duty. By the end of spring, the emaciated Rebecca slept more often than she was awake, until even that preciarious condition d-e-t-e-r-i-o-r-a-t-e-d and she slipped into a coma.

The sad tale might end there but for the fact that Rebecca’s skin turned green while she was in the hospital. A resident physician, running tests for his own inscrutable reaosns, realized that the girl’s body had somehow begun producing c-h-l-o-r-o-p-h-y-l-l, leading to photosynthesis. At her parents’ insistence, Rebecca was taken off the machines to see if she could survive on her own—and not only did she survive, but she flourished. She even regained consciousness on one brief occasion, muttering incoherent v-i-g-n-e-t-t-e-s about her dream life where she studied at a l-y-c-e-u-m in S-m-a-r-a-g-d-i-n-e.

At least she seems happy in her dreams, her parents concluded when Rebecca’s brief wakefulness lapsed. The young doctor, shaking their hands on their way out, added as a minor observation that he had been dreaming himself of green people of late, and wouldn’t it be funny if there were a whole country full of photosynthetic, green individuals? “Smaragdine!” Rebecca’s parents exclaimed simultaneously, looking to their i-n-t-e-r-l-o-c-u-t-o-r with amazement.

“Do you think—do you think it could be true?” Rebecca’s mother asked the doctor.

The doctor shrugged. “I really have no idea,” he said–but in his pocket, he held a single emerald coin.

II. Lady Salt

“Someday I will kill you and escape to the sea,” Lady Salt whispers to her former lover.

They sit together on the airship that destroyed Lady Salt’s village and everything she’d ever known.

Lady Salt’s former lover designed the airship—he designed all airships. He claims he didn’t know that they would be used as weapons. He claims that he fled the Empire once it began using them to rain destruction on neighboring peoples. He claims that he is innocent of their blood.

He listens calmly to her threat. He does not tense or clench his fists. Only his eyes change, stony resignation drifting beneath the blue.

She refuses to call her former lover by the name he used when they lived together in her island village during those years when she knew his skin almost as well as she knows her own. He’d come as a refugee, washed up like the salvage her people used for trade. She had salvaged him and made him her own. Then the airships came and destroyed everything, all because they wanted to recover one man.

She shouldn’t have survived the destruction, but he had been there when the soldiers found her, and he’d told them he’d come back willingly if they took her as well. She could never forgive him for anything, but especially not for denying her a clean death.

Instead of his village name, she uses the same title the soldiers do: Engineer.

The soldiers are deferent. They need the Engineer to invent more weapons. They are in danger of running out of new ways to kill people.

But even their deference does not change the fact that the Engineer and Lady Salt are prisoners. At night, they are placed in the same room. Lady Salt refuses to share the Engineer’s bed. She sleeps on the floor instead, one ear pressed to the door, listening to the click of the guards’ heels as they pace the hardwood.

During the day, the soldiers take the Engineer away to consult with the Captain. While he’s gone, Lady Salt is allowed to explore a small suite of rooms adjoining their bedroom, the guards at her heels.

On the island, there was the asymmetrical, organic beauty of cliffs and beaches, the white dive of ocean birds and the glint of fish scales sliding through water, the whip of agitated waves and the stillness of calm seas. On the ship, there are fine polished woods and objects chipped from shiny stones that Lady Salt doesn’t recognize. Everywhere, the gleam of metal—more metal than Lady Salt saw in a lifetime of salvage. Everything is laid out in regimented designs, almost mechanical in their precision.

The people are equally mechanical, marching in matched-length steps, repeating the same salutations whenever someone enters or leaves a room. The only other woman is the cook who brings their meals while wearing enormous skirts and a cinched bodice that seems to contribute to her pink face and shallow breaths. Lady Salt shouted at the soldiers who tried to bring her similar garb, but in the end it was only the Engineer’s intervention that left her in trousers.

There is one thing she likes onboard: a globe of the world. Despite her refusal to acknowledge him, the Engineer insisted on explaining what it was once he saw that it fascinated her. When he’s gone, she slides her hands over the strangely smooth surface, and lets her fingertips bump up and down as they skim over the raised island chains.

She leaps back in surprise when she feels other hands seizing the globe to stop its spinning. It’s the Engineer. She glances up in disgust, but she’s equally disgusted at herself for becoming so immersed that she failed to hear him enter the room.

The Engineer points to a misshapen green island. “We’re here,” he says.

Lady Salt moves to a porthole which overlooks a barren field. “We’re here,” she says, “but where are the farmers?”

There are scorch marks on the ground. This territory has been burned by the air ships.

“I never meant for this to happen,” says the Engineer. “I wanted to build airships. I was stupid. But what child hasn’t looked at the birds and wanted to fly?”

Lady Salt curls her lip. “Don’t court my pity.”

The Engineer ducks his head. “I wanted to explain,” he says softly, spreading his hands in a gesture of vulnerability.

When they were lovers, Lady Salt had liked his openness. Now she loathes that, too.

Sometimes at night, her dreaming mind conjures scenes best forgotten. The smell of his sweat mingling with ocean salt. The smooth of his teeth. The rough of his thighs.

Can she kill him? She’s killed before, but never someone she once loved. As soon as she considers it, she realizes she can.

Now that she refuses to look at the globe anymore, she spends her time staring out the porthole. They pass over vast tracts of scorched lands. In some places, the Empire’s citizens are building new farms and new cities, all in the same, regimented style. Beyond the wastelands, they reach disputed territories. Now instead of scorch marks, there are corpses rotting into the soil. Everywhere is blood and guns and screaming. Everyone on the airships is responsible—from the soldiers who fire the guns to the cook who fills their stomachs. But the original fault is the Engineer’s.

Lady Salt gets her opportunity one night when the breathless cook tips into a faint, their dinners clattering to the ground. The cutlery is blunt, but a paring knife falls from the cook’s voluminous garments. Lady Salt contrives to take it before the soldiers can notice. The Engineer sees, but he says nothing.

She waits until the soldiers retreat outside their bedroom. The Engineer doesn’t look surprised until she hesitates with the knife against his throat. He squirms. His eyes bug out like a frog’s. “You still… love me?” he asks.

Lady Salt scoffs. “I want more blood than you can give me. I want the blood of all these men.”

The Engineer’s ragged breaths almost cause the knife to cut him without moving. “I can make them trust me.”

“Your problem is that you’re too weak,” says Lady Salt. “You never asked questions. Why do you want missiles on airships? Then when things got violent, you fled. Even in our village, you fixed Hanover, knowing this could happen.”

“You’re not weak,” says the Engineer.

“I’ll still kill you,” says Lady Salt. “When it’s over.”

The Engineer contrives to indicate his agreement without slitting his own throat. “When it’s over, I’ll kill myself.”

Lady Salt withdraws the knife. The Engineer’s breathing eases. He watches her as she crosses the room, tossing the paring knife into a shadow where one of the soldiers will find it in the morning and believe it to have been unused. Together, they will infiltrate the regiments until they find other weapons, better weapons. And when they have them, the airships will burn.

-

*Particularly because I suspect “Fixing Hanover” is itself a form of fan fiction, written in response to a Bradbury story.

**Note: Words spelled out with hyphens are drawn from the list of words that have won the national spelling bee. The idea is lifted from Logorrhea: Good Words Make Good Stories, an anthology edited by John Klima based around the same list of words, in which “Appoggiatura” originally appeared.

Trigger warning: graphic descriptions of medical procedures.

As my Facebook friends are no doubt sick of hearing, I have a blocked tear duct. Turns out you really need your tear ducts! Give them a hug, because they are important! If they’re not working right, then tears that would normally drain through your throat run down your face and grow stagnant in your sinuses and breed bacteria, which leads to swelling and pain all around inside your head. My ophthalmologist thinks that when I broke my nose in high school colorguard fifteen years ago (yes, I was a flag team geek), some debris made its way into the duct and led to scarring, which eventually closed it up. That’s causality for you.

Over the past few years, I’ve been growing steadily more exasperated with my body - my creaking, grinding, breakable body, my body with its killer monthly cramps and its wild hair that got me picked on in school and its hunched shoulders and crooked nose (my mom claims, bizarrely, that a nose job should solve my tear duct problem) and its spazzy brain (since I’m no longer cross-posting on a site with my full name, I feel safe saying that the “chronic pain” I mentioned a while back is depression/anxiety with OCD) and its tear ducts that have now pooped out. I feel like my 2001 Saturn - every day a new issue. It wasn’t until very recently that I learned not to blame my body for its problems, but I still feel off-kilter in that mode of thinking. It’s so much easier to be mad at my body.

I’ve already had one procedure to try and open the duct. The doctor, dressed in full surgical scrubs while I sat in a chair in my street clothes, numbed the area between my eye and nose and proceeded to jab at the inside of me with a tiny flexible rod. At one point he punctured a membrane and my nose started bleeding. At another point I had to ask him to take the thing out because I feared I would throw up from the trauma of it. Finally I felt something give in one duct and he irrigated it; water flowed down my throat as he emptied a syringe into the tiny hole in the corner of my eye. The other duct, though, remained blocked.

When I got home, my eye swollen almost shut and splotched with red, I joked around with my husband and ate some dinner and then let my guard down and shook and cried for the rest of the night. I’d neglected to mention the anxiety disorder before the doctor started. I really should have.

The next step is surgery: dacryocystorhynostomy, or the creation of a new duct. Sometimes it works like an ear piercing; you put a thing in there and eventually it stays open. Other times they have to insert a tiny, permanent tube. In the operating room, the surgeon will make an incision between my nose and eye so that he can access the intricacies underneath the skin. It’s a relatively minor surgery, just a small thing, in and out of the hospital in a few hours’ time. But I keep thinking about the scar. Will my glasses cover it? Will people see? After decades of being told I was ugly, I finally consider myself pretty-in-a-way, and I’m scared that a scar on my face will obliterate my modest progress.

I’m also afraid of general anesthesia, which I’ve never had. When I was a kid, I prayed I’d never have to have my tonsils removed because I was afraid people would laugh at me while I was asleep, or that I’d lose control of myself before or after and blurt out all my secrets. All my life, I’ve kept myself under tight control, never letting people in, hating myself for moments of weakness. I hate myself when I have cramps and I ask my husband for tea. I hate myself when he cooks dinner because my back is out again or I’m too depressed to move. I’ve always been irrationally annoyed by people with lots of little health problems, because I’m disgusted by that aspect of myself. I hate feeling fragile and weak. I hate fearing that I’m acting like a baby.

My biggest fear, though, is waking up to pain. This blogger had the same surgery that I’ll have and she says they put a tube down her throat while she was under, and that afterwards her throat hurt. I came across a picture showing how deep these tubes go - boy, that was a mistake. I’m terrified of the violence of modern medicine: needles and tubes and catheters and monitors and machines. (I had a catheter once and it was awful.) At some point in my life, I became terrified of harsh touches, so much so that sometimes my husband can barely touch me without triggering some ancient, objectless fear. After the tube and the incision and God knows what else, I’ll have to wear a stent for three months before the doctor snips a knot and I blow it out through my nose. The pre-op anxiety has triggered the worst of my mental health problems. I don’t think we as human beings have the instincts to really deal with phenomena like this.

Then there’s the money. Lord, I can’t even think about that right now.

I feel like at some point, I and others around me were trained to be blasé about minor surgeries, to brush off the fear, to treat them like nothing special. There’s no room for the profundity of willingly forfeiting your free will to someone you’ve barely met so that they can hurt you. Even this post feels like a frightful indulgence, considering all the bloggers who have written about cancer, about childbirth, about experiences I can’t imagine.

I feel like I’ve been given no room to really deal with the effects of modern medicine on my mental health.

So I’ll ask you: what are your thoughts on surgery? What are your experiences (especially those of you who deal with anxiety or OCD)? What have you felt and learned? I’d love some reassurances here. People, I’m serious about the mental health thing - I’ve been in a continual state of panic (shaking hands, tears, racing heart) for five days now, and the surgery is almost two weeks away. I don’t know how my body can keep this up. When I say anxiety, I mean ANXIETY. When I say obsession, I mean OBSESSION. When I say disorder, I mean that things that are supposed to be in order are not in order at all.

So I’ve been keeping a worm bin (a compost bin that uses worms to turn food scraps into fertilizer) for about two years now. For the first year or so, I kept the bin in the garage, but that made it too easy to ignore; the food scraps would pile up in the bag in the corner of our kitchen and start to smell, and the worms would tunnel sadly for weeks through their own poop, hoping against hope for a delivery of broccoli stems and wilted chard. Mold would grow. Sprouts would become seedlings and then die from lack of sunlight. So I moved the bin indoors, which led to much better care of the worms and somewhat better care of my plants, too, since I was harvesting the castings more often. But it also led to a pretty harrowing fruit fly problem. So back down to the garage it went.

The city of Long Beach - or, at least, our block - has a giant cockroach problem, by which I mean that both the problem and the cockroaches are giant. A few months ago I caught our cat sniffing and pawing the wall of our living room; I thought he was communing with ghosties and laughed it off, but after the roaches started getting into the apartment, I realized that he was probably hearing and smelling them in the walls. For awhile, my husband and I would come out each morning to find roach parts lying here and there on the carpet, along with the occasional pile of cat puke. The exterminator said they were probably coming in from outside the building. We would see them crawling around on the wall of the garage when we came home from work.

Yes, the garage - where I moved the compost bin. Spoiler alert?

After I moved it back down, I promptly went back to my old habits. It wasn’t until I noticed that my jasmine buds were dying before they bloomed that I realized I couldn’t remember the last time I’d fertilized it. I hurried to the garage, held the bin close to my body as I maneuvered it around the car, and opened it in the shade of the garage door.

Whatever substance was in there was definitely not compost. It was swampy. It smelled like a ripe sewer. The worst part, though, were the three-inch-long cherry red cockroaches that covered the surface of it. I don’t think I’ll ever forget the way they looked as they crawled on top of each other and scurried around the sides of the bin.

My husband heard me scream and came down. We moved it to the sun and kicked it a couple of times, but most of the roaches stayed. To make a long story short, we decided that the worm bin was kaput and the least terrible course of action was to just dump its contents in the garbage. If we’d been thinking more clearly, we would have tried to get it in a bag first; as it was, though, I was panicked and on the verge of dry heaving, so we each grabbed a handle, ran it to the dumpsters, and did our best to pour it in. There were a few worm survivors at the bottom. We paused while I tried to think of a way to save them, but putting them in one of the dusty planters would probably kill them, and keeping the compost bin would only invite more cockroaches. We dumped them. Situations like this are why I observe Yom Kippur.

While we were dealing with this, a guy from next door came out of his gate and sat silently on his bike, not quite staring at us, but making it clear that he was interested. Finally he said, “Not very neighborly, is it?”

“Huh?” we said.

It turned out that we were dumping our catastrophe into his building’s trash can. Or, rather, it had our address written on it, but it was a wee bit closer to his building than it was to ours, so obviously it was his.

“Does it really matter?” we asked.

“Just doesn’t seem very neighborly to me,” he said.

We had to apologize twice, and then remind him that we’d apologized twice, to get him to go away. What I felt genuinely terrible about later, aside from the worms, was dumping without a bag.

I still have a couple of unanswered questions about the whole fiasco. First off, my neglect of the worms wasn’t any worse than it had been in the past. What went wrong this time? Secondly, worm bins are designed to keep out larger animals. How did the giant roaches get in? I have some theories, but honestly, I’m still too revolted to start researching. In any case, we’re moving in a month, so the worm bin is on hiatus until we get settled in our new place - which, according to the UCLA student housing office, will have a balcony.

How are your DIY urban homestead endeavors going? Consider this a place to gripe, whine, and vent about those veggies that are dying, that bread that isn’t rising, and other projects that have gone awry.

To read the rest of my launch pad posts, click here.

We spent the morning playing with images in an astronomy program that you can download for free if you, also, would like to spend your morning playing with images — SAOImage DS9.

Books:

Is Anyone Out There? by Frank Drake and Dava Sobel
The Space Environment: Implications for Spaceship Design by Alan C. Tribble

Distance measurements to other galaxies:

a) Cepheid method: using period/luminosity relationship for classical Cepheids. This is what’s classically done, but it’s hard to do outside the local group of galaxies.
b) More recently, we’ve been able to categorize Type Ia supernovae (collapse of accreting white dwarves in binary systems) to get distances to much more distant galaxies, but these don’t let you calculate within galaxies well.

These are standard candle methods. If you know the brightness of a standard candle, then you can calculate the distance.

Once we have distances, we can calculate size and luminosity.

Cepheid distance measurement– repeated brightness measurements of a Cepheid allow the determination of the period and thus the absolute magnitude and distance.

We can use those kinds of arguments to get distances to nearby galaxies. Historically it’s the only usable technique. And back in the 1920s, Edwin Hubble started calculating things like the distances of galaxies and relating them to the redshift–their velocity moving away from us. He looked at spectra and saw they were redshifted.

From a measured redshift you assume objects are moving away from you. You can get a velocity. When he plotted velocity v. distance, he found a correlation–objects 1 megaparsec distant were redshifted at x, and at 2 megaparsecs at (function)x. This gives us the expansion rate of the universe, although this rate has not been stable throughout the history of the universe. Hubble got this correct, but miscalculated his original distances.

Knowing this relationship, if you just measure a galaxy’s redshift, you can use that to get a distance.

Ian: Is anything blueshifted?

Mike: Andromeda. It will merge with the Milky Way in 3.5 billion years.

Ian: Is anything else?

Mike: Some of the nearby galaxies are blue-shifted. It’s the general expansion of space that carries galaxies apart, but galaxies are also moving in relation to each other with peculiar motion. You have to go out a few megaparsecs before the Hubble reaction (space expansion) moves faster than the peculiar motion.

The extragalactic distance scale.

Many (most) galaxies are millions or billions of parsecs from our galaxy, expressed as mega- or giga-parsecs.

At distances like this, it’s interesting to note that we’re looking at light that left the galaxy we’re looking at millions or billions of years ago. We’re looking at how these objects looked when light left them, when the universe was much younger. This is red-shift time, with “look-back” time of millions or billions of years.

If we want to study the early universe, we just find the most distant objects possible.

So, galaxy sizes and luminosities. Galaxies come in vastly different sizes and luminosities. From small, low-luminosity, irregular galaxies (that are much smaller and less luminous than the Milky way) to giant ellipticals and spirals.

Rotation curves of galaxies–we use the rotation curve of the milky way to get the mass of the milky way. We can do the same with other galaxies. Spiral galaxies have a rotation, with one bit red-shifted and one bit blue-shifted, we can figure out the speed of the rotation. Based on the rotation, we can use Newtonian gravity to determine the galactic mass.

Supermassive black holes–almost all massive galaxies have supermassive black holes at their centers, some of them much more massive than ours (ours is millions, there are some with billions). The simple story is smaller galaxies have smaller ones, larger galaxies have larger ones. We only have dozens of black holes measured. We don’t know whether or not most galaxies have them, though some suspect so. It is also not clear that dwarf galaxies have black holes at their centers.

To explain the rotation curve of these far galaxies, mass does not follow the starlight. In order to understand these rotation curves, most of the mass of the galaxies has to be invisible. We don’t know what it is, but we have ideas about some components, and we know it probably *isn’t* brown dwarfs. Brown dwarfs are failed stars, which may be even fainter than M stars, which don’t shine or have fusion in their cores. They would be really faint. They’re out there and contribute a lot of mass, but calculations to discover how many of them there are indicate that there’s not enough mass from them to comprise all dark matter. The mass might also be small, primitive black holes from the beginning of the universe, but we don’t think that’s it either. It’s also possible that Newtonian physics doesn’t work as we think it should on the galactic scale, so there is no missing mass problem. However, we’re pretty sure most of the mass is exotic particles and anti-particles.

Clusters of galaxies–galaxies tend not to exist in isolation, but in clusters. Rich clusters have more than 1,000 galaxies of approximately three megaparsecs, condensed around a large, central galaxy.

Poor clusters have less than 1,000 galaxies, often just a few, with a diameter of a few megaparsecs, and are generally not condensed toward the center.

The Milky Way is in a poor cluster, the local group has three large spirals and a bunch of dwarf ellipticals.

Hot Gas in Clusters of Galaxies–space between galaxies is not empty, but filled with hot gas that is observable in X-rays. That this gas remains gravitationally bound provides further evidence for dark matter. There is more mass in the hot X-ray gas than there is in all the stars in these galaxies.

When we’re talking about galactic masses… the milky way is maybe 100billion in gas and stars, maybe 1trillion if we include halo and dark matter (that’s solar masses) which is a moderately large spiral galaxy. Some of these elliptical galaxies will be a hundred times more massive. A whole cluster might be as much as 10^15 solar masses.

Gravitational lensing–the huge mass of gas in a cluster of galaxies can bend the light from a more distant galaxy.The image of the galaxy i strongly distorted into arcs. This actually gives us another way to measure mass. You can measure the mass of a cluster in a similar way to how you measure the mass of a galaxy; they may rotate. You look at the velocities; you look at the size scale; you get a mass. Without the mass we calculate, these galactic clusters should fly apart. Even when you add in x-ray gas, they should still fly apart–arguing, again, for dark matter.

Our galactic cluster: the local group. Similar to the diagram we’re looking at. We’ve always thought Andromeda was more massive than our own galaxy, and in fact it probably is, but we recently figured out our estimate of our own galactic mass was off by a factor of 2, so it’s closer. A few of the galaxies in our groups are spirals, but most are dwarf ellipticals. This is a similar thing to the chart of stars–most stars are small, red stars, but if you just look at the brightest stars, then you see the rare massive stars. Likewise, if you just look around the sky, you tend to miss the dwarf ellipticals and see the bright, massive ellipticals and spirals. So probably dwarf ellipticals are the most common kind of galaxy, but we don’t know about many of them because we can only see the local ones and past that they’re too faint.

Ian: So, there are 13 dwarf ellipticals?

Mike: About, although there are edge cases.

Me: Any reason to think having few galaxies in our local group would be conducive to life? Would it reduce

Mike: The type of galaxy and galatic environment is probably correlated with life if we assume that life as we know it on earth happens and the conditions here are preferable because a lot of these rich galaxy clusters have almost no spirals, and the big elliptical galaxies are likely the result of mergers of spiral galaxies, and mergers of spiral galaxies do two things: they disrupt all the stars, they use up gas making mores tars, but passage through this hot medium has a tendency to strip gas from the galaxies themselves, quenching star formation, so that at some point, you stop making new stars, and at some point you’re stuck with older ,less massive stars, and you end up with low metallicity which is important in planet formation. When you crash two galaxies together, the space between stars is so large you essentially never get stellar collisions, but it may be easier to disrupt solar systems.

Me: It’s in those galaxies you see gamma ray bursts?

Mike: No… those are in galaxies with a lot of star formation, they seem to come from hypernovas.

Mike: Let’s talk more about these processes. When you have galaxies merging and colliding, you can set off star formation. Some of these excitements may not come from collisions, but just some kind of interaction.

Starburst galaxies are often very rich in gas and dust, and they’re bright in the infrared because dust forms from supernovas, and gets heated by the supernovas, so they shine very brightly.

Interacting galaxies–Particularly in rich clusters, galaxies can collide and interact. Galaxy collisions can produce ring galaxies like the cartwheel galaxy which we think passed through the center of another galaxy, and when it did, it produced a shockwave that set off star formation around the center. A movie showing the cartwheel galaxy formation.

Questions about movie: Bud: What’s the yellow lump?

Mike: The stars from the other galaxy.

Kelly: What happens to them?

Mike: They keep on flying.

Monte: When a collision does cause a star to end up outside a galaxy, what happens there? Does not being in a galaxy affect them in any way?

Mike: Probably not. They’d have a slightly better chance of not being killed by a supernova.

Monte: So they’d be a bit safer for life?

Mike: Maybe. It could be cool to have aliens on a planet outside a galaxy. They’d figure out galaxies faster than we did. Probably.

Bud: What happens to the momentum of the two galaxies?

Mike: It’s conserved. There is a kind of friction that slows galaxies down, though. As the big galaxy goes through the little galaxy, it pulls some of the little galaxy’s stars into it. As it passes through, the situation is different when it passes through to the other side. Having more stars can slow it down. So it’s slower than when it collided with the other galaxy.

Colliding galaxies can also produce tidal tails with all kinds of star formation going on.

There’s another galaxy called the mice with interesting features.

Galactic interaction simulations:

Models of Merging Galaxies.
Chris Mihos’s New Galaxy Collision Movies

Mergers of galaxies:
*NGC7252: Probably the result of the merger of two galaxies about a billion years ago.
*Small galactic remnant rotating backwards.
*Multiple nuclei in gigantic elliptical galaxies.

Active galaxies: this is Mike’s specialty. So this is an image of a quasar, quasi-stellar radio object. What we see is a bright core with jets spurting out at mega-parsec scales. Jets squirt out. We think we have accretion onto a super-massive black hole in the center of the galaxy and these are giant, intergalactic-scale jets issuing from it. AGN for active galactic nuclei. These things can be thousands of times more luminous that the entire Milky Way, as a result of energy released from within a region about the size of the solar system.

Line Spectra of Galaxies: Taking a spectrum of the light from a normal galaxy they should have all colors.

Seyfert galaxies are unusual spiral galaxies with very bright cores and emission line spectra. They vary up to 50% in a few months, and have as their power source, most likely, accretion into supermassive black holes at about 100solar masses, up to billions of solar masses. They have emission line spectra, not absorption, like new star forming regions. The time scale of the variability can give us an impression of the size of these objects.

We don’t see the black holes, we see the hot gas in their accretion disks.

We see some objects where the accretion disk of the black hole appears to be perpendicular to its galaxy, and is jetting material out into the interstellar medium. Hard to write about this–you could write about aliens in the way of this sort of thing, but either they can’t do anything about it, or they have lots of time to do something about it.

Radio galaxies–Jets visible in radio and x-rays show bright spots in similar locations. Infrared images reveal warm gas near the nucleus. They show evidence for the galaxy moving through the intergalactic material. There are circumstances where the jets hit other galaxies, shock gas clouds, and trigger star formation. We see galaxies with two nuclei, two supermassive black holes, two accretion disks, and two jets coming out.

Formation of radio jets–jet production in active galactic nuclei are not well understood, but we think it has to do with conservation of angular momentum and twisted magnetic fields, that the disk has hot plasma right at the center that gets caught up in these twisted magnetic fields that’s very hot, very high velocity, and gets sent out along these magnetic field lines. This is tough research, we don’t have a lot of good observational data; we need to have solar-system-level data in the centers of galaxies far away, which is very hard to do.

The Jets of M87–nearby giant elliptical with more radio jets, which have a velocity of half lightspeed.

Model for Seyfert galaxies (on scales up to quasars) where we have an accretion disk in the center around a supermassive black hole, and this produces optical UV light. The gas is hot, high velocity, viscous. Heat shines brightly. There are gas clouds outside being ionized, and we see emission lines coming from them. And we think we have this structure called a torus. There are two types of seyfert: I and II. Seyfert I looks like a little quasar, you can see galaxy around it, it produces emission lines. Imagine trying to look through the dense dust torus, though, it would be like looking through something opaque. Try to look through the side and you can’t see the disk, but you can still see jets and ionized radiation. You might see emisison lines, but they’d be narrow. The gas is moving at 10,000km/s around the black hole.

Radio galaxies are Seyfert II, we see jets and the galaxy.

But if we look down the “hole” of the “donut” we get to see quasar light.

We don’t know how these supermassive black holes are made and grown. We know they grow when they shine as quasars, but before they can shine as quasars they have to build up to 100mil or 1bil solar masses. How that happens we don’t know but these things already exist in the early universe.

Quasars are the most luminous types.

Captive nuclei in elliptical galaxies with even more powerful central sources than Seyfert galaxies. Also show strong variability over time scales of a few months. Also show very strong broad emission lines in their spectra.

Kelly: Quasars are in the center of the galaxy just like the black hole is?

Mike: Quasars are kinds of black holes.

The spectral lines of quasars show a large redshit. They’re very distant and indicate they’re from early in the universe. They seem to be a phenomenon from early in the universe.

Quasars have been detected at the highest redshifts.

Quasars are the most luminous, non-exploding objects in the universe. They’re visible across the whole universe. They reveal the large structure of the universe and help us look back to the early history of the universe. They show us things about galaxy evoltuion and dark matter. And observing quasars at high redshifts lets us look back many billions of years to when the universe was only a few billion years old.

Gravitational lensing– we’ll look up and see two quasars in the sky, exactly the same. That’s because there will be a galaxy in front of the quasar, with the quasar almost directly behind, so the light from the quasar passes in two directions, meaning that we see the same quasar twice. There are dozens of these kinds of situations now. We can see quasars quadrupled or quintupled. If you get the geometry lined up perfectly, gravitational lensing can cause you to see the same object in a ring.

Einstein proposed in the 30s that we might see lensed objects in the future, because relativity predicted it. People thought that was ridiculous, but a few decades later, we saw it.

We often see quasars in colliding or merging galaxies. There therefore seems to need to be a trigger to make the supermassive black holes in the centers of galaxies turn on and become active galactic nuclei.

As Mike prepares to move on to cosmology, he reminds us to check out his online resources.

Mike’s quasar research:

He shows us hubble space images of quasars. Many of these have companion galaxies, show evidence of recent collisions (such as tidal tails), or are currently colliding. A video about it.

Back to Hubble’s law and the cosmological implications. We interpret Hubble’s law as an expansion of space. Over time, space itself expands, and carries the galaxies further apart. (The galaxies themselves are not expanding.) The galaxies next to you move away from you some, but the galaxies further move away faster. Space itself increases.

Dave: At what speed?

Mike: We usually characterize the expansion in terms of Hubble’s constant, or H./H. I can go into more detail, but it’s not the most straightforward thing. We use a concept of comoving distance, comoving volume. We concentrate on a region and can imagine it moving forward or backward.

We can take any galaxy and measure the same hubble’s law.

We can do a simple estimate if we assume the rate of universal expansion has been steady over time. For instance, if we run everything backward, assuming that we use today’s hubble’s constant, how long would it be before everything was occupying the same space? We can see objects 13 billion light years away (not well); the universe was only about a billion years old when the light left that galaxy.

Looking back toward the early universe: the more distant the objects we observe, the further back into the past of the universe we’re looking.

The observable universe — We can see in a sphere around us, in any direction, light coming to us from any object that’s emitting light and that’s had enough time for that light to reach us. We can see about 14 billion years.

When you go back far enough, the universe was very compressed, and very dense, and very hot. And at some point, we see light coming to us from the microwave background radiation.

At some point, in the history of the universe, conditions everywhere were similar to conditions on the surface of a star. It doesn’t look like that when we look up.

It turns out when you redshift a black body, it’s still a black body, but much smaller. We see that in all directions. So nearby we see galaxies; further away we see forming galaxies; past that, there’s a void where we see little; we keep going to higher redshifts and we see background microwave radiation. This was predicted before it was seen.

The cosmic background radiation–the radiation from the very early phase of the universe should be detectable today, and is. It was discovered in the mid-1960s as the cosmic microwave background radiation. It is the most perfect black body known to science.

When you first look at the microwave radiation, what you see is the galaxy. Dust, cool dust in our galaxy emits at the same … as the background radiation. Filter that out. Then there’s the dipole, which is the blue and red shift caused by our galaxy’s movement, and you see that effect in the background radiation, so you have to remove it. Then you’re left with an image of a 2.73 kelvin black body that’s got these little tiny deviations, about 1 part in 100,000, that are a little hotter or a little colder. You have to up your contrast to see that. There are a lot of steps to go through before you can discover the temperature fluctuations in the background radiation.

We’ve been looking really hard to find these fluctuations because it’s these hot and cold patches that correspond to the clusters and voids of galaxies that exist today. These small fluctuations represent not just temperature but density. All the gas is distributed very uniformly, except for these tiny deviations. Those deviations grow. The dense bits get denser, the less dense bits become voids. So cosmologists explain how these deviations evolved to become the large scale structure of the universe we see today.

Temperature correlates with density; time correlates with redshift.

Today the universe is about 14bil years old. If we chart temperature/density and time/redshift from one second to 14bil, then we see the temperature moving from 10bil degrees kelvin down to about 2 degrees kelvin. On this logarithmic plot, we can only see a small portion. Most of the dramatic shift of the line characterizes the early universe. The energy of radiation has changed, with the wavelengths increasing as the universe expands, and the energy decreasing. The conditions back in the first few minutes of the universe were similar to that in the cores of stars. We believe we only had hydrogen to start with–protons, electrons, and free neutrons, some of which were able to fuse in the first few minutes into helium. Also some other elements we find in star cores.

And then things cool. This happens before heavier elements like nitrogen and carbon can form.

Bud: Where did the light emerge?

Mike: The very beginning.

The universe is expanding and cooling until at some point you get protons, neutrons, and electrons that are forming without immediate collisions that transform them back into energy. Then you have time to make helium, but before you can make anything heavier, things have expanded too much.

There’s a point at which we go from being dominated by radiation to being dominated by matter, and we get recombination. Recombination is when the universe goes from being ionized to neutral (hydrogen and helium atoms where the electrons combine with ions to form neutrals). When this happens, the radiation decouples from the ions. Before that, the universe is opaque because the radiation is thermally linked to the matter. When we go neutral, and have hydrogen and helium ions, the gas becomes transparent, and there’s no longer thermal equilibrium. The gas becomes transparent. That’s when the background radiation comes to us from. That’s when the photons can fly across the whole universe, and be picked up as background radiation, or as static snow on TV.

Ian: Did the universe become transparent immediately?

Mike: No. It took tens of thousands of years.

There’s some reason why we have an excess of matter versus antimatter today, but this is a recent paper and Mike doesn’t remember. There was an excess initially on the order of one part per billion, and that’s where we are today.

Bud: I understand that the universe became transparent, but at that point there’s still no stuff. Why is there no stuff?

Mike: We think the first stars started forming in the first few hundred million years, but we don’t have observational evidence. We see galaxies from when the universe was less than a billion years old, some of the oldest galaxies.

Mike: It turns out that making the models without the metals is much harder than without the metals. It has to do with the fact that the opacities that govern energy transport in stars are strongly affected ins tars today by the presence of trace metals. Take those away and all the numbers change dramatically and it’s hard to understand how the processes work.

Bud: So we don’t understand how the first objects started to form?

Mike: No, it’s an active area of research. We don’t know, for instance, where these supermassive black holes come from and how they got so large. We see black holes from when the universe was less than a billion yrs old and we don’t understand how you can get that many solar masses so fast.

Mike: In the first few minutes, we get elements, but there are some gaps that make it hard for fusion to proceed. This is one of the strengths of the big bang theory which is what I’m describing-with general relativity, you run the model forward, and you get certain ratios of elements, and these predictions agree with what we observe. The big bang at its essence is correct observationally. There are details, especially in early areas of the big bang, that are active research and not understood. But if you define the big bang more generally, then from an observational point of view, the theory is unassailable. Details are still in question.

This big bang synthesis creates a baryonic mass (not dark matter) creates 25% helium, 75% hydrogen.

So we have this radiation dominated era following that which goes on for a few thousand years where we have conditions like the interiors of stars. The universe is hot. It ranges from millions to tens of thousands of degrees. It takes time to cool. It’s in thermal equilibrium.

Then we get to this redshift of about a thousand where we get recombination. Ions and free electrons make it difficult for photons to travel far before being scattered, like being inside a cloud. Even at relatively low densities, it’s still hard for optical light to travel through that. When things go neutral, suddenly it’s a lot easier. Photons can travel more or less freely through space. The universe becomes transparent. The light from this era can travel all the way across fourteen billion years of space.

Bud: So the universe was 14 bil light years across at that point?

Mike: No, it traveled 14 bil light years to get to us today. The size of the universe is complicated. Our current cosmological understanding points to a model of the universe in which the universe is infinite, which means it was always infinite when it was first born.

Ian: Even though it’s expanding?

Mike: Space gets bigger. Density was infinite at the beginning. Space wasn’t. But if the universe is infinite, it always was, and that’s what our theories indicate. Our observable universe is finite, but we know the universe expands past that; we don’t know whether it’s a lot past that or if it’s infinite.

A lot of times you’re better off thinking about density. What is the universe like in this region of space? How has that expanded over time? You’re safer talking about that rather than the universe which has an infinite space.

Bud: So basically this shell of microwave radiation is expanding outward into infinite space.

Mike: No.

Bud: But you said the universe was infinite.

Ian: Are you saying space is a chunk within the universe?

Mike: No, the universe is all space. The observable space is a chunk inside the space of the universe.

Ian: Okay…

Mike: My understanding of this is more complicated than yours, but there are probably ways in which I have trouble, too.

Ian: It would be easier if it were a closed universe.

Mike: It would, but it doesn’t appear to be.

Kelly: So how fast is the universe expanding?

Mike: It depends on variables like whether we’re dominated by radiation.

Kelly: What about right now?

Mike: We can’t say. We discovered this thing called dark energy, and we don’t know how it expands over time. I can give you two models, but we don’t know which is more likely.

Recombination–at 400,000 years, our universe goes neutral, becomes transparent, photons can fly freely toward us, but between the epoch of recombination when the temperature was 3000K and now, the universe expands by a factor of 1000. So our 3000K black body looks like a 3K black body.

We can’t see with EM any further back because the universe is opaque. In theory if we had neutrinos, we could look back until even earlier when the universe was opaque to neutrinos. So if you want to work on far future with astronomers, they could be working on the neutrino background.

Me: So going back to the one second level is theoretical projection, not observation?

Mike: More or less, though we have observational tests, like seeing how the elements are what we predict. We think we know what happened in the first few minutes. We have observational evidence at 400,000 years.

It turns out the intergalactic medium today is ionized, not neutral. At recombination, it went neutral. Today it’s ionized. So there must be an epoch of reionization. About ten years ago we started discovering objects with redshifts of six and seeing signs of reionization. The first stars form less than a billion years ago, and they reionize the gas.

Even though the universe is ionized now, the photons can still travel unimpeded because the density is so low compared to the last time they were ionized that the universe is no longer opaque.

We need to use general relativity to explain the relationship between stuff in the universe and space. We have to make assumptions that are probably wrong if you look at them in detail. We have evidence they’re wrong. But they seem to be lcose enough to correct that they work together as a predictive model.

One assumption–homogeneity: on the largest scales, the local universe has the same physical properties throughout the universe. Every region has the same physical properties (mass density, expansion rate ,visible vs. dark matter, etc.) It’s like a sponge. If you look at the large view of a sponge, it looks similar, but if you look on the local level, you see it’s not uniform.

Isotropy: On the largest scales, the local universe looks the same in any direction one observes .You should see the same large scale structure in any direction .We have evidence that there are preferred axes, but we don’t know why.

Universality: The laws of physics are the same everywhere in the universe. That may not be true. Observation based on quasars indicates that the speed of light may have changed. There are other versions of the big bang that include things like varying the speed of light. Some of these constants may not be. People are trying to think of experiments to test those assumptions.

Ian: The physical laws may have changed over time, but at any given time, are they the same?

Mike: Maybe. We don’t have any evidence that’s not true.

Shape and geometry of the universe: back to our 2-dimensional reality: how can a 2-D creature investigate the geometry of the sphere? You have to measure the curvature of space. In principle we may have space with a closed surface and positive surface .Or it could have an open surface with negative curvature. Closed surface would be finite space with no edge. Or it could be a flat surface with no curvature.

We have to test the curvature of space to discover what kind of universe we live in.

People experiment like this, not using 2-D shapes, but they try to calibrate things like the radio jets from quasars, and think if they can calibrate cosmic rods and see how their lengths change over different distances, maybe we can discover which of these three options are the case?

But it’s hard to calibrate what the intrinsic size of a cosmic rod is.

Cecilia: If you don’t think of the limit of the universe as an edge… it’s just not an edge… I don’t have a word for what it would be then, but then the universe would be infinite even when it was small because it would be the same inside, but a different density, a different age.

Nick: Like in an egg.

Cecilia: But not in an egg. There’s no shell. The shell is a limit, but not an edge.

Kelly: That’s a good word. Limit> We think of limit as being the same as edge but it’s not.

Ian: The limit is how far you can run in the time available, but there may not be a wlal when you fniish.

Mike: The observable universe gets a little bigger as light comes from slightly further away.

Cecilia: But even if we had a neutrino detector and could see back to the densest…

Mike: We’d still see more of it.

Cecilia: It would be the same thing even if it were a different size.

Mike: Maybe.

Cecilia: It would still be infinite.

Mike: Yes. I like to talk about densities. The volume can stay the same and the density can change. There can be a denser or more rarefied infinity.

Ian: That background temperature is decreasing or staying the same?

Mike: Decreasing.

Einstein’s zombie, breaking into class:Space-time tells matter how to move; matter tells space-time how to curve.

Carrie: Time exists so everything doesn’t happen at once, and space exists so it doesn’t all happen to you.

Deceleration of the universe: for a long time we thought the universe stars off expanding, but gravity, we know there’s stuff in the universe, and there’s gravity associated with that. The gravity should slow the expansion, like breaks on the expansion. So we talked about the universe decelerating by virtue of gravity and the stuff in it. And this was thought to be critical because we thought the universe was initially expanding (like the balance between potential and kinetic energy; throw a ball up and it will come down; throw it with more energy and the gravity will pull it down; there’s a certain point where if you throw it with more energy, gravity will slow it to zero and hold it at infinity; but in each case, the gravity slows it) and the gravity would slow it down.

There’s a critical density where the universe will expand to infinity and stay at infinity.

So for a long time we wanted to measure the density to figure out whether it would continue to expand, or start contracting sometime. We thought the stuff int he universe should be decelerating it.

These models were important because they told us how to modify the hubble constant. In the no gravity model (universe keeps on expanding at the same rate), it would be 14billion years old. In the other two models (collapsing universes or flat universes where the universe expands but not as fast), the universe would be younger.

But the universe is trickier. We have gravity, but we also have other things.

One thing we have is dark matter.

We know that we have about 4% of the critical density to keep expanding from baryons. But we also know there’s about 6-7 times as much unknown dark matter as there is unknown dark matter. Put all this together and you get about 30% of the critical density. In that case, we should be in an open universe, with an expansion rate slowing, but not very much.

So we have to estimate the total amount of matter, including the dark matter. We estimate the mass of dark matter by means like thinking about gravitational lensing.

So this big bang model tells us what the early abundances of light metals should be, and puts a tight limit on what the density of baryon matter can be today, and was at the beginning of the universe. This is why we’ve spent a lot of time and effort trying to figure out the abundances of rare elements like lithium and deuterium; they’re not very abundant, but they tell us a lot about the conditions in the early universe where they were formed.

The nature of dark matter: can dark matter be composed of normal matter? if so then it’s mass would come mostly from protons and neutrons (baryons). The density of baryons right after the big bang leaves a unique imprint in the abundances of deuterium and lithium. The density of baryonic matter can only be about four percent of critical density.

We know that we have about 30% of the critical density in total, and that baryonic matter is only 4%, so therefore we know that most of the stuff out there is dark matter.

(Skipping over MACHOs, which are probably white dwarfs, possibly black holes, but basically we look at the vanishing line of clouds over time and occasionally we see a gravitational lensing event where a star gets 40 or 50 times brighter for a few days and can estimate how many dark things are floating… it’s not enough to make up for all the dark matter.)

(Notes on silly astronomical acronyms like MACHO or WIMP or FIRST.)

Problems with the classical decelerating universe:

1) The flatness problem. The universe seems to be nearly flat. It doesn’t look open. Even a tiny deviation from perfect flatness at the time to the big bang should have been amplified to a huge deviation today.

2) The isotropy of the cosmic background. Why is the microwave radiation the same when you look in different directions? Normally if you want to have things at the same temperature they need to be in thermal equilibrium, but if you do the calculations you find out that the part of the universe we see in the background radiation was not in communication with all the other parts we can see, making it confusing that they could be in thermal equilibrium.

21st century cosmology–the solution: inflation! Inflation is a period of sudden expansion during the very early evolution of the universe, about 10^25 seconds, at a very high temperature, and when that happened there was a time period when neither radiation or matter dominated, but some aspect of the field associated with the splitting of the forces dominated, and in this tiny fraction of a second, the universe expanded by 60 orders of magnitude. So the universe might not be exactly flat, but if it had expanded that fast, it would look flat because the curvature is so small. Start with a very small region of space in thermal equilibrium and blow it up exponentially (faster than the speed of light, without violating relativity because space itself is expanding), it would give us what we see. This is not settled. It seems to work, but there could be alternate solutions.

Inflation is part of the big bang theory that could change in the next decade or our lifetimes, whereas the other parts of the big bang seem very solid and well-tested. Inflation explains some strange properties of the universe, but could change.

Measuring the deceleration of the universe… we talked about standard candles before, like cepheid variables. We can see them far away, but not halfway across the universe. Type Ia supernova, however, we can see halfway across the universe. (Galaxies have about one supernova per century, and the supernovas are visible for about a year, so you can see these pretty easily.) So they looked at the standard candle supernovas according to redshift.

What fits the data we gather from the supernova redshifts is a universe with flat geometry and an accelerating expansion.

People are trying to think of other ways of explaining this.

One explanation could be cosmic dust obscuring the supernovas, but that was disproved.

Another team looked for supernovas again, and found the same results–expansion accelerates today, not slows. Why? And why is the universe flat? Why are we close to criticial density?

One solution that seems consistent with the data is the cosmological constant. The constant refers to a source of energy density through out space. Energy and mass are interchangeable in terms of relativity. So we think dark matter is about 30% of critical density; this constant give us the other 70%. It doesn’t act like gravity to decelerate. It acts to push us apart. This is dark energy.

People like to associate this with the energy from quantum foam, but when they try to make that come out the cosmological constant, it’s way off.

So we don’t understand something. And we don’t understand it a lot.

We don’t know if the dark energy is really a constant. If it is really a constant than we can predict from our current models that initially there was a period of radical acceleration, then a period of deceleration where gravity slowed things, and now we’re in a period where the constant is stronger than gravity again (because the objects are no longer close enough together to make gravity strong enough to overpower the constant), and this gives us exponential expansion. If we have constant dark energy, the universe will evolve so that what happens over time is that parts of the universe that were in causal contact will be disconnected. Our galaxy will hang together, but the other galaxies will fade from sight and we will no longer be causally connected to them, and the light from those galaxies will never reach us.

The other possibility is called a big rip universe in which the dark energy increases in power in the future (and is not a constant) and in that case, it increases and increases and increases and atoms themselves are ripped apart.

Me: What’s the time scale to galactic or atomic separation?

Mike: I’ll have to check it out.

Large-scale structure: we see correlations between the fluctuations in the microwave background, and the kinds of large-scale structure we see today. Our projections from the microwave background don’t produce exactly the universe we see today, but they produce a similar universe with similar clustering and similar properties.

A large survey of distant galaxies shows the largest structures in the universe: filaments, walls of galaxy super-clusters, and voids, basically empty space.

Modern cosmology, the name of the game these days is primarily understanding what we can learn from the microwave background fluctuations. This is not a super-complicated topic, but it’s not conceptually simple either. These fluctuations have to do with acoustic waves, sound waves traveling early through the universe, and which ones get locked in so we can see. Analyzing the pattern of acoustic waves will give you the hubble constant, as well as lots of other important information. We can see structure in the cosmic background pattern. (Here’s the pattern. Thanks, Dave Williams!)

Here’s another way of looking at the microwave background fluctuations. It’s called a power transform. If we talk about looking for fluctuations in different angular sizes, basically if you took a caliper with a separation of one degree and put it down everywhere in that image, you’d be measuring how often you got the same temperature and how often you got a different temperature. We check our data against the model predicted by the flat universe, and they look very similar.

This is cutting edge cosmology, analysis at this level. It’s getting more abstract and harder for the public to follow. (Mike says it’s getting harder for him to follow, too, at the intermediate and advanced levels.)

(Mike says he needs to understand cosmology so he can turn the redshifts of his quasars into real distances.)

Cosmology great web resource–www.astro.ucla.edu/~wright/cosmolog.htm

Contains a cosmological calculator, a tutorial, and an FAQ list.

Also Wayne, with a webpage at background.uchicago.edu/~whu

The angular size of these fluctuations lets us probe the geometry of space-time.

DARK MATTER

Fritz Zwicky discovered dark matter. He invented the term spherical bastard, because any way you look at ‘im, he’s a bastard.

In 1933, he realized that there should be something called dark matter holding structures together since otherwise they would fly apart.

We call him the father of dark matter, but Vera Rubin is called the mother of dark matter. A few decades after Zwicky, she started to notice flat rotation curves in spiral galaxies, noting the shape only worked if you thought about dark matter.

WIMPs are weakly interacting massive particles, such as neutrinos, which have mass but are too small to account for dark matter mass.

Are we sure dark matter is real? Or could we just have gotten gravity wrong on large scales? We are sure, and the smoking gun for the reality of dark matter is the bullet cluster. The bullet cluster is two galaxy clusters interacting, one moving through another. The reason this is important is we can get the total matter of these two galaxies, and also figure out how matter is distributed between the two galaxies .We know dark matter is not strongly interacting, so we know that two clouds of dark matter will pass without interacting. However, most galactic mass is in hot gas, and the two big clouds of hot gas will slow down as they pass through each other. So in principle this kind of cluster collision ought to separate the dark matter and baryonic matter, highlighted by the hot gas. That is a natural prediction based on dark matter. And what the image shows is the red light highlights the gas that dominates the mass of the clusters. The blue light is a model of where the dark matter is based on the gravitational lensing. So the center of mass of this cluster is in the blue, and the baryonic matter is between the blue and red. They’ve been separated.

There have been since then other interacting galaxy clusters that show the same thing. This is unlikely to be gravity being wrong on large scales. This is explained by dark matter theories.

We watched a youtube video simulating the bullet galaxy clusters collision, and then a 4 minute excerpt from Nova. I think this is the NOVA video. I think this is the simulation of the collisions, but I can’t get it to play on my computer, so good luck.

So! This is my last post on the lectures. We’re headed to WIRO (telescope the size of hubble) tonight since we weren’t able to last week. I’ll write a wrap-up in the next couple of days.

It’s been fun!