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Visiting Leiden, reading Richard Powers' "The Echo Maker"

Visiting Leiden, reading Richard Powers' "The Echo Maker"

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Past:

I am on the train, speeding across the damp level ground of Holland, returning south to Paris. The sky is grey, mist hangs on the few open fields that are visible from the train tracks. This part of Europe is densely populated, cities merge one into the other, a continuum of factories and roads and canals and houses.

This morning in my hotel room in Leiden I finished Richard Powers’ latest book, “The Echo Maker”. There was more than one resonance in this; Powers had spent time himself in Holland many years previously and this cold flat part of Northern Europe features in more than one of his books. And the “Echo Maker” situates itself on the plains of Nebraska.

Present:

In Paris: Here is the review of Powers’ book I wrote during this trip, the text which follows after those two paragraphs.

My trip to Leiden was otherwise uneventful, just a handful of days at the start of March. Walking from the University to my hotel through unpredictable sudden showers of rain and hail. In the distance rolling raincloud after rolling raincloud coming in from the ocean only a short distance away. Cold, damp air, fields around sodden with water. In the streets and on the buses I found people to be unfailingly friendly and helpful, all of them speaking perfect English. I was confused: this air and weather told me that I must be in some gloomy corner of a certain set of northern Islands. And at mid-day, almost nothing to eat in the University canteen: my years in France and Italy have made me an unhappy traveler at times. In the canteen, I endlessly slid my tray from the beginning to the end of the line in a desperate and fruitless search for sustenance: instead, I found five different kinds of sandwiches, soup, milk. How could one have such a large canteen with no warm food? The question remains unanswered.

On the preparation of espresso … (part 2)

On the preparation of espresso … (part 2)

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Of course to prepare espresso you need an espresso machine. Bizarrely enough these are not so easy to find in Paris! If you go to Darty or Galleries Lafayete you will certainly find a bewildering variety of coffee machines, but in fact all of them should be avoided. There is also the fashion these days for espresso machines with disposable capsules, made in a variety of interesting shapes, but these only make espresso like you would find in a bar – in Paris. Not what I wanted. You can also decide to spend thousands of euros and buy something which has more transistors than the IAP computer room, but I didn’t want that either. What I really wanted was a Gaggia, one of the oldest brands of Italian espresso machine. In fact, it was mister Achile Gaggia who invented the electric pump-driven espresso machine back in the 1940s (I would really have loved to have seen his laboratory! Did everyone spend all day tasting espresso?). Their most popular espresso machine model, the Gaggia Classic, has been in production for decades. Finding such a coffee machine proved to be impossible in Paris and in the end I bought it from these folks, along with a grinder.

That was around two years ago now. Since then I’ve been making around 10-15 espressos per day, in the morning and in the afternoon. My office has become somewhat of a mecca for coffee at the IAP. The ritual is always the same: the first thing that I do each morning when I arrive is I turn on the espresso machine, and heat the filter holder. This takes around ten to fifteen minutes (the gaggia has a super-powerful 1200W element). Then I grind the coffee. Then I heat the cups with hot water. Then I tamp the espresso down in the now toasty-hot filter holder. I empty the cups. Then I push the button! This is what happens! (The coffee images are courtesy of mr. J. Seagull):

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Look at that lovely crema! It takes about fifteen or twenty seconds to make two excellent espressos. That’s a cup from one of my favourite coffee brands, from Bologna, Caffe 14 Luglio. (The coffee I am using here is Caffe Trobetta, from Rome).

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Here’s what the crema looks like (mmmm):

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And here are some satisfied coffee-drinkers:

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Until the next espresso!

On the preparation of espresso… (part 1)

On the preparation of espresso… (part 1)

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When I arrived in Marseille almost a decade ago now (cripes) I came to a somewhat startling realisation: my path through life seemed to be leading inexorably towards better and better coffee. Now the coffee — espresso — in Marseille is nothing special, but it is infinitely better than what was available in England. And only two years after that, I found myself in Bologna, Italy, and once you have lived in Italy your appreciation of espresso and coffee is changed for life, irrevocably.

I admit to having erred for many years, to having prepared coffee by many different methods. In Canada, I amused myself making large drinks composed primarily of frothy milk with a minute quantity of espresso, prepared in a cheap steam-powered espresso machine. The kind that after only a few months starts to leak dangerously. This kind of beverage is very much the tradition in the pacific north-west, and it was only later I realised that the gallons of milk were necessary to hide the terrible burnt taste of the espresso they have over there (try drinking just the espresso and you will see). That was the beginning of my habit of preparing coffee at work. In Durham, England, I fought a losing battle with overzealous health and safety officials, who cut off the power cable for my coffee machine whilst I was away observing in Hawaii. They were also worried that my office would become infested by coffee-drinking mice, attracted by the coffee grains. So I switched to what they call in England a “french press” or a “bodum”. A fine way making strong coffee, but it’s not espresso. In Marseille, I found out about the ‘moka’, the Italian coffee-making hand-grenade, and I installed a hot-plate in my office and it became my preferred way of making coffee until I bought a slightly more expensive coffee machine, a krups nova. Then I moved to Bologna.

At which point all coffee preparation stopped. I found that even coffee which came from the departmental coffee machine produced superior espresso to my krups, something which I very soon realised actually made very bad espresso. It amazed me, wandering around Bologna and Italy how good the espresso actually was in almost every bar you went to. On the internet one can find long and painful stories of uber-geeks striving to make the perfect espresso, roasting grinds in their garden sheds, carrying out complicated electro-mechanical modifications to espresso machines costing perhaps thousands of dollars when….in Italy, you wander into a random bar lost in the outskirts of a nondescript town run by an elderly couple who haven’t changed the decor since 1970s and you find … they make perfect espresso.

But only in Italy. I was amazed, driving across to France in my old Ascona, that the minute you cross the border, the espresso quality immediately drops. You can go into an Autogrill / Autostop on either side of the border, and on one side, you will get Italian espresso, on the other side what passes for espresso here in France. That’s another the paradox, incidentally: in France, we have wonderful cafes, but the coffee is of mediocre quality. In Italy, no-one spends more than about fifteen seconds drinking their espressos. Their cafes are places to spend very little time in at all.

How is espresso different between France and Italy? It is kind of remarkable that this difference even exists, because if you go into any bar in Paris you will see that they have the same machines that one finds in a bar in Italy. But here in France the espresso is thin, watery, and bitter, with very little crema. The amount of espresso served too is a lot larger — I would say that it is about twice as large as you might find it standard Italian measure (I’m not talking about Naples, of course, because that is another extreme). The unfortunate difference seems to stem from a combination of inferior coffee beans and preparation, as far as I can tell. So, returning to France, to Paris, from my two years in Italy I knew that if I wanted real espresso I would have to prepare it myself…

Dark matter, dark energy, epicycles

Dark matter, dark energy, epicycles

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Two years of blog posts and not a single one about astrophysics! But today, once again, I was interviewed by a journalist who wanted to know about dark matter. Wouldn’t we all! Around a year ago the maps of dark matter made by my collaborators in the
COSMOS project made the front page of Nature and as I was a co-author on the paper I got quite a few questions from curious journalists. I have a particularly fond memory of the intensive questioning I was given by Raphael Hittier of E-tele on the roof of the IAP building in the middle of a particularly cold Paris winter with a Siberian wind blasting across the terrace whilst Raphael asked me: “Qu’est-ce-que la matiere noir”? Ahhh…brr….

What indeed? I remember being astonished whilst I was a postdoctoral student in Durham to find out about the current orthodoxy, the Cold Dark Matter model (CDM for the initiated). And to learn that people had spent millions of hours of computer time on the world’s fastest computers making model universes filled with a mysterious substance whose exact properties were known very well (it’s a cold, dark, collisionless fluid which doesn’t interact with ordinary matter) — but whose precise nature was and still is a complete mystery. Okay, so we know what this stuff does — but what is it, anyway?

People have speculated that dark matter exists since at least the 1930’s when Fritz Zwicky realised that the rotation curves of galaxies could only be explained if there was a lot of matter in those galaxies which was not luminous. And in recent years gravitational lensing has given us spooky cosmic x-ray vision showing us where exactly the mass is, thanks to the deflection of light near gravitational sources. So maybe this stuff is really there.

As a graduate student, under the shadow of the cathedral in Durham, the mystery deepened even further. A lunch-time talk, I think it was, that wonderful Anglo-Saxon tradition (no-one would ever countenance such a thing in Italy or France, can you imagine working whilst eating?), rustling brown paper bags, crisp packets, coca-cola, and a presentation with a graph showing distance to supernovae plotted against the speed they were moving away from us. The “Hubble diagram”, named after mr. Edwin Hubble, who presented some of the first observational evidence that the Universe was expanding (which some of the theorists of the time actually expected). Every Hubble diagram I’d seen until then had showed a neat, linear relation between distance and velocity; the universe, the fabric of space and time itself, was expanding, and as a consequence more distant objects were moving away more rapidly. Except that in this Hubble diagram, there was something not right: some of the most very distant supernovae were just off the simple linear relation. Their error bars grazed the arrow-straight line of constant slope. But only a few of them.

It was an error, right? There was some mistake with the observations? Nobody wanted to believe that those outliers were real. It would meant that not only the Universe was expanding but also- gasp – accelerating. The cosy preferred model of the Universe that theorists had built up (which admittedly was looking a bit frayed for other reasons) would have to be discarded, radically revised, and someone would have to explain what exactly was pushing distant objects faster and faster apart, almost like a negative gravity.

But the outliers were real, and the Universe really is accelerating. The universe it seems is filled with some kind of invisible, dark energy, the exact nature of which is still unknown. It is this, somehow, which is accelerating the expansion of the Universe. Most of the mega-projects planned for astronomy in the next ten or twenty years will be devoted to finding out more about dark matter and dark energy, projects like LSST or Pann-starrs, which will map thousands of square degrees of sky to incredibly faint limits, making the most detailed maps of the universe, and hopefully ruling out some of the wackier models of dark energy.

But you do wonder, don’t you? I think of Mr. Ptolemy and his planetary epicycles, a complicated model which was replaced by something simpler and more universal (newtonian gravitation). The current cosmological model works really well — add in dark matter, dark energy turn the handle, and you can reproduce incredibly well all of the current cosmological observations to exquisite precision (modeling the formation of galaxies is another story). But the fact that almost all of the Universe (70% dark energy, 25% dark matter) consists of material of which we know almost nothing is more than a little unsettling — there may well be a hidden truth lurking in there, waiting to be discovered. A sign change that changes everything? An extra ingredient added to the model that makes 70% of the Universe suddenly become something else? We will find out soon enough, I hope.

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