Arrivato a Bologna

After after a journey consisting of train+bus+plane+bus I’ve made it to my destination. I’m here in Bologna for a few days, giving a couple of talks and hopefully having some useful discussions. They’ve booked me into the Hotel Paradise shown above. The title may be a little overstated but it’s a nice friendly little place right in the centre of the city.

Tomorrow I shall be visiting the Osservatorio Astronomico di Bologna, which is part of the Istituto Nazionale de Astrofisica. I’ve been to Bologna before, but the astronomers have moved to a new building which is further out of town than the old one, so it will be a bit of an adventure trying to find it. No doubt I’ll demonstrate yet again my ability to get on the wrong bus…

Anyway, that’s all for now. It is necessary for me to eat a pizza. I hope to have the chance to take a few pictures while I’m here, but that can wait!

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From here to Astragalo

Now that I’m back to the relatively autumnal setting of Brighton, I can’t help reflecting on last week’s meeting. On Monday evening I attended a cocktail party in a very pleasant bar in Castiglioncello overlooking the sea. Sunset views are something of a speciality from this location:

Anyway, the name of the place we were in was Astragalo. I checked and, as I suspected, this the Italian word for astragalus, which has an approximately tetrahedral shape. Astragalus is also a kind of plant, which is perhaps more likely to be associated with the name of a seaside bar, but that spoils the connection I wish to make with probability theory, a topic that came up regularly during the conference I was attending, so I’ll ignore it.

Nowadays gambling is generally looked down on as something shady and disreputable, not to be discussed in polite company, or even to be banned altogether. However, the formulation of the basic laws of probability was almost exclusively inspired by their potential application to games of chance. Once established, these laws found a much wide range of applications in scientific contexts, including my own field of astronomy. The astragalus provides a very early example.

Gambling in various forms has been around for millennia. Sumerian and Assyrian archaeological sites are littered with examples the astragalus (or talus bone). This is found just above the heel and its roughly tetrahedral shape (in sheep and deer at any rate) is such that when it is tossed in the air it can land in any one of four possible orientations; it’s fairly similar in fact to the four-sided dice used in some role-playing games. The astragalus can be used to generate “random” outcomes and is in many ways the forerunner of modern six-sided dice. The astragalus is known to have been used for gambling games as early as 3600 BC.

Unlike modern dice, which began to appear around 2000BC, the astragalus is not quite symmetrical, giving a different probability of it landing in each orientation. It is not thought that there was a mathematical understanding of how to calculate odds in games involving this object or its more symmetrical successors (right).

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Planck 2014: The Results That Weren’t….

A big conference started today in Ferrara, Italy, which my duties here at the University of Sussex unfortunately did not allow me to attend. The purpose of the meeting was to announce the latest science results and data products from the Planck mission. There was quite a lot of excitement in advance of today’s session as there was supposed to be a press conference at which some exciting results would be announced. Although I’m in Sussex rather than Italy, I have been doing my best to keep up with some of the goings-on via Twitter.

From what I have gathered, it has so far been a bit of an anti-climax. For a start, it was announced some time ago that the full data sets would not be released during this meeting after all, with the effect the conference would just give a preview of the final Planck results. Here’s an explanation from the Planck website:

– The data products and scientific results will be presented at a public conference in Ferrara.

– It is planned to release full mission data products and scientific papers to the public before the end of 2014. A few of the derived products will need a little more time to be readied for release, but will be made public within the month of January 2015.

So the results were to be “presented”, but not “released”. Hmm..

The press conference scheduled for this morning didn’t actually happen either, so we had to wait for the science sessions for juicy information. Not being there in person I had to pick up what I could from Twitter, which included only a few images with accompanying text (only in French).

Here, for example are the main power-spectra for temperature (TT), E-mode polarization (EE) and the cross-spectrum between the two (TE), together with a picture of the temperature pattern across the sky:

Lovely results of course – look how accurately the data fit the theoretical model curves – but notice that both the TE and EE spectra are cut off at low l. That’s because the polarization signal on large angular scales is so heavily affected by systematics that measurements for l<30 are unreliable. It’s not clear when, if ever, those systematic issues will be resolved. There’s no measurement of the primordial B-mode spectrum to compare with BICEP2, either, although there is a strong detection of a B-mode lensing signal obtained by cross-correlating Planck data with galaxy maps.

Still, that doesn’t mean that there is no polarization data at all. There is for example, this rather beautiful visualization of the polarized emission at 353 GHz, together with the Galactic magnetic field, shown over a thirty-degree square region of the sky:

The science results that I’ve been able to glean from social media largely amount to minor corrections to last year’s results, with only small changes (less than ~1σ)  to the cosmological parameters derived from them. Good science, of course, but nothing to get too worked up about. What with the “now you see it, now you don’t” press conference, the decision not to release the data, and the polarization data  still being in a mess, I can’t help feeling distinctly underwhelmed by the whole thing. This might be a bit harsh, but I think it’s been a bit of a farce…

Still, at least I’m no longer sad I couldn’t make the conference!

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Arrival in L’Aquila

If you were baffled by yesterday’s post then I hope today’s will explain. Yesterday, after an early morning meeting at the University of Sussex, I took the train to Gatwick Airport and thence a flight to Rome; hence volare. The British Airways Flight to Fiumicino Airport I was on arrived about 8 minutes ahead of schedule at 18.12, and I managed to get my luggage and clear passport control and all that in time to catch the 7pm coach to my present location, the city of L’Aquila, which is in the Abruzzo region, about 65 miles East of Rome. I’ve never made this trip before so I was a bit anxious about finding my way here and indeed it would have been a pain had I not caught the 7pm bus, because that would have meant either waiting for the next one (not until 9.30) or going by an alternative route involving a train and a different coach. As it happened, I needn’t have worried.

I’m here to attend a meeting entitled Multiple Messengers and Challenges in Astroparticle Physics, which is taking place at the Gran Sasso Science Institute. As well as the cosmology sessions, which are directly related to my own research, I’m hoping over the next ten days or so to take the opportunity to catch up on the  wider developments in astroparticle physics.

L’Aquila was badly damaged by an earthquake in 2009 and there was plenty of evidence of repair and reconstruction work still going on. I’ll take a few pictures here and there, but for the time being I’ll just share the view from my hotel window for the enjoyment of any readers back in rainy England…

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Via Beato Angelico

So here I am, then, in Milan(o). I’m just here for a short visit in order to participate in a PhD examination tomorrow at the Universita Degli Studi di Milano. I’m looking forward to it, actually, as I’ve never done such an examination in the Italian system before. It will also give me the chance to meet up with a couple of old friends I haven’t seen for a while before flying back to London tomorrow night.

I don’t know if I’ve mentioned this before on this blog but I was a fairly long-term resident in Milan some years ago. In fact I’ve just checked the dates and it was in 1994, i.e. twenty years ago. Time flies indeed. All those years ago I was here as a Professore a Contratto, which means I gave some lectures and did a small research project. The invitation for this came via Silvio Bonometto. I didn’t get paid a huge amount for this visit, but as part of the deal I did get use of an apartment organized by the University. It was on the Via Beato Angelico and this photograph, which I have just ripped off from my own facebook page, shows the view from the balcony:

It was a nice enough flat and in a good location just around the corner from the University. The one thing I remember well is that one of the main tram lines ran along the street below; their sound has stuck with me through the years, as they often woke me up very early in the morning. I think there was an ice cream place over the road too.

During my stay here I was accompanied by a friend, Anna, whom I invited to come when they told me I was going to have use of an apartment. Anna wanted to try to find a job in Italy so it seemed a great chance to spend three months or so looking around while I worked. The place was easily big enough for two and I was grateful for the company in the evenings. We had a lot of fun doing the tourist things, visiting night clubs, and the rest. Most people thought we were an item, I suppose, but we weren’t. Her long red hair gave her the nickname Anna Dai Cappelli Rossi, after the cartoon character. Here is a picture of Anna I took on the roof of the Duomo:

Anyway, when it was time for me to return to England, Anna stayed in Milan because she had found a job (and a man). She did return to England though and now lives in the Midlands in a place called Liverpool.

I’m mentioning all this because the hotel I’m now staying in, the Hotel Dieci, is just a short walk from that old place. I’ll probably have enough time in the morning to take a walk past and see if I can find it. I wonder how much the area around here has changed in the last twenty years? I’ll have time to find out tomorrow but for tonight I had better read the thesis again!

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