Archive for September, 2015

The Day of Daltonism

Posted in History with tags , on September 6, 2015 by telescoper

Having a quick look at Twitter this morning as I drank my coffee I discovered that it is the birthday of the English scientist John Dalton, who was born on 6th September 1766. Dalton is most famous in the United Kingdom for his work on chemistry and physics, but somewhat less so for his pioneering studies of colour blindness. I didn’t know until today, in fact, that the birthday of John Dalton, who was himself colour blind, is Colour Blindness Awareness Day so I thought I’d do a quick post to mark the occasion. You might also be interested in this guest post on the subject of colour and colour perception.

Here’s a test for some of the main types of colour blindness – can you read the numbers?

Colour_Blind

Colour blindness comes in different forms and affects a significant fraction of the population, with a much higher rate of occurrence in males (up to 1 in 10 in some groups) than in females (about 1 in 200). It also varies significantly across different populations, with particularly low rates for, e.g., Fijian males (0.8 %) and much higher frequencies among, e.g. Russian males (9.2%). I am not colour-blind myself, but I know several colleagues who are. In fact at the meeting I was at last week, when one speaker decided to show two different sets of results on a graph by plotting one in red and the other in green, there were howls from several in the audience who couldn’t tell them apart. It’s very easy to make careless mistakes like this in preparing lecture materials when it takes only a small effort to make them suitable for all. I urge colleagues who teach to remember that if they are 100 men in the audience the likelihood is that there will be around 8 to 10 who are colour blind.

Thinking about this makes you realise how many maps and other designs rely on full colour perception for their effect. I’ve previously celebrated the London Underground map as an excellent example of graphic design, but it must be a nightmare to a person who is colour blind!

tube_map

Last week I gave a short speech at the workshop to celebrate Sabino Matarrese’s 60th birthday, in the course of which I mentioned the late Francesco Lucchin, who first invited to Italy to work with the Padova group (of which Sabino was a member) back in the early 90s. Francesco and I ended up writing a book together and during the course of working on that he told me that he was “daltonic”. I later found out that this word does exist in English, but it is not in common usage as a word meaning “colour blind”. In fact the standard word in Italian for “colour blind” is “daltonico” and there are many other variants in other European languages, such as the French “daltonien”. It’s very curious that Dalton’s name is so strongly associated with colour blindness across the European continent but not in the country of his birth. I wonder why?

By the way, if I understand correctly, the English word “daltonic” refers to a specific form of red/green colour blindness called deuteranopia, whereas the foreign variants can refer to any form of colour blindness.

Anyway, must wrap it up there. I have to mark some resit examinations which, according to the instructions, should be done in red ink by the first marker and in green ink by the second marker…

From here to Astragalo

Posted in Biographical, History with tags , , , , on September 5, 2015 by telescoper

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:

image

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.

images

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).

your guide on how to celebrate World Beard Day on 5th September

Posted in Beards on September 5, 2015 by telescoper

I’m concentrating on (4) myself, at today’s University of Sussex Open Day..

kmflett's avatarKmflett's Blog

The Beard Liberation Front, the informal network of beard wearers, has produced a brief guide on how to celebrate World Beard Day on 5th September

1 do not shave and avoid all barbers shops

2 marinate your beard in imperial stout

3 at midday raise a glass and chant Jeremy Corbyn: beard power

4 celebrate pogonophilia by making sure your beard is seen in public places

5 if you do not have a beard wear a knitted organic version

Have fun, stuff pogonophobes

marx

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“Credit” needn’t mean “Authorship”

Posted in Science Politics, The Universe and Stuff with tags , , , on September 4, 2015 by telescoper

I’ve already posted about the absurdity of scientific papers with ridiculously long author lists but this issue has recently come alive again with the revelation that the compilers of the Times Higher World University Rankings decided to exclude such papers entirely from their analysis of citation statistics.

Large collaborations involving not only scientists but engineers, instrument builders, computer programmers and data analysts –  are the norm in some fields of science – especially (but not exclusively) experimental particle physics – so the arbitrary decision to omit such works from bibliometric analysis is not only idiotic but also potentially damaging to a number of disciplines. The “logic” behind this decision is that papers with “freakish” author lists might distort analyses of citation impact, even allowing – heaven forbid – small institutions with a strong involvement in world-leading studies such as those associated with the Large Hadron Collider to do well compared with larger institutions that are not involved in such collaborations.  If what you do doesn’t fit comfortably within a narrow and simplistic method of evaluating research, then it must be excluded even if it is the best in the world. A sensible person would realise that if the method doesn’t give proper credit then you need a better method, but the bean counters at the Times Higher have decided to give no credit at all to research conducted in this way. The consequences of putting the bibliometric cart in front of the scientific horse could be disastrous, as insitutions find their involvement in international collaborations dragging them down the league tables. I despair of the obsession with league tables because these rankings involve trying to shoehorn a huge amount of complicated information into a single figure of merit. This is not only pointless, but could also drive behaviours that are destructive to entire disciplines.

That said, there is no denying that particle physicists, cosmology and other disciplines that operate through large teams must share part of the blame. Those involved in these collaborations have achieved brilliant successes through the imagination and resourcefulness of the people involved. Where imagination has failed however is to carry on insisting that the only way to give credit to members of a consortium is by making them all authors of scientific papers. In the example I blogged about a few months ago this blinkered approach generated a paper with more than 5000 authors; of the 33 pages in the article, no fewer than 24 were taken up with the list of authors.

Papers just don’t have five thousand “authors”. I even suspect that only about 1% of these “authors” have even read the paper. That doesn’t mean that the other 99% didn’t do immensely valuable work. It does mean that pretending that they participated in writing the article that describes their work isn’t be the right way to acknowledge their contribution. How are young scientists supposed to carve out a reputation if their name is always buried in immensely long author lists? The very system that attempts to give them credit renders that credit worthless. Instead of looking at publication lists, appointment panels have to rely on reference letters instead and that means early career researchers have to rely on the power of patronage.

As science evolves it is extremely important that the methods for disseminating scientific results evolve too. The trouble is that they aren’t. We remain obsessed with archaic modes of publication, partly because of innate conservatism and partly because the lucrative publishing industry benefits from the status quo. The system is clearly broken, but the scientific community carries on regardless. When there are so many brilliant minds engaged in this sort of research, why are so few willing to challenge an orthodoxy that has long outlived its usefulness. Change is needed, not to make life simpler for the compilers of league tables, but for the sake of science itself.

I’m not sure what is to be done, but it’s an urgent problem which looks set to develop very rapidly into an emergency. One idea appears in a paper on the arXiv with the abstract:

Science and engineering research increasingly relies on activities that facilitate research but are not currently rewarded or recognized, such as: data sharing; developing common data resources, software and methodologies; and annotating data and publications. To promote and advance these activities, we must develop mechanisms for assigning credit, facilitate the appropriate attribution of research outcomes, devise incentives for activities that facilitate research, and allocate funds to maximize return on investment. In this article, we focus on addressing the issue of assigning credit for both direct and indirect contributions, specifically by using JSON-LD to implement a prototype transitive credit system.

I strongly recommend this piece. I don’t think it offers a complete solution, but certainly contains  many interesting ideas. For the situation to improve, however, we have to accept that there is a problem. As things stand, far too many senior scientists are in denial. This has to change.

 

 

The Best of Times

Posted in Literature, The Universe and Stuff with tags , , on September 3, 2015 by telescoper

Well, I made it to Pisa Airport in time to sample the Club Europe lounge, which offers free wifi access (as well as other luxuries).  It seems I have a bit of time before my flight so thought I’d do a quick post about this morning’s events. I had the honour to be asked, along with Rocky Kolb, to deliver the concluding remarks for the meeting I’ve been at since Monday. Rocky and I had a quick discussion yesterday about what we should do and we agreed that we shouldn’t try to do a conventional “summary” of the workshop, but instead try something different. In the end we turned to Charles Dickens for inspiration and based the closing remarks on the following text:

IT WAS the best of times, it was the worst of times, it was the age of wisdom, it was the age of foolishness, it was the epoch of belief, it was the epoch of incredulity, it was the season of Light, it was the season of Darkness, it was the spring of hope, it was the winter of despair, we had everything before us, we had nothing before us, we were all going direct to Heaven, we were all going direct the other way…

This is of course part of the famous opening paragraph of Book 1 of A Tale of Two Cities.

The idea was to use the text to discuss different perspectives on the state of the Universe, or at least of cosmology. For example, the fact that we now have huge amounts of cosmological data might lead you to view that this is the  “the best of times” for cosmology. On the other hand, this has made life much harder for theorists as everything is now so heavily constrained that it is much more difficult to generate viable alternative models than it was thirty years ago.  We also now have a standard cosmological model which some physicists believe in very strongly, whereas others are much more skeptical.  This the “epoch of belief” for some but the “epoch of incredulity” for others. Now that the field is dominated by large collaborations in which it is hard for younger researchers to establish themselves, is this a “winter of despair” or do the opportunities presented by the new era of cosmology offer a “spring of hope”.

I haven’t got time to summarize all the points that came up, but it was fun acting as a “feed” for Rocky who had a stream of amusing and insightful comments. There aren’t any “right” or “wrong” answers of course, but it seemed to be an interesting way to get people thinking about where on the “best of times/worst of times” axis they would position themselves.

My own opinion is that cosmology has changed since I started (thirty years ago) and the challenges by the current generation are different from, and in many ways tougher than, those faced by my generation, who were lucky to have been able to learn quite a lot using relatively simple ideas and techniques. Now most of the “easy” stuff has been done, but solving difficult puzzles is immensely rewarding not only for the scientific insights the answers reveal, but also for their own sake. The time to despair about a field is not when it gets tough, but when it stops being fun. I’m glad to say we’re a long way from that situation in cosmology.

 

Last Day Blues

Posted in Biographical on September 3, 2015 by telescoper

Well, here I am. My last day in Castiglioncello. I’m all packed and ready. Just time for a quick post before I go down to breakfast overlooking the sea..

After breakfast I have to check out and then head up to the conference for the final session, concluding remarks, farewells and all that. Then I have to get back to Pisa for the flight home.

It’s been a fun meeting, but all too brief. I wouldn’t have minded staying here a lot longer, because that would have given me the chance to have a proper holiday before term starts, but now it’s just a week before our new students arrive and it will be back once more into the regular cycle of academic term.

Deep in Thought

Posted in Biographical, Talks and Reviews on September 2, 2015 by telescoper

It’s very hard work attending scientific meetings. A colleague snapped this picture of me deep in thought at a fascinating talk this afternoon. It only looks like I was asleep.

2015-09-02%252017.08.18

Adventures with the One-Point Distribution Function

Posted in Bad Statistics, Books, Talks and Reviews, Talks and Reviews, The Universe and Stuff with tags , , on September 1, 2015 by telescoper

As I promised a few people, here are the slides I used for my talk earlier today at the meeting I am attending. Actually I was given only 30 minutes and used up a lot of that time on two things that haven’t got much to do with the title. One was a quiz to identify the six famous astronomers (or physicists) who had made important contributions to statistics (Slide 2) and the other was on some issues that arose during the discussion session yesterday evening. I didn’t in the end talk much about the topic given in the title, which was about how, despite learning a huge amount about certain aspects of galaxy clustering, we are still far from a good understanding of the one-point distribution of density fluctuations. I guess I’ll get the chance to talk more about that in the near future!

P.S. I think the six famous faces should be easy to identify, so there are no prizes but please feel free to guess through the comments box!