Archive for July, 2019

Interlude

Posted in Uncategorized on July 29, 2019 by telescoper

I have only a short window of opportunity to take a bit of holiday before the  Repeat examination period begins (after which I take over as Head of Department)  so I’ve decided to take a week off starting tomorrow morning. I don’t think I’ll be blogging while I am away, so there will now follow a short intermission. Normal service will be resumed as soon as I’m back

 

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News of the Views

Posted in Uncategorized on July 28, 2019 by telescoper

Just a quick post to mention that at some point in the early hours of Saturday morning the total number of views of this blog exceeded four million.

I have no idea whether that’s a lot or not for a blog , but I am vastly tickled by the level of interest, which has been fairly steady for about a decade now.

Thanks to everyone for reading (or at least viewing) my ramblings!

P. S. Interestingly, over the last year the six countries with most views were (in decreasing order): UK, USA, Hong Kong SAR China, Germany, Ireland and Australia. I’m quite surprised to see Hong Kong so high but wish all my readers there all the best in what seem to be turbulent times!

Crossword Collision

Posted in Biographical, Crosswords with tags , , , , on July 28, 2019 by telescoper

I was thinking recently that it’s been a while since I posted anything about crosswords, and today I got a nice surprise that gives me an excuse for a short post.

As a subscriber to the Azed Slip detailing the outcomes of the monthly Azed crossword puzzle competition, I knew a week or so ago that I’d got a VHC (`Very Highly Commended’) in Azed No. 2456. That’s not enough to merit a prize but at least gets me on the scoreboard for this year’s competition. I have been entering this competition for almost 20 years with decidedly modest success, though I did reach the dizzy heights of 15th place in 2010/11. I stopped for a while when I was at Sussex, as I switched to the Independent whose prize crossword yielded a steady stream of dictionaries. I resumed in 2017 but have found it difficult to get back into the swing of writing clues (at which I’ve never really been very good anyway).

Anyway, Azed No. 2456 was a `special’ puzzle of a type described as `Collisions’. All the Across solutions consisted of two words with one or more letters in common entered in such a way that the two words run into each other. The pairs of words are clued in such a way that the definition part relates to the full word, but the cryptic indication relates only to the part not involved in the collision, i.e. omitting the overlapping letters. Down clues were `normal’, which helped a lot in providing checked lights to help in solving the trickier across clues.

The puzzle was fairly tricky to solve but, as always with the Azed Competition entrants also have to compose a clue of their own. In this case the pair of colliding words was TRACTOR/TORMINAL. My clue (which I don’t think was all that good, really) was:

One feeds paper endless number of gripes threatening to replace Tory with Liberal

Here `One feeds paper’ defines TRACTOR (re: tractor-feed printer); `endless number’ is TRAC (i.e. TRACK with the end missing and with number meaning a track on a record); `of gripes’ defines TORMINAL; the rest is MINATORY (threatening) with TORY replaced by L for Liberal.

You can find the (far better) prize-winning clues here. There’s no actual prize for a VHC – except for a warm glow of satisfaction – but y effort was at least deemed good enough to get my name in this week’s Observer:

But if that wasn’t enough it turns out that I also won this week’s Everyman!

I’m pretty sure that’s the first time I’ve been named in both Observer Crossword competitions. Now that is a nice collision!

P.S. In case you’re wondering the reason it gives Cardiff as my address is that (a) I still have a house there and (b) I’ve had some problems with things being delivered to Ireland from the UK and (c) I recently found a stash of sticky address labels with the Cardiff address on which saves the hassle of writing my address out on each entry.

 

 

Old-School Physics

Posted in Education, History, The Universe and Stuff with tags , , , on July 27, 2019 by telescoper

The recent circulation to his staff of daft (and in some cases erroneous) rules to be used when writing documents has led to much hilarity on the media we call social. Among the obvious errors are that the correct abbreviation for `Member of Parliament’ is `MP’ not ‘M.P.’ and that `full stop’ is actually two words (not `fullstop’). On top of those his insistence that civil servants use Imperial units for everything actually may be unlawful as the official system of units for the United Kingdom is the metric system.

The latter exhortation has caused a particular outcry among people under the age of about 50 (who have never been taught Imperial units), and especially scientists (who understand the obvious superiority of the SI system).

Anyway, all this reminded me that many years ago when at Cardiff there came into my possession a book of very old school and university physics examinations, which are of interest because I’ve been posting slightly less ancient examples in recent weeks. These examinations were set by the University College of South Wales and Monmouthshire, which was founded in 1883,  an institution which eventually became Cardiff University. I find them absolutely fascinating.

The papers are rather fragile, as is the book containing them, so I daren’t risk trying to scan them systematically in case flattening them out causes damage. Here instead are a few random examples that I photographed on my desk, in the manner of an old-fashioned secret agent. Sorry they’re not all that clear, but you can see them blown up if you click on them.

The collection is fairly complete, covering most of classical physics, at all examination levels from university entry to final Honours. Of course there are no questions on relativity or quantum physics appear (which had yet to be invented) but other than that – and the units! – they’re not too different from what you might find in the examinations for the early stages of contemporary physics programmes.

The Wonderful Barn

Posted in History, Maynooth with tags , , on July 26, 2019 by telescoper

Despite the fact that it’s only a few miles away from Maynooth (in Leixlip) I had never heard of this extraordinary building until yesterday. The Wonderful Barn (for that is its name) is known to have been built in 1743 but nobody actually knows what its purpose was. Probably the best theory is that it was designed to be used as a granary, as it was built immediately after a severe famine (in possible anticipation of others in the future), but alternative possibilities to have been suggested are a tower from which people could shoot game birds, a folly (it was built by the Conolly family, owners of Castletown House and is on the Estate which has another famous folly), and simply as a means of providing work for poor people in a time of great hardship. Anyway, it’s a weird building, built from bricks but faced with what looks like recycled stone rubble.

Here’s a short video that includes some drone footage of the Wonderful Barn that gives you an idea of its corkscrew-shaped construction.

Hubble Tension: an “Alternative” View?

Posted in Bad Statistics, The Universe and Stuff with tags , , , , , on July 25, 2019 by telescoper

There was a new paper last week on the arXiv by Sunny Vagnozzi about the Hubble constant controversy (see this blog passim). I was going to refrain from commenting but I see that one of the bloggers I follow has posted about it so I guess a brief item would not be out of order.

Here is the abstract of the Vagnozzi paper:

I posted this picture last week which is relevant to the discussion:

The point is that if you allow the equation of state parameter w to vary from the value of w=-1 that it has in the standard cosmology then you get a better fit. However, it is one of the features of Bayesian inference that if you introduce a new free parameter then you have to assign a prior probability over the space of values that parameter could hold. That prior penalty is carried through to the posterior probability. Unless the new model fits observational data significantly better than the old one, this prior penalty will lead to the new model being disfavoured. This is the Bayesian statement of Ockham’s Razor.

The Vagnozzi paper represents a statement of this in the context of the Hubble tension. If a new floating parameter w is introduced the data prefer a value less than -1 (as demonstrated in the figure) but on posterior probability grounds the resulting model is less probable than the standard cosmology for the reason stated above. Vagnozzi then argues that if a new fixed value of, say, w = -1.3 is introduced then the resulting model is not penalized by having to spread the prior probability out over a range of values but puts all its prior eggs in one basket labelled w = -1.3.

This is of course true. The problem is that the value of w = -1.3 does not derive from any ab initio principle of physics but by a posteriori of the inference described above. It’s no surprise that you can get a better answer if you know what outcome you want. I find that I am very good at forecasting the football results if I make my predictions after watching Final Score

Indeed, many cosmologists think any value of w < -1 should be ruled out ab initio because they don’t make physical sense anyway.

 

 

 

A Comment on Comments

Posted in Biographical with tags , , , on July 24, 2019 by telescoper

Given some recent activity on this blog, I think it’s time to do another post stating  my policy on comments.

This is what it says on the front page of this blog:

Feel free to comment on any of the posts on this blog but comments may be moderated; anonymous comments and any considered by me to be abusive will not be accepted. I do not necessarily endorse, support, sanction, encourage, verify or agree with the opinions or statements of any information or other content in the comments on this site and do not in any way guarantee their accuracy or reliability.

That statement has been there since 2009. I don’t mind people posting contrary views as long as they’re not abusive, but if you use a fake email address and/or a fake name then your comment will be blocked. If you’ve got something to say then at least have the courage to identify yourself!  I do block comments for other reasons, including if they’re silly or demented or just plain tedious.

When I first started blogging, over a decade ago, I decided to have an open comment policy so that anyone and everyone could comment without any form of intervention. That turned out to be a disaster because of the number of automatically generated  SPAM comments that clogged up the boxes. I therefore switched on a SPAM filter so it could veto obvious garbage, but otherwise kept an open policy. The alternatives offered by WordPress include one that requires all comments to be from people registered at the site (which I thought would probably be a deterrent to people only wanting to comment on the odd post). Another option is to maintain a blacklist which treats all messages from persons on the list as Spam. It’s also possible to block all comments entirely, of course, but I enjoy reading most of them so I think it would be a shame to do that just because of a few breaches of netiquette.

All went fairly well and I only had to ban a couple of individuals for abuse. I did for a time receive a stream of crudely abusive comments (of a personal nature) from various anonymous sources. These were mostly depressingly puerile and they didn’t affect me much but I did find it very disconcerting to think that there are people sitting out there with nothing better to do than write such stuff.

Take Mr Hine, for example – no, go on, take him! -:

This chap attempts to post comments usually saying the same thing several times every day (weekends included). In fact on Monday 22nd July there were no fewer than 17 messages from him.  Occasionally I can’t resist showing bits I’ve found in the spam folder for comedy value but I have no intention of allowing him free rein to fill up every thread.I know I should probably stop winding him up so that he stops trying, but alas I am weak.

Since WordPress notifies me every time a  comment is posted (or an attempt is made to post a comment) it is quite easy to remove this junk, but I found it very tiresome (when there were several per day) and eventually decided to change my policy and automatically block comments from all anonymous sources. Since this requires a manual check into whether the identity information given with the comment is bona fide, comments from people who haven’t commented on this blog before may take a little while to get approved.

There are still comments on here which may appear to a reader anonymous (or with a pseudonym), but these are from people who have identified themselves to me with a proper email address or who the software has identified through their IP address or information revealed by their web browser (which is probably more than you think…). I’m happy for people to comment without requiring they release their name to the world, and will do my best to ensure their confidentiality, but I’m not happy to publish comments from people whose identity I don’t know.

To give you an idea of the scale of the problem, as of today, 32,689 comments have been published on this blog. The number rejected as SPAM or abuse is 2,399,850. That means that fewer than 1 in 70 are accepted. I simply don’t have time to go through all the flagged comments individually, so I usually just delete them all.

Am I denying freedom of speech by rejecting anonymous comments? I don’t think so. If you want freedom of speech that much, you can write your own blog (anonymous or otherwise). And if every sight of this blog makes you want to write abusive comments, perhaps you should exercise your freedom not to read it.

I’d be interested to know from any fellow bloggers if they have the same problems with abusive comments. If not, perhaps I should start taking it personally!

More generally, I will not accept anonymous comments on the subject of the anonymity of comments, but any other contributions are welcome via the box.

Unless, of course, you’re banned.