Archive for the ‘Fun’ Category

Nobody expects the Strings Inquisition

June 13, 2006

The Spanish InquisitionThe recent comments by you-know-who against the positive press that Peter Woit’s book Not Even Wrong is receiving just reminded me (by some weird association of ideas) of this epoch-making gag by Monty Python. I was about to write an entry on my recently ordering this book and planning to read it on a trip next week, but now i’m scared of confessing having bought it! (and, anyway, Christine Dantas has recently put quite nicely almost my exact feelings on this matter). Imagine, i might even like it, and got immediately classified as a crackpot and a nincompoop by the theoretical physics community!

I’m trying hard to respect string theory and theorists (and even plan on reading Zee, Weinberg and Zwiebach’s books, already waiting on my shelf). Why, i even admire several string theorists. But it would help if someone told me that Motl is not the string community’s spokesman. Or to read every now and then a bit of self-criticism from said community (something in the vein of Smolin’s comments in, say, Three Roads to Quantum Gravity). For if the (so to speak) dialectic battles between those two are to be taken as the kind of discussion we theoretical physicists favour these days, poor Monty Python are just out of business. Paraphrasing Erwin Schrodinger, i wouldn’t like it, and i would be sorry i ever had anything to do with it.

Update: Christine’s again right on the spot. And this is much, much closer to the kind of discussion i was asking for!


The third policeman

May 28, 2006

I’ve just finished The Third Policeman, my discovery of Flann O’Brien‘s hilarious and extremely witty work. I’ve enjoyed so much this novel that i had to find an alibi for posting it here. But that was easy. Let me introduce to you the prolific and sadly forgotten Irish physicist and philosopher de Selby, whose highly original theories constitute a reference frame of sorts in The Third Policeman’s plot. We learn in there, for instance, how de Selby foretold modern ideas about the problem of time:

Human existence de Selby has defined as ‘a succession of static experiences each infinitely brief’ […] From this premise he discounts the reality or truth of any progression or serialism in life, denies that time can pass as such in the accepted sense and attributes to hallucinations the commonly experienced sensation of progression as, for instance, in journeying from one place to another or even ‘living’.

Granted, other ideas of his were much more debatable, as his theory about night being caused by black air accumulation, but to err is the mark of genious. Other characters are also prone to philosophical digressions. For instance, one would say that policeman MacCruiskeen is well acquainted with some of our modern theories of quantum gravity:

That is the real point, said MacCruiskeen, but it is so thin that it could go into your hand and out in the other extremity externally and you would not feel a bit of it and you would not see nothing and hear nothing. It is so thin that maybe it does not exist at all and you could spend half an hour trying to think about it and you could put no thought around it in the end. The beginning part of the inch is thicker than the last part and is nearly there for a fact but i don’t think it is if it is my private opinion that you are anxious to enlist.

And there’s more, including a theory of everything based on a single, possibly relational, entity: the omnium. But i won’t spoil the fun by giving up the plot, which, to tell the truth, has nothing to do with physics, but rather with the Carollian travels of an unnamed murderer through a surrealist, almost quantum world. (In case you’re not yet convinced, here you have yet another excerpt from the novel; or see here for more about O’Brien.)

Update: MacCruiskeen’s needle seems to have been finally found!

A magic cloak

May 26, 2006

This PhysicsWeb article describes a very fun proposal for invisibility cloaks. Come to think of it, the principle is simple: cover your object with a material than bends light coming from its rear around the body and forwards it afterwards reversing the deviation.
Snell-1Not surprisingly, the idea was “inspired by the geometry of curved space — a discipline that is normally in the firm hands of researchers in general relativity.” The tricky part is, of course, finding a material with the right behaviour. The feat seems to be possible thanks to the so-called metamaterials, which may have negative-index refraction. As shown in the figure on the right (taken from the link above), according to Snell’s law, a material with a negative index of refraction is able to reflect light through negative angles with respect to the surface’s normal. As you can see, with an apt enough arrangement of such prisms, you can obtain the needed light twist around the cloaked object. Curious? More on negative index refraction in this list of publications.

How to write papers

May 20, 2006

I’ve just found a brief but very well written Guide to Writing Papers by S. Majid (of quantum groups fame). He makes many a good point, specially for those of us whose mother tongue is not English. And you’ll find also useful advice on contents and organization.

When it comes to writing good English prose, Strunk and White’s classic “The Elements of Style” (also available and searchable online) is, of course, required reading, but i find Dupré’s “BUGS in Writing: A Guide to Debugging Your Prose” much more fun and equally insightful. Also worth a look is the online Researcher’s Bible (hat tip Jocelyn Paine), which is similar in scope to Majid’s tutorial. And for a good, thought-provoking laugh, don’t miss the indispensable How to Write a Scientific Paper, over at Improbable Research.

Let me take the opportunity to recommend two of my all-time favourite essays on scientific writing: the classic How I Write by Bertrand Russell, and the recent A parallel tradition, where Ian MacEwan beautifully makes the case for a scientific literary tradition. So much for the science/humanities divide!

Finally, lest you had not enough, this blog entry by W. Zinsser is, in my opinion, an excellent guide to improving your writing skills (scientific or otherwise), and contains links to several other interesting books on the subject.

Ghostly syllabus for new degree

May 11, 2006

Are you thinking about starting a Ph.D.? Podering string vs. loops? Condensed matter you say? Nah, doubt no more: finally, Coventry University offers you the degree you always wanted. Over at OmniBrain, all the, uh, gory details.

Uncle Al was all too right:

Only two things are infinite, the universe and human stupidity, and I’m not sure about the former.

Albert Einstein

Albert the robot

May 5, 2006

And now for a bit of fun, courtesy of GeekLand :

This amazing robot has been developed at the Hubo Labs. More links and fun with robots at Roborama. Enjoy!

Cosmic Variance’d

May 3, 2006

To my great surprise and pleasure, Sean has been so kind as to mention physics musings in his last post at Cosmic Variance. First of all, I just wanted to say thanks: i’m sure that in many cases reading Cosmic Variance is one of the reasons one starts thinking of writing a physics blog in the first place. At least it was for me. I’m also happy because i’m fond of Sean’s writings in more than a way. A few months ago, i spent some weeks getting up to speed, again, in General Relativity, and carried home several textbooks. Some from my university days, and others published in the interim. And of all those books, the only one that i finally read (and enjoyed) from cover to cover was Sean’s “Spacetime and Geometry: An Introduction to General Relativity”. I’m sure it needs no presentation or recommendation, but, just in case, you can get a feeling of how good it is by reading the notes it’s based on or visiting the book’s website.

Sean’s post has also enlarged my list of monitored blogs with several interesting new entries. Among them, there’s one i’ve been enjoying specially during the last couple of hours. Lest you miss it in the post’s comments, here’s my recommendation: Alejandro’s Reality Conditions is just excellent. He has a lot to say about quantum gravity and the interpretation of quantum mechanics (two of my favourite areas), but also frequently touches more philosophical themes i find absorbing, like cognitive science and the problem of consciousness. With a dose of humor and many interesting links for a good measure. Highly recommended!

Lost causes in physics

April 30, 2006

Before you start your brand new research programme, you may be interested in at least skim over R.F. Streater‘s twenty-six lost causes in physics, if only to have a laugh at some of them (like, e.g., number seventeen, converting R. Penrose to the Copenhagen view). But make no mistake: the list is not intended as a humorous compendium and many of its entries come with a quite detailed rationale and pointers to the literature, which make it an interesting, if highly opinionated, reading. On a more positive note, in Regained Causes in Theoretical Physics, Streater gives advice on research topics, according to him, worth pursuing.

In case you need a refresher, Streater, now seventy, besides having Erdös number 3, wrote his thesis under Abdus Salam‘s supervision, and is the coauthor (with A. S. Wightman) of the classic book “PCT, Spin and Statistics, and All That”. Most of his almost five decades long research career has been devoted to axiomatic quantum field theory. Not that bad for getting an advice, i think. He has also a bit to say about many, many physicists, present and past. Pretty interesting.

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Fun problem

April 23, 2006

In a recent post on sci.physics.research, Igor Khavkine proposes a fun problem (requiring no more than high school classical mechanics) whose solution, he claims, is ‘a little surprising and intriguing’. Here is the problem:

BallConsider a point particle sliding on a flat table (ignore friction). The table has a cylindrical hole of finite depth (vertical walls, flat bottom). The particle can approach the hole with different velocities and with different impact parameters (the particle’s motion need not be directed toward the center of the hole). As the particle falls into the hole, it starts bouncing off the walls and the bottom (assume elastic collisions). Sometimes it gets stuck in the hole forever, sometimes it escapes (bounces out). Determine the relation between the depth of the hole, its radius, the particle’s initial velocity, and impact parameter necessary for the particle to escape after it falls in.

Some people have already chimed in with comments, but you may want to try your hand at it first!

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Physics fiction

April 6, 2006

Just to start on the light side, i like to read novels and fiction featuring scientists, provided they present convincing, well-documented characters and situations. An excellent example of such a work i read recently (and wholeheartedly recommend) is Neal Stephenson‘s Quicksilver, where you’ll find Newton, Leibniz and the whole Royal Society playing an important part in the (otherwise fictional) history. Quicksilver’s sequels, which conform the so called Baroque Cycle, are awaiting in my shelves.

My other physics-fiction all time favourite is Gregory Benford‘s Timescape. Benford is a theoretical physicist, and it shows: this history about time travel is as sound as modern physics can make it.

I’m not much of a comic reader, but today this post captured my attention. Matt Fraction shares a sneak-preview of his forthcoming graphic novel, The Five Fists of Science, starring Mark Twain and Nikola Tesla in a race to save the world from Thomas Edison and J.P Morgan. The PDF preview looks pretty nice, with a charming nineteenth century atmosphere all around. Surely, not as good as Stephenson or Benford, but worth a look nonetheless.

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