Kathleen Lonsdale: Master of Crystallography

Posted on April 6, 2015 by skullsinthestars

In recent years, there has been a wonderful explosion of interest in the often-neglected historical women of science, and more information is available than ever before about the lives and achievements of these women.  Nevertheless, there are still some truly accomplished women of science who have not received as much attention as they deserve. This post is a small attempt to rectify this in the case of Kathleen Lonsdale (1903-1971), an Irish crystallographer who made fundamental contributions in her field and had influence far beyond, including socially and politically.

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Posted in History of science, Women in science | 1 Comment

My favorite “classic” horror stories

Posted on March 26, 2015 by skullsinthestars

Even though I blog about horror fiction of all eras, regular readers of this blog know that I particularly love older stuff.  There’s something about the ghost and horror stories of the late 1800s and early 1900s that is particularly compelling, and so many classic and timeless tales came out of that era.  I was recently pondering those classic stories, and thought it would be worthwhile to put together a list of my favorites, as far as I can remember.

Such a list is necessarily incomplete, and constantly changing: I’m sure I’ll remember a handful of other stories as soon as I post this!  I limit myself to stories that are readily available to read online, so that I’m not a terrible tease.

I’ll start with a simple list of the stories, with links, and then say a bit more about each of them with significant spoilers afterwards.  IF YOU DON’T WANT THINGS SPOILED, READ THE STORIES BEFORE READING MY DESCRIPTIONS! I’ve put the earliest definite date of publication for each story, though several of them may have first appeared several years earlier.

  1. The Upper Berth, F. Marion Crawford (1894).
  2. How Love Came to Professor Guildea, Robert Hichens (1900).
  3. Lukundoo, Edward Lucas White (1927).
  4. Confession, Algernon Blackwood (1921).
  5. The Whisperer in Darkness, H.P. Lovecraft (1931).
  6. Afterward, Edith Wharton (1910).
  7. Oh Whistle, and I’ll Come to You, My Lad, M.R. James (1904).
  8. The Dead Valley, Ralph Adams Cram (1895).
  9. Mysterious Maisie, Wirt Gerarre (1895).
  10. The Shadows on the Wall, Mary E. Wilkins Freeman (1903).
  11. The Masque of the Red Death, Edgar Allan Poe (1842).
  12. The Monkey’s Paw, W.W. Jacobs (1902).
  13. A Night at an Inn, Lord Dunsany (1916).

Hey — that’s 13 total! A good number!

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Posted in Horror | 2 Comments

#365 papers, part 4!

Posted on March 15, 2015 by skullsinthestars

I’ve joined a group of folks on Twitter who have vowed to read roughly a paper a day for an entire year, and will summarize my reading here occasionally.  Part 1 can be read here, part 2 can be read here, and part 3 can be read here.  Links are provided for those with university access who are interested in reading more.  These posts are a bit more technical than my usual fare, so feel free to ignore if you’re not an optics enthusiast! More fun stuff to come soon.

2/23: Circularly symmetric operation of a concentric‐circle‐grating, surface‐ emitting, AlGaAs/GaAs quantum‐well semiconductor laser, T. Erdogan, O. King, G.W. Wicks, D.G. Hall, E.H. Anderson and M.J. Rooks (1992).  I’ve been reading a lot about “vector beams” these past few weeks, in which the polarization of light either points radially from the center of the beam or circulates azimuthally around it.  This paper, which describes a new laser design with azimuthal polarized light, sparked the modern interest in such beams.

2/24: Focusing of high numerical aperture cylindrical vector beams, K.S. Youngworth and T.G. Brown (2000).  So what good are “vector beams,” that possess unusual polarization? This paper, combining theory and experiment, noted how radial beams produce a strong longitudinal electric field at focus, which can be used to accelerate charged particles.

2/25: The electric and magnetic polarization singularities of paraxial waves, M.V. Berry (2004).  I’ve been extensively studying the “polarization singularities” of light for my chapter on the subject in my singular optics book.  Basically, points in a field where light is circularly polarized may be considered “singular” and distinct from other points.  This paper is one in a long set of articles studying the properties of such singularities.

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Posted in Optics | Leave a comment

A.M. Burrage’s Waxwork and Other Stories

Posted on March 10, 2015 by skullsinthestars

I’ve long been a fan of the work of A.M. Burrage — that little of it that I’ve been able to find, that is.  His ghost stories, originally published in six volumes from the 1920s to the 1960s, have been rarely in print since then and used copies are only available at exorbitant prices.  I was therefore delighted a month ago or so when I found, during one of my regular searches*, that all of his works have been reprinted in a series of volumes!

burrage

There look to be at least 9 volumes — like I said, Burrage was a busy writer — and I have three of them.  I’ve only read the first so far, so I’ll have more thoughts in future posts.

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Posted in Horror | 2 Comments

Michael Faraday and the waterspouts (1814)

Posted on March 6, 2015 by skullsinthestars

This week, one of the most fascinating/frightening videos to be posted online was of a waterspout that ran aground on a Brazilian beach, hurling debris and terrifying vacationers.  Weaker than the similar-looking tornadoes that appear over land, most waterspouts have speeds no greater than 50 miles per hour, though that is certainly fast enough to hurl debris and cause damage, injury, and possibly death.

Waterspouts on the beach of Kijkduin near The Hague, the Netherlands on 2006 August 27. Photo by Skatebiker, released into public domain & available on Wikipedia.

Waterspouts on the beach of Kijkduin near The Hague, the Netherlands on 2006 August 27. Photo by Skatebiker, released into public domain & available on Wikipedia.

The video reminded me again of an event from the life of Michael Faraday, one of the most important researchers in the history of physics.  Faraday would make a number of fundamental contributions to science, including the discovery of electromagnetic induction as well as the link between magnetism and light.  Long before his fame, however, he wrote about waterspouts that he observed while traveling in Italy. I thought I would share his remarks, providing a little context as to his circumstances at the time.

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Posted in History of science | Leave a comment

#365papers, part 3!

Posted on February 22, 2015 by skullsinthestars

I’ve joined a group of folks on Twitter who have vowed to read roughly a paper a day for an entire year, and will summarize my reading here occasionally.  Part 1 can be read here, and part 2 can be read here.  Links are provided for those with university access who are interested in reading more.

One note: I’ve been using twitter, for the most part, to record which papers I’ve read, but I’ve been really bad at it!  In some cases, I’ve ended up “filling in” papers that I read to make up for those I’ve lost track of, and the dates between twitter and here may not always agree.

1/31: Rotational frequency shift, I. Bialynicki-Birula and Z. Bialynicka-Birula (1997).  I’ve mentioned the “angular Doppler effect” before, in which circularly polarized light undergoes a frequency shift when the source or detector is rotated.  It also turns out that vortex beams, with a “twist phase,” experience such a rotational shift as well!  This is something I’m gearing up to blog about in the near future.

2/1: Radiation pressure on a free liquid surface, A. Ashkin and J. M. Dziedzic (1973).  There is a long-running controversy in optics: does the momentum of light increase, or decrease, on entering a transparent medium?  We still don’t have a definite answer, but this paper in the 70s made an ingenious test.  By shining a beam of light onto a liquid from above, they found that the liquid bulged outward slightly, suggesting that the momentum increases.  Others have found other effects…

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Posted in Optics | 1 Comment

Dr. SkySkull and the mystery of the subluminal superluminal light!

Posted on February 17, 2015 by skullsinthestars

References in a scientific paper are supposed to answer questions, not raise them, but sometimes they inadvertently create a minor mystery for the reader.  A few weeks back, I blogged about the curious phenomenon of subluminal vacuum beams of light, i.e. pulsed beams of light that travel slower than the vacuum speed of light c = 3 × 108 meters/second even in vacuum.  One of the pulses beams tested experimentally, a so-called Bessel beam, has had its speed measured extensively in the past — however, the original paper* on the speed of a Bessel beam, published in 2000, refers to it as a superluminal beam of light!  This paper contains both theoretical and experimental work verifying their result, which I should say at the get-go is all correctly done.

There was no explanation in the subluminal paper for this discrepancy — how can a pulse of light moving slower than the vacuum speed c also be considered as moving faster than the vacuum speed c?  The answer leads us to some interesting aspects of Einstein’s special relativity as well as optics — Dr. SkySkull is on the case!

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Posted in ... the Hell?, Optics | 5 Comments

Robert Aickman’s Dark Entries

Posted on February 9, 2015 by skullsinthestars

It took me far longer than it should have, but I have finally read a collection of short stories by Robert Aickman (1914-1981).  Though the 1960s and 1970s, he published 48 supernatural tales, some of which are acknowledged as classics, that were collected in 8 volumes.  These collections were hard to find until last year, when new editions finally came out.  I picked up the first of these, Dark Entries, and devoured it last week.

darkentries

I was doubly intrigued to read Aickman’s work.  Not only is he highly regarded by some of the greatest weird fiction writers of our time such as Neil Gaiman, Ramsey Campbell and Peter Straub, he comes from an impressive lineage: his grandfather is none other than Richard Marsh, the master of the macabre that I’ve obsessively written about many times on this blog.

On this first outing, though, I have to admit that I was a little underwhelmed.  There are stories of undeniable brilliance, but an equal number of stories that I found primarily baffling.  Let’s summarize each of them…

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Posted in Horror | 5 Comments

#365 papers, part 2!

Posted on February 1, 2015 by skullsinthestars

I’ve joined a group of folks on Twitter who have vowed to read roughly a paper a day, and will summarize my reading here occasionally.  Part 1 can be read here.  Links are provided for those with university access who are interested in reading more.

1/12: Shadow effects in spiral phase contrast microscopy, A. Jesacher, S. Fürhapter, S. Bernet, and M. Ritsch-Marte (2005).  It turns out that filtering an image through an optical vortex phase mask performs excellent edge enhancement of the image!  In this paper, the authors demonstrate that this enhancement can be tweaked to provide directional “shadow effects,” allowing different edges to be selectively highlighted.

1/13: Radial Hilbert transform with Laguerre-Gaussian spatial filters, C-S. Guo, Y-J. Han, J-B. Xu, and J. Ding (2006). Obviously I’m working on the section of my book discussing using vortex masks for edge enhancement!  In this paper, the authors look at using Laguerre-Gaussian filters, which represent very “pure” vortex states, for this filtering.

1/14: Image processing with the radial Hilbert transform: theory and experiments, J.A. Davis, D.E. McNamara, D.M. Cottrell, and J. Campos (2000).  This was the first paper about using vortex filters for edge enhancement.

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Posted in Optics, Personal | Leave a comment

So what’s up with that “slower than light” light?

Posted on January 31, 2015 by skullsinthestars

Over the years, there has been a lot of hype about the possibility of “superluminal” light: namely, light than can travel faster than the vacuum speed of light c = 3\times 10^8 meters/second, which is overwhelmingly considered the absolute speed limit of the universe.  I’ve talked about superluminal light before, and the related discoveries always turn out to be somewhat less spectacular than they sound, though they always provide some strange insights into the physics of light.

Recently, though, an even stranger discovery has been making the rounds in the press*: an experiment performed by researchers in Glasgow and Edinburgh** shows that appropriately-prepared light particles (photons) can travel even slower than the vacuum speed of light — in vacuum!

Kind of like its superluminal siblings before it, this discovery has caused a bit of confusion.  In this post I’ll try and shed some light on the phenomenon, showing why it is both less and more than it appears.

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Posted in Optics | 4 Comments