Sometimes you just have to read a book because of its title. This was certainly the case when I decided I wanted to read Prisoner of the Vampires of Mars (1908-1909), by Gustave Le Rouge!
Like, the title has everything! Mars! Vampires! Prisoners! How could I not read it? I put the book on one of my holiday wishlists, and my roommate got it for me this past Christmas. It took me some time to read it, an admittedly my expectations were not particularly high, but I ended up enjoying the book immensely! Let’s take a look at the book, without major spoilers, below.
The fields of optical science and engineering have undergone dramatic changes over the past twenty years. Through most of its history, stretching back for hundreds of years, optics researchers have been asking the question, “what can light do?” Revolutionary discoveries have changed the question to, “how can we make light do whatever we want it to?”
One area where there has been dramatic change in recent years is in the very structure of a beam of light itself. Ever since the invention of the laser, it has been the standard source of light for experiments an applications, far superior to using natural light sources, which must be collimated and filtered to produce a directional and monochromatic beam. Most ordinary laser sources, like a laser pointer you might use to entertain your cats or give a presentation, produce a Gaussian beam, so named because they produce a brightness (intensity) spot shaped like a Gaussian function, as shown below.
On the left: a simulation of the brightness of a Gaussian spot, as if you would see if you looked directly in the beam (don’t do that). On the right: the cross-section of the spot, showing its Gaussian shape.
A Gaussian beam is great for most uses: it is very directional, and propagates long distances without significant spreading, it is very close to being a single frequency wave, which also means it is coherent (more on this momentarily). However, researchers have gradually realized that beams with properties different than a Gaussian beam could show unusual, beneficial, and even seemingly impossible behaviors! These beams are created by modifying, or “structuring,” the properties of the beam spot.
There are a number of properties that can be structured in the transverse cross-section of the beam. The shape of the intensity spot can be changed, the phase of the light wave can be modified, the polarization properties of the light can be manipulated, and the spatial coherence can be adjusted. Let’s look at examples of each of these “structured” light beams, and see what weird things can be done!
In my investigations of classic pulp magazines over the past year, I’ve come across some classic stories and real gems that I had forgotten about. One of these guilty pleasures is “Giants From Eternity,” by Manly Wade Wellman, published in the July 1939 issue of Startling Stories.
The cover image, incidentally, doesn’t represent Wellman’s story in the magazine.
I’m a big fan of Manly Wade Wellman’s work; his Silver John series of stories and novels, about a wandering Appalachian minstrel who fights evil with wit and a song, are absolutely delightful. With his son, he wrote a story about Sherlock Holmes squaring off against H.G. Wells’ invaders from The War of the Worlds! I’ve also written about Giants From Eternity before, when I read it in a modern edition, though I read it and blogged about it over a decade ago!
Digging up the story in magazine form gives me an excuse to take another look at the story, and share the original images from the magazine! (And once you know what the story is about, you’ll see why.) If you want to read it in advance, the issue is available on the Internet Archive, or you can buy a modern edition.
I’ve spent a lot of time talking about short stories about invisibility, but my searches have occasionally reminded me of some of my other favorite, non-invisibility-related, science fiction stories. Today I thought I’d take a short look at “A Subway Named Mobius,” written by Armin Joseph Deutsch and which appeared in the December 1950 issue of Astounding Science Fiction.
This story is one of the true classics of science fiction, all the more remarkable because I believe it is the only story that Deutsch ever published! It is a semi-humorous story based on one of the more challenging subjects in mathematics, topology: the study of those properties of sets or objects that are invariant under continuous deformations of the object. A classic example of this line of thinking is the topological similarity of a coffee cup and a donut; both of them have a single hole, and if we imagine them made out of clay, one could be molded into the other, as long as we obey the rule that we can stretch and compress and warp the clay, but not tear it.
Another classic structure from topology is the Möbius strip, a one-sided surface, that gives the story its name. It is created by taking a ribbon of paper, giving one end a half-twist, and then taping the ends together. It is distinct from a cylinder, which could be created by taping the ends of the paper together without the half-twist.
A paper Mobius strip.
So let’s take a look at “A Subway Named Mobius!” You can read the entire story from its original source at this link.
Oh, what the heck — as long as I’m thinking of Algis Budrys’ work, and I’m still on a blogging roll, let me say a few words about his most famous novel Rogue Moon (1960). I read it on a Kindle on a trip a few years ago, which is why I suppose I never got around to blogging it — by the time I returned from the trip, I was already reading other things.
But Rogue Moon is a classic of science fiction, and well worth exploring. However, readers may find that the novel is not exactly about what it seems to be about at first glance!
I’m part of an episode discussing the righting reflex. Click on the image above to go to the episode, or this link here. Thanks again to Amanda for having me on the show!
Fate has led me to another invisibility story while looking for something completely different! This gives me one more opportunity to remind people that my book on invisibility is available while I blog about this story.
One of the very oldest stories about invisibility in the history of humanity is the story of Perseus from ancient Greek folklore. Perseus, the son of Zeus, is given gifts by the gods to accomplish his quest. One of these is the Cap of Hades, that confers invisibility on the wearer; Perseus uses it to sneak up on Medusa and her immortal sisters and escape safely with her head. This story has been told in many versions, though one of the most detailed was written in the first or second century CE in the Bibliotheca of an author known as pseudo-Apollodorus. (For years, scholars thought that Apollodorus wrote the Bibliotheca, but now believe this not to be true, so the unknown author is simply known as pseudo-Apollodorus.)
With this in mind, you’d think that I would’ve found a significant number of modern stories inspired by Perseus, but so far I’ve only found one: “Perseus Had a Helmet,” by Richard Sale, which appeared in the very first issue of The Magazine of Fantasy, Fall 1949. (I’ll give a few spoilers again, so please read the story first if you’re concerned.)
Some time ago, I read Rogue Moon (1960), by Algis Budrys, a classic science fiction novel about an alien deathtrap maze discovered on the moon and the man willing to die over and over again to discover its secrets. I found it fascinating, even though for some reason I never blogged about it. I’ve thought about looking up more of Budrys’ work, and after recently rereading his invisibility-related story “For Love,” I decided to give Hard Landing (1993) a try.
Hard Landing is a very unusual but compelling novel — it tells the story of alien explorers from another solar system who crash land on Earth and are forced to “go native,” and the ways they go about it.
The early years of quantum physics, from Einstein’s explanation of the photoelectric effect in 1905 through the introduction of the Schrödinger equation in 1926, was a remarkable time for science and filled with novel ideas, speculations, and experiments. In the teaching of physics, some of these results get more attention, and some absolutely beautiful experiments are not discussed as often as others, as they are not essential to understanding the phenomena, even if they were essential in proving them.
One example of this I’ve had on my mind for some time is the Franck-Hertz experiment, reported in 1914. This experiment was the first demonstration that the energy levels of atoms are quantized, and that an atom can only absorb or emit energy in discrete amounts referred to as “quanta.” I did the Franck-Hertz experiment as an undergraduate, and it has always stuck with me. A few years ago, I tried to track down the original paper, but found to my surprise that it was extremely difficult to find — even an attempt to acquire it through Interlibrary Loan failed! This week, however, I took another look, and managed to get the original paper in German and translate it, and wanted to share a description of it here.
You know what I haven’t talked about much lately? My own research! Well, today is a great day for it, because a paper I wrote with my student Ray Abney just came out in Physical Review A, titled “Nonradiating orbital motions.” It’s actually invisibility-related, and I thought I would say just a few words (and pictures) of what it’s all about!
So, one of the earliest physical phenomena studied that can be connected to invisibility is known today as a nonradiating source. The oxymoronic name refers to a source of electromagnetic radiation (or more generally other types of waves) that, in fact, does not produce any radiation at all.
This is counterintuitive because the mathematical formulas that describe electricity, magnetism and light, called Maxwell’s equations after their discoverer, predict that an oscillating electrical current will produce electromagnetic waves. All of our wireless communications technology is based on that principle; when you see a radio antenna, such as the mast radiator pictured below, you are looking at a metal structure that has an oscillating electrical current driven through it to produce radio waves.
Image of an AM radio tower in Chapel Hill, North Carolina, via Wikipedia.
Your cell phones produce a signal in a similar manner; they have an antenna for broadcasting and receiving. Apple infamously ran into trouble with the iPhone 4 when they changed the antenna design and put it around the edge of the case, causing dropped calls when people held the phone “wrong!”
If charges are accelerated more strongly, they can produce higher-energy electromagnetic waves such as X-rays. The Advanced Photon Source at Argonne National Laboratory takes advantage of this and sends electrons around an 1,100 meter ring at nearly the speed of light; the circular path of the electrons causes them to constantly shed X-rays that can be used for basic and applied research.
Night view of the Advanced Photon Source, via Wikipedia.
So it is widely known and assumed that accelerated electric charges produce electromagnetic radiation of some form. But this is not always the case!
The author of Skulls in the Stars is a professor of physics, specializing in optical science, at UNC Charlotte. The blog covers topics in physics and optics, the history of science, classic pulp fantasy and horror fiction, and the surprising intersections between these areas.
Skulls in the Stars 