Just a short note to let folks know that issue number 33 of the horror and weird fiction periodical Dead Reckonings is now available, and it includes another review by me!
If you enjoy reading reviews and commentary on horror fiction both old and new, Dead Reckonings is a fun (and inexpensive) option, and regularly includes articles by some really well-known names in the business, such as Ramsey Campbell and Darrell Schweitzer.
Continue readingI have been criminally unaware of the works of Lillian Lieber until recently. Somehow, I got wind of one of her books, the extremely unconventional 1945 book The Einstein Theory of Relativity, and from the description I knew I had to read it!
The 1945 edition is in fact an expanded version of the 1936 edition, which only covered the special theory of relativity; the 1945 edition more than doubles the size of the book and includes a detailed discussion of the general theory of relativity.
There are many books on relativity, so why did I absolutely need to read this one? For two very big reasons: its style and its audience. Both of these reasons are evident in the preface to the book, which I include an image of below.
Continue readingThis is gonna bit a bit of a rant like the old days of blogging. A few days ago we had anti-vaccine crank and poison pill presidential candidate Robert F. Kennedy Jr. show up on Joe Rogan’s equally cranky podcast to talk about how vaccines are killing us all, or something. This led Professor Peter Hotez, an actual scientist and professor who works on vaccines, to call out the show for spreading misinformation.
Proving that we live in the dumbest of all possible timelines, Joe Rogan was angered by this, and more or less demanded that Hotez appear on his show to “debate” RFKj about vaccines, offering him $100k to do so and badgering him about it. This, in turn, led to antivaxxers showing up at Hotez’s home to yell at him and demand he “debate” on Rogan’s show.
Rogan, of course, full well knows that this sort of harassment is inevitable when he sics his followers on someone; he has nearly 12 million Twitter followers, and they are not exactly what I would call reasonable people, so stalking is a very foreseeable consequence of his actions. Hotez, for his part, was gracious and offered to talk to Rogan directly, but did not fall for the “debate” trap.
And it is a trap. What I want to talk about here, and rant about, is the notion that scientists somehow are obligated to perform public debates. Here’s one Roganbro’s tweet arguing that science is supposed to be “debated.”
Scientists do debate science, but do not do it in the traditional public person-to-person format. And there are very good reasons that we don’t.
Continue readingI need to talk about more of my own research on this blog, and a new collaborative paper that just came out is a good opportunity! This paper presents collaborative work I did with researchers in India at the Physical Research Laboratory and elsewhere, building on some theoretical work I did a few years earlier. (I’ve blogged about some of the theoretical work before, so I will be dipping into that post for some of my images.)
The work in question is titled, “Simple experimental realization of optical Hilbert Hotel using scalar and vector fractional vortex beams,” and it appears in the June issue of APL Photonics. It is also a “featured” article, which means the editor found it interesting enough to feature, and is a “Scilight,” which means that the editor felt that it is interesting enough to have a separate description given!
Continue readingSo yesterday’s blog post marked a silly milestone: I posted 69 days in a row!
Why 69? Because I thought it would be nice?
More seriously, I was posting every day for a while as an excuse to promote my book on invisibility, and I just wanted to have an arbitrary milestone to end it on. Now that I’ve wrapped this up, I’ll probably go back to posting one to three times per week. I’ve been much more in a blogging mood the past few months, so hopefully I’ll keep it up!
Speaking (again) of my book, the audiobook version is available for preorder, and will be released on June 27, two days before my birthday! If you’ve been waiting because you prefer audiobook format, now’s your chance to get it.
Okay, I’m going to take a bit of a break, and be back in a couple of days!
Einstein’s special theory of relativity still is met with disbelief by a lot of non-physicists, and it is probably one of the most active areas of physics science denial out there. Write about relativity, and it is quite likely that you’ll get an angry commenter arguing that the entire theory is nonsense.
To be fair, it is extremely shocking and non-intuitive at first glance, as it forces us to reevaluate our notions of space, time, and simultaneity. In short: in response to a baffling inability to measure variations of the speed of light in vacuum with respect to relative motion, Einstein suggested that our laws of relative motion needed to be changed and he introduced two new postulates. The first postulate is that all the laws of physics are the same for every observer in acceleration-free motion. This was a big change from the Newtonian relativity picture, which said that the laws of kinematics (forces and motion) are the same for every observer, but not the laws of electromagnetism. The second postulate is that the speed of light is constant for every acceleration-free observer, regardless of the motion of the source or the observer.
This second postulate is the one that directly leads to some of the most bizarre consequences for physics. In order for observers to agree on the speed of light regardless of their relative motion, they must disagree on the length of moving objects (length contraction) and on the clock rate of moving objects (time dilation). Furthermore, the speed of light, c = 300,000,000 meters per second, ends up being an absolute speed limit that nothing can beat. Objects with mass always move slower than the speed of light, and light itself moves at c (though that is a bit of an oversimplified statement). Perhaps the strangest consequence of special relativity is the relativity of simultaneity: observers in relative motion will disagree about whether spatially separated events happen at the same time or not. Time and space cannot be considered separate independent quantities, and instead we must think about a unified spacetime.
These effects typically become significant only at speeds comparable to the speed of light, so in our day to day activities we don’t experience them. This is why relativistic effects are so perplexing at a first look: they conflict directly with our intuition.
Nevertheless, physicists are quite confident in special relativity, because it has been tested experimentally in many, many different ways since Einstein first introduced it in 1905. Some of these are so common that they hardly classify as “experiments” anymore! For example, high energy particle colliders like the Large Hadron Collider at CERN know how fast their particles are moving, and they’re always moving slower than c and in accordance with special relativity. Unstable muon particles that are created in the upper atmosphere can be detected at ground level because of time dilation: their average rate of decay is slower because of their high speed.
I’ve been looking into some of the actual laboratory experiments to test special relativity recently, and thought I would share a very elegant one that tests time dilation. Titled, “Measurement of the Red Shift in an Accelerated System Using the Mössbauer Effect in Fe57“, it is work done in 1960 by researchers at the Atomic Energy Research Establishment in Harwell, England1. It is a relatively simple and straightforward test, so let’s take a look!
Continue readingI’ve been trying to post something every day to the blog for as long as I can, and it has been quite an exhilarating ride! I’m nearing the end of that run, and what better way to celebrate it, and the release of my book on invisibility, than to talk about another invisibility story that I just found!
In a random bit of inspiration, I realized today that I hadn’t looked at the classic magazine Planet Stories for invisibility fiction, and in looking I was instantly rewarded! “Phantom of the Seven Stars,” by Ray Cummings, appeared in the 1940 winter issue of the magazine.
The story “Beyond Light” was what caught my eye as a possible invisibility story, but Cummings’ tale fits the bill perfectly!
Continue readingThere is a quite long history of novels published by TSR based on Dungeons & Dragons, and the quality is definitely a mixed bag! Some of the earliest were the classic Dragonlance novels by Weis and Hickman, the first of which came out in 1984. Those are quite highly regarded, but other early novels, such as the 1987 Darkwalker on Moonshae, have been remembered less fondly. The irregularity, especially for the early novels, likely stems from the fact that the books were written by the same people who wrote D&D adventures, who often had no prior experience writing novels.
With all this in mind, I was quite surprised a while back when I came across the TSR-published 1990 novel Dark Horse, by Mary H. Herbert!
This novel is not, as far as I can tell, based on any existing Dungeons & Dragons setting, and is original to the author. Even though it is her first novel, it is also quite well-regarded, and has generally excellent reviews. So of course I had to take a look at it, and let’s see what it’s all about!
Continue readingAnother reblog from the archives! One of my favorite posts, talking about the weird properties of quantum spin.
Some time ago, I wrote about a fascinating 1975 experiment in which the relationship between quantum mechanics and gravity was tested. The experiment was made possible by the new — at the time — technique of neutron interferometry, in which the wave properties of matter are exploited to test quantum effects. The experiment confirmed a very odd theoretical prediction: that the particle-like aspects and the wave-like aspects of matter are effected differently by a gravitational field. What, exactly, this implies about the nature of the universe is still, as far as I know, unclear!
Not long after this work was done, further investigations using essentially the same neutron interferometer tested, and confirmed, what I consider to be one of the strangest aspects of quantum mechanics, and another powerful illustration of how the universe obeys really different rules on the atomic scale.
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In Part 1 of What the heck is the “speed of light?”, we noted how light in matter can move much slower than the vacuum speed of light c, or even appear to move much faster than c, under the right circumstances. We even noted that, thanks to the phenomenon of dispersion, there are cases where a single number cannot adequately describe the speed of light of a pulse in matter, because the pulse may break up into multiple pieces, each traveling at its own speed.
All of this may be summarized by saying that a pulse of light is “squishy,” and not a rigid object like a car or a softball. To measure the speed of an object, we look at how long it takes some part of the object to travel the distance from point A to point B. For a car, we can use the front bumper; for a softball, we can use its center of mass. But a pulse of light, which can change shape or break into multiple parts, there isn’t in general a clear mark we can use to define its absolute speed.
This problem of “squishiness” even arises when we look at light propagating in vacuum, and it leads to more unexpected surprises. This is what we look at in this post: the speed of light can be tricky to define sometimes, even in vacuum!
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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 