Sometimes one can demonstrate very profound and remarkable physics with very simple, even mundane, tools. Last week I received the tools to perform one such demonstration by mail:
This pair of iron hemispheres, with handles attached and a valve on one side, are a small scale model of one of the earliest and most dramatic displays of the power of atmospheric pressure. They are now known as the Magdeburg hemispheres, and they still work as a great demo to this day.
Part 6 of a photo travelogue of my recent trip to Spain with my wife and her family! (Part 1, Part 2, Part 3, Part 4, Part 5)
On our first full day in Seville, we spent the morning visiting the Seville Cathedral, as described in the previous Spain post. That was only the beginning of the day, however, as we went directly from the cathedral to the Alcázar, a beautiful royal palace with a long and storied history. It is still used by the Spanish Royal family as a residence when staying in Seville.
Entrance to the Real Alcázar of Seville, the Puerta del León.
This palace-fortress has such a long history, with such extensive renovations and changes, that even its date of origin is unclear! It seems that many of the surviving structures date from the 14th century, though some remains could date back as early at the 10th century.
I don’t often talk about my own research on this blog… heck, I don’t think I’ve ever talked about my own research here, come to think of it! I thought it would be a nice change of pace to describe a paper that recently appeared in the journal Plasmonics of which I am a co-author. The paper, titled, “Coherence converting plasmonic hole arrays”, describes how one can use an array of subwavelength-size holes in a thin metallic screen to alter the statistical properties of a light beam incident upon it! It has appeared online at Springer’s site and will be “officially” published later this year.
For those not familiar with optics, there’s a lot to unpack in even the title of the paper: What is “coherence”? What is a “plasmon”? Why do we care about “converting” coherence? Let’s take a look at each of these ideas in turn as we build an explanation of what my collaborators and I have accomplished!
This is just a short post to announce that my third popular science article written for a magazine appeared online today! ”Arago’s inadvertent test of relativity” has appeared in the May issue of Optics & Photonics News, the news magazine of the Optical Society of America. The article discusses how François Arago stumbled across the first experimental evidence for Einstein’s special theory of relativity, though he didn’t realize it!
Unfortunately, the article is only available to subscribers; however, if you’re interested in reading about Arago’s exploits, you can look at a blog post I did on the subject a few years ago at this link.
Most of us are familiar with the Greek myth of Pandora and her eponymous box. In a standard telling, Pandora is given the box by Zeus but is explicitly told never to open it. Pandora’s curiosity gets the better of her, however, and when she raises the lid she releases all the evils of the world. She attempts to put the lid back on, but it is too late — what is done cannot be undone.
The myth of Pandora came to my mind while pondering the novel Exogene, by T.C. McCarthy.
In this second book of the Subterrene War trilogy, one gets the ominous feeling that, like Pandora, humanity is being enticed by the allure of short-term gain into making decisions that will lead to doom. As happened with the first book in the trilogy, Germline, I found Exogene pretty much impossible to put down.
The past few weeks I’ve been preparing a lot of entertaining demonstrations of physics principles for a Science and Technology Expo to be held at UNC Charlotte on April 29th. I thought I’d start writing short posts highlighting the various gadgets and gizmos I’ve encountered.
At first glance, it seems like a very ordinary, if ornate, drinking cup:
There is an odd bump in the center of the cup, but otherwise, it seems quite normal, and if it is filled to a certain level can be used without incident.
However, if the cup is filled higher than the bump, the drink starts to drain out of the bottom — in fact, the cup will completely empty itself!
This is the trick of the Pythagorus cup, also known as the Pythagorean cup or the Tantalus cup! It can be used as a nice prank to play on someone (don’t use red wine, unless you need to replace your carpeting anyway), but also serves as a nice demonstration of some physics of fluids.
Delayed a week due to technical issues, the long-awaited 46th edition of The Giant’s Shoulders history of science blog carnival is up at Providentia! It’s a doozy, featuring things such as:
Thanks to Romeo Vitelli for hosting an excellent carnival!
The next edition of The Giant’s Shoulders will be hosted by The Medical Heritage Library and entries are due by May 15. Entries can be submitted directly to the host blog or throughblogcarnival.com, as usual.
The author of Skulls in the Stars is an associate 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.
