Dr. SkySkull in Mexico: The Great Pyramid of Cholula

Posted on June 7, 2018 by skullsinthestars

A couple of weeks ago, as a part of the SPIE Visiting Lecturer program, I went and gave three talks at the Instituto Nacional de Astrofísica, Óptica y Electrónica (INAOE) in Cholula, Mexico. I had a great time, the Institute is lovely, and my hosts were wonderfully hospitable (if you’re reading this: thanks again!).

Life has been rather hectic and stressful lately, and I didn’t have time to research my destination before I got there. Imagine my surprise, then, when I found that I was staying only a block away from an ancient pyramid! Not only that, but I was staying only a block away from the largest pyramid in the world!

The Great Pyramid of Cholula.

I was kind of surprised that I hadn’t heard of this pyramid before (or had forgotten about it, due to age), considering I am very much a huge fan of ancient history and ancient pyramids.  The Great Pyramid of Cholula is, remarkably, relatively unknown for an archaeological site of such significance; hopefully this blog post will partly change that.

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Posted in Travel | 1 Comment

RIP Emil Wolf, 1922-2018

Posted on June 4, 2018 by skullsinthestars

On Saturday morning, my PhD advisor and friend Professor Emil Wolf passed away at the age of 95.  He was a singularly gifted scientist as well as an extraordinarily kind and wise person.  It is fair to say that I would not have made it to through my own PhD, and onward to being a full professor, without his support, patience, and guidance.

I’m sure that much will be said about Emil’s life and legacy in the near future; I thought I would share some of my personal experiences from being advised by him, working with him, and being his friend.

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Posted in Optics, Personal | 7 Comments

RIP Sabrina, 2006-2018

Posted on May 26, 2018 by skullsinthestars

Even when you know it is coming, and soon, it is never easy to lose a animal friend.  Last night, after a six month struggle with cancer, my beloved Sabrina passed away at the age of 12.

Sabrina in November 2008, on top of the refrigerator.

I had been away in Mexico for work earlier this week, and very worried about leaving Sabrina behind, though she had excellent care with my ex-wife Beth and my roommate Sarah.  When I arrived home Friday night, Sarah and I found Sabrina had collapsed. Beth came over and Sabrina passed away on the sofa at home she had slept on so many times before, surrounded by those people who loved her.

Sabrina was a wonderful, clever, silly, and strong cat, and a good friend. She was incredibly strong-willed, and wasn’t shy about making demands for food or attention in her own unique ways, which I will share below.

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Posted in Animals, Personal | 19 Comments

Dr. SkySkull on WCNC!

Posted on April 28, 2018 by skullsinthestars

For those who just can’t get enough of seeing me on camera (read: my parents), yesterday I did a very short spot on WCNC TV to promote UNCC’s Science and Technology Expo that is happening tomorrow, noon-4 pm, on the UNCC campus.  More information about the Expo can be found here!

My TV spot is “blink and you’ll miss it,” but I do mess with the theremin on camera!  The WCNC site doesn’t seem to allow embedding, so here’s a link to the clip. (Thanks to Sarah for tracking it down online for me!)

I mentioned to my colleague Jim, who was there with me demonstrating robots, that I have done a few TV spots before. He, probably presciently, asked me, “Have you used up your fifteen minutes of fame yet?” I think I’m on minute 11 at this point!

Just so this post isn’t a bunch of words, here’s a few photos I took at the recording!

My traditional “panicked selfie before I do a presentation.”

You KNOW that there’s a story behind this sign.

One decent post-appearance selfie to commemorate the event.

Posted in Entertainment, Personal, Physics | 2 Comments

The Broken Earth Trilogy, by N.K. Jemisin

Posted on April 24, 2018 by skullsinthestars

Let’s start with the end of the world, why don’t we? Get it over with and move on to more interesting things.

So begins the beautiful, haunting, and apocalyptic Broken Earth Trilogy, written by N.K. Jemisin.  It begins with The Fifth Season (2015), continues with The Obelisk Gate (2016), and concludes with The Stone Sky (2017).

The trilogy is a masterpiece in fiction writing, an utterly unique blend of science fiction and fantasy.  Jemisin crafts a completely novel world and story unlike anything else I’ve seen in the genre(s), and the books stayed with me long after I finished reading them.

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Posted in Fantasy fiction, Science fiction | 1 Comment

Arago finds new physics with a compass (1824)

Posted on March 24, 2018 by skullsinthestars

One of the challenges of doing physics outreach is that there are so many cool phenomena which simply can’t be demonstrated in an eye-catching way, because they are too small, too subtle, or too complicated.  So whenever I find a demo that really has a “WOW!” factor to it, I treasure it.

A perfect example of this is a demonstration of what are known as eddy currents, which can be done with a simple copper pipe and a neodymium magnet that fits easily inside it. I took the following video a few days back:

Isn’t this the coolest thing? The magnet seems to float down the tube, only occasionally touching the walls of the pipe, seeming to defy gravity.

The phenomenon is cool, and the way it was discovered is also fascinating: it was first observed by the Most Interesting Physicist in the World™, François Arago, using an ordinary compass!  It is one of those remarkable discoveries that is, however, largely unknown to most physicists, much less the general public — I only came across a chance mention of it recently that led me to explore further. In this post I want to look at both the physics and the history — and the arguments that followed.

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Posted in History of science, Physics | 1 Comment

Fred Saberhagen’s Brother Assassin

Posted on March 13, 2018 by skullsinthestars

An army of intelligent war machines are dedicated to the utter annihilation of humanity.  When they begin to lose their war in the present, they send an unstoppable cybernetic assassin back into the past to kill a key figure in humanity’s history, in order to destroy their resistance before it can begin. Humanity’s only option is to send one of their own back as well, to protect the key figure no matter the cost.

Does that story sound familiar?  It very well may, but I’m probably not talking about the one you’re thinking of!  I’m summarizing Fred Saberhagen’s Brother Assassin (1969), the second in his long-running Berserker series of books.

For those unfamiliar, the “Berserkers” are a fleet of massive and intelligent machines, mostly spacecraft, that were created by an alien empire millennia past in order to destroy their enemies.  The Berserkers did their job too well, though, and destroyed both civilizations, and then moved on to relentlessly hunt down and eradicate all biological life in the galaxy.   And they were incredibly successful at it — until they finally met effective resistance in the form of humanity, whose violent tendencies ironically made them the galaxy’s best hope for survival.

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Chladni patterns, now in color!

Posted on March 6, 2018 by skullsinthestars

One of my favorite physics demonstrations to perform at local schools, conventions, and expos is the production of Chladni patterns, such as the one shown below.

I’ve blogged about these patterns before. They are formed by vibrating a metal plate at one of its special resonance frequencies, which causes the plate to form standing waves.  These waves have some locations — antinodes — where they vibrate a lot, and other locations — nodes — where they don’t vibrate at all.   By sprinkling sand over the plate, the sand will be pushed to the nodes allowing the otherwise invisible vibrations to be visualized.

This technique is remarkably old, first published by German physicist Ernst Chladni in 1787; the patterns created are therefore known as Chladni figures.  Chladni used a violin bow to excite his plate, but today we can use a speaker and frequency generator to produce the effect more readily.

I’ve been doing Chladni pattern demos for nearly five years, and when I recently did them again at a local school, I decided to spice things up with colored sand, to produce multicolored patterns.   This results in lovely things such as the pattern below!

This became a bit of an art project for me, and I spent a couple of hours over the past few days making pretty colored Chladni patterns!  I thought I would share the results here. In addition, I learned a little bit more about the physics of these patterns that I will share along the way.

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Posted in Physics, Physics demos | 3 Comments

Somnium, by Johannes Kepler

Posted on February 23, 2018 by skullsinthestars

I’ve had an interest for a while in ridiculously old science fiction, such as Margaret Cavendish’s 1666 novel The Blazing World, as well as science fiction written by prominent scientists, such as Simon Newcomb’s His Wisdom the Defender (1900), Robert Williams Wood’s The Man Who Rocked the Earth (1915), and Fred Hoyle’s The Black Cloud (1957). But if I want to combine “ridiculously old” and “prominent scientist,” there’s no book that can beat Somnium, written by Johannes Kepler in 1608!

Often billed as the earliest science fiction novel, Somnium provides probably the earliest descriptions of a journey to the Moon and the beings that live there. But is it really science fiction? Let’s take a look at it more closely…

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Posted in Physics, Science fiction | 3 Comments

The Stories of Ibis, by Hiroshi Yamamoto

Posted on February 16, 2018 by skullsinthestars

I have a long backlog of book blogging to do, but I had to jump and do the back of the queue first.  Every once in a while I read a book that is so thought provoking and moving to me that I have to write about it right away while the multitude of ideas are fresh in my mind. That book for me is Hiroshi Yamamoto’s The Stories of Ibis (2006), which I just finished yesterday.

The novel is set in a future in which the human population, and its civilization, has collapsed.  Artificial intelligence, in the form of androids and robots, is now the dominant intelligence on the planet, with its own massive cities, technology, and civilization.  Humanity scrounges a living in small communities around the world, making regular raids of android supply trucks and warehouses for needed supplies.  They have never forgiven the AI for rebelling against them in the distant, almost legendary, past.

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