Physics demonstrations: Geiger counter

Update: Fixed a couple of incorrect statements regarding cosmic rays and the radiation of uranium.  Thanks to encephalartos for the corrections!

In recent months, I’ve been diving wholeheartedly into learning how to build and design electronics.  My ultimate goal is to build a Tesla coil, but before I do, I’ve been warming up with a variety of kits and designs online.

Not too long ago, I learned that it is possible to buy a kit to build a basic Geiger counter, for only around $100!  I jumped at the opportunity and, after some minor modifications, started checking for radioactivity!



If you compare this with the image of the original kit below, you can see that I’ve protected all of the circuitry in a plastic case.  I also added an external switch as well as a spiffy drawer handle from Lowe’s.


So you probably know that a Geiger counter detects radioactivity, but how does it work — and what sort of things can you detect?  I thought I would write a short post discussing this, ending with a video showing my Geiger counter in action.

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Posted in Physics demos | 5 Comments

Cloaking from earthquakes?

There has been a lot of excitement among researchers about the science of invisibility over the past decade, and a variety of designs of invisibility cloaks have been suggested since the groundbreaking 2006 papers.  I’ve talked a lot about invisibility on this blog, but I haven’t said a lot about one of the most intriguing — and overlooked — possibilities: the use of cloaking to protect objects, instead of just hide them!

What do I mean?  Well, an invisibility cloak is, in principle*, a material structure that guides light around a central space — the cloaked region — and sends it on its way as if it had hit nothing at all.  An illustration of how this would work for light rays, from the original paper by Pendry, Schurig and Smith, is shown below.


The black lines represent the light rays, being bent around the cloaked region (inner sphere).  Such a cloak, however, is not limited to rays of light; it has been demonstrated that it guides waves of light perfectly, as well.

But if a cloak can be designed to deflect light waves, it stands to reason, then why not other types of waves, or fields?  Magnetic fields could be deflected, to protect sensitive electronics within.  Water waves could be deflected, to protect offshore platforms or buoys from damaging waves during extreme storms.  Or, maybe — just maybe — seismic waves from earthquakes could be guided around vulnerable buildings!

Recent research* suggests that protecting buildings from earthquakes might be possible, at least to a limited extent.  In experimental work published in April of this year, French researchers were able to screen, or protect, a region of earth from artificially generated seismic waves.

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The Lost Skeleton Walks Among Us! (hopefully)

Proving once again that you can’t keep a good undead down, at least not the first or second time, it was recently announced that there will be a third film in the Lost Skeleton of Cadavra (soon-to-be) trilogy!

Being that I am pretty much a floating skull in space (at least in my twitter and blog identity), I’m pretty excited about this development.  The project, which brings back the original cast, including star/writer/director Larry Blamire, is being crowdfunded on Kickstarter this month; the video introduction can be watched on the Kickstarter page.


I’ve already got the giggles just watching the faux documentary A World Without Lost Skeleton included in the Kickstarter video!  I’ve been a big fan of the original 2001 movie The Lost Skeleton of Cadavra and its 2009 sequel, The Lost Skeleton Returns Again, and would love to see the third film get made.*

If you’re familiar with The Lost Skeleton, I probably need say no more; if you’re not, I thought I would give a brief intro to the series, because the films are a total treat!

But there’s more: I managed to score some production art and storyboards from the upcoming film from the promotional team to use in a blog post!  Let’s take a look at the saga of the skeleton…

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The Giant’s Shoulders #72: The Seven Wonders

The 2nd century BCE marked an unusual milestone in the history of civilization.  As the Greeks had conquered most of the civilized world, its citizens were more or less free to travel widely through Europe and the Middle East, to see different cultures and their accomplishments.  Soon, travel guides — the Fodors of their time — were written, providing a list of “must see” attractions throughout the world.

Today, of course, we refer to these as the Seven Wonders of the World.  Not every list was the same, but the most commonly-listed attractions were the Great Pyramid of Giza, the Hanging Gardens of Babylon, the Temple of Artemis at Ephesus, the Statue of Zeus at Olympia,  the Mausoleum at Halicarnassus, the Colossus of Rhodes, and the Lighthouse of Alexandria.

The Seven Wonders of the World, as imagined by Maarten van Heemskerck in 1572.  Via Wikipedia.

The Seven Wonders of the World, as imagined by Maarten van Heemskerck in 1572 (w/ exception of Gardens picture). Via Wikipedia.

Of course, nothing lasts forever —  all seven wonders existed at the same time only over a short span of sixty years.  Then, one by one, they succumbed to natural disasters and deliberate destruction, and now only the Great Pyramid of Giza survives.

Blog carnivals can’t last forever, either! The Giant’s Shoulders has been ongoing for six years now, an eternity in internet time, and the decision has been made to bring it to a close.  This will be the final edition, and what better way to send it off than to take a tour of the history of science along with the Wonders of the World?

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Posted in General science, History of science | 1 Comment

Help me help you!

Things have been rather busy and stressful at work over the past few weeks, in spite of the summer break starting, and I’ve consequently been neglecting the blog.  I will be catching up again in the near future, but in the meantime I thought I’d address something blog-related that’s been on my mind for some time.

One of the most common things I hear about my blog when I talk to family members and non-science friends who have read it is something along the lines of “I was reading one of your science articles but I got lost halfway through it.”

This isn’t necessarily surprising, as I’m often trying to write about rather complicated scientific stuff in a non-technical way, and it’s not always going to be as comprehensible as I hope.  What is kinda surprising, though, is the way in which people tell me this, as many people say it so matter-of-factly that they seem to intend it as a compliment.  Or just the way things are.

But here’s the thing I don’t think that many of them understand: when I’m writing these blog posts, I’m trying to write them so that they can be comprehensible to a non-technical reader.  Saying that you’ve gotten lost in a post, but not telling me where, or why, or asking for clarification, doesn’t help me write better posts.  I often feel as exasperated as Jerry Maguire:

“Help me help you.”  That’s a request I’d like to make to my readers: give me feedback! Let me know what you don’t understand, and I’ll try and explain it better. It isn’t always easy to understand the subtleties of physics and optics, but that’s what makes putting in the effort to learn it so rewarding.  It’s a puzzle, like solving a crossword or a jigsaw, and deciphering the mystery can be just as satisfying.

When I think about the phrase “help me help you,” though, it occurs to me that there are two ways to interpret it.  The way I just described it could be emphasized as “help me help YOU,” where “you” are the beneficiary of understanding.  Really, though, it works with a different emphasis, as well: “help ME help you.”  In other words, when you comment on my posts and explain what part lost you, you are helping me to be a better teacher.

Education is really a two-way street, both in online communication as well as in the classroom.  The teacher is, hopefully, imparting knowledge to the student, but the student can also help the teacher learn how to do his job better.*  So rather than simply make this a somewhat condescending plea for the reader to “learn harder,” I am really asking you a favor:  educate me, as well.  Teach me what works, and what doesn’t work, when I explain things.

Hopefully we’ll both find the experience rewarding.


* Random aside: this two-way street is part of the reason why I’m skeptical about MOOCs.

Posted in General science, Personal | 2 Comments

Love is the Law, by Nick Mamatas

In my experience, Nick Mamatas’ novels are not pleasant to read — and I mean that in a good way.  He is willing to dive wholeheartedly into ugly situations in his writing and challenge the reader with unhappy observations about the world we live in.  I somewhat subconsciously noted this when I read his earlier novel Sensation, but it was really driven home to me in his most recent work, Love is the Law.


 Love is the Law is, like much of Mamatas’ work, an unusual mix of genres: depending on how you look at it, the novel is part horror, part science fiction, part domestic drama, and part weird tale.  It is, however, primarily a mystery novel — it follows punk rock girl Dawn Selinger as she attempts to solve the murder of her mentor Bernstein.  Mentor teaching her what, you may ask? Communism and black magic.  The mystery leads her to uncover secrets more horrifying than any supernatural menace.

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Posted in Horror, Mystery/thriller | Leave a comment

A Michael Faraday primer for COSMOS!

I’ve really been enjoying the new version of “Cosmos: A Spacetime Odyssey,” though this Sunday’s coming episode has me more excited than any other!  Titled “The Electric Boy,” the episode will focus on Michael Faraday (1791-1867), one of the most influential scientists of the 19th century and my personal hero.

So who was Michael Faraday?  He came upon the scientific scene at a time when physics was on the verge of a revolution that would unify the seemingly disparate forces of light, electricity and magnetism — and he played a pivotal role in unifying all of them!  He also made fundamental contributions to chemistry, and on top of it was an amazing teacher whose surviving Christmas lectures are insightful and enjoyable 150 years after their conception.

Portrait of Michael Faraday, 1842.  Via Wikipedia.

Portrait of Michael Faraday, 1842. Via Wikipedia.

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Posted in History of science, Physics | 6 Comments