Physics demonstrations: vortex cannon!

Posted on August 28, 2012 by skullsinthestars

As I’ve said before, some of the best scientific demonstrations are things that can be put together with simple everyday components and exhibit surprising, even counter-intuitive, phenomena.

One of my all-time favorite demonstrations is of this form!  All one needs is a plastic garbage can, a plastic shower curtain, and a bungee cord that hooks snugly around the top of the can.  Optional but quite useful is a fog machine.

What happens?  We cut a roughly 4-5” diameter hole in the bottom of the garbage can, and use the bungee cord to seal the shower curtain to the other end.  Fill the garbage can with fog, strike the shower curtain and — voila! — smoke rings!

These are actually vortex rings — circulating masses of air (and fog) that can persist and travel over a surprisingly long distance.  They also carry enough “oomph” to knock over a stack of plastic cups or scare the heck out of one’s housepets*.

So how does this “vortex cannon” work, and what does it demonstrate?  There is a surprisingly amount of physics and history behind such vortices, and they can be a lot more powerful!

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Posted in Physics demos | 20 Comments

Dennis Wheatley’s To the Devil a Daughter

Posted on August 19, 2012 by skullsinthestars

Occasionally, I just have a feeling about a book.  I’ve read a number of novels by the author Dennis Wheatley (1897-1977) and have generally been impressed.  Way back in 2008 I favorably reviewed Wheatley’s supernatural thrillers The Devil Rides Out (1934) and The Haunting of Toby Jugg (1948) as well as his bizarre adventure novel They Found Atlantis (1936).  Not long afterwards I picked up a copy of one of Wheatley’s most famous novels, To the Devil – a Daughter (1953):

Oddly, however, though To the Devil – a Daughter looked to be another entertaining Satanic thriller like Rides Out and Toby Jugg, I found myself curiously unable to dive into the book.  On numerous occasions when I’ve been looking for something new to read, I passed over Daughter or even picked it up off the shelf and started to read the first chapter.  I never got very far, however: was it intuition, or was I just not in the mood for that sort of story?

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Posted in Horror | 1 Comment

The Giant’s Shoulders: The Fiftieth Anniversary edition is out!

Posted on August 16, 2012 by skullsinthestars

The fiftieth edition of the history of science blog carnival The Giant’s Shoulders is up at From the Hands of Quacks!  In this lovely edition, you can read about science history in the Olympics, new blogs on women in science, and posts that put the historic Mars Curiosity rover in perspective.  Among the excellent submissions:

  • The athlete in 1913 who drank too much Coca-Cola,
  • A frustrating search for the “truth” about decapitation,
  • How a fragmentary Ichthyosaur skull inspired Jules Verne,
  • and much more!

Thanks to Jai Virdi for putting together a lovely and intriguing carnival!

It looks like we’ll be keeping the carnival going for the near future: The Giants’ Shoulders #51 will be hosted by David Bressan at his History of Geology blog on 16 September 2012. Submissions can be made till 15 September 2012 either directly to the host, to The Renaissance Mathematicus or to me directly via email.

Posted in General science, Science news | Leave a comment

My 5-year blogiversary!

Posted on August 14, 2012 by skullsinthestars

I almost missed it!  It turns out today, August 14th, 2012, is the 5-year anniversary of the founding of this blog!

I would have in fact missed my “blogiversary” entirely if Jason Goldman of The Thoughtful Animal hadn’t tweeted congratulations to Ed Yong yesterday for the 6th anniversary of his blog!

My very first post on August 14th, 2007 was titled, “Educate or Bust” and that title describes the purpose of this blog just as well today as it did back then.  (Though, hopefully, the writing has improved over the years.)

To celebrate, I thought I’d share links to some of those science blog posts I’ve written that I am particularly fond of.  I hope you enjoy this trip back through my blog’s history!

  • Optics in the Haunted Mansion! (May 12, 2009).  One of the perks of being a scientist is being able to peek “behind the scenes” at places like Disney World without actually being behind the scenes! While on our honeymoon at Disney, my wife and I took numerous trips through the Haunted Mansion.  I had never thought about how its illusions worked before, but once I thought about it I was able to correctly deduce the answer.
  • Faster than a speeding photon?  Precursors test whether light can be faster than light (October 9, 2011).  Last year, there was a media frenzy when it looked, briefly, like neutrinos might have been detected moving faster than the speed of light (they weren’t).  At nearly the same time, researchers were performing independent experiments to see whether light could violate its own speed limit while traveling in matter.  I was quite happy with my explanation of the difficult physics behind the experiment, and managed to get a mention on “Boing Boing”!
  • Attack of the giant squid! (August 4, 2010).  After I blogged an old paper describing a sighting of a “kraken”, Sarah Kavassalis asked if I could find the most famous paper about the giant squid: an 1874 incident in which a recklessly curious fisherman ran afoul of a squid bigger than his boat!  I found not only the original paper, but a wonderful story and a significant moment of scientific history.
  • The saga of the scientific swindler! (February 24, 2011).  Speaking of wonderful stories: some of the most remarkable stories of scientific history have been forgotten through the years, just waiting to be rediscovered in technical journals!  When I started to browse through the first issues of Science in the late 1800s, I kept finding mentions of a “swindlers” of geologists and paleontologists.  The con man’s story is a fascinating one, and basically forgotten until I rediscovered it.  Also got featured in Boing Boing!
  • The gallery of failed atomic models, 1903-1913 (May 27, 2008).  One of my first major posts on the history of science was one of my most elaborate!  Before the structure of the atom was elucidated by the experimental work of Rutherford and the theoretical work of Bohr, many physicists guessed wildly at it.  Tipped off by a vague comment in a book on the history of atomic physics, I tracked down the original papers describing pretty much all of these early atomic models and explained them all in some detail.  Not my best writing (one of my earliest science blog posts), but one of my favorite posts.
  • So, what is a “temporal cloak”, anyway? (January 7, 2012).  I actually did my PhD on the physics of invisibility before it was a “cool”, and still remain actively interested in the subject.  In this post, I explained how a new form of cloaking known as “temporal cloaking” works, and related it back to its more famous counterpart.

Here’s hoping I have many more years of science (and weird fiction) writing ahead of me!

Posted in Personal, Physics | 10 Comments

What’s the difference between “transparency” and “invisibility”?

Posted on August 8, 2012 by skullsinthestars

In writing my previous post on The Murderer Invisible, I started thinking again about the relationship between something being “transparent” and something being truly “invisible”. Most of us can appreciate that, under the right circumstances, a transparent object like a glass window can be very hard to see, but most of us also appreciate that glass is not even close to fitting the popular perception of invisibility.  In fact, though we encounter plenty of transparent things in nature, we don’t encounter invisible things.

What’s the difference?  In this short post, I thought I’d try and clarify things.

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Posted in Invisibility, Optics | 8 Comments

Philip Wylie’s The Murderer Invisible

Posted on August 5, 2012 by skullsinthestars

If it were a mystery novel, The Murderer Invisible would be a failure right off the bat, as the plot twist is explained right there in the title!  As science fiction and horror, however, this 1931 book by Philip Wylie is eerily effective, and the title is in fact an understatement of the acts that transpire within its pages.

Perhaps the best short description of The Murderer Invisible is to call it “H.G. Wells’ The Invisible Man on crack cocaine.”  The villains of the two stories have similar backgrounds and similar goals; they also share in the unpleasant realization that invisibility has some unexpected and unpleasant side effects.  However, where the invisible scientist Griffin of Wells’ tale is defeated before he can carry out his plans for world domination, Wylie’s William Carpenter manages to achieve many of his goals.  The result is death, destruction and worldwide panic.

I came across a reference to this novel while researching one of Wylie’s famous stories, Gladiator, which was likely a partial inspiration for Superman!  Philip Wylie was a prolific author who made his mark on science fiction most notably with the novel When Worlds Collide, which was also turned into a 1951 movie.  Many of his other novels seem to have faded into relative obscurity — as I’ve learned through experience, however, this does not mean that they are of poor quality.

Let’s take a look at The Murderer Invisible; some mild spoilers follow.

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Posted in Invisibility, Science fiction | Leave a comment

The Giant’s Shoulders #49: “Crisis what crisis?” edition is out!

Posted on July 30, 2012 by skullsinthestars

I’m a few days late in noting this, but the 49th edition of the history of science blog carnival The Giant’s Shoulders is up at The Renaissance Mathematicus! In this edition, you can read about:

  • Sports doping, Victorian style,
  • The deadly dead!
  • Inventions of Thomas Edison you’ve never heard of,
  • and much more!

Thanks to Thony for handling this edition of the carnival!  By the way, we’re still trying to decide the future of the carnival; please read the post here.  The next edition will be held at From the Hands of Quacks on August 16th; please nominate posts by emailing the carnival hosts (me or Thony) or putting suggestions in the comments here.

Posted in General science, Science news | Leave a comment

Wackerbarth whacks Piazzi’s pyramid power! (1867)

Posted on July 29, 2012 by skullsinthestars

One aspect of science that I try and emphasize time and again is that it is a community effort.  Individuals can make discoveries, but individuals are subject to mistakes (such as the recent arsenic life brouhaha), deliberate fraud (as in the fictitious MMR-autism link fabricated by Andrew Wakefield) or can simply go crazy!  Individual scientists, or even small groups of them, can give life to incredibly damaging nonsense; fortunately, there are usually other enlightened researchers out there that will boldly do battle with this misinformation.

One bit of pseudoscientific nonsense that still, sadly, remains with us today is what is known as pyramidology.  Broadly speaking, it is the belief that pyramids in general, and the Great Pyramid of Giza in particular, holds hidden secrets — lost knowledge, secret builders, even supernatural powers.

The Great Pyramid of Giza. (image via Wikipedia)

This “science” of pyramidology is surprisingly old: its biggest proponent was Charles Piazzi Smyth (1819-1900), an important astronomer who began his own pyramid researches in the 1860s and wrote a number of “scholarly” books on the subject that arguably sparked the persistent pyramid craze.  Fortunately, pyramidology did not survive long in the scientific community, thanks to a number of pointed critiques by Smyth’s scientific colleagues.    Of all the abuse that Smyth received at the hands of other scientists, however, none was more hilariously devastating than that delivered by Athanasius Diedrich Wackerbarth.  In 1867 he wrote a critique of Smyth’s work that was read before the Royal Society of Edinburgh and left the distinguished astronomer fuming!Smyth’s deluded view of Egyptology, and Wackerbarth’s rebuttal of it, are great illustrations of common scientific fallacies.  We can learn a lot about the way science is done by taking a look at Smyth’s scientific and mathematical mistakes.

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Posted in ... the Hell?, History of science | 9 Comments

A. Merritt’s Seven Footprints to Satan

Posted on July 20, 2012 by skullsinthestars

Abraham Grace Merritt (1884-1943) was an author with an vivid and bizarre imagination!  Among his surreal fiction stories one can find a hive-like race of metal, electrically powered geometric shapes (The Metal Monster, 1920), a colossal stone face dripping tears of gold above a massive abyss (The Face in the Abyss, 1923), a lost world hidden in a valley concealed by a massive mirage (Dwellers in the Mirage, 1932), and a battle between gods taking place on a boat sailing interdimensional seas (The Ship of Ishtar, 1924).

Merritt was wildly popular in his time, but most of his works are out of print and can be quite hard to find.  I recently finished one of the rarer of Merrit’s books, namely Seven Footprints to Satan (1927):

My 1942 edition of Seven Footprints to Satan.

I’ve actually had Seven Footprints on my shelf for a couple of years.  At first glance, it looked to be a rather mundane tale about Satanism similar to the works of Dennis Wheatley that I’ve discussed before (and will return to in a later post).

Boy, was I wrong!  Seven Footprints to Satan is a surprisingly engaging thriller and weird tale about an evil super-genius, his ingenious schemes, and a diabolical wager he poses that can cost losers their very souls!

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Posted in Mystery/thriller | 11 Comments

Optics basics: refraction

Posted on July 16, 2012 by skullsinthestars

In all of my discussions of basic principles of optics, I’ve so far neglected to talk about one of the most fundamental and important: refraction!  In short, refraction is the bending of a ray of light when it passes from one medium to another.  Unlike optical phenomena like diffraction and interference, which usually require careful experimental preparation to be observable, refraction is readily seen all around us.  If you’ve ever seen a seemingly bent straw in a glass of water, you’ve seen the effect of refraction.

A straw which seemingly has a kink in it, thanks to refraction. The red line highlights the kink.

So we’ve all seen refraction, and can recognize it, but how does it work, exactly?  And why does it happen?  And what can we do with it? All of these questions are surprisingly non-trivial, and we’ll tackle them in this post.

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Posted in Optics basics | 6 Comments