The Skeptical Teacher

Musings of a science teacher & skeptic in an age of woo.

Archive for January, 2009

There’s a dragon in my garage!

Posted by mattusmaximus on January 14, 2009

I wanted to do a brief follow up to yesterday’s post – Why Science Matters – because I felt I left something out. Namely, while I mentioned the process of scientific investigation & thinking, I never really outlined it.

I know, we’ve all been told repeatedly about the scientific method – yadda, yadda – but I’ve got a neat way to get you to understand it and the thinking behind it. But I can’t claim credit for this story, as I stole the idea for it from Carl Sagan – it’s called “There’s a dragon in my garage!”


Imagine that one day you are working in your yard and your neighbor runs over to you, panting heavily and out of breath. You ask them what’s wrong, and they excitedly state, “There’s a dragon in my garage!” You figure that you have to see this for yourself, so you grab your camera and head over to your neighbor’s garage.

Once there, you see the usual garage stuff: parked car, workbench and tools, pile of rags, boxes against the wall, some sawdust in a bucket, etc. But no dragon.

“I don’t see any dragon,” you tell your neighbor.

“Oh, I forgot to mention the dragon’s invisible,” comes the response.

Willing to give your neighbor the benefit of the doubt (after all, plenty of invisible things – such as ultraviolet light and radio waves – exist), and you decide to find a different way to detect the dragon. You pick up the bucket-full of sawdust and spread it on the garage floor, thinking that the dragon would leave footprints. After a while, no footprints.

Looking at your neighbor for an explanation, they say (flapping their hands for effect), “Silly me. I neglected to mention the dragon floats above the ground – little wings.”

Growing a little suspicious, you opt for a third test: you decide to throw some of the rags in the air so they’ll flutter down and drape over the dragon, outlining it like a kid dressed as a ghost on Halloween. You toss the rags in the air… and they fall to the ground every single time. Still no dragon.

“Well, the dragon must also be non-corporeal, so that solid objects pass right through it!” comes the frantic response from your neighbor.

Growing frustrated, you decide to attempt one final method of dragon-detection. You set your camera to “infrared” [work with me on this, we are talking about dragons, after all] and set out to see the heat signature of the dragon’s fiery exhalations. You sweep the garage, again and again, with your infrared camera and see no sign of any dragon breath.

Turning an increasingly skeptical gaze upon your neighbor, you ask, “What gives?”

After staring blankly for a moment, snapping their fingers as if receiving a revelation, your neighbor exclaims, “I know! The dragon’s fiery breath must not give off any heat!!!”

At this point, if you’re anything like me, you are likely to head back to your yard work, wondering if your neighbor has been taking too many liberties with their medication.

So what’s the point of this story? It’s simple, actually. The process of science (often called methodological naturalism) is concerned about dealing with ideas that can be tested for validity. You claim there’s a dragon in your garage (an extraordinary claim, I’d say), so in order for the neighborhood to treat you at least a little bit seriously there should be some way in which to test your claim. Otherwise, people start looking at you… that way.

After all, what’s the difference between an invisible, floating, non-corporeal, and completely undetectable dragon… and no dragon at all?

Good question.

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Why Science Matters

Posted by mattusmaximus on January 13, 2009

Sometimes I have to deal with this very question from my own students: “Why should I care about science?” It’s a good question which deserves a well-reasoned response.

Science forms a critical part of our society. Many people can understand the importance of science in relation to technological development – such as the creation of new vaccines every year to deal with the annual influenza cycle, for instance. When people can see the direct application of science to their immediate lives, then it is easy to justify the resources necessary to pursue such scientific work. I often like to say that people have no problem with building a better I-pod and the research that goes with it.

I’m not talking so much about building a better I-pod (though they are very cool). I’m talking more about both the process of scientific thinking as well as the pursuit of pure (or theoretical) science.

Think about it – you are reading this blog post on a device that is the direct result of purely theoretical scientific investigation by individuals who had no notion or motivation to create computers or the Internet. Let me give you a little history lesson…

Around the end of the 19th century, many scientists believed that purely theoretical science was nearing its end. That is, they thought that through the process of science we learned all there was to learn – the rest was simply filling in details, or, as one put it, just getting experimental results to more and more decimal places. Throughout the 1800s, the development and rise of science using methodological naturalism as its method yielded astonishing advances in every field – biology, geology/earth science, astronomy, physics, chemistry. I’ll speak specifically about physics, since that is my area of expertise.

The cornerstones of 19th-century physics were classical Newtonian mechanics, Maxwell’s electricity & magnetism, and thermodynamics. Many physicists of the day thought that with these crown jewels of theoretical physics, we’d figured everything out. But they were wrong.

The Rise of Relativity
Around the year 1900, there were two major developments in physics which shattered the (comforting, to some) notion that we’d figured out all of theoretical physics. The first was the dissolution of ether theory – the idea that all motion (including the motion of the Earth) was relative to some absolute frame of reference called the “ether”. The ether was supposed to be some kind of imponderable substance which was postulated to exist throughout all of space. In fact, it was believed that light used the ether as a medium through which to propagate; many scientists disliked the idea that light (commonly understood as an electromagnetic wave) could travel through completely empty space because all waves were believed to have a medium which they had to disturb in order to propagate.

By the late 1800s, two scientists – Albert Michelson and Edward Morley – decided to perform an experiment which would indirectly detect the ether, thus taking it from mere speculation to a firmly established phenomenon. In 1887, they performed their now-famous experiment where they attempted to use a beam of light traveling relative to the Earth’s supposed motion through the ether to detect changes in the speed of the light beam. But they got a surprising result – no matter in which direction they oriented their device (called an interferometer) relative to the direction of Earth’s motion, they got the same result: the speed of light was unchanged. No matter what they did, no matter how many times they ran their experiments, the light beams traveled at the same value: 3×108 meters per second.

This “failed” experiment led to the eventual acceptance that the ether was a fiction.  And not only that, but the speed of light being constant, no matter the relative motion of the observer, led to the foundations of the theory of relativity.  In 1905, Albert Einstein formulated his special theory of relativity, and in 1916 he followed this with his general theory of relativity. You may have heard of general relativity (GR for short), because it is the theory that outlines space & time as woven into a strange fabric known as space-time; in this space-time fabric objects with lots of mass (such as planets, stars, and black holes) warp or dent the fabric. These space-time dents are what Einstein viewed as gravity, and GR now forms our current views on gravitation.

We now use GR to deal with everything from understanding the physics of black holes to dealing with time-delays between ground stations and geosynchronous satellites. Believe it or not, without an understanding of gravity via GR, your GPS receiver wouldn’t work – here’s why not.

Quantum Weirdness
At the beginning of the 20th-century there was another shakeup in the world of physics. This had to do with (among other things) three pesky phenomena the classical physicists of the 19th century were having a hard time explaining: the photoelectric effect, blackbody radiation, and spectral lines. I’ll focus upon blackbody radiation for the purposes of this example, but all three phenomena are explained the same way.

For a long time, scientists knew that when an object heated up it tended to glow. The object would start off feeling warm (which we now know to be infrared radiation), then it would glow red, then orange, and – if it got really hot – white! It was believed that the reason for the white-hot glow of extremely hot objects was due to the emission of all colors of visible light (ROYGBIV) added together – this was confirmed by viewing such objects through a spectrometer. However, there was a big problem – it was believed by the classical physicists that the intensity of the light as a function of wavelength should follow the Rayleigh-Jeans Law (shown below)…

The Rayleigh-Jeans Law as compared to Planck's Formulation of blackbody radiation.

The picture says it all – the data collected from hot objects simply didn’t fit with the classical view of blackbody radiation (this is the “ultraviolet catastrophe” listed above). Physicists were at a loss to explain this contradiction between their theories and observations. Then one day, Max Planck, brought forth a hypothesis which many found to be crazy: Planck proposed that light was not a continuous phenomenon, but instead light was given off in small, discrete bundles of energy called photons. Not only that, he further postulated that the energy of a particular photon of light was directly proportional to its frequency…

E = hf

Planck’s little equation did the trick. It provided a theory which explained the blackbody radiation perfectly, but it rocked the foundations of the physics community. In fact, many people refused to accept the idea, especially when the fuller implications of Planck’s idea (sometimes referred to as the “quantum hypothesis”) were realized.

Over time, many physicists used the new quantum physics to go on to explain all manner of phenomena, and the new theory of quantum mechanics was born. By the 1940s and 50s, quantum mechanics was being used to pave the way for a new kind of technology called computers. And, with the advent of more widespread computer technology – including the desktop computer, the Internet, and the World Wide Web – our society has been changed in ways that no one could have possibly ever predicted, certainly not Max Planck when he was pondering a solution to the ultraviolet catastrophe.

So, the next time you get online, pause for a moment and think about it – the reason you are able to surf the Web on a computer is because over 100 years ago someone was attempting to figure out a purely theoretical problem in physics. The next time you log on, think about

E = hf

In conclusion, I hope this post has given you a better idea of why pure scientific research is useful. It not only helps to address purely theoretical questions of interest to scientists, but the effects upon all of us can be quite profound – from how we view the universe to how our very society functions on a day-to-day basis.

Yes friends, pure science does matter. And don’t you forget it.

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Welcome to The Skeptical Teacher!

Posted by mattusmaximus on January 12, 2009

Greetings and welcome to my new blog.  My name is Matt and I’m a high school physics teacher (plus a part-time physics & astronomy college professor) with a strong interest in promoting science education & critical thinking among my students and the population in general.  I am a self-described skeptic, someone who believes in Carl Sagan’s adage that “extraordinary claims require extraordinary evidence.”

The purpose of this blog is to allow me to expound upon various topics related to skepticism, science, and education.  Some of my posts will be about specific topics – such as scientific illiteracy, pseudoscience, tips & tools for promoting skepticism & critical thinking in the classroom, current events in the news, etc.  Other posts could consist of my random thoughts of the day.  I might post regularly, but since I’m a pretty busy guy there will likely be times when I’m away from the blog for a few days.

If you ever have questions, criticisms, or wish to leave me feedback, feel free to contact me.  I will attempt to respond to all communication in a timely manner.  Thanks for visiting!

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