The Skeptical Teacher

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

Posts Tagged ‘falsifiability’

Testing String Theory? How Real Science Progresses

Posted by mattusmaximus on September 16, 2010

Something very interesting has happened recently in the world of theoretical physics.  One of the hottest ideas around is the notion of so-called string theory: it’s the idea that all matter & energy in the universe – from the electrons & quarks that make up atoms to photons of light to everything in between – is composed of ultra-tiny strings of vibrating energy.  It’s a marvelous and mathematically elegant idea, one which many theoretical physicists believe holds the key to unifying the fundamental forces of nature, but it suffers from a big flaw: these strings are, according to the theory, so small that we have no way to experimentally detect them. Thus, if such is the case, then many physicists & critics of string theory have equated the idea with a dragon in the garage, an unfalsifiable notion which isn’t subject to scientific investigation.  I have placed myself into this category of string theory skeptics for quite a long time for this very reason…

… up until now, that is.  It seems that the question of whether or not string theory is testable, and therefore real science, has been answered.  That’s because recent theoretical analysis of string theory has revealed that it makes unique predictions which can be tested in a controlled laboratory setting having to do with a weird phenomenon called quantum entanglement. Up until now, physicists haven’t had a good way to really predict the behavior of systems that coupled via quantum entanglement, but it seems that some aspects of string theory can shed some light on this…

New study suggests researchers can now test the ‘theory of everything’

String theory was originally developed to describe the fundamental particles and forces that make up our universe. The new research, led by a team from Imperial College London, describes the unexpected discovery that string theory also seems to predict the behaviour of entangled quantum particles. As this prediction can be tested in the laboratory, researchers can now test string theory.

Over the last 25 years, string theory has become physicists’ favourite contender for the ‘theory of everything’, reconciling what we know about the incredibly small from particle physics with our understanding of the very large from our studies of . Using the theory to predict how entangled quantum particles behave provides the first opportunity to test string theory by experiment.

“If experiments prove that our predictions about quantum entanglement are correct, this will demonstrate that string theory ‘works’ to predict the behaviour of entangled quantum systems,” said Professor Mike Duff FRS, lead author of the study from the Department of Theoretical Physics at Imperial College London.

“This will not be proof that string theory is the right ‘theory of everything’ that is being sought by cosmologists and particle physicists. However, it will be very important to theoreticians because it will demonstrate whether or not string theory works, even if its application is in an unexpected and unrelated area of physics,” added Professor Duff. …

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Posted in physics denial/woo, scientific method | Tagged: , , , , , , , , , , , , , , , , , , , , , , , , , | 1 Comment »

The Importance of Being Wrong

Posted by mattusmaximus on January 26, 2009

I was initially planning on titling this post “The Importance of Being Right” – but then I thought that we all pretty much already knew that. We all know that if you don’t do the engineering calculations correctly, for instance, the car engine doesn’t work. Or if you don’t really know what you’re doing with biochemistry, the drug/vaccine/antibiotic you’re making doesn’t cure disease effectively. Clearly, because the universe functions according to a set group of natural laws we must make sure that our science & technology fits with those laws. To insist the universe adhere to our own preconceptions while ignoring how it really behaves is a sure path to self-delusion. Taken to its logical extreme, such thinking leads towards solipsism – also known as the philosophical idea that “My mind is the only thing that I know exists.”

Aside: I like to ask those espousing solipsism whether or not they look both ways before crossing the street – strangely enough, the answer has always been “yes.” The following cartoon also illustrates the silliness of taking solipsism too seriously…

solipsism

So, we all know that because there is an external reality beyond our own mind that functions independently of that mind, the importance of being right is unquestionable.

But what about the importance of being wrong? I will tell you this… it is very important to not only be wrong (to a certain degree) but, more importantly, how to learn about why we were wrong. I had the idea for this post because I was at my martial arts dojo today, and I was trying to help a less-experienced student with a technique which is a defense against mae-giri, also known as a front kicking attack. As I attacked him, he had a hard time avoiding my kicks, and he grew frustrated that he wasn’t able to perform the technique easily. I responded by telling him not to let it bother him, because he’ll do it wrong 100 times before he gets it right once. Hopefully, throughout the process of doing it wrong so many times, my junior student will learn how to do it correctly. We learn by making mistakes.

It is no different in my classroom – I’ve dealt with many a frustrated student who was having trouble learning how to do a physics problem or attempting to work their way through a lab. Only with constant practice, and by making a plethora of errors, can most students effectively learn what not to do. As I tell my students, the reason why I’m so good at physics is because I’ve had so many experiences making mistakes! 🙂

There is another issue – many students are stuck on always getting the “right” answer in science class, and sometimes teachers (myself included) are guilty of overly reinforcing this attitude. But to get the process – and not merely the facts – of science across to our students properly, I think we have to walk a fine line as educators. And this is where the importance of experimental lab work in science classes cannot be overstated.

In my classes I require my students to do a lot of lab work. Many times I purposefully set up scenarios in which the students are to draw conclusions from their data. A perfect example is when I ask them to make a series of measurements on the period of a simple pendulum, and they are to isolate three variables in the process – mass of the pendulum bob, amplitude of the swing, and the pendulum’s length. I then ask them to, based upon their data, determine how (or even if) each of these variables affects the period of the pendulum as it swings to and fro.

pendulum

The responses I get from my students are interesting, because despite the fact that they’ve collected the data, many answer the question incorrectly. Many will say that the more massive the pendulum bob or the smaller the amplitude, the shorter the period of the pendulum. And this is incorrect – under controlled conditions, the period of a simple pendulum is only affected by its length! That is, the longer the pendulum, the longer its period, and the mass & amplitude don’t affect the period.

Often, when I point this out to students, they don’t believe me at first. But then I point to the data which they collected, and then they see it – they allowed their preconceived biases of how they thought the pendulum should behave to creep into the scientific process. In so doing, they were giving me what they thought ahead of time to be the “right” answer, instead of gleaning out the proper answer from their data in a non-biased manner. Their conclusions were wrong, but when it comes to such a lesson I want them to understand why they were wrong – experimenter bias.

I mention all of this because it should be noted that science cannot be done in a vacuum – this is why we often speak of a scientific community. Scientists are just as human as anyone, and we all come to the process with our own biases & preconceptions, and – just like my students – we sometimes see what we want to see. But the scientific endeavor is different from all others in one critical way – peer-review. Peer-review is necessary in science precisely to make sure that our biases, preconceptions, mistakes, and sometimes outright fraud do not unduly influence the results of our explorations. Through peer-review we often catch each others mistakes, we demand that proposed hypotheses be falsifiable, we insist that experiments be repeatable and verifiable. As such, we get things wrong all the time in science, but we figure out why we get it wrong – and this puts us closer to the path of getting things right. Through this rigorous peer-review process, we see that science is self-correcting.

And that is a major distinction between science and pseudoscience. The scientific community does peer-review, learns from its collective mistakes, and employs a largely self-correcting process in its search for our understanding of the universe. Pseudoscientists of all stripes – astrologers, homeopaths, creationists, and conspiracy theorists to name a few – make this one fatal flaw: lacking adequate peer-review, they don’t learn from being wrong. Rather, they insist upon molding the universe to fit with their worldview, and in so doing they delude themselves & others. This cartoon illustrates the point rather well…

science vs. pseudoscience

Now I’m off to grade some exams. Hopefully my students have learned from earlier mistakes.

Posted in scientific method | Tagged: , , , , , , , , , , , , , , , | 2 Comments »

 
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