Testing String Theory? How Real Science Progresses

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 cosmology. 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. …

There’s a dragon in my garage!

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.