Wednesday, November 17, 2010

What Should We Ask of a Theory?

First, an update on the poll. So far, Newton's laws appears to be winning, but since the poll runs for a little while longer, I thought I'd share a brief essay I wrote on "What Should We Ask of a Theory?" Maybe I'll post its companion essay, "The Job of Science," later.

What should we ask of a theory? That's a somewhat broad question, but one vitally worth answering. Specifically, what should physicists ask of a physical theory? Already the classic divide between theoreticians and experimentalists springs up. The theoreticians would likely extol the virtues of beauty and logic in a physical theory, while their experimental counterparts would be more practical, demanding simply that a theory work. Much as I would love to smooth over the division, I must here side with the experimentalists. All we can ask of a theory is that it work.

What's wrong with beauty? Nothing. I love beautiful theories, Maxwell's breathtaking equations being the first ones that spring to mind. But how did Maxwell discover these equations? Not by looking for what was the prettiest, that's for sure. He looked for an explanation that worked, and found that the explanation that worked was beautiful. This happens so often, I believe, because the world is beautiful and we were created to appreciate and seek the beauty in the world. Nevertheless, beauty in a theory is a “bonus,” as it were. I can think of half a dozen ways of putting together the quarks, or of making relativity, that would be just as beautiful as the contributions of Gell-Mann and of Einstein to those subjects. So why are Gell-Mann and Einstein famous physicists while I'm a mere amateur? Because their theories are not only beautiful, they work – and they were found by searching for a theory that works. Let us not look for beautiful theories and hope they will work; let us look for working theories and know they will be beautiful.

What does it mean that a theory work? Obviously, we can't just say that a theory works in the same way as a car or a tool works. However, the tool analogy is closer than it seems, because a theory has a specific job to do, also – namely, to describe some aspect of the observed physical world. So a theory that works is a theory that describes the world, and it seems reasonable to add that we must be able to make predictions with it, and that the predictions must be accurate within their own sphere. (This last prepositional phrase allows theories like Newton's mechanics to make the definition of a working theory, even after the advent of relativity and quantum mechanics.)

What about replacement theories? When the old theory really fails to properly describe the world, a new theory is always to be commended, assuming it works (i.e. describes the world) better than the old theory. Sometimes, however, the new theory is put forth on purely hypothetical considerations, or considerations of beauty. What then? My advice to these theorists would be: Play with your theory a little bit. See whether it makes the same predictions as the old theory. If it does, is it easier to use? If so, you've found an alternative formulation or method that could be worth a shot. This is where beauty can become a “tiebreaker question” between two otherwise identical-in-practice theories. If it makes different predictions than the old theory, have they been tested already? Are they reasonable? If they are reasonable but untested, it has the potential to be an entirely new theory, and my advice is to ask the nearest experimentalist about testing it.

How do we judge a theory? What should the international scientific community do when some crazy-haired guy in a patent office says he's improved on Newton? I suggest that any new theory be judged based on its adherence to three simple standards:

  1. Does it explain everything its predecessor explains? (If not, it's falsified.)

  2. Does it explain something its predecessor doesn't explain? (If not, it's unnecessary.)

  3. Does it explain anomalous observations other than those that inspired it? In other words, does the idea designed to explain unusual occurrences A and B also explain unusual occurrences C and D? (If not, it's undesirably ad hoc.)

Although requirement (3) appears the most rigorous, right now in physics requirement (2) is the hardest to meet. Quantum theory explains everything observed on the small scale, relativity explains everything observed on the large scale, the point where they might come into contradiction is far beyond the limits of current observation. So, unfortunately for the physicists, most puzzles in physics are those of beauty, logic, and order – not ones of “I saw this particle do that, and it shouldn't have, according to our theory's predictions.” I don't believe that beauty is a characteristic we should make our primary goal in physics, but I do believe that the most effective theories have always been the most beautiful ones, so it is likely that the anomalies from what the Standard Model “ought” to look like really do indicate anomalies from what actually happens, which we simply haven't been able to observe yet. But can a theory based, like string theory, on what logical considerations would indicate really be a theory that ends up describing the real world? Only time and experiments will tell.

Monday, October 25, 2010


I'm putting a poll on the sidebar to find out what y'all want to hear about on Strangely Charming next. Please, please, please vote!
Physics forever,

Monday, October 11, 2010

The Five Problems of Modern Physics

I'm sure everybody who reads this blog will sooner or later get thoroughly tired of me talking about Lee Smolin. Nevertheless, in the hope that it's "later" rather than "sooner," here's yet another thing inspired by Smolin: my list of Five Problems of Today's Physics. The general outline of the problems is his; some of them are taken almost exactly from his book The Trouble with Physics (speaking of which, read it), and some, especially the last one, I have changed to reflect my worldview and my beliefs about cosmology.

Enough preface already!

    The Five Problems of Today's Physics

    largely taken from Lee Smolin, The Trouble with Physics

  1. The problem of quantum gravity: Combine general relativity and quantum theory into a single theory, preferably with no infinities, singularities, or universe-eating monsters.

  2. The foundational problems of quantum mechanics: Resolve the philosophical problems in the foundations of quantum mechanics, either by making sense of the theory or by inventing a new theory that does make sense.

  3. The problem of the unification of particles and forces: Determine whether or not the various particles and forces can be unified in a theory that explains them all as manifestations of a single, fundamental entity.

  4. The problem of the adjustable constants: Explain how the values of the free constants in the standard model of particle physics are chosen in nature. [I think this one is not such an issue, because I believe that God could have set the constants to whatever He pleased. However, it does seem possible that He might instead have chosen a scheme for nature that sets its own constants; we can see from the universe and from His Word that He loves beauty and order.]

  5. The problem of cosmology: Describe what the universe used to be like and how it got to what it is like now. [Smolin has this as “Explain the dark matter and dark energy.” I have adjusted it to reflect the need to offer a biblically-consistent alternative to the big bang model.]

Physics forever,

Friday, October 1, 2010

Another Physics Cake

This one isn't a birthday cake, either, but it's pretty awesome.

Yes, those are Maxwell's equations. Written in icing.

I love this cake decorator.

(Google "physics cake" and you'll find even more. Physicists like their cake, especially grad students. There's even a Fermat's Last Theorem cake, which is technically math, but... oh well.)

Physics forever,

Wednesday, September 29, 2010

Happy Birthday CERN!

Exactly 56 years ago today, a convention was signed creating the European Organization for Nuclear Research, otherwise known as CERN. In those 56 years, CERN has produced 5 Nobel prizes for its physicists, discovered innumerable particles and effects (including "neutral currents" and the first antihydrogen atoms, to name just a few), nurtured many bright young physicists, and created the World Wide Web -- originally intended to enable easy communication of results among researchers! So happy birthday, CERN, and may you have many more decades of discovery.

(Yes, I know this is a wedding cake, but isn't it amazing? Besides, the only physics-related birthday cake photo I could find was kind of ugly.)

Physics forever,

Saturday, September 18, 2010

Science Has Limitations

As I like to say: "Even if we find a TOE*, where's the rest of the foot?"

As C. S. Lewis put it in Mere Christianity: "Suppos[e] science ever became complete so that it knew every single thing in the whole universe. Is it not plain that the questions, 'Why is there a universe?' 'Why does it go on as it does?' 'Has it any meaning?' would remain just as they were?"

Although Lewis put it better than I can, the thrust of these comments is that science has limitations -- it cannot deal with beauty and ugliness, with good and evil, probably not with thought and consciousness, and it can never, ever explain anything which is not observable in the physical universe, such as the reason for things. Science can never answer the last of the small child's string of "why"s. It can explain why the sky is blue, why the photons behave that way, but it can never explain where its own physical laws come from -- why, for instance, there are exactly three dimensions of space and one of time. (If some future theory should explain this, then the question will simply be: why does this theory apply to the universe?) While this may seem a strange thing to emphasize on a science blog, it is actually the most important thing in all the philosophy of science. Science has limitations, but science's limitations are a good thing. By delineating the boundaries of science, the limitations turn our experimentation to areas where it can produce results, and turn us to the Word of God for those essential questions that science cannot answer: Is there meaning in the universe? Does anything exist beyond matter and energy? What is right and what is wrong? Is there a God? What is God's nature? How can a mere human become accepted by the Creator?

*Theory Of Everything, a scientific theory that (if ever discovered) would explain the actions of every physical object in the universe

Sunday, September 5, 2010

In case you haven't heard about it...

Wolfram|Alpha! It's a "computational knowledge engine", which means that rather than searching the web for relevant links, it translates your question into computer code, then uses its own (enormous) databases to calculate the answer to your question, which it then returns, in comprehensible English! It's a very useful piece of software, and although it's not perfect, it can calculate the answers to questions on topics from math to linguistics -- and, of course, physics.

So why are you still reading my confusing explanation? Go try it out at, or in the search box labeled "Wolfram|Alpha" right here on Strangely Charming!

Physics forever,
P.S. Sorry this isn't exactly physics-related, but I felt the need to explain the W|A search box on the blog. :D

Saturday, September 4, 2010

A bit of physics-related fun

This is "The Particle Physics Song" sung by the CERN Choir. Yes, there is a CERN Choir.
I thought some of y'all might enjoy it!

Explanation: SUSY is supersymmetry, a much-sought-for but never yet found phenomenon that physicists hope to simplify the laws of physics with. "Higgs" is the Higgs boson, another predicted but not found particle that many physicists spend their lives looking for. It's supposed to explain where mass comes from.
Physics forever,

Thursday, September 2, 2010

Tied Up with Strings

Or, Why I Don't Believe in String Theory.

String theory has a large body of ardent fans, both physicists and laypeople. I am not one of them.

"But string theory is so beautiful!"
a) Beauty does not mean truth. I can think of half-a-dozen symmetries at least as beautiful as Gell-Mann's Eightfold Way. So why is he a world-famous physicist and I'm an insignificant blogger? Because his version is not only beautiful, it works. Yes, most good theories are beautiful, but not every beautiful theory is a good theory.
b) Beauty is in the eye of the beholder. I actually don't think string theory is that beautiful! People complain about the ugliness of the Standard Model's eighteen adjustable constants; well, I find string theory's six (or seven, in M-theory) extra dimensions just as ugly and wasteful.

"It's going to be a unique theory of nature."
"Going to" is the operative word here. Perhaps someday, if we can ever get M-theory written down (see next point), it will be a unique theory of nature. But then it won't be string theory, it will be some other theory. There are several thousand, possibly several million, different string theories, and our universe could have been any one of those. (Of course, I believe that God could definitely control the string theory our universe is described by; however, I don't think he would have designed our universe so messily.)

"But M-theory is a unique theory of nature!"
And so it may be, but it doesn't do anyone any good. We can't even write down all of M-theory's solutions (string theories), and we can barely prove that M-theory exists! Even regular string theory is pretty useless: the theorists can't calculate with it and the experimentalists can't test it, so what are we to do with it?

"Well, anyway, it's the only game in town for quantum gravity."
No way. Loop quantum gravity! Noncommutative geometry! Doubly special relativity (in which lightspeed depends on the photon's energy)! Maybe none of these are any good. In that case, let's invent some more!

So my words to the string theorists: By all means, keep working on string theory; it's a fascinating structure with interesting symmetries. Just don't call it physics. Call it pure math.

Physics forever,

P.S. If you enjoyed this post, check out Lee Smolin's books The Trouble with Physics and Three Roads to Quantum Gravity. He's a skeptic, but a very refreshing kind: he's as skeptical of established science as he is of religion.

Wednesday, September 1, 2010

Who am I, anyway?

Hi! I hope you like physics, because you have stumbled into the deep and devious lairs of my physics blog! This blog consists of the ramblings, musings, and rants of a (hopefully) future physicist, with a few quotes thrown in for good measure. You don't have to know physics to read this blog, although some background might help in understanding it. Hope you don't mind putting up with my physics obsession!

Oh, wait. I was supposed to be talking about me, right? I'm a high-school student with - you guessed it - a physics obsession. You can call me CoolCat. I love the Standard Model and I REALLY love Relativity; I think quantum physics is philosophically unsound and will soon be superseded by a theory in which waves/particles/whatever have real, precise properties; I think entanglement/nonlocality is a real phenomenon, though without any mystical implications; I don't believe in string theory (future post topic!). About me outside of physics: I also like learning languages/linguistics, I'm homeschooled, and I am incredibly blessed to be a Christian and a child of God.

Thanks for stopping by, and enjoy the (quantum) weirdness!

~CoolCat, the future physicist

(Oh, and if you don't get the title of the blog: "charm" and "strange" are the second-generation quarks in the Standard Model. You think those are odd names? The third-generation quarks are either "top" and "bottom" or - get this - "truth" and "beauty". Physicists have a bizarre sense of humor.)