Thursday, October 27, 2011

Science has a lot of explaining to do

First up, let's be clear. This is not an anti-science rant. I'm an avid science-follower and I wish scientists were held in more esteem in the world of sound bites, spin, and outright fabrication of "facts" that passes for decision-making in this world.

This is a lament at the hubris that surrounds much of science, particularly its claims of explaining the physical world.

Physicists are searching for "theory of everything" and hunting for super-symmetry and the Higgs boson to bolster or disprove various theories. This is all very exciting stuff. At least, I think so. But while we may one day have a "theory of everything", I suspect an "explanation of everything" will prove rather more elusive.

My contention is that, while scientific theories are good at describing things in a way that allows us to calculate and predict the behaviour of the physical world with exquisite accuracy, these theories don't go very far in terms of true explanation.

In other words, theories tend to be very good at answering questions of "what", "where", "when", but fall far short of "how" and "why".

Let's have a look at gravity, for example.

Newton's law of gravity provided a remarkable mathematical description for the motions of the planets, that accurately modeled what 17th century astronomers observed. Moreover, it made testable predictions, leading two centuries later to the discovery of Neptune, and then Pluto. These planets were not discovered, like the others, by spotting a point of light moving across the night sky, but by observing the motions of the known planets and deducing the existence of another, as yet to be seen, body. Newton's laws enabled astronomers to work out where to look, and - lo! - there it was.
As far as explanation goes, Newton's law tells us that there is a force of attraction between any two bodies. That works as an explanation on one level. But if you keep poking at it, you soon realise that no-one can really explain what the force is, or why two masses should attract each other in the first place.

Einstein's theory of general relativity goes further, and describes gravity in terms of the curvature of space. Again, the theory has remarkable descriptive and predictive powers, showing how light gets bent as it passes close by a massive body like the sun.

Yet again, this seems to take the explanation, the insight, to another level. It provides a means by which gravitational attraction takes place. But it still leaves open the questions of how a mass bends space. In other words, when you look closer, it doesn't really explain anything much.

Where I get hot under the collar, though, is when we enter the world of particle physics and quantum mechanics.

Yet again, the standard model of particle physics, and the weird world of quantum theory, provide huge descriptive and predictive power. They give us ways of viewing the subatomic world that provides insight undreamt of to scientists prior to the 20th century.
But when it comes down to understanding at a deeper level what's going on, scientists tend to wave their hands in the air and say things like, "The particles exchange force-carrying particles. That explains it."

No, it freakin' well doesn't!

It explains nothing. It just pushes the explanation a bit further away.

Nothing in any of the theories really tells us how an electron knows a photon when it meets one, or how a quark gets handcuffed to other quarks by a string of gluons. Those are the kinds of questions that I really want to answer.

All the theories do is provide a conceptual analogy that we can manipulate to get results that match observations.

I'm not knocking these achievements, don't get me wrong. Quantum theory in particular has been described as the most successful scientific theory ever. It makes some utterly bizarre predictions that have been proved right time and again by experiment, and you can thank these predictions for the existence of computers, GPS, cell phones, and many more modern conveniences.

It's just that, for all these successes, we are really no nearer to understanding - on a satisfying level - why the universe is the way it is.

Yes. Science still has a lot of explaining to do.

10 comments:

  1. Hee hee. Yeah, for all our accumulated intelligence we have yet to definitively prove anything. I'm of the opinion the "why" is more important than the "how", since understanding the why will often open our eyes to the how--as in math. There's my two bits. =)

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  2. My instinct tells me that science will never be able to answer "why?". I think we should consider addressing this question to other recipient(s). Interesting thoughts though....always a pleasure reading you :).

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  3. Crystal, I'm a "why" person too. Last time I created a "standards and procedures" database at work, a fundamental principle in it was that every standard had to include a reason why the standard existed. In other words, people should not only understand what to do to follow it, but also why it was important.

    Unikorna, that question may well prove to be outside the realm of science, but I'd be sad if that were the case. I am still hopeful that eventually we will have such a deep theory that makes everything we see an inevitable consequence. My rant is that we shouldn't congratulate ourselves too soon, as some scientists tend to do.

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  4. Hi Ian,
    Heavy stuff and I considered what you wrote an insightful, fascinating read. Relatively speaking, I guess, everything's a theory. Scientists and in particular, astronomers, have some explaining to do as to downgrading poor Pluto. No longer a significant planet, but a meaningless clump of rock wandering aimlessly around the solar system...
    Have a good weekend, my friend.

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  5. One would hope that someone with the moniker of 'The Botanist' was not anti-science.
    While shaking the twin branches of physics, as described by Newton and Einstein, make sure a apple doesn't fall on your head!
    Click here for Bazza’s Blog ‘To Discover Ice’

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  6. Gary, good point! What did Pluto ever do to them?

    Bazza, I'll keep an eye out for errant apples. I wonder if quantum theory allows Newton's apple to have an entangled twin out there somewhere? Would that mean that apples come in pears? Ouch :)

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  7. Botanist, I love a good Physics rant. Science predicts a lot, and isn't that another word for guessing? How much work is need to prove a hypothesis up to the point where there are no more questions to be asked. When all the measures are exhausted and we're not that much futher all we really have left is a lot of questions and a huge leap of faith. :) Happy Halloween! Wait, do they have that in Canada?

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  8. Laila, I wouldn't really call it guesswork. When you develop a theory that matches what you can observe, and from there you make a calculated prediction of something new that nobody's ever seen before, and you look for it and there it is exactly where you expected to find it, that is hardly guesswork. (Wow, what a long sentence!)

    On the other hand, a true scientist never believes a theory is proven beyond doubt. All we ever have are theories that nobody has yet managed to disprove. That is the strength of science, which sadly its detractors like to abuse to their own ends.

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  9. Love quantum physics and you have a great point. When I was researching quantum mechanics I couldn't have put it this concisely at the time but it did become frustrating (and confusing) that nobody could really explain why. In fact I felt like if I just understood the why I might understand the whole field better. The bad news we seem to be pretty far away from that kind of explanation. The good news is that we have learned so much in the last 100 years- perhaps they'll have the answers sooner than we think- relatively speaking ;)

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  10. Danette, I suspect the real insight is related to the philosophical question of "why is there something rather than nothing." Physics is pushing ever deeper for a theory of everything, but this feels like a bottomless pit to me. I think it will need a fundamental shift in how we look at the problem to make that breakthrough.

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