Monday, July 28, 2008

English Versus Physics

Here's a good enough example of popular physics writing, even an interesting one in terms of subject matter:

The warp engine is based on a design first proposed in 1994 by Michael Alcubierre. The Alcubierre drive, as it's known, involves expanding the fabric of space behind a ship into a bubble and shrinking space-time in front of the ship. The ship would rest in between the expanding and shrinking space-time, essentially surfing down the side of the bubble.

The tricky part is that the ship wouldn't actually move; space itself would move underneath the stationary spacecraft. A beam of light next to the ship would still zoom away, same as it always does, but a beam of light far from the ship would be left behind.

That means that the ship would arrive at its destination faster than a beam of light traveling the same distance, but without violating Einstein's relativity, which says that it would take an infinite amount of energy to accelerate an object with mass to the speed of light, since the ship itself isn't actually moving.
All well and good; I'll let the physics nerds pronounce on whether the technology described is even remotely possible, and for that matter, on whether the passage as written successfully captures the underlying science as opposed to trimming it too much or "dumbing it down" in the service of popularization.

For me, it does not work. Though I'm not proud to admit it, I need it dumbed down a few more notches, because it leaves me cold. I know what a bubble looks like, and I can easily enough picture something riding the surface of a bubble, but phrases like "expanding and shrinking space-time" and "space itself would move underneath the stationary spacecraft" might as well be the squeakings of mice for all the sense I can make of them.

Nor do I mean to single out this particular article; I have the same experience every time I try to read, say, A Brief History of Time, which is, by most accounts, a great achievement of popular physics writing -- although the mere fact of A Briefer History of Time suggests I'm not completely alone on this score.

This is not a plea for someone to explain the explanation, but an exercise in mild self-flagellation. I think it's worthwhile to take stock of one's limitations from time to time -- rest assured I have more where this came from.

6 comments:

Samuel John Klein Portlandiensis said...

Well, that's the thing about abstracting explanations ... you have to abstract those things to an absurd degree in order to make them comprehendable without destroying the meaning utterly.

The problem with that becomes that you start to think (for instance) of space as a flat rubber sheet, or (my personal thinking glitch) the univers as an actual huge expanding bubble (when that's just the device used to explain the theory behind the "big bang".

A good example of an abstracted explanation is that of the tesseract. It's a construct in four dimensions. You know how if you extend a square into three dimensions you get a cube? If you extend a cube into four dimensions you get a tesseract.

If you read A Wrinkle In Time you've heard of one. This is what one looks like when drawn on flat plane.

It looks like its a cube with eight chambers. If you were a four-dimensional creature and could climb into one, though, you wouldn't see all those diagonal lines. Each chamber would be absolutely square.

After that point, the eyes glaze over. You're better off contemplating Zen koans

The point here is not so much to reel off how erudite I am (though I do enjoy that) but to note with insight how tough it is to distill these concepts down and the pitfalls in demonstrating advanced concepts with the big crayon. We just have to be aware of that going in. And I think it's important to note that, even though some of us are quite sharp (or fancy themselves to be) we have to accept that there are some things you'll just never understand; like, even though cosmological expansion is usually explained with a bubble analogy, by definition the Universe isn't something you can physically be outside of, so the analogy breaks down; or, why people will still vote republican even though they've utterly soiled the place beyond redemption in some cases.

Oh, yes, and a book recommendation. Edwin Abbot's Flatland is a wonderful thing that can be found in libraries and ordered through bookstores pretty much everywhere. It was written in 1885, was intended as a satire on Victorian social structures and accomplished this by exploring a Square's experiences in his 2D world and his exploration of the 1D world (with a visit from a spherical resident of a 3D world).

It won't necessarily add to your understanding of things like tesseracts and what exists outside the Universe, but it will add to your personal gestalt, thus enabling you to hang on with a little less motion sickness with people describe things like the Alcubierre drive and tesseracts.

Dale said...

SJKP, If I may offer a lame excuse, I think my problem with physics writing is both more basic and more intractable: I rarely find physics interesting. As soon as the discussion turns to weensy particles that might be waves and might be particles, the hazards of event horizons, musings about the beginning of time and multiverses and backward-running causality, the enchantments of dimensions 4 through N, etc., I am pretty quick to lose interest. I realize there are all sorts of amazing possibilities and realities in all of that, and I certainly realize sci-fi would be nowhere without all of it, but it just doesn't move me.

And please understand I am not saying "physics is useless" or "physics is phony" or anything like that. Gawd no. I am glad there are incredibly smart people doing physics. And I think a basic understanding of physics is an indispensible element of cultural literacy.

It's important, it's just not my cup o' tea. And I think one's ability to puzzle things out correlates pretty well with one's level of interest. (That last part is the excuse stated overtly.)

Samuel John Klein Portlandiensis said...

Well, that's fair enough. I just saw your post and started freestylin' the response.

Ain't no sin in just not being interested in physics. Hell, I'm just glad there are people interested in being doctors, lawyers, etc. That way, I don't necessarily have to be one, if you catch my drift here.

Dale said...

SJKP, I do appreciate your comments and I hope I didn't come off as too feisty or crabby in my comment. I didn't mean it that way.

I definitely agree with you about that last part -- thank goodness there are people willing to be doctors, lawyers, dentists, plumbers, and quite a few other things that aren't on my Really Cool list.

Martin R. said...

I think I have a similar problem with this approach to popular physics writing but I think what is required here is not further dumbing down but rather smartening up (if that is the right term). Such unhelpful descriptions and analogies such as “…essentially surfing down the side of a bubble…” doesn’t help (me at least) with understanding but actually works to further obscure, particularly as it is at odds with the immediately preceding description of “…rest[ing] in between the expanding and shrinking space-time…” – this does not conjure up images of bubbles to me.

Essentially it is lazy and imprecise and fails to really describe the issue at hand by shying away from explaining this in terms that operate at an appropriately technical level. The belief that we can only understand a thing if we talk instead about bubbles or fabrics or bunnies is, I think, doing us all a disservice. As SJKP points out there is a risk of abstracted analogies destroying meaning and I’m sure that this is not really guarded against with sufficient proficiency by editors of these books.

However, in the spirit of furthering my understanding, I decided to test the value of this particular description by actually trying to purchase some “fabric of space” from my local haberdashers to see how it would behave if I tried to expand it or shrink it. I have an uncanny knack of being able to expand and shrink many different fabrics through my scant regard for material washing instructions and I thought that the “fabric of space” would pose me few challenges. I was, however, still surprised when I found that said haberdashers did indeed stock “fabric of space” at a mere £8.99 per yard. Unfortunately when the assistant tried to cut me a yard of the material with which to support my test programme, she created a tear in the fabric of space into which the whole shop collapsed leaving only myself and one small packet of faux-pearl buttons. If only the shop assistant had a better understanding of the fabric of space than is provided by ‘popular’ science writing she would still be with us now. A lesson for us all there, I think.

Dale said...

Martin, thanks for that. You have chastened and edified in the best way.