9/19/2010

Hands up if you think the Moon has no gravity

I don't usually have a problem with artistic licence in movies and TV shows, but sometimes there are limits.

I can just about deal with the spaceships in Star Wars rumbling or making pew-pew noises when they shoot at each other because it is, essentially, a fantasy - or at least, that's how I always managed to suspend my disbelief, even though when I first saw them as a kid I'd read enough Clarke and Asimov and Heinlein and popular science texts to know there was no air in space to transmit sound. I can let a lot of things slide, as a matter of fact, but every now and then I run up against something that really takes me by surprise; like discovering that some people think the Moon has no gravity, or that the long, whizzy blue tunnels  like cosmic spaghetti that usually act as stand-ins for hyperspatial wormholes in shows and films like Stargate and Contact are accurate renditions of the same.

I'm damned if I can remember where I read about it, but there was a survey that showed a substantial number of college students in the US thought the moon had no gravity; one question they were asked (I recall) asked them what would happen to a golf ball if an astronaut, standing on the surface of the moon, were to let go of it. Apparently a number of them answered that it would fly away from the Moon and towards the Earth since, presumably, that's where all the gravity in the universe is.

I find this incredibly depressing. I was less than heartened to find out recently that some people, perhaps influenced by TV shows like Stargate, think that a 'wormhole' really is a whizzy blue tunnel of light that could actually be seen stretching across space.

At this point I should probably take a step back and explain just exactly what a 'wormhole' is. Your best source of information is the main Wikipedia article, but I've also copied and pasted the first paragraph here for your benefit; you should also go and check the Wikipedia illustration if you can't quite visualise it.

"In physics and fiction, a wormhole is a hypothetical topological feature of spacetime that would be, fundamentally, a "shortcut" through spacetime. For a simple visual explanation of a wormhole, consider spacetime visualized as a two-dimensional (2-D) surface (see illustration, right). If this surface is "folded" along a (non-existent) third dimension, it allows one to picture a wormhole "bridge". (Please note, though, that this image is merely a visualization displayed to convey an essentially unvisualisable structure existing in 4 or more dimensions. The parts of the wormhole could be higher-dimensional analogues for the parts of the curved 2D surface; for example, instead of mouths which are circular holes in a 2D plane, a real wormhole's mouths could be spheres in 3D space.) A wormhole is, in theory, much like a tunnel with two ends each in separate points in spacetime."

Note the phrase 'essentially unvisualisable structure existing in 4 or more dimensions'.

This matters to me right now because wormholes are what my new book Final Days is all about. That, and time travel (since, you see, if such wormhole tunnels could ever really come into existence, their essential properties would, according to Kip Thorne, until recently the Feynman Professor of Theoretical Physics at CalTech, allow for time travel). But it's not an easy concept to get your head around. I had to spend a couple of days working really, really hard to get my own head around how all of this works before I started on the book. That means I have to take an essentially difficult-to-understand idea and try and explain it to people who've probably, in most cases, never heard of it before. When Hollywood deals with it - as it has - it finds it easiest to portray it as a whizzy blue tunnel of light. It's a metaphor.

Mind you, when you play around with things like wormholes in a story set only a few centuries in the future, you're taking some pretty big leaps of imagination with a concept that is, at best, theoretical. Things like wormhole construction are frankly more likely in the context of a Type 3 Kardashev civilisation than, say, human beings in the 23rd Century. But, as I always like to say, a little over a century ago most people didn't know that the coming years would bring flying machines, nuclear bombs and space craft.
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