Yet, it's also possible to get carried away with this sort of thing; to take hold of an idea and charge toward the end zone without stopping to think about it, to allow the ooh-ah majesty of your chosen Big Dumb Object to take a prime role in whatever you're putting together, regardless of whether or not it actually makes sense. That, unfortunately, is one of the impressions I'm getting from the preliminary reports I've seen about the new Total Recall movie - and I can only hope that those reports are, in some way, incomplete or misrepresenting the movie's Big Dumb Object. The 1990 film had the Martian reactor, but since nobody will be getting their asses to Mars in 2012, something new had to be brought in to replace it - something that, for me, goes beyond "god damn, that is awesome" to "god damn, what were they thinking?"
Something like this.
"The lynchpin of Wiseman's action movie," wrote Meredith Woerner on io9, "is The China Fall. A massive elevator that takes thousands of people from one side of the Earth to the other. Through the center of the Earth."
This was pretty much my reaction.
This idea isn't original to the movie. It's called a gravity train, and the idea - as many ideas are, in a vacuum - is simple: you dig a straight tunnel through a planet and drop in a capsule. Gravity will accelerate the capsule until the midpoint, and as it climbs out the other side gravity will work against it until it arrives at the other end with zero velocity. In this regard, it works just like a constant-thrust spaceflight except with no thrust at all. On paper, it's a hell of a transportation system; the only fuel that would be required would be for whatever has to catch the cab on the other end, though you'd need systems in place to take care of atmospheric friction; otherwise, you'd run the risk of a bad catch resulting in a capsule trapped in the center of the shaft.
However, as anyone who's seen The Core may know, the innards of Earth aren't that simple. In particular, there's a certain thing called pressure; even The Core didn't ignore this, which is why the craft's unobtanium hull was so vital there. In the inner core of Earth, a section that you'd need to pass through in order to make a functioning gravity train, the pressure is more than three million times what it is at sea level, and so hot that even an Arwing might not be able to take it - over nine thousand degrees Fahrenheit. There's something else you might be familiar with that has the same kind of temperature - the surface of the sun.
I'll admit the concept is not impossible - just horrendously difficult and hideously expensive. If you're going to bring something like this in, though, you can't just do it piecemeal: the techniques and materials needed to build a tunnel through the world would of necessity find far wider applications in general society. If you've got enough unobtainium to build a twelve thousand kilometer-long tunnel through the planet in any kind of believable time frame, you've by necessity also got enough unobtanium to do whatever the hell you want with it. Buildings should be made out of this. Imagine active volcanoes plugged with unobtanium tubes that, upon eruptions, feed the ash and lava and what have you into huge storage tanks, rather than have it spat into the sky.
I have difficulty suspending my disbelief in regard to the notion that the people behind the new Total Recall seriously considered these issues... and consequently, I don't think I'm going to have an easy time accepting this movie. An ancient alien reactor on Mars? It's out there, but I can get behind it. A tunnel through the world? ...Let me get back to you on that.