movie physics

I guess some people will do anything to get on television. In the media blitz last week, nobody seemed to pause to wonder whether the escaped helium-filled contraption would in fact have sufficient buoyancy to carry a 40-pound boy to a height of 7000 feet. Let's apply some physics to the case.

This video puts some perspective on the action-movie high-speed car chase jump phenomenon. Notice how close this car comes to wrecking when launched off of a little teeny two-foot-high ramp and moving at a relatively slow velocity.

In fact, just for fun, let's do a rough estimate of the takeoff velocity. We approximate that the car lands about 10 meters from its takeoff point and is in the air for close to one second. Applying this information we can do a simple calculation to determine its horizontal component of velocity on takeoff:

v_x = Δx/ t = 10 m/1s = 10 m/s

Using a little vector addition we can also determine the net velocity off the ramp based on the ramp angle. We'll leave this as an exercise for anyone so inclined (no pun intended), but because the take off angle is pretty small (we estimated 17 degrees) the net velocity is still only approximately 10.5 m/s or 23 mi/hr -- not really a high-speed stunt.

Fun, games and calculations aside, one of many problems any "would-be" stunt car driver is going to face on attempting a jump, is that the car is generally going to follow the standard parabolic trajectory of a projectile.

In keeping with our movie physics theme of the past few weeks, it seems appropriate to take a look at the trailer from the action "science" disaster film The Core. As with Armageddon and its deadly asteroid, The Core starts with an interesting premise -- the possible disappearance of the Earth's magnetic field.

Heeding a suggestion from one of our readers, let's follow up on our discussion of artificial gravity. As we described last week, although the film Armageddon attempts to portray artificial gravity aboard a rotating space station, it does not take into account the fact that unless the radius of the station is very large compared to the height of a person, anyone on board will feel significantly different forces acting along the length of their bodies. The result: nausea, vomiting, dizziness, disorientation, and nothing similar to the sense of gravity as we experience it on Earth.

There are certain movies that wreak such havoc with the laws of the universe as we know them that, despite the risk of irate readers who only want to enjoy the fantasy, and despite the fact that they may not care about accurate science (after all "we all know it's just a movie), we have to deconstruct them anyway as a public service. Now Armageddon (along with The Core and The Day After Tomorrow) forms part of a "trifecta" of bad movie physics, and, although it's not a new release, it epitomizes its genre.

As a followup to last week’s discussion of the new Star Trek movie trailer, let’s spend a few more minutes on this most appealing of themes. Now remember we have nothing but affection for the phenomenon of Star Trek, and the creators of the various series, movies etc. sometimes really give it a shot with trying to connect the technology to ideas in the forefront of modern physics. Where would we be without anti-matter reactors, the warp drive, and inertial dampers, to name a few?

As a long-time aficionado of the original Star Trek series, it's always exciting for me when I hear that Captain Kirk and Mr. Spock are going to make a reappearance on the big screen. Although it'll be a bit strange without William Shatner and Leonard Nimoy running the show, what recourse is there? We've got the next generation playing the previous one.

Anyway, in the trailer we get a glimpse of the juvenile origins of the future Captain Kirk's daredevil thrill-seeking persona, not to mention his incredible physical prowess. In the scene in question we see young James T. leap out of his classic convertible sports coupe moments before it projects itself off of a several-thousand-foot precipice. James saves himself by gripping the sandy ground and pulling himself to a stop just as he reaches the edge of the cliff.