A Physicist Breaks Down One of Roger Moore's Iconic Bond Stunts

Our resident expert examines Bond's wild skydive in 'Moonraker.'

Roger Moore died today. Now, you could argue that Moore was not the best James Bond, and I'd be willing to have that discussion at some point, but I think everyone agrees he made significant contributions to the 007 canon. I certainly think so, if only because when I was a kid, Moore was the James Bond I saw in movie theaters. Sean Connery was the James Bond who appeared on television with older, outdated gadgets.

To honor Moore's passing, I thought I'd use physics to analyze one of the many cool scenes in his Bond oeuvre. I considered taking a look at his amazing submersible Lotus Esprit from The Spy Who Loved Me, but I've already written about the physics of submarines. Instead, I'll examine a crazy scene in Moonraker in which the henchman Jaws throws 007 out of a plane without a parachute, and Bond must steal a parachute from some other evil dude while plunging toward earth. Allow me to pose some questions, and answers.

Could Bond Catch Another Skydiver?

Looking at the clip, Jaws' minion jumps from the plane and Bond follows about five seconds later. If both men were in free fall, Bond would be hosed. There's no way he could catch up, because both men would be accelerating at 9.8 m/s2---the acceleration of a free falling object.

Ah, but the men are not in free fall. Free fall occurs when an object is under the influence of a gravitational force alone. But a skydiver is subjected to two forces (for the sake of this discussion, anyway). The first is the downward force of gravity, which depends upon the mass of the object and the gravitational field. The second is air resistance. This force depends upon several things, including air density, the shape of the object, and its velocity.

You can test this yourself, and you don't even have to jump (or be pushed) out of an airplane. Just stick your hand out the window of a moving car. Feel that force pushing it back? That's air resistance. Place your hand straight up like you're making the sign for "stop," and you'll feel greater resistance (force). Now make a fist. You should feel less resistance (because you've decreased the surface area, but that's a topic for another post).

So. Back to Bond tumbling from that plane. Both gravitational force and an air resistance force act on 007 and that minion he must catch up to. At first, the air resistance force and gravitational force act in different directions, because the two guys are moving sideways. But as the skydivers increase their downward speed, the air resistance increases in magnitude and points in the opposite direction as velocity. Within seconds, the air resistance pushing up and gravitational force pulling down add up to zero. With zero net force, each of them tools along at a constant speed. Physicists call this terminal velocity. A normal human achieves a terminal velocity of about 50 to 55 m/s, or around 120 mph.

At this point, the minion is just chillin', observing the scenery and maybe wondering what he will have for dinner. No big deal. Bond, on the other hand, has work to do. He must catch up with the guy, or die trying. All he has to do is decrease his surface area (notice how he moves his arms closer to his body). This decreases the air resistance, allowing Bond to accelerate as he continues plummeting until he again achieves a terminal velocity greater than that doomed henchman. So, yes, Bond could totally catch another skydiver.

But How Far Would Bond Fall?

Bond certainly has his work cut out for him. He must catch the henchman, fight him, and steal his parachute before donning that chute and fighting Jaws. That's a lot to do. Looking at the video clip, the dive appears to last 115 seconds. How far would Bond fall in that time? Let's do the math.

Allow me to make the rough estimate that Bond moves at a generally constant speed. He eschews the standard skydiving position for most of his dive, so let's assume a terminal velocity of 60 m/s. With this, I can use the definition of average velocity (in the y-direction) to solve for the change in vertical position:

La te xi t 1

Falling 6,900 meters (more than 22,000 feet) is a stretch. Such an altitude is clearly higher than you'd want to go without supplemental oxygen, but lower than the "death zone" of 8,000 meters at which there is too little oxygen to survive. Still, for Bond to fall that far, the plane would have to be flying even higher, and it would still leave Bond no more than 1,000 meters to pull his 'chute and survive the dive. Overall, I guess this is at least plausible.

Could Jaws Use His Arms to "Fly"?

No, but it looks funny.

Would a Circus Tent Save Jaws From Certain Death?

As the scene ends, Jaws breaks his parachute and lands on a circus tent. Suppose he had a speed of 50 m/s when he hit the tent. Looking at the video, the tent slows him to a stop in three seconds. What would be his acceleration? I can use the definition of average acceleration:

La te xi t 1

Jaws experiences a change in velocity of 50 m/s, so I simply divide this by the time interval of three seconds to get an acceleration of 16.7 m/s2. It turns out that acceleration provides a good indicator of human damage. Too high of an acceleration results in a dead person. Typically, physicists consider acceleration in units of g's where 1 g = 9.8 m/s2. Jaws would have a landing acceleration of only 1.7 g's. According this table of human tolerance to g-force, Jaws should easily survive this landing and live to die another day.