# Was Ewan McGregor TOO Fast For Star Wars? Physics and Video Analysis Gives the Answer.

I ran across a video on YouTube — it was about Ewan McGregor and Star Wars, so I was legally required to watch it. Check it out.

In this video, Ewan states that when he did the lightsaber fights with Ray Park (who played Darth Maul) — they were too fast. To fix this, the scene is actually played in “slow motion” to make it look better.

Wow. That’s crazy. Oh, but maybe I can use some physics to verify if this is actually true. Maybe — just maybe. Well, I’m going to try.

# Video Analysis

If you aren’t familiar with video analysis, let me give a brief overview. Basically, it’s possible to position-time data from a video. The time part is usually easy. If the video plays at 30 frames per second, then the time from one frame to the next would be 1/30 seconds. The position of an object can be determined by looking at the location in terms of pixels (where a video might be 1080 pixels high and 1920 wide (for a typical video).

Of course, no one wants the position of an object in units of pixels — that’s not very useful. We can fix this if there is an object of known size in the video frame. This can be used to scale the video and get a conversion factor between pixels and meters (the preferred unit of distance for Rebels — the Imperials use feet).

There are multiple software options for video analysis. Personally, I’ve used Tracker Video Analysis for a long time — so, that’s what I will use today.

# Three Parts of Projectile Motion

Now consider an object that’s tossed into the air (we call this projectile motion). Since there’s only the downward gravitational force, the vertical position (y) can be described with the following kinematic equation:

There are really three things to consider in this equation:

• The position (y) — based on the scale of the video.

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Physics faculty, science blogger of all things geek. Technical Consultant for CBS MacGyver and MythBusters. WIRED blogger.