Another year Another Star Wars Day, May 4 is with you.According to my tradition, I want take some element From Star wars with do some Cool physical.For this year’s post, I will look at Empire Strikes Back. The biggest benefit of using this movie is that it has a history of more than 40 years, so that I don’t have to worry about spoilers. I mean, if you haven’t watched it now, do you really want to watch it?
So here is the scene: Leia, Lando and Chewbacca use Millennium Falcon Escape from the army of the Bespin Empire. On their way out, they caught Luke (he was actually just wandering around). Once they leave the earth, of course, Darth Vader will be there with his “interstellar destroyer” to intercept them. Lando said, “Oh, it’s no big deal. We just jumped to the speed of light and then jumped out of this system.” Well, that doesn’t work. The Imperial Army has disabled the Super Drive.
R2-D2 is the real hero here.He is on the boat falcon Talk to the Bespin central computer-you know, just share the lubrication technology and leave gossip on the stupid words C-3PO said. A rumor spread from the central computer: Hyperdrive has been shut down. So now R2 knows what to do. He turned over, pressed it lightly, turned and flew.There falcon, Immediately enter the hyperspace. Hope they look where they are going, and will not hit planets or other things.
Now let’s talk about cool physics.When the interstellar spacecraft jumped into hyperspace, R2 flew backwards inside the spacecraft falcon. Just like he was on a turbocharged bus when the driver stepped on the accelerator, he did not fasten his seat belt. If we use the interior of the bus as the frame of reference, then we will need to add false forces to account for acceleration. I mean, this is not necessarily the power of forgery. According to Einstein’s principle of equivalence, There is no difference between the acceleration frame of reference and gravity.
Therefore, in the accelerated frame of reference falcon, There seems to be a force similar to gravity, which pushes in the opposite direction of acceleration. The force exerted on R2 is equal to its mass multiplied by the acceleration of the spacecraft.If R2 has a completely frictionless wheel (or at least has very low friction), then as falcon Accelerate forward and he will accelerate backward relative to the frame. This is a good thing-because I only need to measure the acceleration of R2 observed from inside the spacecraft.
This means that we need to do some video analysis.If i know the size of the stuff inside falcon, You can determine the position of R2 in each video frame. Again, at a known frame rate, I can get the time for each of these locations.For the distance scale, I will use Height of R2-D2 And the frame rate embedded in the video (so that it can be played at the correct speed).My favorite tool for obtaining this data is Tracker video analysis. (It’s free.) Of course, there are some minor problems with this analysis. Camera panning and zooming-but I can compensate for that movement by looking at the movement of R2 relative to the wall. In this way, I get the following position vs. time diagram: