It truly is one more calendar year and a different Star Wars Day—May the 4th be with you. Adhering to my custom, I’m likely to get some ingredient from Star Wars and do some awesome physics. For this year’s post, I’m heading to glance at the conclude of The Empire Strikes Again. The good matter about applying this motion picture is that it is so old—more than 40 years—that I don’t have to worry about spoilers. I indicate, if you haven’t seen it by now, are you seriously likely to view it?
So, in this article is the scene: Leia, Lando, and Chewbacca use the Millennium Falcon to escape from the Imperial forces on Bespin. On their way out, they seize Luke (he was actually just hanging all-around). When they get off the earth, of training course, Darth Vader is there to intercept them with his Star Destroyer. Lando says, “Oh, no biggie. We will just make the bounce to lightspeed and skip out of this system.” Very well, that does not operate. The Imperials have disabled the hyperdrive.
R2-D2 is the true hero below. He’s onboard the Falcon chatting to the Bespin central computer—you know, just sharing lubrication techniques and dropping some gossip on the silly issues C-3PO states. The central laptop or computer comes back again with a rumor: The hyperdrive has been turned off. So now R2 is aware what to do. He rolls over, and with the flick of a switch—boom. There goes the Falcon, proper off into hyperspace. Ideally they are seeking where by they’re likely and won’t strike a earth or anything.
Now for the interesting physics. When the starship tends to make the bounce to hyperspace, R2 goes flying backwards inside of the Falcon. It can be as nevertheless he was on a turbocharged bus when the driver strike the gasoline, and he is not seatbelted in. If we just take the inside of the bus as the reference body, then we will will need to include a phony power to account for the acceleration. I necessarily mean, it really is not always a fake power. According to Einstein’s equivalence principle, there’s no variance amongst an accelerating reference body and a gravitational drive.
So, in the reference body of the accelerating Falcon, there appears to be a gravitational-like pressure that pushes in the reverse path as the acceleration. The magnitude of this pressure on R2 would be equivalent to his mass multiplied by the acceleration of the spaceship. If R2 has absolutely frictionless wheels (or at minimum extremely very low friction), then as the Falcon accelerates ahead he would accelerate backwards with regard to the ship’s body. That’s a excellent thing—because I just require to evaluate R2’s acceleration as seen from within the spacecraft.
This means we get to do some online video examination. If I know the dimension of stuff within the Falcon, then I can decide the situation of R2 in just about every video clip body. Also, with a regarded body level I can get the time for each and every of these positions. For the length scale, I am going to use the height of R2-D2 and the frame level that is embedded in the online video (so that it performs again at the appropriate speed). My favored device for having this details is Tracker Movie Evaluation. (It really is totally free.) Of program, there are some compact problems with this evaluation. The digital camera pans and zooms—but I can compensate for that movement by hunting at how R2 moves with regard to the wall. With that, I get the next plot of posture vs. time: