Well, it wasn't so clearly formulated then. I think at the time it was formulated as "Why do they call it a centrifuge if there isn't a centrifugal force?" "Or is it centripital?" "Wait, which is which again?"
Rather than pull up some internet-friendly phone type device right then and solve the issue, we just discussed it. I like arguing thing sometimes even though you could know the exact right answer in a few minutes, because conversations with a hard stop of "wait, i'll find out the truth so we can stop arguing" make interesting conversations abruptly short.
I insisted that centrifugal force was the force you *thought* you felt acting upon you while you were in something that changed direction. Like the feeling that you're being pushed to the left when the car turns right. But that force doesn't exist, there's nothing pushing you to the left; you've just got momentum going forward and the car is pushing you to the right. There is no active force to the left.
I was convinced, but Kathryn wasn't. But by that time we had made it back to her place and I think we had delicious cookies waiting for us or something so the argument was dropped.
But today's XKCD kindly linked to an older XKCD which had this very debate in it. I sent Kathryn the older XKCD as proof that I was right.
Apparently XKCD doesn't hold weight with Kathryn, so she instead sent me the link to the Wikipedia entry on Centrifugal force.
To which I then read to her a line from that entry:
"In Newtonian mechanics, the term centrifugal force is used to refer to one of two distinct concepts: an inertial force (also called a "fictitious" force) observed in a non-inertial reference frame, and a reaction force corresponding to a centripetal force. "She didn't believe me, and said that a fictitious force is still a force. To which I responded with a different fictitious force.
But it did get me thinking. I had completely forgotten that the basis for it being a real force or not was based on weather the point of view was accelerating or not. I still don't completely remember why this distinction was the difference between what is real and what is fictitious, but it sent some wheels in motion.
Is there a way to actually have the Star Wars Force effect happen in real life by simply looking at it from an accelerating point of reference? I'm not talking about all the Force abilities, namely the ability to make the lightsaber fly straight across the room into a jedi's hand.
Imagine an empty room in space, with Luke in it and his lightsaber on the other side of the room. To an observer inside the room, everything is motionless. However, this room is actually traveling very quickly through space, based on another point of reference. This is essentially a giant space car, with Luke on one side and the lightsaber on another.
Luke puts out his left hand, and this magic "space car" turns to the left. The inertia will keep the lightsaber traveling forward in space, although as the car rotates, it will appear to move straight across the room into Luke's hand. Indeed, in this scenario, the fantastical Force of Star Wars could very well be attributed to the fictitious centrifugal force that started this whole debate.
You know, assuming that, without exerting a force of his own, Luke was able to change the trajectory of the space car. And assuming he could simultaneously change the trajectories of all other free body objects inside the space car, such that everything didn't *also* accidentally accelerate across the room and crush Luke.
All in all, it was a fun thought experiment. I really should do these more often.
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