this post was submitted on 04 Jul 2023
145 points (91.9% liked)
Asklemmy
44266 readers
907 users here now
A loosely moderated place to ask open-ended questions
Search asklemmy π
If your post meets the following criteria, it's welcome here!
- Open-ended question
- Not offensive: at this point, we do not have the bandwidth to moderate overtly political discussions. Assume best intent and be excellent to each other.
- Not regarding using or support for Lemmy: context, see the list of support communities and tools for finding communities below
- Not ad nauseam inducing: please make sure it is a question that would be new to most members
- An actual topic of discussion
Looking for support?
Looking for a community?
- Lemmyverse: community search
- sub.rehab: maps old subreddits to fediverse options, marks official as such
- [email protected]: a community for finding communities
~Icon~ ~by~ ~@Double_[email protected]~
founded 5 years ago
MODERATORS
you are viewing a single comment's thread
view the rest of the comments
view the rest of the comments
Centrifugal force does not exist
"A laughable claim, Mister Bond, perpetuated by overzealous teachers of science. Simply construct Newton's laws into a rotating system and you will see a centrifugal force term appear as plain as day." https://xkcd.com/123/
Do you seriously expect me to do this while strapped to a centrifuge?
It does, itβs just called a different thing. Centripetal force is exactly the same thing as what most people assume centrifugal force means.
Ahem AKSHULLY
The centripetal force is the one that is directed directly towards the center (hence its name) of the virtual circle your object is rotating about (the blue arrow in this diagram). It is the "physical" force that acts on the object to make it follow a circular path, except it isn't because that force doesn't exist either, it's just a convenient model for billions of billions (of...) of fundamental particles interacting together in probabilistic ways that, statistically, makes the thingamabob go round the imaginary point.
The centrifugal force is, as Black Hat eloquently puts it, the force that appears when you use the rotating object as the frame of reference (which is like saying that the entire world revolves around the object). This isn't any more or less "correct" than using the ground as the frame of reference (in fact the ground itself is an accelerating frame of reference, which is why the Coriolis effect is a thing, it just is almost never significant except in weather-related applications and using the ground as a frame of reference is usually more useful than a "more stable" frame of reference like the solar system, or the milky way, or whatever, because honestly calculating train arrival times relative to saggitarius A* means that all trains are going about 225000 m/s which is just a pain in the ass to deal with let's be real).
If you're trying to build, say, "gravitational rings" for a sci-fi space station, then talking about the "centrifugal force" (which is proportional to the velocity arrow in the previous diagram) is a whole lot more relevant to the people you're providing fake gravity to than saying "well akshully the force that you feel keeping your feet on the ground of the station doesn't exist, you just exist in an accelerating frame of reference".