Wait, Centrifugal Force Isn’t Real?! | What the Physics?!
Here’s why centrifugal force is considered a “fictitious” force.
Centrifugal force feels completely real — but physicists call it a pseudo-force. So why does it feel so powerful?
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@cammychoate
August 9, 2026 at 5:45 pm
I can't believe I spent my whole life until now thinking centripital force and centrifugal force were the same thing and some people just said it differently. I don't know who decided to name these things but I want to go back in time and explain to them how confusing it is and appeal to them as a person of science to be like, 'come on, you know how dumb that is right?'
@MoebiusStrip
August 9, 2026 at 5:45 pm
1:43 Interestingly, an object moving in a circular path where it is spinning around tied to a string; when the string breaks, the object will momentarily continue to move in a circular path, until the elastic wave of the string reaches the object at which point is when the object will move in a straight line.
this "elastic wave" is similar to the thought experiment where if the sun suddenly disappeared, Earth would continue in its normal orbit and light up for 8 minutes and 20 seconds.
see this demonstration where a string is replaced with a spring https://www.youtube.com/watch?v=AL2Chc6p_Kk
@BTWPhysics
August 9, 2026 at 5:45 pm
The centrifugal force is born out of circular motion and ceases the instant circular motion stops. It arises as a result of an interaction. It is not a real force in the sense of it being an external force. Rather, centrifugal force is an outward internal force (push or pull) on an object in circular motion that is due to its inertia. The outward push you feel is really an outward push, only that it is not due to another object. Objects, including celestial bodies, want to move in a straight line and a centripetal force is required to work against this inertia to move them in a circle. But, if circular motion only required a centripetal force working against this tendency to move in a straight line, then celestial bodies would have circular orbits. This tells you that a centripetal force only prevents an object from moving in a straight line, but does not in itself cause an object to move in a circle. It requires a centrifugal force to balance the centripetal force. There are no centrifugal forces on celestial bodies because objects do not have inertia against gravitic acceleration. This is why orbiting bodies would require having orbital speeds that match the curvatures of the central bodies in order to have circular orbits. A yo-yo or a rock being swung in a circle has a centrifugal force on it which balances the centripetal force on it by the string. The centrifugal force balances the centripetal force and, thus, there is no change in its radial velocity which is zero. The object in circular motion is kept in equilibrium in that it has no radial displacement. Not that it would no longer have a change in its tangential velocity. This is an important distinction.
@1a1u0g9t4s2u
August 9, 2026 at 5:45 pm
Okay then show us what the force vector diagram looks like for a tetherball as it is swinging around the pole after being struck by a child, or a cat being swung around in a bucket by a child or the earth/moon system as it orbits the sun. This is not sarcasm, a force vector diagram would be useful to accompany this discussion. Thanks for sharing.
@HuaWuMing2025
August 9, 2026 at 5:45 pm
Quantum Mechanics? Got anything to say?
“Ahem. Gravity is impossible."
@amblinalong
August 9, 2026 at 5:45 pm
They were silly to come up with a word to describe nausea and allow people to think it is a force. Hmm. volatile…
@romascesas8216
August 9, 2026 at 5:45 pm
Ha! I'm 79 years old and a retired chemist. Back in the day when I had to take physics (in college) this whole comcep[t was brought up. The professor said there is no such thing as centrifugal force only centripetal force. The it was also brought up that for ever force there is an equal and opposite force. So here we go a one way force (being pulled in according to physics) that has nothing opposite.
OK, sure let's create rules and then break them. Anyone who has taken physics has to have found out that physics does not like anything without an explanation, their answer to the unknown is it doesn't exist.
If centripital force is so great why does it not pull anything in that breaks free of the string? Why not say there is no such thing as centripetal force and call it a day. This has always irked me nd will continue to do sop until the day I expire.
@Leftysrev3nge
August 9, 2026 at 5:45 pm
Centrifugal force is just constrained inertia
@jamestsou-wong8120
August 9, 2026 at 5:45 pm
Like
@Anson120
August 9, 2026 at 5:45 pm
I always referred it as a phenomenon.
@In_the_Plums
August 9, 2026 at 5:45 pm
Physicists also say that gravity isn’t a force. I want to push them off of a tall building to test that hypothesis.
@waterforfuel
August 9, 2026 at 5:45 pm
I split distilled water.
https://youtu.be/lhbN0ixeACY?is=QaDx47cg6E7ewQV6
@moabyte2
August 9, 2026 at 5:45 pm
Click bait title. Crap move.
@ClaytonMacleod
August 9, 2026 at 5:45 pm
There are so many things wrong with this lame video it isn’t even funny.
@existenceisillusion6528
August 9, 2026 at 5:45 pm
3:18 I wanna complain … 4:21 nevermind. 😂 Really well done video. Clear, concise, and accessible.
@rajdivecha
August 9, 2026 at 5:45 pm
2:10 this explanation is the same record playing over and over again without adding any value. If centripetal force is a force then what, is there a centripeton, a force carrying boson? There is none! As such, even the centripetal force is also not real. In reality, the motion is causing a person to push towards the walls and the electromagnetic force between them gets concentrated and exerts pressure, which also increases friction and the person stays stuck to the walls. Thus, there is no centripetal force or centrifugal force. It’s just the electromagnetic force that is working here!
@paulc96
August 9, 2026 at 5:45 pm
In English. it's called Centrifugal force. And the laboratory devices / machines, are called Centrifuges.
@josephm.rathke8001
August 9, 2026 at 5:45 pm
🖖🖖🦄🦩🤓🖖
@David-r9e3w
August 9, 2026 at 5:45 pm
100,000 years and 20 billion brains later one brain — Mark McCutcheon:" The Final Theory: Rethinking Our Scientific Legacy", for proper physics including the CAUSE of gravity, magnetism, electricity, light and well… everything — finally (2002) gives the pukka understanding of reality. No energy, charge, photons, waves, fields, spin, quantum,,quarks, space, time, spacetime, potential, kinetic etc. ALL Standard Theory/Model was replaced by Expansion Fact in 2002. Nothing to see/lear(n) here.
@lisastratton3869
August 9, 2026 at 5:45 pm
Well I thought I understood why the water stayed in the bucket in the 4th grade science experiment my teacher did to demonstrate this not-force…but now I'm back to thinking it must be magic. 🪄
@patrickinsocal
August 9, 2026 at 5:45 pm
Athena! 🥰
@si-vis-pacem-parabellum
August 9, 2026 at 5:45 pm
what about the tool in the lab that spinning tubes containing blood samples or uranium plutonium enrichment ? can you add some explanations for me the common people.
@ZMAN_420
August 9, 2026 at 5:45 pm
Gravitron is GREAT!
@sternmg
August 9, 2026 at 5:45 pm
Sorry, a 5-minute explainer video is ill-suited to do this topic justice. It comes across as "preachy" and brings little clarity. The coverage was superficial and inconsistent: We hear that observers outside a carnival ride are in an inertial frame, yet weather and ocean circulation happen in a non-inertial frame? It cannot be both in the same model. Jumping over the boundaries of models is, I think, a major reason for misperceptions in this arena.
What do we say about Coriolis forces? Eötvös measured an apparent weight change on ships traveling east vs. west. Still fictitious? What about "Einstein's elevator", let alone "Newton's bucket"?
"Force" can be defined as a kind of influence from one part of the world onto another, and depending on what "part" one focuses on, different interactions appear as forces.
@tafdiz
August 9, 2026 at 5:45 pm
who would guess she is already 34
@nightlightabcd
August 9, 2026 at 5:45 pm
Yeah, like gravity is not real to!!
@gorgthesalty
August 9, 2026 at 5:45 pm
Physics Girl v2?
@beepboop204
August 9, 2026 at 5:45 pm
sometimes i feel dizzy and feel spinning
@redtwox9708
August 9, 2026 at 5:45 pm
There is always a relevant XKCD /123
@davevann9795
August 9, 2026 at 5:45 pm
"Fictitious" forces are REAL forces that can be measured and obey F=ma. Using the name "fictitious" is as bad as "imaginary" numbers, or telling somebody their pain is all "in their head". These names mess-up many student's concepts. Making too many people think they are not real or to be dismissed as unimportant or too confusing.
Those "fictitious" forces are very real and ignoring them could be catastrophic.
At one time, zero, infinity, irrational numbers, and negative numbers were considered to be "fictitious" math concepts proposed by crazy people. People who didn't like the value of pi to be an irrational number, passed laws to limit the number of digits pi was allowed to have. Those extra digits of pi may have been legally fictious, but nature is good at treating human laws as fictitious, and nature is the ultimate arbiter of deciding what is real.
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