10 Brilliant Paradoxes in Physics and Philosophy

The mind-bending conflict between reality and illusion

Sunny Labh


Collage created by the author. Images from respective owners and archives.


1. Archimedes Paradox

We all know the principle of floatation states that ‘when an object floats in a liquid, the buoyant force acting on the object is equal to the object’s weight. This means, the heavier the object, it has to displace an equally large amount of water to be able to float on it. But this paradox is contrary to that. This paradox states that

“if the average density of an object is less than that of water then it can float on quantity of water that has less volume than the object itself “

Rather than taking a concern on the volume of water displaced, we need only take into account the volume of water surrounding the object. Thus arises the paradox where no fluid actually needs to be displaced for Archimedes’ principle to take effect.

2. Aristotle’s wheel Paradox

This is a mathematical conundrum that has left many mathematicians scratching their heads over the years. We could practice this experiment in real life by attaching a small wheel to the larger wheel but they both should be concentric (i.e. having the same center). When the wheels are rolled over a surface, the path traced by the bottom of two concentric circles would be the same length. Yes, it is logical that the length of the path the larger circle travels in one turn is equal to its circumference, but the smaller circle also travels the same length in one turn which makes its circumference larger than it actually is. This is physically impossible and thus arises the paradox.

3. Bell’s spaceship paradox

This is a thought experiment directly associated with Special Relativity. Say a very delicate thread hangs between two spaceships. Say they start accelerating at the same time under the inertial frame ‘F’. So just considering the initial frame, they should be at the same velocity at all times. Therefore, they are all subject to the same Lorentz contraction (Phenomenon that a moving object’s length is measured to be shorter than its proper length, which is the length as measured in the object’s own rest frame)…



Sunny Labh

Science writer and communicator majoring in Quantum Mechanics. Curator of @PhysInHistory on twitter. Twitter: @thePiggsBoson