💡 Did You Know?App
← All facts 🔢 Maths

DID YOU KNOW…

The Banach-Tarski Paradox: How Math Can Double a Sphere!

The Banach-Tarski Paradox: How Math Can Double a Sphere!

Imagine slicing a solid ball into just a few pieces, then rearranging them to form two identical copies of the original ball – without adding any new material! The Banach-Tarski paradox describes this astonishing mathematical possibility.

This mind-bending theorem doesn't violate the laws of physics or conservation of mass because the "pieces" are not ordinary, measurable solids. Instead, they are highly intricate, non-measurable sets of points, so convoluted that they don't possess a definable volume in the usual sense. The paradox relies fundamentally on the Axiom of Choice, a controversial but widely accepted principle in set theory, revealing how counter-intuitive results can arise when dealing with infinite sets and abstract constructions.
🔗 Banach-Tarski Paradox🔗 The Axiom of Choice

Love discovering things like this?
A new fact every day with photos, on the free app.

📲 Download the free app

Run a business? This line is for you. Everyone else, read on.

I wrote this page once and it has been working on its own ever since, including tonight while I sleep.

I build the storefront for your business, under your own name, and you see it before you pay anything. If you don't like it, that's the end of it.

Show me my shop

Blackstar Digital Studio · Las Palmas de Gran Canaria · Made in Italy 🇮🇹