The Collatz conjecture involves a sequence where a number is divided in half if even or multiplied by three and added one if odd. It is assumed that all positive integers eventually end up in a loop that ends in 1, but this remains unproven.
The Simplest Yet Unsolvable Math Problem
Related Posts
Trauma is carried in your DNA. But science reveals a more complicated story
Radu Bercan/Shutterstock Tara-Lyn Camilleri, Monash University As war continues to rage in Gaza and Ukraine, there is concern…
August 6, 2025
Measuring the True Scale of the Universe, Part 1
Starting with Eratosthenes’ clever calculation of Earth’s circumference using shadows and wells, early astronomers used geometric reasoning and…
April 5, 2025
Body armour made from silk is being developed – but this apparently cutting-edge idea is centuries old
FeyginFoto / Shutterstock Lloyd Strickland, Manchester Metropolitan University Separate teams of Chinese and American scientists are reported to…
April 22, 2024
Where Does Gold Come From? Black Holes With Accretion Disks, Scientists Think
Earlier this year we at Modern Sciences did a piece on how the work of two bored astronomers…
December 1, 2021

If you complete the whole numbers at the prime two the collatz iteration extends to this enlargement.
Then the even step “taking out the power of two” increases the natural “two“size and the second half step “multiplying by three“
preserves the natural “two” size
while the remaining second half step “adding one” decreases the natural “two” size.
Lunch comment by Alain Connes at IHES almost fifty years ago which continued to a proof of the Collatz conjecture for almost all two adic integers relative to the natural measure.
Thus
On mobile the video plays with no sound. And tapping on the video does not give an option to turn sound on. And there is nowhere to tap to go watch it on YouTube. This page needs some fixes.
The Collatz Conjecture is unsolved, not unsolvable.
It’s not “unprovable”, just “unproved”. And it’s not “assumed”, it’s “conjectured”. Mathematicians are picky about terminology.
Is this a joke? I am no mathematician, and so I can’t speak to the arguments on terminology, but I do know that (1) any even integer with an absolute value greater than two may be divided by two to produce another even integer with a lesser absolute value, (2) any two odd integers multiplied together will produce another odd integer, (3) all odd integers have two even integers adjacent to them (e.g. if |x%2|==1 then (x+1)%2==0), (4) the product or quotient of any two numbers can be determined to be positive or negative based on the count of signs such that provided that the number of positive terms is an even number, the resulting sign will always be positive, otherwise the resulting sign will be negative. Therefore, the conjecture only works for Natural numbers (positive integers excluding zero), and does work for all of them in a way so predictable that an algorithm could be written to shortcut the loop and predict instead the number of steps required to reach 1 from any given Natural number. Wherefore is this conjecture considered unproven? All the axioms are there, well-known, and quite self-evident, and all the more so with the epoch of calculus.