What's up in
Finding out whether a question is too difficult to ever solve efficiently depends on figuring out just how hard it is. Researchers have now shown how to do that for a major class of problems.
The existence of secure cryptography depends on one of the oldest questions in computational complexity.
A recent paper set the fastest record for multiplying two matrices. But it also marks the end of the line for a method researchers have relied on for decades to make improvements.
The way you learned to multiply works, but computers employ a faster algorithm.