In principle, this impossible math allows for a glue-free bridge of stacked blocks that can stretch across the Grand Canyon—and into infinity Keep going. If you stack as many blocks as you can, what ...

One idle evening last October, Mehtaab Sawhney took up an old pastime. He began perusing the website erdosproblems.com, an updated record of the 1,179 conjectures left behind by the eccentric and ...