One of the biggest mysteries in physics is what happens when the field's two most advanced,

established theories collide. Einstein gave us a theory for how gravity works, that objects

with mass, curve space-time itself, and that's why the Earth goes around the sun and apples fall to the ground.

We call it general relativity.

And a century of work by many scientists has given us another theory,

quantum mechanics, which explains very consistently and accurately

how atomic and subatomic particles work. So there are two

internally consistent visions of reality, one for kind of the fabric of reality itself, and one for

the particles that fill it, and each of them works beautifully. The problem is that mathematically, they don't agree

with each other. Getting these two ideas together is the so-called theory of quantum gravity,

and one way to get closer to that idea might be to, well, push Einstein's gravity until it breaks.

And when that happens, something monstrous and a little terrifying happens,

a place where matter vanishes and time stops the literal edge of the cosmic map.

Welcome to the Quanta podcast where we explore the frontiers of science and math.

I'm Samir Patel, editor-in-chief of Quantum Magazine.

A quantum-based description of gravity, a way to bring these two theoretical frameworks together,

is a problem that comes up regularly in our physics stories, in part because lots of folks are still trying to figure it out.

Our physics writer, Charlie Wood, is with us today

to talk about one approach to getting closer and closer

to quantum gravity that he explored in a recent story

on quantum magazine.org called Singularities in Space Time

prove hard to kill. Welcome, Charlie.

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