White Holes by Carlos Rovelli

Carlo Rovelli takes us on this time warp journey In his book, but without any formulas, equations or math. Instead he takes a more poetic approach, relating the journey into a black hole with Dante’s Divine comedy and his journey through hell. Personally I found the book to be refreshing. It’s a short book that gets your mind moving and wanting to explore more. And the way he is able to weave the different levels of hell that Dante experiences in the Inferno adds depth and keeps it from being just a theoretical book. 

Introduction to White Holes 

Carlo Rovelli makes sure to note that this is still a working theory and we haven’t observed any white holes yet. Interesting though was his idea, using gravitational wave detectors to try and see white holes passing by. He even goes as far as saying white holes could be what’s making up dark matter.

Planck Scale 

Even though White holes are a specific theoretical topic, Carlo writes most of his books so that beginners can pick them up and follow along without getting lost in technical jargon. Not that it’s necessary, but a basic understanding of Loop Quantum Gravity would be beneficial. It’s Carlo’s main study of work which attempts to take Einstein’s general relativity a step further and quantize the fabric of space. 

This means that space is a discrete structure at the planck scale, 10^ -35 meters, and composed of loops that form a spin network. From our scale space appears smooth, but when you get down to the planck scale, space has a grainy angular structure that’s connected to itself. 

Typically, when working with black holes you end up with singularities and infinities. Loop quantum gravity avoids these and represents them as quantum bridges with the spin networks that make up space. Unfortunately, this eliminates the ideas of black holes leading to extra dimensions or worm holes. 

Down the Rabbit Hole 

I also enjoyed how Carlo doesn’t get lost in history lessons or tangents. Still, I do enjoy hearing stories of ancient people who get surprisingly accurate measurements with simple geometry. And the stories involving David Finkelstein working out the black hole horizon are entertaining. 

Carlo does break away to kick around the idea that even the big bang was really a white hole forming and that we may be living within a white hole. He doesn’t go down the rabbit hole on these ideas, but gives you enough to suspect it might be feasible. 

In Conclusion 

Like I said before, this is a fun book that’ll get your mind moving and break away from the traditional science book writing style. It also gives you a little look at what a theoretical physicist, like Carlo Rovelli, is doing with his work in Loop quantum gravity and how he’s applying it. Maybe our new gravitational wave detectors will help us understand if spacetime is made of loops and if we’re living in a white hole.