# When Einstein Walked with Gödel | Jim Holt

Summary of: When Einstein Walked with Gödel: Excursions to the Edge of Thought

By: Jim Holt

## Introduction

Embark on a journey into the brilliant minds of two great thinkers, Albert Einstein and Kurt Gödel, as they delve into the nature of reality, time, and the universe in Jim Holt’s ‘When Einstein Walked with Gödel: Excursions to the Edge of Thought’. This summary explores the transformative friendship between these two intellectual giants, from their meetings at Princeton to their shared questioning of quantum mechanics. Uncover Gödel’s groundbreaking conclusions aboutspace, time, and the possibility of time travel, as well as fascinating insights into the nature of mathematics, the challenges of string theory, and the potential fates of the universe.

## Einstein’s Unlikely Friendship

Albert Einstein’s isolation in his later years led to a strange but fruitful friendship with Kurt Gödel, a genius logician.

Albert Einstein, the iconic German-born physicist, forever changed how we understand the world with his groundbreaking papers in 1905. However, few people know that toward the end of his life, he found an unlikely walking companion in Kurt Gödel, a much younger genius logician.

In 1933, Einstein fled to the US and settled in Princeton, where he spent his days going on long, solitary walks around the campus. However, he found an intellectual connection in Gödel, who challenged the notion of absolute knowledge with his incompleteness theorems. Despite their personality differences, the two men shared a belief that mathematics was rooted in physical reality and a skepticism of quantum mechanics.

Gödel’s star was shining brighter than ever while Einstein’s star was fading due to his opposition to quantum mechanics. But their friendship brought new ideas, as Gödel took Einstein’s famous relativity theory even further. The strange but fruitful friendship between Einstein and Gödel shows that even geniuses need companionship and intellectual stimulation in their later years.

## The Absurdity of Time

Einstein’s theory of relativity and Gödel’s interpretation of it challenge our understanding of time and the universe.

In the early 20th century, physicists believed that the laws of physics were absolute and the speed of light was consistent for everyone and everywhere. However, Einstein’s theory of relativity debunked these concepts and suggested that space and time could be relative. What Einstein proposed meant that the distances and times measured by two observers in motion relative to each other must appear to be different, despite the speed of light remaining constant.

Gödel, who was a brilliant mathematician, took Einstein’s theory further and theorized that the universe rotates instead of expands. Such rotation would make it theoretically possible to travel back in time. Gödel concluded that if time travel is mathematically possible, then time itself doesn’t exist, making our concept of it an illusion.

Einstein’s theory upset many scientists who initially refused to accept it. Despite the opposition, experiments conducted since Einstein’s time have shown that he was right. However, even today, we don’t entirely understand time and its role in the universe. We are still grappling with concepts such as black holes and time travel.

Gödel’s own tragic end adds to the mystery surrounding the subject. Gödel grew increasingly paranoid after Einstein’s death and eventually stopped eating until he died of self-starvation. His interpretation of relativity theory posits that time itself is impossible, making his own time on Earth an illusion.

Einstein and Gödel’s theories, which may seem abstract, challenge our fundamental beliefs about the universe and our existence within it. Their work pushes us to question our understanding of time and reality and remains relevant today.

## The Music of Numbers

The brain is wired for numbers, and even those who struggle with math have a basic “number sense” that allows them to estimate and add objects in their environment. The Riemann zeta conjecture, which holds the key to understanding prime number distribution, remains unsolved but is so beloved by mathematicians that they often assume its truth in calculations.

## The Beauty of Pure Mathematics

Pure mathematics is about finding beautiful proofs rather than practical solutions to real-world problems. Mathematicians search for simplicity, strangeness, and inevitability in a theory to measure its beauty. Beauty is often equated with truth and it is more about painting a compelling picture using the language of mathematics. Benoit Mandelbrot’s fractal geometry is an example of the beauty of pure mathematics. Certain physical structures are “self-similar,” or “fractal,” making it possible to achieve complex fractal patterns from simple formulas.

## The Puzzling Nature of Infinity

Humans have always been fascinated by the concept of infinity. The idea of endless space, time, and numbers has intrigued people throughout history. Infinity can be infinitely big, almost mystical, or the infinitely small, which is equally perplexing. Mathematicians of ancient Greece used infinitely small fractions to calculate geometric shapes and volumes, but the idea of infinitely small quantities was rejected by most scientists for centuries. Blaise Pascal and Isaac Newton briefly revived the concept in the seventeenth century, but Newton believed it to be a “well-founded fiction” in mathematics. It was not until the 1960s that mathematician Abraham Robinson was able to rehabilitate the idea of the infinitesimal, proving its logical consistency and satisfying the standards of modern mathematics. Today, we know that atoms can be divided into electrons, protons, and neutrons, and even quarks may be divisible into smaller particles. The universe may be both infinitely big and infinitely small, making infinity a concept that does not come in just one size.