“It now appears that the way the universe began can indeed be determined, using imaginary time.”
- January 8, 1942 – March 14, 2018
- British
- Theoretical physicist, science writer
- Announced the black hole singularity theorem and Hawking radiation, and contributed to the popularization of science with his book “Talking about the Universe”
Quote
“It now appears that the way the universe began can indeed be determined, using imaginary time.”
Explanation
In this quote, Stephen Hawking is referencing one of his most groundbreaking ideas in theoretical physics, specifically related to the origin of the universe. He suggests that the beginning of the universe—a question that has fascinated scientists, philosophers, and theologians for centuries—can, in fact, be understood using a concept known as imaginary time. Imaginary time is a mathematical concept that extends the idea of time beyond the conventional, linear understanding we have in everyday life. Unlike the “real” time we experience, which flows in one direction, imaginary time involves using complex numbers (i.e., numbers that include the square root of -1) in equations, particularly in the context of cosmology.
Hawking’s work on imaginary time became part of his contribution to quantum cosmology, an attempt to describe the universe at its very beginnings, before the Big Bang. In traditional models, time is viewed as a linear progression from past to future. However, Hawking proposed that in the very early universe, time could behave more like a spatial dimension, effectively removing the singularity at the Big Bang. In this framework, the universe would have no boundary or edge, and the initial conditions of the universe could be determined by the laws of physics without requiring a cause. Using imaginary time allowed him to reconcile the Big Bang with quantum mechanics, providing a new way of thinking about the creation of the universe—one that didn’t require a “first cause” in the traditional sense.
Hawking’s suggestion that the universe could be determined by imaginary time represents a major shift in our understanding of cosmology and time itself. It challenges the idea of a beginning in a conventional sense and proposes that time, as we know it, may not have had a clear starting point. This concept has deep implications for both the philosophy of science and the nature of existence, as it suggests that the universe might have always existed in some form, even if we cannot directly observe or experience it in our everyday lives. By using imaginary time, Hawking opened new avenues for exploring the early universe and the possibility of a unified theory of physics that could explain both the large-scale structure of the cosmos and the quantum behavior of the smallest particles.
