Radio Universe
by Emma Chapman
John Murray

At the age of 16, Albert Einstein imagined racing alongside rays of light, an idea that laid the groundwork for his renowned theory of special relativity. Now, physicist Emma Chapman invites readers to embark on their own journey through the cosmos with her upcoming book, Radio Universe: How to Explore Space Without Leaving Earth (American title: Echoing Universe), set to be released on May 19th.

Chapman’s exploration of light signals provides an understanding of how radio telescopes communicate with the universe. “The universe already speaks the language of light,” she states, guiding readers into the world of radio astronomy.

Light, as an electromagnetic wave, varies across wavelengths. While ultraviolet (UV) light has shorter wavelengths than visible light, radio waves—Chapman’s specialty—have much longer wavelengths, enabling them to traverse vast distances. This characteristic gives radio telescopes the capability to observe deeper into space, effectively operating day and night. According to Chapman, these versatile machines can trace signals from our Moon to potential alien habitats.

Radio Universe is structured into three sections: the solar system, the galaxy, and the universe, each delving into how radio waves propagate. The first chapter reveals how radio waves were used to communicate during humanity’s lunar explorations, emphasizing the pivotal role of radio in modern space research.

One notable chapter focuses on Venus, a planet so hostile that conventional light-based observation methods are ineffective. However, radio waves bridge the gap, allowing scientists to ‘see’ this otherwise obscured environment.

Subsequent chapters illustrate how radio astronomy has contributed to iconic black hole images, gravitational wave detection, and exoplanet discoveries.

In discussing the search for extraterrestrial life, Chapman emphasizes that “contact via radio signals is more probable than an invasion,” suggesting that radio waves serve as the primary medium for interstellar communication.

Chapman’s book also addresses dark matter and dark energy, two of the universe’s biggest enigmas. While these substances dominate the cosmos, they remain difficult to detect directly. However, radio telescopes can infer their presence, such as tracing radiation from interstellar hydrogen gas to map dark matter’s location.

Throughout the book, Chapman’s accessible and engaging writing resonates with readers. As she describes Mercury’s swift orbit around the sun, the sensation of its rapid movements is felt, making her explanations relatable. Her exploration of the asteroid belt not only teaches radio astronomy but also offers insights into classic astronomical concepts, akin to learning from a knowledgeable companion.

The book concludes with an appendix detailing various radio telescopes that readers can visit as tourists.

While Chapman exudes enthusiasm about commercial space ventures including Mars colonization, there are some areas where her optimism may overlook critical discussions about the implications of private space exploration. Addressing the potential conflicts between scientific and commercial interests on the Moon, she questions whether researchers aiming to place telescopes there will face opposition from those driven by profit.

Moreover, her narrative largely highlights American and British contributions to radio astronomy, overlooking significant advancements made in countries like Puerto Rico and Chile, which are home to some of the world’s most important radio telescopes.

Ultimately, Chapman conveys a powerful message: our universe is never silent. “Surrounded by radio waves,” she explains, “we just need to close our eyes and listen.”

The next time I gaze at the night sky, even beneath urban lights, I will remember to follow her advice and listen intently.

Two More Recommended Books on Astronomy

Fear of a Black Universe: An Outsider’s Guide to the Future of Physics
By Stephon Alexander

In this compelling narrative, Alexander weaves together his journey as a practicing cosmologist with reflections on his life experiences as a black man, drawing inspiration from diverse influences, including art and spirituality. Feynman diagrams and personal anecdotes coalesce to create a captivating story about the universe.

The Disordered Cosmos: A Journey into Dark Matter, Spacetime & Dreams Deferred
By Chanda Prescod Weinstein

Chanda Prescod Weinstein ingeniously intertwines the scientific with the personal in this compelling narrative. As a columnist for New Scientist, she delivers not only detailed descriptions of phenomena like dark matter but also insightful critiques of the sociopolitical factors influencing scientific discourse. The book highlights the significance of consent and representation in the scientific community, emphasizing that rigorous science extends beyond mere observation.