“A Traveller’s Guide to the Stars” with Physicist, Author and Nasa Technologist Les Johnson

Reviewed on Bridging the Gaps

The ancient ambition of exploring the cosmos and possibly even inhabiting other planets may one day come true, as we discover more and more exoplanets and intend to develop innovative propulsion techniques suitable for interstellar travel. Projects like 100 Year Starship and Breakthrough Starshot enable us to study the challenges involved with a view to develop solutions, furthering the idea of interstellar travel. In his new book “A Traveller’s Guide to the Stars” physicist and Nasa Technologist Les Johnson takes the readers on an exciting journey through the science and innovations that could help us get to the stars.The book gives a thorough account of the next great frontier of human exploration, outlining exclusive inside look at the amazing advances in science and technology that will aid today’s astronauts in setting out for the stars.

Les Johnson is a physicist, author, and NASA technologist. He leads the development of advanced, in-space spacecraft propulsion technologies at the NASA George C. Marshall Space Flight Center in Huntsville, Alabama. During his career at NASA, Les served as the Manager for the Space Science Programs and Projects Office, the In-Space Propulsion Technology Project, and the Interstellar Propulsion Research Project.

We begin by reviewing the impact of discovery of exoplanets on the ambition of travelling to and inhibiting these distant alien worlds. Next we look at the precursors that we must take into consideration before building the ships and embarking on interstellar journeys. We discuss in detail the presently used propulsion technologies and evaluate their shortcomings for interstellar journeys. While discussing the future, we first discuss in detail two rocket technologies of the future: nuclear fusion and antimatter. Then we discuss in detail the innovative and promising propulsion approaches such as solar sails and laser-beamed energy. We discuss in detail how these technologies may one day enable us to embark on interstellar journeys. Les Johnson has written a number of science fiction books; I ask him to expand on his view that science fiction is an effective tool to imagine future technologies. No discussion on the topic of space exploration is complete without discussing the possibility of life out there; we discuss this as I ask Les to give us his views on the possibility of life out there and on the question “are we alone”. This has been a fantastic discussion.

Complement this discussion with “The Next 500 Years: Engineering Life to Reach New Worlds” with Professor Christopher Mason and then listen to “The End of Astronauts”, Robotic Space Exploration and Our Future on Earth and Beyond with Professor Martin Rees”

By |March 13th, 2023|Future, Physics, Podcasts, Technology|
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“When Galaxies Were Born: The Quest for Cosmic Dawn” with Professor Richard Ellis

When Galaxies Were Born book Review on Bridging the Gaps

Looking for the earliest galaxies is like travelling back in time. Something that astronomers do all the time. Astronomers use huge and powerful telescopes to see not only farther and deeper into space, but also back in time. The hunt for the oldest galaxies using observational astronomy needs not only a thorough grasp of the physics and chemistry of the early cosmos, but also the human ingenuity of building large size telescopes and designing innovative instrumentation. Large and complicated telescopes, as well as supporting processes, techniques, and devices, allow astronomers to make more clear and accurate observations in their search for the first galaxies. In his new book “When Galaxies Were Born: The Quest for Cosmic Dawn” professor Richard Ellis presents a firsthand narrative of how a pioneering group of scientists used the world’s greatest telescopes to unravel the history of the universe and witness cosmic dawn, when starlight first illuminated the cosmos and galaxies formed from darkness. The book also gives a narrative of a golden age of astronomy, outlining many achievements and disappointments, and discussing rivalries with competing teams. This is also an account of professor Elis’s remarkable career spanning more than forty years. In this episode of Bridging the Gaps I speak with professor Richard Ellis. We discuss amazing progres that astronomers have made in building ever larger and more powerful telescopes; we also dig deep on the fascinating research on the birth of galaxies and our quest for the cosmic dawn.

Richard S. Ellis is professor of astrophysics at University College London and a world-renowned observational astronomer who has made numerous discoveries about the nature and evolution of the universe.

We start off discussing the human aspects of observational astronomy where teams from all over the world first compete for participating in constructing large telescopes and then compete for securing blocks of time to make observations. We review the taxonomy of large and most powerful ground based telescopes and discuss effectiveness and contribution of space telescopes towards observational astronomy. First light in the universe and the assembly of galaxies in the early universe are among the four main areas that the James Webb Space Telescope will focus on. We dig deep on these points, and what expectations researchers have from this new space telescope. We then discuss how human ingenuity has led to the development of techniques such as adaptive mirrors and application of gravitational lensing to improve our observations. We then focus on the cutting edge research on the quest for cosmic dawn and dig deep on the physics and chemistry of the early universe. We discuss the role dark matter might have played in the formation of early galaxies. We also touch upon the origin of life in the universe, and briefly debate the question “are we alone”. This has been a fun discussion that is highly informative.

Complement this discussion with Exploring the Mysteries of Our Universe’s First Seconds” with Dr Dan Hooper and then listen to “The End of Everything (Astrophysically Speaking)” with Dr Katie Mack.

By |January 29th, 2023|Cosmology, Physics, Podcasts, Technology|
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“Exploring the Mysteries of Our Universe’s First Seconds” with Dr Dan Hooper

Scientists now have a good understanding of how our universe evolved over the past 13.8 billion years, but we know very little about what happened in the first few seconds after the Big Bang. Dr Dan Hooper, a senior scientist at Fermi National Accelerator Lab and a professor of astronomy and astrophysics at the University of Chicago, emphasises that understanding the earliest moments of the universe is vital to tackle, and to decipher mysteries such as dark matter and dark energy. In his book “At the Edge of Time: Exploring the Mysteries of Our Universe’s First Seconds” Hooper outlines four foundational questions as puzzles that we must solve and the key to solving these puzzles is in understanding what happened at the very beginning of our universe.

In this episode of Bridging the Gaps I speak with Dr Dan Hooper. We discuss intriguing questions and fascinating research that he presents in the book “At the Edge of Time: Exploring the Mysteries of Our Universe’s First Seconds”. At the start of the book Hooper gives a thorough description of the timeline of how we got here where we are now from the Big Bang to the present day and how did our universe evolve over the past 13.8 billion years; he presents this narrative backwards, from the present time to the Big Bang. I open our conversation by asking him to describe this timeline and this journey from the present day to the Big Bang. We then discuss the four puzzles that Hooper outlines in the book and examine that understanding what happened in the first few seconds after the Big Bang holds the key to solving these puzzles. We also discuss the progress that is being made in developing a theory of everything, gravitational waves and his views on the multi universe theory. This has been a fascinating discussion with a very passionate researcher.

Compliment Professor Hooper’s insights with equally fascinating discussion with Dr Katie Mack “The End of Everything (Astrophysically Speaking”, and then listen to discussion with Nasa’s Spitzer project scientist Michael Werner “Spitzer Space Telescope: Discovering “More Things in the Heavens”.

By |September 20th, 2020|Cosmology, Physics, Podcasts|
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