Smitha Vishveshwara is a Professor of Physics at the University of Illinois at Urbana-Champaign. Her research in quantum condensed matter physics includes studying emergent phenomena in correlated systems, such as collective excitations and particles known as anyons; percolation behavior in protein networks; gravitational parallels in quantum matter; and realization of ultracold quantum bubbles aboard the International Space Station. She recently served as the American Physical Society's Chair of the Division of Condensed Matter Physics. She collaborates with artists to create works that explore the wonders of physics, including the theatre piece Quantum Voyages and the circus performance Cosmic Tumbles, Quantum Leaps.C.V. Vishveshwara was a Senior Professor of Astrophysics at the Raman Research Institute and the Indian Institute of Astrophysics in Bengaluru, India. As a pioneer of black hole studies, he proved their stability and predicted their ringdown signature in gravitational waves. He wrote several popular articles and two popular books, including Einstein's Enigma or Black Holes in my Bubble Bath, and richly illustrated his presentations with his cartoons. As the founder-director of the Jawaharlal Nehru Planetarium in Bengaluru, he established youth educational programs and wrote and directed several planetarium shows.

This is an engaging and thought-provoking exchange of letters between two insightful physicists, a father and daughter, explaining clearly the principles of both general relativity (including black holes and the detection of gravitational radiation) and quantum theory (including the difference between bosons and fermions, entanglement, a Bose-Einstein condensate, and magnetic resonance imaging). It is delightfully illustrated and does not shy away from presenting relevant key equations. The father-daughter relationship at the centre of the book gives it a unique quality that makes it a great read.

• RELATIVITY Part 1: Beginnings Part 2: Developments Part 3: Modern Times QUANTUM PHYSICS Part 1: Beginnings Part 2: Developments Part 3: Modern Times Parting Letter and Epilogue Acknowledgements

Smitha Vishveshwara is a Professor of Physics at the University of Illinois at Urbana-Champaign. Her research in quantum condensed matter physics includes studying emergent phenomena in correlated systems, such as collective excitations and particles known as anyons; percolation behavior in protein networks; gravitational parallels in quantum matter; and realization of ultracold quantum bubbles aboard the International Space Station. She recently served as the American Physical Society's Chair of the Division of Condensed Matter Physics. She collaborates with artists to create works that explore the wonders of physics, including the theatre piece Quantum Voyages and the circus performance Cosmic Tumbles, Quantum Leaps.C.V. Vishveshwara was a Senior Professor of Astrophysics at the Raman Research Institute and the Indian Institute of Astrophysics in Bengaluru, India. As a pioneer of black hole studies, he proved their stability and predicted their ringdown signature in gravitational waves. He wrote several popular articles and two popular books, including Einstein's Enigma or Black Holes in my Bubble Bath, and richly illustrated his presentations with his cartoons. As the founder-director of the Jawaharlal Nehru Planetarium in Bengaluru, he established youth educational programs and wrote and directed several planetarium shows.

This is an engaging and thought-provoking exchange of letters between two insightful physicists, a father and daughter, explaining clearly the principles of both general relativity (including black holes and the detection of gravitational radiation) and quantum theory (including the difference between bosons and fermions, entanglement, a Bose-Einstein condensate, and magnetic resonance imaging). It is delightfully illustrated and does not shy away from presenting relevant key equations. The father-daughter relationship at the centre of the book gives it a unique quality that makes it a great read.

• RELATIVITY Part 1: Beginnings Part 2: Developments Part 3: Modern Times QUANTUM PHYSICS Part 1: Beginnings Part 2: Developments Part 3: Modern Times Parting Letter and Epilogue Acknowledgements

Smitha Vishveshwara is a Professor of Physics at the University of Illinois at Urbana-Champaign. Her research in quantum condensed matter physics includes studying emergent phenomena in correlated systems, such as collective excitations and particles known as anyons; percolation behavior in protein networks; gravitational parallels in quantum matter; and realization of ultracold quantum bubbles aboard the International Space Station. She recently served as the American Physical Society's Chair of the Division of Condensed Matter Physics. She collaborates with artists to create works that explore the wonders of physics, including the theatre piece Quantum Voyages and the circus performance Cosmic Tumbles, Quantum Leaps.C.V. Vishveshwara was a Senior Professor of Astrophysics at the Raman Research Institute and the Indian Institute of Astrophysics in Bengaluru, India. As a pioneer of black hole studies, he proved their stability and predicted their ringdown signature in gravitational waves. He wrote several popular articles and two popular books, including Einstein's Enigma or Black Holes in my Bubble Bath, and richly illustrated his presentations with his cartoons. As the founder-director of the Jawaharlal Nehru Planetarium in Bengaluru, he established youth educational programs and wrote and directed several planetarium shows.

This is an engaging and thought-provoking exchange of letters between two insightful physicists, a father and daughter, explaining clearly the principles of both general relativity (including black holes and the detection of gravitational radiation) and quantum theory (including the difference between bosons and fermions, entanglement, a Bose-Einstein condensate, and magnetic resonance imaging). It is delightfully illustrated and does not shy away from presenting relevant key equations. The father-daughter relationship at the centre of the book gives it a unique quality that makes it a great read.

• RELATIVITY Part 1: Beginnings Part 2: Developments Part 3: Modern Times QUANTUM PHYSICS Part 1: Beginnings Part 2: Developments Part 3: Modern Times Parting Letter and Epilogue Acknowledgements