Twinkle, Twinkle Little Star
Do you know why stars twinkle? It's time to find out!
Written to the classic melody of "Twinkle Twinkle Little Star" by an expert in astrophysics, this book is the perfect introduction to the real science behind the magic of stars. Discover how stars are created, what they're made of, and even what makes them look like they're twinkling.
Stars are not only great for wishing upon, but they are also spectacular examples of scientific magic. From atmospheric turbulence to fusing atoms, these delightful (more accurate!) lyrics will become your new favorite version of this classic tune. Instead of wondering what stars are, you will know for sure!
Twinkle Twinkle Little Star
I know exactly what you are
Opaque ball of hot dense gas,
million times our planet's mass,
looking small because you're far,
I know exactly what you are.
Astrophysics is the branch of astronomy that employs the principles of physics and chemistry "to ascertain the nature of the astronomical objects, rather than their positions or motions in space". Among the objects studied are the Sun, other stars, galaxies, extrasolar planets, the interstellar medium and the cosmic microwave background. Emissions from these objects are examined across all parts of the electromagnetic spectrum, and the properties examined include luminosity, density, temperature, and chemical composition.
Because astrophysics is a very broad subject, astrophysicists apply concepts and methods from many disciplines of physics, including classical mechanics, electromagnetism, statistical mechanics, thermodynamics, quantum mechanics, relativity, nuclear and particle physics, and atomic and molecular physics. In practice, modern astronomical research often involves a substantial amount of work in the realms of theoretical and observational physics. Some areas of study for astrophysicists include their attempts to determine the properties of dark matter, dark energy, black holes, and other celestial bodies; and the origin and ultimate fate of the universe.
Topics also studied by theoretical astrophysicists include Solar System formation and evolution; stellar dynamics and evolution; galaxy formation and evolution; magnetohydrodynamics; large-scale structure of matter in the universe; origin of cosmic rays; general relativity, special relativity, quantum and physical cosmology, including string cosmology and astroparticle physics.