How Does Gravity Affect Celestial Bodies?
Gravity is the fundamental force that governs the motion of celestial bodies. The law of universal gravitation, formulated by
Isaac Newton, states that every mass attracts every other mass with a force proportional to the product of their masses and inversely proportional to the square of the distance between their centers. This is crucial in understanding
orbital mechanics and the structure of
galaxies.
How Do Nuclear Reactions Power Stars?
Stars generate energy through
nuclear fusion, where lighter nuclei combine to form heavier nuclei, releasing energy in the process. In the core of stars like the Sun, hydrogen nuclei fuse to form helium. The balance between gravitational collapse and outward radiation pressure from fusion reactions determines a star's lifecycle and its eventual fate, be it a
white dwarf,
neutron star, or black hole.
What is Dark Matter and Dark Energy?
Dark matter and dark energy are two of the most profound mysteries in astrophysics.
Dark matter is an unseen form of matter that does not emit, absorb, or reflect light, but its presence is inferred from its gravitational effects on visible matter.
Dark energy is an unknown form of energy that is driving the accelerated expansion of the universe. Together, they make up about 95% of the total mass-energy content of the universe.
How Do Astrophysicists Study Exoplanets?
Astrophysicists use various methods to discover and study
exoplanets, or planets orbiting stars outside our solar system. Techniques include the transit method, where a planet passes in front of its host star and causes a temporary dip in brightness, and the radial velocity method, which detects wobbles in a star's position due to gravitational interactions with an orbiting planet. These methods help in understanding the
habitability and potential for life on other worlds.
