Unit 12- Astrophysics

Wormhole

A theoretical passage through space-time that allows for shortcuts between two distant points in the universe, potentially enabling faster-than-light travel.

White dwarf

A small, dense star that is typically the remains of a red giant after it has exhausted its nuclear fuel, characterized by a high temperature but low luminosity.

Supernova

A powerful and luminous explosion that occurs when a star reaches the end of its life cycle, resulting in the ejection of its outer layers and a significant increase in brightness.

Singularity

A point in space-time where gravitational forces are so intense that spacetime curves infinitely, often associated with black holes, leading to infinite density and zero volume.

Spacetime

The four-dimensional continuum that combines the three dimensions of space with the dimension of time, where all physical events occur.

Red Shift

The phenomenon where light from an object moving away from the observer shifts to longer wavelengths, indicating its velocity and distance.

Red Giant

A large, luminous star that has expanded and cooled after exhausting the hydrogen in its core, characterized by its red color and significant increase in size before it evolves into a planetary nebula or supernova.

Neutron Star

A dense remnant core left after a supernova explosion, composed mainly of neutrons and known for its strong gravitational and magnetic fields.

Gravitational Wave

A ripple in spacetime caused by the acceleration of massive objects, such as merging black holes or neutron stars, predicted by Einstein's theory of general relativity.

Event Horizon

The boundary surrounding a black hole beyond which nothing can escape, including light, marking the point of no return.

Galaxy

A vast system of stars, gas, dust, and dark matter bound together by gravity, with billions to trillions of stars organized in various structures.

General Relativity

A theory of gravity proposed by Albert Einstein, describing gravity as the curvature of spacetime caused by mass, which explains the gravitational effects of massive bodies.

Cluster

A group of galaxies held together by gravity, often containing hundreds to thousands of member galaxies.

Dark Energy

A mysterious form of energy that makes up about 68% of the universe, driving its accelerated expansion and having repulsive gravitational effects.

Dark Matter

A form of matter that does not emit, absorb, or reflect light, making it invisible and detectable only through its gravitational effects on visible matter and radiation.

Cosmic Rays

High-energy particles originating from outer space that travel at nearly the speed of light and can collide with Earth's atmosphere.

Big Bang

the leading explanation for the origin of the universe, suggesting it began from a singular point and has been expanding ever since.

Black Hole

A region of spacetime where gravity is so strong that nothing, not even light, can escape from it.

Nebula

A giant cloud of gas and dust in space, often the birthplace of stars.

Light Year

A unit of distance that represents how far light travels in one year, approximately 5.88 trillion miles or 9.46 trillion kilometers.

Nucleosynthesis

The process by which elements are formed through nuclear reactions in stars, including the fusion of hydrogen into helium and heavier elements during stellar evolution.

Accretion Disk

gas and dust surrounding a newly formed star or black hole, where material accumulates due to gravitational forces.

Paralax

The apparent shift in position of a nearby star against the background of distant stars as observed from different points in Earth's orbit.

Hawking Radiation

Theoretical prediction that black holes can emit radiation due to quantum effects near the event horizon, leading to a slow loss of mass and energy.

Quantum Loop Gravity

A theoretical framework that attempts to reconcile quantum mechanics and general relativity by describing gravity in terms of quantized loops of spacetime, suggesting a discrete structure at the Planck scale.