Galaxies
What is a spiral galaxy?
most common galaxy with lots of gas, dust, and stars that revolve around a central black hole
What is general theory of relativity?
Theory proposed by Einstein to incorporate gravity into the framework of special relativity .
What is convection?
it is the process by which hot air rises while cool air sinks.
What are the 3 outer layers of the sun that constitute its atmosphere?
Photosphere, Chromosphere, Corona
What is Cosmology?
Cosmology is the study of the composition and evolution of the universe on large scales.
What is a Ellipitical Galaxy?
closely packed cluster of older stars in an oval shape
What is gravitational redshift?
A prediction of Einstein’s general theory of relativity. Photons lose energy as they escape the gravitational field of a massive object. Because a photon’s energy is proportional to its frequency, a photon that loses energy suffers a decrease in frequency, which corresponds to an increase, or redshift, in wavelength.
What is Aurorae?
Its when charged particles enter Earth's atmosphere, they excite electrons in the atoms of the atmosphere
What is Hydrostatic Equilibrium?
Condition in a star or other fluid body in which gravity’s inward pull is exactly balanced by internal forces due to pressure.
What is Thermodynamics?
it is the study of heat and energy
What is Irregular Galaxy?
youngest of all galaxies with lots of gas and dust. AKA stellar nurseries
What is curvature?
it is an intrinsic property of the space-it is a product of its geometry, meaning that it is innate to the space & doesn't depend on the embedding of the space.
What is the 2 surfaces of the moon called?
Maria "Mare"are the dark areas on the moon and the "highlands" are the lighter areas on the moon.
What is nuclear fusion?
Mechanism of energy generation in the core of the Sun, in which light nuclei are combined, or fused, into heavier ones, releasing energy in the process.
What is Cosmic Microwave Background Radiation (CMBR)
This is the left over radiation from 380,000 yrs after the Big Bang. The almost perfectly isotropic radio signal that is the electromagnetic remnant of the Big Bang.
What is the Hubble's Law?
Law that relates the observed velocity of recession of a galaxy to its distance from us. The velocity of recession of a galaxy is directly proportional to its distance away.
What us a blackbody curve?
The characteristic way in which the intensity of radiation emitted by a hot object depends on frequency. The frequency at which the emitted intensity is highest is an indication of the temperature of the radiating object. Also referred to as the Planck curve.
What is Earth's atmosphere made up of?
Our atmosphere is
about 78% Nitrogen,
21% oxygen, 0.9%
argon, and 0.03%
carbon dioxide, by
volume.
What is Solar Neutrinos?
Neutrinos are tiny particles that are about 1 millionth as massive as electrons, they are produced in large quantities in the sun, and Neutrinos are produced in the sun mostly by the proton.
What is Isotrophy & Homogeneity?
Isotropic-Assumed property of the universe such that the universe looks the same in every direction.
Homogeneity-Assumed property of the universe such that the number of galaxies in an imaginary large cube of the universe is the same no matter where in the universe the cube is placed.
What is cosmological redshift?
The component of the redshift of an object that is due only to the Hubble flow of the universe.
What is a event horizon?
Imaginary spherical surface surrounding a collapsing star with radius equal to the Schwarzschild radius, within which no event can be seen, heard, or known about by an outside observer.
What is the greenhouse effect?
The greenhouse effect raises the average temp of Earth surface from about -23 degrees C to 17 C.
Why is the corona so hot?
extreme temps are a mystery, some proposals assert that waves carry energy to the corona.
What is the flatness problem?
One of two conceptual problems with the standard Big Bang model, which is that there is no natural way to explain why the density of the universe is so close to the critical density.