An image of two galaxies moving away.
Astronomy

The Expanding Universe: Are the Galaxies Moving Away?

January 6, 2023

The universe, when examined using the doppler shift, does seem to support the observation that it is expanding, with galaxies moving, some away and some toward us. However, there’s no unique ‘center’ of the expansion. […]

An image of a blue spiral galaxy.
Astronomy

The Rotation Velocity of Elliptical and Disk Galaxies

January 6, 2023

Newton’s theorem, used to calculate rotation velocity, applies to elliptical galaxies. It doesn’t apply to flat disks as, in order to do so, one has to do integrals involving modified Bessel functions of the second kind. […]

A 3D rendition of a black hole.
Astronomy

How Active Galaxies and Black Holes Are Related

January 5, 2023

When it comes to understanding the relationship between an active galaxy and a black hole, it is one of cause and effect. There is a negative feedback between the black hole and the surrounding galaxy as when the galaxy grows too fast, the black hole produces out-flows that halt any further growth. […]

An image of a starry disk around supermassive black hole.
Astronomy

Dark Matter: Accreting Black Holes

January 5, 2023

Accreting black holes at the center of a galaxy are slightly more massive. Gas is funneled toward the innermost edge of the accretion disk. The gas is hot, ionized, plasma and is likely to turn into a tangled internal magnetic field. […]

Bright moon at night with clouds
Astronomy

How Did the Moon Form?

December 21, 2022

Where did Earth’s Moon come from and how did it form? The nearest celestial body shines big, bright, and round in the sky, but how did it get there? Humanity’s renewed interest in the Moon raises questions. […]

Diagram representation of Kepler's laws
Astronomy

The Physics behind Kepler’s Laws

November 20, 2022

Kepler’s laws of planetary motion are not really laws of physics. To understand the reason behind these laws, we need to consider Newton’s law of motion. […]

Diagram showing Kepler's second law of planetary motion
Astronomy

Kepler’s Second and Third Laws

November 20, 2022

Kepler’s second and third laws are about how fast the planets move and about the time required to go around the orbit, respectively. His third law helps measure the mass of everything in astrophysics. […]

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