Guide to the Cosmos
Making the Wonders of our Universe

Accessible to Everyone

Robert L. Piccioni, Ph.D.

Stars, Energy and Black Holes

Dr Robert Piccioni


Award winning books

Feynman Simplified
ebook series
About Dr. Piccioni
Video Lecture Series
Free Videos

sketch of black hole

This sketch shows the two parts of a black hole: the central singularity and the event horizon. The singularity contains all the black hole’s mass in a volume much smaller than a single atom. The event horizon is the limit of what we can see from the outside. Inside the event horizon, the escape velocity exceeds the speed of light, thus nothing inside can ever escape, not even light,

How a rocket can overcome its negative potential energy with sufficient kinetic energy to allow it to escape a gravitational field

Escape velocity - speed needed to escape gravitational field

Black hole accretion disk and jets

Material from interstellar gases, stars, etc., is pulled toward the central black hole accumulating in an "accretion disk".
About 75% of the material will eventually fall into the black hole, while 25% will be ejected along the spinning black hole's north and south poles, forming immense jets, some longer than our Milky Way galaxy.

Cluster of new stars less than 2M years old.

Star cluster

cat's eye nebula - white dwarf

When lower mass stars run out of fuel, the core collapses in an immense implosion, creating a White Dwarf, the central white dot, and blowing the star's outer layers off into space, creating beautiful nebula.

Penrose's scheme to achieve 100% mass conversion efficiency with a spinning black hole. The rocket dumps material, which could be trash, at the event horizon and returns to an orbiting society (shown in green) with excess energy = mass of trash times c2.

Scheme by Roger Penrose