Eposode 57: The birth of stars – Part 2


Panel 1.
Second Hijacker: If the mass of the disturbed molecular cloud is large enough, the mutual gravity of the interstellar molecules will take over and cause the cloud to collapse.

Panel 2.
Hijacker: Is that when a star is formed?
Second Hijacker: No. Wait a minute. I need to set the computer to start taking measurements.

Panel 3.
Second Hijacker: Okay. As the cloud collapses the gravitational potential energy of the molecules is turned into heat.
Hijacker: Ah. And that’s when a star is born.

Panel 4.
Second Hijacker: Ah, no. Once the temperature of the cloud gets high enough, the hydrogen molecules in the cloud break into atoms and are eventually ionized.

Panel 5.
Hijacker: And then…
Second Hijacker: Then, if the temperature grows much higher still, nuclear fusion is initiated, balancing the gravitational collapse.

Panel 6.
Hijacker: And then…
Second Hijacker: And then a star is born.

What does it mean?

Potential energy – The energy that is stored in objects due to is position in a force field. For example, the atoms in a molecular cloud have gravitational potential energy that is turned into heat energy, which is just the energy of the random motions of the particles as the cloud collapses towards its gravitational center.

Ionized – is the term for an atom which has lost one or more electrons causing it to become positively charged.

Nuclear fusion – is the process by which lighter elements like hydrogen and helium fuse together to make heavier elements like lithium, carbon, oxygen, etc.