In the television series "cosmos" the astronomer carl sagan used to say, "we are all made of star stuff." what did he mean by that?

All of the chemical elements in our solar system were forged in an ancient star that went supernova.

Explanation:

This phrase means that the carbon, oxygen and nitrogen atoms in our bodies, as well as the other heavy elements in our solar system were created from previous stars over 4.5 billion years ago.

Star stuff got to Earth by means of a supernova explosion, which is an explosion of a massive star. This kind of stellar explosion creates a large cloud of gas and dust in space and the amount of material that the cloud is composed of depends on the type of supernova. The material from a supernova eventually disperses into interstellar space. The oldest stars consist of hydrogen and helium. Oxygen and the rest of the other heavier elements in the universe come from supernova explosions.

Therefore, stars make heavy elements and later in their lives, they eject gas into the medium between stars so it can be part of subsequent stars, planets and eventually people.

the order for strong to weak forces such as

strong nuclear force → electromegnetic force → weak nuclear force → gravitational force

the fundamental forces are those forces that act between to objects or element to make interactions. there are four types of fundamental forces such as strong and weak nuclear forces (due to protons and electrons), electromagnetic force (due to the motion of electrons) and gravitational force (due to orbital movement of the planet). if these forces are arranged on the basis of their maximum strength then the order is

strong nuclear force → electromegnetic force → weak nuclear force → gravitational force