Theme Week, Part Sun

Jeremy’s Sametime Status Proudly Presents:   

Music Fact Check Week!   

The sun does not have enough mass to go Supernova and become a black hole

We wrap up Music Fact Check Week with a little trip through a Garden of Sound.  And science!  Don't forget science! 

We never forget science here at Jeremy Is In The Office, do we?  Let's look into the creation of black holes.

Stars are amazing things.  They spend their lives generating unfathomably powerful nuclear reactions, converting hydrogen into helium at temperatures somewhere in the 4-10 million degree mark.  Officially, I'm presenting that temperature in terms of Kelvin degrees, but once you get that high, it doesn't much matter what units you use.  It's really really hot.  That said, certain types of Blue Giant stars can reach temperatures of up to 50 million degrees, so it's a complete ballpark anyway.  For reference, our sun is in the main sequence of yellow stars, hovering just a little south of 6 million degrees.  

Once all of the hydrogen in a star is used up, (a process which takes a couple billion years) various things happen.  The outward pressure of constant nuclear explosions is no longer greater than the force of gravity keeping the star together, so the core of the star begins to collapse in on itself.  In most cases, these forces equillibrate over time, and the star ends its life as a white dwarf, slowly cooling adrift in space.  

In the case of especially large stars, the force of the star's core collapse causes the outer layers to be violently expelled into surrounding space in a phenomenon called a Supernova (there is no champagne involved).  Supernovae are unbelievably powerful.  One of my favorite physics facts to come from the whimsical webcomic xkcd shows that a supernova viewed at 1 AU (The distance from the earth to the sun) would appear over a billion times brighter than an exploding hydrogen bomb pressed directly against your eye.  ( Citation Needed )  If the star core remaining after all this supernova activity is sufficiently massive (we're talking multiple times more massive than the sun is now), then no force within the core can resist the force of gravity, and the entire core collapses into an infinitesimally small point of effectively infinite density.  The gravitational escape velocity of this singularity is greater than the speed of light, meaning anything caught within its gravity well has no chance of escape...even light.  This is what is referred to as a "Black Hole." 

In order to pull this all off, a star has to be remarkably larger than our sun in order to explode into a supernova and have its core collapse into a black hole.  Fortunately or otherwise, our sun will never do this, so Soundgarden's claim of a Black Hole Sun will never come true.  Also fortunately, we won't have to find this out for certain for another 7 billion years or so.