Scientific Forums


 

Add reply Start new topic Start new poll


> Gas Giants And Black Holes
Helios
Posted: Dec 29 2011, 10:19 AM


Newbie
*

Group: Members
Posts: 1
Joined: 29-December 11

Positive Feedback: 0%
Feedback Score: 0


I was watching a program on the Science Channel and it ran you through the sequence leading to the creation of a black hole and it didn't quite add up for me.

The example was of a blue giant star with 1000x more mass than our own sun.

The sequence was roughly star runs out of hydrogen nuclei to fuse into helium --> fuses helium nuclei into heavier elements --> eventually fuses heavier and heavier nuclei all the way to iron --> fusion stops --> star collapses under gravity --> an explosion (supernova) ensues (and somewhere in all this, elements heavier than iron are formed) --> a black hole forms.

I guess I don't understand how / why a black hole forms only *after* there is a significant loss of mass due to a supernova explosion... if the mass left over after such an explosion is great enough to collapse into a singularity where not even light can escape, how is it not great enough to prevent the explosion in the first place?

Sorry if this is too elementary... my degree is in biological sciences, but I really love astrophysics (in my laymans' way) and this is bugging me.
Top
Lady Elizabeth
Posted: Dec 29 2011, 02:30 PM


Dame of the British Empire.
*****

Group: Power Member
Posts: 2259
Joined: 11-December 10

Positive Feedback: 85.71%
Feedback Score: 5


Even though a significant mass from the outer-shell is ejected, there's more than adequate enough jobbies to pull the remainder into singularity mode. smile.gif


--------------------
Hobbies:
Needlecraft
Flower Arranging
Cake Decoration
Mutilating psychotic imbeciles
Hairdressing
Art
Romantic Classical Music

RealityCheck is a terrorist, crybaby and poster of anti-scientific crap.
RealityCheck is the sound of one hand wanking.
Top
Lasand
Posted: Dec 29 2011, 06:48 PM


Advanced Member
*****

Group: Power Member
Posts: 669
Joined: 8-December 07

Positive Feedback: 77.78%
Feedback Score: 2


After fusion stops, the core becomes INERT. That's an important consideration along with the amount of mass.

http://en.wikipedia.org/wiki/Type_II_supernova


--------------------
"It's elementary, My Dear Quantum"...The Sherlock Holmes of physics.

Top
mandykk
Posted: Dec 31 2011, 04:05 AM


Newbie
*

Group: Members
Posts: 1
Joined: 30-December 11

Positive Feedback: 0%
Feedback Score: 0


Hard to imagine .... After fusion stops, the core becomes INERT.
Love my I report with sigh, hate my me to smile away, regardless head top what kind of the sky, I will greet the whole storm.
Top
AlexG
Posted: Dec 31 2011, 05:02 AM


Advanced Member
*****

Group: Power Member
Posts: 5648
Joined: 8-September 06

Positive Feedback: 73.91%
Feedback Score: 108


QUOTE (Lasand @ Dec 29 2011, 01:48 PM)
After fusion stops, the core becomes INERT. That's an important consideration along with the amount of mass.

http://en.wikipedia.org/wiki/Type_II_supernova

No, that's not what happens.

After fusion stops, there is not sufficient energy to prevent gravitational collapse. When that happens, there is further fusion, fueled by the energy of the gravitational collapse, which produces the elements above iron. The energy of the gravitational collapse fuels the supernova, which simultainiously blows the heavier elements into the universe, and implodes the remaining core into a black hole.


--------------------
Its the way nature is!
If you dont like it, go somewhere else....
To another universe, where the rules are simpler
Philosophically more pleasing, more psychologically easy
Prof Richard Fyenman (1979) .....

God does not roll dice with the Universe" - A. Einstein

"God not only plays dice with the Universe, He rolls them where you can't see" - N. Bohr


Top
Majkl
Posted: Jan 24 2012, 07:52 AM


Advanced Member
*****

Group: Power Member
Posts: 716
Joined: 11-April 06

Positive Feedback: 39.39%
Feedback Score: -29


Just a short remark about black holes. I consider black holes as a pink unicorn of science. Its there and its black but no one can see it.
Top

Topic Options

Add reply Start new topic Start new poll


 

Terms of use