did you know

Ameesh

Lifer
Apr 3, 2001
23,686
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that all the elements heavier then iron on the periodic table in the universe are only formed through super nova explosions.
 
Jul 12, 2001
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Originally posted by: Ameesh
that all the elements heavier then iron on the periodic table in the universe are only formed through super nova explosions.

for some reason i read it like this the first time-
'that all elephants are heavier then iron on the periodic table and are only formed through super nova explosions'
:)
 

Grasshopper27

Banned
Sep 11, 2002
7,013
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Originally posted by: Ameesh
that all the elements heavier then iron on the periodic table in the universe are only formed through super nova explosions.

Argh, another useless fact stuck in my brain...

Q. How exactly does knowing this make my life better?

Grasshopper
 

Ameesh

Lifer
Apr 3, 2001
23,686
0
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Originally posted by: grasshopper26
Originally posted by: Ameesh
that all the elements heavier then iron on the periodic table in the universe are only formed through super nova explosions.

Argh, another useless fact stuck in my brain...

Q. How exactly does knowing this make my life better?

Grasshopper

knowledge almost always makes your life better!
 

ROTC1983

Diamond Member
Oct 2, 2002
6,130
0
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Originally posted by: Ameesh
that all the elements heavier then iron on the periodic table in the universe are only formed through super nova explosions.

Crap, you are taking up valuable space in my brain. :)
 

lukatmyshu

Senior member
Aug 22, 2001
483
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Hmm ... the reason that iron would be the cutoff point is 'cuz elements below irongain energy when they fuse, whereas elements above iron lose energy when they fuse (I think that's right). So basically you can't just take two elements together, bang them together at high speeds and get an element with atomic number higher than lead. It takes a certain amount of energy in addition to the two elements. The reason it only occurs in supernovas is that stars convert hydrogen to helium (via nuclear fusion) ... that's the majority of their life cycle (and the reason why those are the two most common elements in our Solar System). As the star gets older it moves to ther elements ... at some point it begins to fuse iron. (Mind you it only progresses to this stage if it has some critical mass equal to 2-3 times the size of our sun). It can't progress past lead so it "cools" down and the fusion process stops. This causes the star to contract (since the gravitational pressure is no longer countered by the heat). The resulting contraction will cause a huge amount of heat and since the iron can't fuse anymore it explodes. If the star is less than 5 solar masses or so the neutrinos can prevent the core from collapsing (the star will still supernova though) and it becomes a neutrino star. If it's more than this however, it becomes a black hole. Interesting stuff, eh?
But to negate your theory I'm pretty sure it's iron that is the cutoff point in this process so I don't see why only supernovas can produce elements w/ atomic number greater than lead.
 

gopunk

Lifer
Jul 7, 2001
29,239
2
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Originally posted by: Ameesh
Originally posted by: grasshopper26
Originally posted by: Ameesh
that all the elements heavier then iron on the periodic table in the universe are only formed through super nova explosions.

Argh, another useless fact stuck in my brain...

Q. How exactly does knowing this make my life better?

Grasshopper

knowledge almost always makes your life better!

i wouldn't say that... if your dad liked to dress up like a woman, would that knowledge make your life better? :p
 

Kadarin

Lifer
Nov 23, 2001
44,296
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Actually, I knew that. I had read it somewhere years ago, and the theory behind it.
 

Maggotry

Platinum Member
Dec 5, 2001
2,074
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Yes, I knew that. I love astronomy. Actually more into cosmology.

600,000 tons of hydrogen per second are fused into helium in the sun's core. It takes thousands of years for the photons released in the fusion to make it to the sun's surface.
 

Linflas

Lifer
Jan 30, 2001
15,395
78
91
Originally posted by: gopunk
Originally posted by: Ameesh
Originally posted by: grasshopper26
Originally posted by: Ameesh
that all the elements heavier then iron on the periodic table in the universe are only formed through super nova explosions.

Argh, another useless fact stuck in my brain...

Q. How exactly does knowing this make my life better?

Grasshopper

knowledge almost always makes your life better!

i wouldn't say that... if your dad liked to dress up like a woman, would that knowledge make your life better? :p

Yes then I would know better than to enter his room without knocking so I would not have to see the unthinkable. :Q
 

gopunk

Lifer
Jul 7, 2001
29,239
2
0
Originally posted by: Linflas
Originally posted by: gopunk
Originally posted by: Ameesh
Originally posted by: grasshopper26
Originally posted by: Ameesh
that all the elements heavier then iron on the periodic table in the universe are only formed through super nova explosions.

Argh, another useless fact stuck in my brain...

Q. How exactly does knowing this make my life better?

Grasshopper

knowledge almost always makes your life better!

i wouldn't say that... if your dad liked to dress up like a woman, would that knowledge make your life better? :p

Yes then I would know better than to enter his room without knocking so I would not have to see the unthinkable. :Q

hmm... you have a point...
 

jorken

Golden Member
Oct 9, 1999
1,143
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Originally posted by: Ameesh
that all the elements heavier then iron on the periodic table in the universe are only formed through super nova explosions.

Ameesh, have you been watching Carl Sagan's Cosmos video's again? ;)
 

Moonbeam

Elite Member
Nov 24, 1999
73,793
6,517
126
Actually your comment is kind of self defining since a supernova is an event in which iron burning collapses a stars core causing a supernova.
 

klah

Diamond Member
Aug 13, 2002
7,070
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Q: My question is this: If iron fusion seems to be the last step in stellar life, then where did we get all the heavier elements on earth? My understanding is that all of the elements on earth heavier than helium were produced in stellar furnaces.

A: All of the post-iron elements are formed in supernova explosions themselves. So much energy is released during a supernova explosion that the freed energy and copious free neutrons streaming from the collapsing core drive massive fusion reactions, long past the formation of iron. Sure, this absorbs a lot of energy, but there's plenty available once the explosion has begun.


from: http://curious.astro.cornell.edu/question.php?number=77