NationStates Jolt Archive

Note: Upon further inspection, I have found that the remedial course "Debunking the Big Bang 101" has been eliminated due to budget cuts, but some of you probably remember what I said.

According to most scientists, the only source of heavy elements is from fusion in the cores of stars. However, it is an acknowledged fact that the heaviest element that can be produced in a star's core is iron. After that, even supermassive stars like the ones that turn into black holes cannot continue the process. Yet we have dozens of elements that are higher in atomic number than iron, some of them radioactive. You will argue that these elements were made in the Big Bang, but you have to count in atomic half-life.

The focus elements of this topic is U-235 and U-234. The first has a half-life of 704 million years, the second 244 thousand years. The big bang supposedly happened 4.5 billion years ago. If these elements were created in the big bang, why do they still exist? They would have decayed by this point to the point that (for U-234, at least) they would no longer exist.

Where does this element truly come from?

$&*#%@ server!

According to most scientists, the only source of heavy elements is from fusion in the cores of stars. However, it is an acknowledged fact that the heaviest element that can be produced in a star's core is iron. After that, even supermassive stars like the ones that turn into black holes cannot continue the process. Yet we have dozens of elements that are higher in atomic number than iron, some of them radioactive. You will argue that these elements were made in the Big Bang, but you have to count in atomic half-life.

http://curious.astro.cornell.edu/supernovae.php

"Stars of all masses spend the majority of their lives fusing hydrogen nuclei into helium nuclei: we call this stage the main sequence. When all of the hydrogen in the central regions of a star is converted into helium, the star will begin to "burn" helium into carbon. However, the helium in the stellar core will eventually run out as well; so in order to survive, a star must be hot enough to fuse progressively heavier elements, as the lighter ones become exhausted one by one. Stars heavier than about 5 times the mass of the Sun can do this with no problem: they burn hydrogen, and then helium, and then carbon, oxygen, silicon, and so on... until they attempt to fuse iron. Iron is special in that it is the lightest element in the periodic table that doesn't release energy when you attempt to fuse it together. In fact, instead of giving you energy, you end up with less energy than you started with! This means that instead of generating additional pressure to hold up the now extended outer layers of the aging star, the iron fusion actually takes thermal energy from the stellar core. Thus, there is nothing left to combat the ever-present force of gravity from these outer layers. The result: collapse! The lack of radiation pressure generated by the iron-fusing core causes the outer layers to fall towards the centre of the star. This implosion happens very, very quickly: it takes about 15 seconds to complete. During the collapse, the nuclei in the outer parts of the star are pushed very close together, so close that elements heavier than iron are formed."

Note: Upon further inspection, I have found that the remedial course "Debunking the Big Bang 101" has been eliminated due to budget cuts, but some of you probably remember what I said.

According to most scientists, the only source of heavy elements is from fusion in the cores of stars. However, it is an acknowledged fact that the heaviest element that can be produced in a star's core is iron. After that, even supermassive stars like the ones that turn into black holes cannot continue the process. Yet we have dozens of elements that are higher in atomic number than iron, some of them radioactive. You will argue that these elements were made in the Big Bang, but you have to count in atomic half-life.

The focus elements of this topic is U-235 and U-234. The first has a half-life of 704 million years, the second 244 thousand years. The big bang supposedly happened 4.5 billion years ago. If these elements were created in the big bang, why do they still exist? They would have decayed by this point to the point that (for U-234, at least) they would no longer exist.

Where does this element truly come from?

$&*#%@ server!

They weren't. Hydrogen was created from the big bang (well...a bit later) and after a few stages of stars being created/destroyed we had heavier and heavier elements being formed.

Yes, all right. Let's do this.

First, a little background. Most of this is speculative because, well, we weren't there and we have no way to recreate it. However, this is how current evidence suggests it happened.


Hot Time In the Old Town

The early universe was hot. Very hot. It was so unbelievably hot that even very hot things today would have been dead impressed by how unimaginably hot it was. One second after the "Big Bang" event, the temperature of the univers was over 3,000 billion Kelvin and, no matter what scale you're using, that's a lot of heat.

There were no complex structures of any kind because, frankly, it was too darn hot. The 1 second old universe resemled a particulate soup of matter and anti-matter flying away in all directions. As the universe cooled, an initial asymetry between the nearly equal concentrations of matter and anti-matter began to fall in favor of matter. Hence, we have a matter-based universe today and I, for one, am glad of it.


Chill out, Baby Universe!

As nanoseconds pased and the Universe cooled, matter particles began to dominate anti-matter particles, common particles began to form, namely baryons. Baryons are photons, neutrinos, electrons and quarks. There were still no "atoms" yet or more complex elements because it was too hot.

After further cooling to a barely tepid temperature less than 3,000 billion Kelvin, a sort of cosmic phase shift occured and hadrons began to appear and we see our first protons and neutrons. It was still far too hot for more complex structures to form

Atomic love is in the air

Finally, after an eternity of waiting, the impatient baby universe cooled down within the first one to three minutes of it's existance enough for atomic structures to beging forming. Protons and neutrons took one look at each other, decided they liked what they saw and started pairing off in Deuterium isotopes. Deciding the more the marrier, deuterium isotopes quickly collected another passing neutron to form tritium. Because the group thing was fun, tritium quickly snatched a passing proton and formed the energistic orgy which is the common helium nucleus. Most scientists put the ratio of helium nucleii to protons at 1 to 10 within the first 3 minutes of the universe. Further cooling allowed for formation of Hydrogen and thus the ratio provides concordance with modern day observations of one helium nucleus for every ten or 11 atoms of hydrogen. Trace elements of lithium were also produced at around the three minute mark.


Nucleosynthesis: You know, heavy elements and junk

You are right that the internal fires of stars can most likely only produce up to iron. However, there are two other areas where nucleosynthesis can occur. Area one is in the outer envelopes of supermassive stars and area two is in supernovae. Let's look at supernovae first.


Supernova Nucleosynthesis: More than just another crappy sci-fi flick.

A pre-supernova star has a layered structure with an iron core at the center and various layers of material wrapped around it. Upon the core collapse, a shock wave is generated which propogates out through the surrounding layers. Initially, the wave produces incredibly high heat at the inner layers, leading to standard formation of elements less massive than Iron through normal nuclear fusion. However, the wave is also a strong source of neutrinos. As there are no energistic restrictions to the addition of neutrons to nuclei, you can have the build-up of massive "neutron-wells" which lead to the spontaneous formation of massive elements by neutron beta-decay into protons. This can be through either rapid neutron addition (the r-process) or slower neutron addition (the s-process).

This accounts for creation of elements like U-235 and U-234 and the trace amounts (on a cosmic scale) we find of their existance.

Here endeth the lesson.

Owned. You know this stuff is pretty basic cosmology reynes.

First things first - the poll topping this thread is misleading. The Big Bang theory is NOT mutually exclusive with Creationism. In fact, the theory is highly compatible with the Creationist view. The idea of the Big Bang is a Christian idea, first suggested by a Catholic preist. I point this out not because I'm a Creationist (I'm far from it), but because this is the truth.

Second, why is it that regular stars cannot fuse heavy elements? From what I have read, it is because the stars cannot provide enough energy to do so. If this is the case, then couldn't these heavy elements be formed from the energy released in annihilation when matter and antimatter meet?

First things first - the poll topping this thread is misleading. The Big Bang theory is NOT mutually exclusive with Creationism. In fact, the theory is highly compatible with the Creationist view. The idea of the Big Bang is a Christian idea, first suggested by a Catholic preist. I point this out not because I'm a Creationist (I'm far from it), but because this is the truth.

Second, why is it that regular stars cannot fuse heavy elements? From what I have read, it is because the stars cannot provide enough energy to do so. If this is the case, then couldn't these heavy elements be formed from the energy released in annihilation when matter and antimatter meet?

First things first - the poll topping this thread is misleading. The Big Bang theory is NOT mutually exclusive with Creationism. In fact, the theory is highly compatible with the Creationist view. The idea of the Big Bang is a Christian idea, first suggested by a Catholic preist. I point this out not because I'm a Creationist (I'm far from it), but because this is the truth.

Yep. First proposed in 1927 by Georges Lemaitre and later experiementally accounted for by Edwin Hubble who showed distant galaxies are moving away from us with speeds proportionate to their distance.

.
Second, why is it that regular stars cannot fuse heavy elements? From what I have read, it is because the stars cannot provide enough energy to do so. If this is the case, then couldn't these heavy elements be formed from the energy released in annihilation when matter and antimatter meet?

Well, the problem with them spontaneously forming from a matter-antimatter collision is, I think, there is too much energy released at such a point for a stable structure to form. Once you hit Iron, the strong repulsive force of the heavy nuclei make thermonuclear fusion reactions very unlikely. Nuclei do capture neutrons, though, which can then decay into protons which neatly circumvents the energistic barrier.

If the Big Bang is so easily debunked, or even disputed, it would have long ago - or else you'd be a Nobel laureate by now. :lol: The Big Bang is a theoretical model of the creation of the universe, that has and can be tested and has a plethora of science and math behind it.

A great deal of evidence also supports this scientific model, and basically a question or inconsistency that doesn't seem to make sense to a few people doesn't overturn a theory. If something doesn't work in the current model, it can be altered and the theory improved...

For instance, every so often in say, Math class someone will 'not get' something. That isn't to say math is false.

If you want to 'debunk' the big bang, you have to have experimental evidence that proves it is false, and scientific data to support it. So far, though, the big bang is a solid theory...even if it can be improved upon and isn't totally right - no theory is, or else it wouldn't be a theory. We've yet to see a better one.

I also believe the answer to the question here has been thoroughly answered ;)

(Ahck, forums. This post and all duplicates are from Zoogiedom (West Scotland)...sorry about that)

First things first - the poll topping this thread is misleading. The Big Bang theory is NOT mutually exclusive with Creationism. In fact, the theory is highly compatible with the Creationist view. The idea of the Big Bang is a Christian idea, first suggested by a Catholic preist. I point this out not because I'm a Creationist (I'm far from it), but because this is the truth.

The Big Bang theory is incompatible with some versions of "Creationism". It's hardly a coherent school of thought. The origin of a theory does not necessarily influence how it will be received by people with a view of God that is firmly rooted in the middle ages. Copernicus was a Catholic monk, yet various strands of Christianity, including Catholicism, expended a lot of time, effort and firewood trying to stamp out the idea of a heliocentric solar system. Some few elements of the lunatic fringe are still inisting that everything orbits around the earth. Still others are insisting that, not only is the earth at the centre of all creation, it's also flat. No matter how silly something is, or how much evidence to the contrary is piled up in front of them, there will be people who will believe it.

Second, why is it that regular stars cannot fuse heavy elements? From what I have read, it is because the stars cannot provide enough energy to do so. If this is the case, then couldn't these heavy elements be formed from the energy released in annihilation when matter and antimatter meet?

Regular stars in the main sequence don't produce enough energy to make elements heavier than iron, but supernovae do. That's where all the heavier elements come from. Odd to think that I have stuff in my teeth that was born in a supernova. It seems... excessive, somehow. Still, mustn't grumble. :)

The energy released from matter-antimatter collisions might be high enough, but since there's very little antimatter around, and since any such collisions convert both matter and antimatter into energy with nothing left over, it's probably academic.

The Big Bang Didn't Happen ... forget who wrote the book, google it. Bases his proposal on Nobelist Hannes Alfven's plasma-physics cosmology.

There was no beginning; the Universe has always existed. Anything else is Creationist in one form or another!

:twisted:

Oh, and your starting premise is still wrong, because your forgetting that they are "half-lifes", the amount of time it takes for half of the atoms to decay- so for U-235 it would be
100% at zero years
50% at 704 million years
25% at 1408 million years
12.5% at 2112 million years
6.25% at 2816 million years
3.125% at 3520 million years
.....
ect

U-235 is rather rare (I believe), so even if every U-235 molecule now in exsistance was created back at the creation of the universe, you would still have a sizable portion of U-235 left.

(Correct me if I'm wrong, all from memory)

The big bang supposedly happened 4.5 billion years ago.
The Big Bang happened 13.7-14.7bn years ago. You are getting confused with the age of the Solar System, which is estimated at around 4.6bn years.

EDIT: And you still get heavy radioactive elements produced by supernovae.

Not to mention, half-life means what it says - a continual halving. Only at an imaginary point at t = infinity, does the number of radioactive nuclei fall to zero. At this point, the abundance of some in a given sample simply means that there was more in the past.