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4He + 4He + Δ → 8Be

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= +100keV Endothermic

Be ~ 10-17 s 8Be metastable

2B ~ 10-21 s He/He collision time

Helium Burning inside a Carbon Star

4He + 8Be

4He + 12C

16O non-resonant

12C*

Resonance with an excited nuclear state of carbon Predicted by Hoyle to be 7.7 MeV

7.6557.366 + Δ

7.1187

7.1616 + Δ

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MeV

X

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The Triple Alpha process

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4He + 8Be

4He + 12C

16O

12C*

Hoyle predicted 7.7 MeV

7.6557.366 + Δ

7.1187

7.1616 + Δ

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MeV

X

4He + 8Be

4He + 12C

16O

12C*

Hoyle predicted 7.7 MeV

7.6557.366 + Δ

7.1187

7.1616 + Δ

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MeV

X

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4He 8Be 12C 16O

4He

+

4He4He

(1) (2) (3)

+

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4He 8Be 12C 16O

4He

+

(1) = 100keV Endothermic

4He4He

(1) (2) (3)

+

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4He 8Be 12C 16O

4He

+

(1) = 100keV Endothermic

2B ~ 10-21 s lifetime of He-He collision

4He4He

(1) (2) (3)

+

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4He 8Be 12C 16O

4He

+

(1) = 100keV Endothermic

2B ~ 10-21 s lifetime of He-He collision

Be ~ 10-17 s 8Be metastable

4He4He

(1) (2) (3)

+

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4He 8Be 12C 16O

4He

+

4He4He

(1) (2) (3)

+

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4He 8Be 12C 16O

4He

+

4He4He

(1) (2) (3)

+

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(2) resonant

4He 8Be 12C 16O

4He

+

4He4He

(1) (2) (3)

+

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(2) resonant

(8Be + 4He) = 7.3667 MeV

4He 8Be 12C 16O

4He

+

4He4He

(1) (2) (3)

+

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(2) resonant

(8Be + 4He) = 7.3667 MeV

Hoyle predicted an excited C* state at ~7.7

4He 8Be 12C 16O

4He

+

4He4He

(1) (2) (3)

+

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(2) resonant

(8Be + 4He) = 7.3667 MeV

Hoyle predicted an excited C* state at ~7.7

Found at 7.656 MeV

4He 8Be 12C 16O

4He

+

4He4He

(1) (2) (3)

+

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4He 8Be 12C 16O

4He

+

4He4He

(1) (2) (3)

+

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(3) Non – resonant

4He 8Be 12C 16O

4He

+

4He4He

(1) (2) (3)

+

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(3) Non – resonant

E(12C+4He) = 7.1616

4He 8Be 12C 16O

4He

+

4He4He

(1) (2) (3)

+

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(3) Non – resonant

E(12C+4He) = 7.1616

> E(16O) = 7.1187 MeV

4He + 8Be12C*

7.7 predicted

7.6557.366

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MeV

Nuclear reaction cross section

E1 E2 E3

Energy

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S&CB shorts: Fred Hoyle and the Big BangThe BBC, the Victoria Institute, and the Theological Context for the Big Bang – Steady State Debate, Craig Sean McConnell, S&CB (2006), 18, 151-168. The emergence of the 'big bang' as a model for the origins of the universe was resisted by a group of scientists who preferred a 'steady state' universe, with no definite 'cause'. Today Christians are often quick to adopt the big bang as a model compatible with the Genesis account of creation. It's interesting to look at where these theories came from, and the different reactions to them on either side of the Atlantic. Fred Hoyle is now famous for his astronomy, and is much quoted, or perhaps misquoted, in the debate concerning the 'fine tuning' of the universe. He grew up in Yorkshire, and won a scholarship to study physics at Cambridge in 1933. He shone as a student, came top of his class, and started a PhD in theoretical physics. As time went on though, Hoyle became convinced that this field was running out of steam, so he moved to astronomy and published several papers on star formation. During World War 2 he ran a research group working on radar systems for the admiralty. On his team were the two men, Hermann Bondi and Thomas Gold, would become close collaborators on the steady state theory. The three worked on the steady state model of the universe alongside their more mundane research on radar. It was a new idea that fitted the data available at the time, but they had trouble publishing it. Whether this was because the model meant that matter had to be continually created in the centre of their expanding universe, or because it avoided the need for a moment of 'creation' is difficult to tell. Bondi had a Jewish background, but disliked religion, and later in life he was president of the British Humanist Association. With Hoyle's rejection of religion after experiencing Catholic–Protestant rivalries as a child, and Gold's secular upbringing, the trio weren't eager to support a creation ex nihilo (from nothing) event…The unusual aspect of this story is the role of popular media in providing an alternative platform to get their theory some attention. Fred Hoyle developed a reputation as a populariser of science when he gave a series of talks for BBC radio in 1949. Through these he was able to talk about the steady state theory, and coined the term 'big bang' for the alternative model (as a joke, but it stuck!) He used this platform to vent his views on politics and religion, causing a serious backlash, and his views on religion attracted more attention than his science. The chairman of the BBC commented that "Hoyle has not the humility of a good scientist".Hoyle did get the chance to broadcast the same lectures again, with very few changes. This time though, the religious programmes department made a few shows with scientists who were more sympathetic to faith, including Dorothy L Sayers, who was known for her work on science and Christianity as well as her detective novels. The BBC's magazine The Listener was bombarded with letters from people on both sides of the debate, including some containing very technical details from a number of scientists. It's amazing that the written debate over the data on the origins of the universe was played out in this public forum, mixed in with fairly hostile personal attacks. The response from the Victoria Institute (a Christian philosophical society, most of whom were scientists) was at a complete, and apparently publicly voiced, tangent to the polemic so far. Here the steady state model was given proper consideration as a scientific theory, without discussing Hoyle's religious views, and the religious implications of both the steady state and big bang theories were discussed. For example, Charles Coulson, the Oxford mathematician who wrote two of the most useful books at the time on science and faith from an evangelical viewpoint pointed out that the steady state theory involved continuous (although very slow) creation of new atoms – which could be said to be evidence of God¹s sustaining power. The reaction to the steady state theory in the USA was very different. The physicist George Gamow, who was famous for his popular science books where he discussed both models, was working on the big bang. He had some lively public discussions with Hoyle, but these didn't get anything close to the exposure Hoyle's views had in the UK, and the steady state model seems to have generally been seen as a more obscure British theory. It was seen as less of a threat to religion, with more attention given to the big bang as a compatible theory with Genesis. The most significant difference here compared with the UK reactions was the lack of public discussion between the scientists and Christians in the '50s. What does this show us? That the steady state theory was given prominence only because of Hoyle's antagonism towards religion, and the interchange between scientists and Christians (and Christian scientists) in the public arena. This raises some interesting questions about science. Although the process of acceptance or rejection of cosmological theories has once again come down to experimental evidence, with larger and more accurate telescopes, personal belief plays a part in what scientists choose to pursue. It is also a cautionary tale for those who are too quick to 'baptise' any one scientific theory. Ruth Bancewicz, CiS Development Officer© 2009 Christians In Science | All Rights Reserved

Christians in Science Ltd., incorporated in England and Wales. Registered address 4 Sackville Close, Sevenoaks, TN13 3QD. Company No. 05959444. Registered Charity No. 11

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In 1968, polycyclic aromatic molecules were detected in interstellar dust (4). In 1972, convincing evidence that the dust contained porphyrins was obtained (5). Then in 1974 Wickramasinghe demonstrated that there are complex organic polymers, specifically molecules of "polyformaldehyde" in space (6). These molecules are closely related to cellulose, which is very abundant in biology.

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By 1975, Hoyle and Wickramasinghe were convinced that organic polymers were a substantial fraction of the dust. This line of thought was considered wildly speculative at that time. Now however, the idea that organic polymers in space are abundant and may be necessary for life is well accepted. Today we often see stories about things like vinegar among the stars (7), or "buckyballs" from space as "the seeds of life" (8). To that extent the scientific paradigm for the origin of life on Earth has already shifted.

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The triple alpha process is a set of nuclear fusion reactions by which three helium nuclei (alpha particles) are transformed into carbon.[1][2]Older stars start to accumulate helium produced by the proton-proton chain reaction and the carbon-nitrogen-oxygen cycle in their cores. The products of further nuclear fusion reactions of helium with hydrogen or another helium nucleus (isotopes with mass number 5 or 8 respectively) are highly unstable and decay almost instantly back into smaller nuclei.

When the star starts to run out of hydrogen to fuse, the core of the star starts to collapse until the central temperature rises to ~100×106 K. At this point helium nuclei are fusing together at a rate fast enough to rival the speed at which the product, Beryllium-8, decays back into two helium nuclei. This means that there are always a few Beryllium-8 nuclei in the core, which can fuse with yet another helium nuclei to form Carbon-12, which is stable:

42He + 42He → 84Be -92 keV

84Be + 42He → 126C + γ + 7.367 MeV

The net energy release of the process is 7.275 MeV.

Because the triple-alpha process is unlikely, it requires a long period of time to produce carbon. One consequence of this is that no carbon was produced in the Big Bang because within minutes after the Big Bang, the temperature fell below that necessary for nuclear fusion.Ordinarily, the probability of the triple alpha process would be extremely small. However, the beryllium-8 ground state has almost exactly the energy of two alpha particles.

In the second step, 8Be + 4He has almost exactly the energy of an excited state of 12C.

These resonances greatly increase the probability that an incoming alpha particle will combine with beryllium-8 to form carbon.

The existence of this resonance was predicted by Fred Hoyle before its actual observation, based on the physical necessity for it to exist, in order for carbon to be formed in stars. In turn, prediction and then discovery of this energy resonance and process gave very significant support to Hoyle's hypothesis of stellar nucleosynthesis, which posited that all chemical elements had originally been formed from hydrogen, the true primordial substance.

As a side effect of the process, some carbon nuclei can fuse with additional helium to produce a stable isotope of oxygen and release energy:

126C + 42He → 168O + γ + 7.161 MeVSee alpha process for more details about this reaction and further steps in the chain of stellar nucleosynthesis.This creates a situation in which stellar nucleosynthesis produces large amounts of carbon and oxygen but only a small fraction of these elements is converted into neon and heavier elements. Both oxygen and carbon make up the 'ash' of helium burning.

The anthropic principle has been controversially cited to explain the fact that nuclear resonances are sensitively arranged to create large amounts of carbon and oxygen in the universe.Fusion processes produce elements only up to iron;

heavier elements (those beyond Fe) are created mainly by neutron capture. The slow capture of neutrons, the S-process, produces about half of these heavy elements. The other half are produced by rapid neutron capture, the R-process, which probably occurs in a core-collapse supernova.

The triple alpha process is a set of nuclear fusion reactions by which three helium nuclei (alpha particles) are transformed into carbon.[1][2]Older stars start to accumulate helium produced by the proton-proton chain reaction and the carbon-nitrogen-oxygen cycle in their cores. The products of further nuclear fusion reactions of helium with hydrogen or another helium nucleus (isotopes with mass number 5 or 8 respectively) are highly unstable and decay almost instantly back into smaller nuclei. When the star starts to run out of hydrogen to fuse, the core of the star starts to collapse until the central temperature rises to ~100×106 K. At this point helium nuclei are fusing together at a rate fast enough to rival the speed at which the product, Beryllium-8, decays back into two helium nuclei. This means that there are always a few Beryllium-8 nuclei in the core, which can fuse with yet another helium nuclei to form Carbon-12, which is stable:

42He + 42He → 84Be - 92 keV84Be + 42He → 126C + γ + 7.367 MeVThe net energy release of the process is 7.275 MeV.Because the triple-alpha process is unlikely, it requires a long period of time to produce carbon. One consequence of this is that no carbon was produced in the Big Bang because within minutes after the Big Bang, the temperature fell below that necessary for nuclear fusion.Ordinarily, the probability of the triple alpha process would be extremely small. However, the beryllium-8 ground state has almost exactly the energy of two alpha particles. In the second step, 8Be + 4He has almost exactly the energy of an excited state of 12C. These resonances greatly increase the probability that an incoming alpha particle will combine with beryllium-8 to form carbon. The existence of this resonance was predicted by Fred Hoyle before its actual observation, based on the physical necessity for it to exist, in order for carbon to be formed in stars. In turn, prediction and then discovery of this energy resonance and process gave very significant support to Hoyle's hypothesis of stellar nucleosynthesis, which posited that all chemical elements had originally been formed from hydrogen, the true primordial substance.As a side effect of the process, some carbon nuclei can fuse with additional helium to produce a stable isotope of oxygen and release energy:

126C + 42He → 168O + γ + 7.161 MeVSee alpha process for more details about this reaction and further steps in the chain of stellar nucleosynthesis.This creates a situation in which stellar nucleosynthesis produces large amounts of carbon and oxygen but only a small fraction of these elements is converted into neon and heavier elements. Both oxygen and carbon make up the 'ash' of helium burning. The anthropic principle has been controversially cited to explain the fact that nuclear resonances are sensitively arranged to create large amounts of carbon and oxygen in the universe.Fusion processes produce elements only up to iron; heavier elements (those beyond Fe) are created mainly by neutron capture. The slow capture of neutrons, the S-process, produces about half of these heavy elements. The other half are produced by rapid neutron capture, the R-process, which probably occurs in a core-collapse supernova.