Nucleosynthesis beyond iron

In lateHoyle left Cambridge to go to Portsmouth to work for the Admiralty on radar research, for example devising a method to get the altitude of the incoming aeroplanes. He was also put in charge of countermeasures against the radar guided guns found on the Graf Spee. Two key colleagues in this war work were Hermann Bondi and Thomas Goldand the three had many and deep discussions on cosmology.

Nucleosynthesis beyond iron

See my copyright notice for fair use practices. Hydrogen and helium and some lithium, boron, and beryllium were created when the universe was created. All of the rest of the elements Nucleosynthesis beyond iron the universe were produced by the stars in nuclear fusion reactions.

These reactions created the heavier elements from fusing together lighter elements in the central regions of the stars. When the outer layers of a star are thrown back into space, the processed material can be incorporated into gas clouds that will later form stars and planets.

The material that formed our solar system incorporated some of the remains of previous stars. All of the atoms on the Earth except hydrogen and most of the helium are recycled materialthey were not created on the Earth.

They were created in the stars. The use of the word "created" here is different than what is normally meant by scientists. In chemical reactions, different atoms or combinations of atoms are said to be produced or created when a reaction takes place.

For example, in the Earth section of the planets chapterI said that oxygen was produced in the photosynthesis process of plants. That oxygen then goes into the air and you breathe it in.

Nucleosynthesis beyond iron

To be more correct I should have said that the oxygen atoms were moved or broken off from one set of compounds [carbon dioxide CO2 and water H2O ] to form a molecule of two oxygen atoms bound together O2 and a molecule of carbohydrate made of carbon atoms, hydrogen atoms, and oxygen atoms C6H12O6.

Each atom is rearranged or re-used. It was much simpler to say that oxygen was "created" as a by-product of the photosynthesis process. I hope you did not mind. In defense I want you to know that practically everyone, except for the astronomer researching stellar evolution, uses this loose meaning of "creation".

However, now that you know about stellar nucleosynthesis, I need to be more careful about what is being created from scratch and what is being re-used.

Except for the hydrogen and most of the helium atoms, all of the materials around you, in the food you eat and drink, in the air you breathe, in your muscles and bones, in the paper and ink or toner of this book or computer screen you are readingeverything!

Those atoms are rearranged to produce the vast variety of things around and in you. In the cores of stars and in supernova explosions, new atoms are manufactured from nuclear fusion reactions.

You will find out where the hydrogen and most of the helium atoms came from in the cosmology chapter. The atoms heavier than helium up to the iron and nickel atoms were made in the cores of stars the process that creates iron also creates a smaller amount of nickel too.

The lowest mass stars can only synthesize helium. Stars around the mass of our Sun can synthesize helium, carbon, and oxygen.

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Elements heavier than iron are made in supernova explosions from the rapid combination of the abundant neutrons with heavy nuclei. Massive red giants are also able to make small amounts of elements heavier than iron up to mercury and lead through a slower combination of neutrons with heavy nuclei, but supernova probably generate the majority of elements heavier than iron and nickel and certainly those heavier than lead up to uranium.

The synthesized elements are dispersed into the interstellar medium during the planetary nebula or supernova stage with supernova being the best way to distribute the heavy elements far and wide.

These elements will be later incorporated into giant molecular clouds and eventually become part of future stars and planets and life forms? Although the particulars of various nucleosynthesis processes are beyond the scope of this website, it is important to note a couple of things:leslutinsduphoenix.com is for anyone who wants to learn more about astronomy events, cosmology, planets, galaxies, asteroids, astrophotography, the Big Bang, black holes.

Certain wonderfully gifted scientific scholars often vent their rightful frustration about people's ignorance concerning evolution theory — which is the whole body of inquiry into the curious and fascinating phenomenon of change, and which itself contains a wide and ever evolving variety of .

Certain wonderfully gifted scientific scholars often vent their rightful frustration about people's ignorance concerning evolution theory — which is the whole body of inquiry into the curious and fascinating phenomenon of change, and which itself contains a wide and ever evolving variety of theories, proofs and postulates.

leslutinsduphoenix.com is for anyone who wants to learn more about astronomy events, cosmology, planets, galaxies, asteroids, astrophotography, the Big Bang, black holes. Stellar Nucleosynthesis Chapter index in this window — — Chapter index in separate window This material (including images) is copyrighted!.See my copyright notice for fair use practices..

Hydrogen and helium and some lithium, boron, and beryllium were created when the universe was created. b) Hubble Diagram. The basic idea of an expanding universe is the notion that the distance between any two points increases over time.

One of the consequences of this effect is that, as light travels through this expanding space, its wavelength is stretched as well.

Evidence for the Big Bang