Question

Tell the story of how a proton created in the Big Bang made its way into your body, and is now a part of a carbon atom in your cell's DNA. Think of some the places where this atom might have lived over the years, and remember that atomic nuclei get transformed within stars and may be incorporated into future planets. Include at least 4 different stages of development including the processes that drove the transformations.

Answer 1

The early Universe contained what would become all the matter and energy we see today. However, since it all existed in such a small space, the Universe was very, very dense. This meant that the temperature was also incredibly high - over 10³² Kelvin. The familiar matter we know today didn't exist, because the atoms, protons, neutrons, and electrons all would have been crushed by the incredible density and temperature. The Universe was a "soup" of matter and energy. The Big Bang theory describes how the Universe expanded from this tiny dot, and how the first elements formed. The "Big Bang" is the moment the expansion of the Universe began.

Within the first second after the Big Bang, the temperature had fallen considerably, but was still very hot - about 100 billion Kelvin (10¹¹ K). At this temperature, protons, electrons and neutrons had formed, but they moved with too much energy to form atoms. Even protons and neutrons had so much energy that they bounced off each other. However, neutrons were being created and destroyed as a result of interactions between protons and electrons. There was enough energy that the protons and the much lighter electrons combined together with enough force to form neutrons. But some neutrons "decayed" back into a positive proton and a negative electron¹.

As the Universe expanded, the temperature fell. At this point the protons and electrons no longer had enough energy to collide to form neutrons. Thus, the number of protons and neutrons in the Universe stabilized, with protons outnumbering neutrons by 7:1. At about 100 seconds after the Big Bang, the temperature had fallen to one billion degrees Kelvin (10⁹ K). At this temperature the neutrons and protons could now hit each other and stick together. The first atomic nuclei formed at this point. These neutron-proton pairs formed the nuclei of deuterium, a type of hydrogen with an extra neutron. Deuterium nuclei occasionally collided at great speed to form a helium nucleus. On rare occasions there were enough collisions of the deuterium to form lithium. Due to the ongoing expansion of the Universe, the temperature continued to fall rapidly, and soon it was too cool for further nuclei to form. At this point, the Universe was a little more than a few minutes old, and consisted of three elements: hydrogen, helium, and lithium. The high number of protons in the early Universe made hydrogen by far the dominant element: 95% percent of the atoms in the Universe were hydrogen, 5% were helium, and trace amounts were lithium. These were the only elements formed within the first minutes after the Big Bang.

As the Universe continued to expand and cool, the atoms formed in the Big Bang coalesced into large clouds of gas. These clouds were the only matter in the Universe for millions of years before the planets and stars formed. Then, about 200 million years after the Big Bang, the first stars began to shine and the creation of new elements began.

As the Universe continued to expand and cool, the atoms formed in the Big Bang coalesced into large clouds of gas. These clouds were the only matter in the Universe for millions of years before the planets and stars formed. Then, about 200 million years after the Big Bang, the first stars began to shine and the creation of new elements began.

Stars form when the giant clouds of gas, light-years across and consisting mostly of hydrogen, begin to contract under their own gravity. First, clumps of denser hydrogen gas form, which over millions of years eventually combine to form a giant ball of gas hundreds of thousands of times more massive than the Earth. The gas ball contracts under its own gravity, creating enormous pressure at the center. The increase in pressure causes an increase in temperature at the star's center. It becomes so hot that the electrons are stripped from the atoms. What's left are hydrogen nuclei, moving faster and faster as the ball of gas contracts and the temperature at the center continues to increase. Once the temperature reaches 15 million Kelvin, the hydrogen nuclei are moving so fast that when they collide they fuse together. This releases a great deal of energy. The energy from this nuclear fusion pours out from the center of the ball of gas and counteracts gravity's relentless inward pull. The ball of gas is now stable, with the inward pull of gravity exactly balanced by the outward pressure from the exploding fusion energy in the core. This energy flows out through the star, and when it reaches the surface, it radiates off into space. The ball of gas begins to shine as a new ..

Stars come in a variety of sizes, anywhere from one-tenth to sixty (or more) times the mass of our Sun. At their hearts, all normal stars are fueled by the energy of nuclear fusion. Depending on the size of the star, however, different elements are created in the fusion process including carbon which scattered when star went supernova. Resulting debris formed planet and finally people who are made of carbon.