Eras of the Big Bang

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Big Bang

About 15 billion years ago the universe was created from a dense, hot and unstable state of being.

Inflation Era

The universe undergoes a brief explosive period where it grows from a dime to a grapefruit size. At this point the force driving it is transformed to matter and energy and is no longer effective.

Radiation-Dominated Era

Most of the energy is in electromagnetic radiation, visible light, X rays, radio waves, and ultraviolet rays. There is more radiation than matter. Further, quarks clump in to proton and neutrons as a result of the expanding and cooling universe. In this era nuclei are formed.

Stelliferous Era

Electrons now have slowed down enough with the cooling universe as to be capture by the nuclei; hydrogen and helium form. The hydrogen collides as a result of gravity and through fusion helps to build stars.

A star is a globe of compressed gas producing its own heat and light by nuclear reactions in the process of nuclear fusion. They are born from nebulae and consist mostly of hydrogen and helium gas. Surface temperatures range from 2000ºC to above 30,000ºC, and the corresponding colours from red to blue-white. The temperature is dependent on the fuels being burnt during nuclear fusion. The brightest stars, which are white in color, have masses 100 times that of the Sun and emit as much light as millions of Suns. They live for less than a million years before exploding as supernovae as they burn their fuels so quickly due to their size and abundance of fuel. The faintest stars are the red dwarfs, less than one-thousandth the brightness of the Sun, however, since they burn less fuels, they live longer.

The smallest mass possible for a star is about 8% that of the Sun (80 times the mass of the planet Jupiter), otherwise nuclear reactions do not take place. Objects with less than critical mass shine only dimly and are termed brown dwarfs or a large planet. Towards the end of its life, a star like the Sun swells up into a red giant, before losing its outer layers as a Planetary nebula and finally shrinking to become a white dwarf.

Our sun and solar system were formed 4.6 billion years ago. Life appears after the explosion of stars which released heavier elements like carbon. Human life commenced 100 000 years ago. Various star formation occurs including:

This is a large bright star with a cool surface. It is formed during the later stages of the evolution of a star like the Sun, as it runs out of hydrogen fuel at its center. Red giants have diameters between 10 and 100 times that of the Sun. They are very bright because they are so large and thus burn more fuel. Although their surface temperature is lower than that of the Sun, about 2000-3000ºC. Very large red giants are often called super giants. These stars have diameters up to 1000 times that of the Sun and have luminosities often 1,000,000 times greater than the Sun.

Red Dwarf/Brown Dwarf

These are very faint and small stars, approximately one tenth the mass and diameter of the Sun. As a result their temperatures are low. They burn very slowly and have estimated lifetimes of 100 billion years. The characteristic properties of red dwarves stem ultimately from their low mass. Further, their low surface temperature, in the range 2,500 to 3,500°C, causes a rusty shade, while their combination of low temperature and small surface area results in them being very faint. Red dwarves survive the longest next to the brown dwarf, which is the least massive kind of star and bears properties of the red dwarf. Red dwarves burn little fuel at a time.

White Dwarf

This is very small, hot star, the last stage in the life cycle of a star like the Sun. White dwarfs have a mass similar to that of the Sun, but only 1% of the Sun's diameter; approximately the diameter of the Earth. The surface temperature of a white dwarf is 8000ºC or more, but being smaller than the Sun their overall luminosity's are 1% of the Sun or less.

White dwarfs are the shrunken remains of normal stars, whose nuclear energy supplies have been used up. White dwarf consist of degenerate matter with a very high density due to gravitational effects, i.e. one spoonful has a mass of several tones. White dwarfs cool and fade over several billion years.

Supernova

This is the explosive death of a star, and often results in the star obtaining the brightness of 100 million suns for a short time. There are two general types of Supernova. Type I occur in binary star systems in which gas from one star falls on to a white dwarf, causing it to implode due to too an abundance of fuel causing nuclear fusion to reach a peak, and then as gases are exhausted, gravity takes over. Nuclear fusion and gravity maintain a balance in the star in which nuclear fusion expands the star while gravity contracts it. The balance prevents the star from exploding, due to nuclear fusion dominance (rare), or imploding, due to gravitational dominance (common). Type II supernovae occur in stars ten times or more as massive as the Sun, in which they exhaust their fuel supply quickly leading to a drastic decrease in nuclear fusion and a dominance of gravity. Therefore, this leads to an implosion. They leave behind neutron stars and black holes. Supernovae are thought to be main source of burning elements heavier than hydrogen and helium.

Neutron Stars

These stars are composed mainly of neutrons and are produced when a supernova explodes, forcing the protons and electrons to combine to produce a neutron star. Neutron stars are very dense. Typical stars have a mass of three times the Sun but a diameter of only 20 km. If its mass is any greater, its gravity will be so strong that it will shrink further to become a black hole. Pulsars are believed to be neutron stars that are spinning very rapidly.

Degenerate Era

10 trillion trillion trillion years after the Big Bang bonds will begin to break. Protons will begin to decay. Eventually when the inertia carrying the expansion of the universe is less than the gravity, the universe will begin to recede, heat and energy will be gained as density increases, and more bonds will break. As a result planets will detach from stars and both will evaporate from galaxies. Most matter will be locked up in to stellar remenants of dead stars that are white dwarfs, blown up, collapsed into neutron stars and black holes. Protons will decay.

Black-Hole Era

10,000 trillion trillion trillion trillion trillion trillion trillion trillion years after the Big Bang, after proton and matter decay, the only large objects remaining are black holes, which eventually evaporate into photons and other types of radiation as the universe begins to recede.
A black hole is born when a star with a huge mass implodes and becomes a supernova. The implosion occurs when the nuclear fusion is reduced due to a low reservoir of fuels and gravity becomes more dominate. This imbalance will cause the core’s gravity to draw in the matter of the stars, as the nuclear fusion is too weak to stop it. From the supernova, which is a partially imploded star, nuclear fusion will continue to decrease, allowing gravity to become more dominate to a point where it is difficult for even light to escape. Eventually, the star will implode to what is known as a black hole and light can no longer escape, causing darkness (hence the name “black” hole). The black hole has no volume due to its extreme compression, and thus by finding density by using the formula (Density=mass/volume), the density is undefined, meaning the black hole will have infinite density. Thus in theory, any amount of matter can create a black hole as long as it is compressed to zero volume. However, in space, the only things in space that are capable of exerting that amount of force are large stars.

Dark Era

Now only waste products remain: mostly photons, neutrinos, electrons and positrons, unable to react as temperatures are increasing with the receding universe and particles are moving quickly. Occasionally, electrons and positrons meet and form atoms. As well energy is becoming more dominant and eventually the energy will become compacted densely and tightly together. Another Big Bang will result.