Origin of the Universe

Origin and Age of the Universe Humans have observed celestial objects for thousands of years contemplating their place in the universe. Celestial objects are objects outside of Earth’s atmosphere including stars, planets, galaxies, etc… The universe is everything that exists in any place – matter and energy alike. It is estimated that the Universe is between 10 – 13.7 billion years old. One theory explaining the origin of the Universe is known as the Big Bang Theory.

The Big Bang Theory The Big Bang Theory states that all matter and energy started out in a concentrated form in a small area. For reasons still debated, this concentrated form of matter/energy exploded leading to a series of changes: 1. After the explosion, all matter began to organize into subatomic particles (protons/electrons) and small atoms (hydrogen and helium). 2. Within one billion years after the explosion, matter (atoms) became organized into celestial bodies. 3. These new celestial bodies developed gravitational fields. Stars and solar systems became grouped within these fields. From the moment of the Big Bang, the universe continues to expand in all directions – even today!

Evidence for the Big Bang Theory 1. Energy created by the Big Bang is still evident in the form of microwaves – long wavelength background radiation emitting from all parts of the universe. RT = Pg. 14

Evidence for the Big Bang Theory 2. The shifting of characteristic wavelengths (colored lines) due to the Doppler effect. The blue end of the colored light spectrum indicates shorter wavelengths = celestial objects are moving closer to the Earth. The red end of the colored light spectrum indicates longer wavelengths = celestial objects are moving away from the Earth. The Doppler effect is a phenomena that illustrates the shifting wavelengths of electromagnetic energy from objects moving in an expanding universe. RT = Pg. 14

The Doppler Effect As the motorcycle moves closer to “Person A” the sound waves from the motorcycle compress (wavelengths decrease) – an increase in sound. For “Person B” the sound waves are spread out (wavelengths increase) and there is a decrease in sound. Person BPerson A As the universe continues to expand from the Big Bang, the electromagnetic radiation of celestial objects that are closest to the Earth have smaller wavelengths (blue shift) than those that are moving away from the Earth (long wavelength – red shift). wavelength

Spectral Evidence of The Doppler Effect Spectral lines will shift toward the red end of the spectrum when the object emitting energy is moving away from Earth. A spectrometer is an instrument that will measure properties of light emitted from an element. Visible light can broken down into the colored spectrum Each element produces a unique spectrogram – a series of black bands (spectral lines) placed across the colored spectrum. Spectral lines appear when specific wavelengths on light are absorbed. Spectral lines will shift toward the blue end of the spectrum when the object emitting energy is moving towards Earth.