Theory on the Formation of the Universe

Popular Theories Steady State Theory - theory suggesting that the universe & everything within it is unchanging. Elastic Theory - the universe acts like a rubber band, expanding & contracting over time (currently it is expanding) Big Bang Theory - most widely accepted theory by scientists today

What is a Theory? Theories are an explanation of a natural phenomenon that is supported by a large body of scientific evidence obtained from many observations, experiments and laws. Theories are: Based on evidence Tested Effective in problem solving The explanation of HOW

Origin of the Universe Big Bang Theory occurred approx. 14 billion years ago model for the beginning of the universe

Building a Universe Infinitely dense point not governed by our physical laws or time All matter and energy contained in one point the size of a pinhead. The temperature was so great that atoms could not exist Einstein’s theory of relativity predicts this “smaller than a proton” time=0 state http://rainbow.ldeo.columbia.edu/courses/v1001/7.html

Building a Universe Instantaneous filling of space with all matter. Universe came into existence at one moment in time and then expanded rapidly Instantaneous filling of space with all matter. Not an explosion, but rather an expansion of space itself, with all its matter and energy http://rainbow.ldeo.columbia.edu/courses/v1001/7.html

After the Bang Ever since the big bang, the universe has been expanding and cooling. 10-43 seconds after the Big Bang… (that’s 0.00000000000000000000000000000000000000000001 seconds) The four fundamental forces were created: Gravity, Electromagnetic, Weak Nuclear, Strong Nuclear

After the Bang 3-20 minutes after the Big Bang… Nucleosynthesis = creating new nuclei from existing nuclei (two H’s make one He) It took billions of years for the universe to cool down enough to allow stars and planets to form.

Today All the matter and energy in the universe is still expanding. And has been expanding for the last 10-15 billion years. Summarizing, “A cosmological theory theory that the universe originated approximately 13.7 billion years ago from the violent explosion of a very small point of matter of extremely high density and temperature.” The Size of the Universe

Edwin Hubble found… Universe is continuously expanding Galaxy’s velocity is proportional to its distance (galaxies that are twice as far from us move twice as fast) Taken every galaxy the same amount of time to move from a common starting position to its current position Edwin P. Hubble (1889-1953) Hubble's Law

Wave compression or stretching due to velocity Hubble’s Evidence of an Expanding Universe Doppler shift - wavelength emitted by something moving away from us is shifted to a lower frequency Sound of a fire truck siren - pitch of the siren is higher as the fire truck moves towards you, and lower as it moves away from you Wave compression or stretching due to velocity Works with sound or light (electromagnetic waves), but…velocity changes have to be comparable to their speed to some degree. Sound-340.29 m/s Light-300000 m/s

Visible Light

Visible wavelengths emitted by objects moving away from us are shifted towards the red part of the visible spectrum The faster they move away from us, the more they are red-shifted. Thus, red-shift is a reasonable way to measure the speed of an object

When we observe the red-shift of galaxies. The galaxy appears to be moving away from us – universe is expanding. Expanding Demo

Red Shift - moving away since the wavelength is getting longer and the frequency shorter Blue Shift - moving closer since the wavelength is getting shorter and the frequency higher

Evidence for Big Bang Red shift - as light from distant galaxies approach earth there is an increase of space between earth and the galaxy, which leads to wavelengths being stretched Cosmic Microwave Background radiation (CMB) left over from the Big Bang shows that as the universe expands the wavelength of its energy wave expand, stretch and cool An abundance of hydrogen and helium in the far reaches of the universe - consistent with the Big Bang theory that a mixture of hydrogen and helium was created at the beginning of the universe

Working timeline since the Big Bang