The Big Bang! This sample of the heavens is “considered representative of the typical distribution of galaxies in space, because the universe, statistically, looks largely the same in all directions. Gazing into this small field, Hubble uncovered a bewildering assortment of at least 1,500 galaxies at various stages of evolution.”

Olber’s Paradox In 1826, the astronomer Heinrich Olber’s asked, "Why is the sky dark at night?" By his time, physicists had learned enough to realize that, in a stable, infinite universe with an even distribution of stars, the entire universe should gradually heat up. Prior to this, many believed the universe simply had existed for all time – a steady state model of the universe. Source: http://www.arachnoid.com/sky/index.html

An Expanding Universe The beginnings of the theory… Edwin Hubble – Astronomer 1923 Proves that the universe extends far beyond the edges of the Milky Way galaxy Notices that galaxies are “red-shifted” – moving away from us

An Expanding Universe Hubble's Law: The farther away a galaxy is from Earth, the faster it is moving away. Note the use of the term “law” here – this is still only theoretical, but it has become dogma in cosmology.

The Big Bang Theory Where do cosmologists get the idea that the universe originated in a Big Bang? Expanding Universe Redshift Cooling Cosmos Cosmic Microwave Background Radiation Abundance of Light Elements Hydrogen, Helium, and Lithium

The Big Bang Theory Where do cosmologists get the idea that the universe originated in a Big Bang? Expanding Universe Redshift Cooling Cosmos Cosmic Microwave Background Radiation Abundance of Light Elements Hydrogen, Helium, and Lithium

An Expanding Universe - Redshift Source: image: http://www.astrocappella.com/images/shifted_spectrum.jpg

Raisin Bread Dough Analogy Makes no sense without caption in book

An Expanding Universe In 1948, Russian-born physicist George Gamow took the next step by realizing that if all the galaxies are flying apart at high speed, the entire universe must have been concentrated in a single point at some time in the past. Let’s review: Hubble observed that there existed galaxies in the universe besides our own Hubble began measuring the amount of spectral red-shift in the light observed from those distant galaxies or nebulae Hubble correlated the relationship between distance and red-shift This was then determined to be similar to the Doppler Effect and implied the observed objects were moving away from the viewer. This then led others to hypothesize that if distant objects were all moving away from us, the universe must be expanding. Gamow proposed that if galaxies are moving away from one another now, they must have been concentrated in a single point at some time in the past. Thus, we have the origin of the Big Bang Theory. Source: http://www.arachnoid.com/sky/redshift.html; Image: http://www.astromia.com/biografias/fotos/gamow.jpg

Reverse Time The Primordial Atom

An Expanding Universe During a radio interview, scientist, Fred Hoyle, coined the name "Big Bang“ – some say Hoyle was making fun of the theory, he claims he was only trying to explain how it was different than his own “steady state” theory. … but the term became popular, and has prevailed to the present day. Let’s review: Hubble observed that there existed galaxies in the universe besides our own Hubble began measuring the amount of spectral red-shift in the light observed from those distant galaxies or nebulae Hubble correlated the relationship between distance and red-shift This was then determined to be similar to the Doppler Effect and implied the observed objects were moving away from the viewer. This then led others to hypothesize that if distant objects were all moving away from us, the universe must be expanding. Gamow proposed that if galaxies are moving away from one another now, they must have been concentrated in a single point at some time in the past. Thus, we have the origin of the Big Bang Theory. Source: http://www.arachnoid.com/sky/redshift.html; Image: http://www.ananova.com/images/news/fredhoyle350x531.jpg

The Big Bang Theory Where do cosmologists get the idea that the universe originated in a Big Bang? Expanding Universe Redshift Cooling Cosmos Cosmic Microwave Background Radiation Abundance of Light Elements Hydrogen, Helium, and Lithium

A Cooling Cosmos - CMB Cosmic Microwave Background Radiation (CMBR) NASA projects COBE (Cosmic Background Explorer) WMAP (Wilkinson Microwave Anisotropy Probe) Source: http://map.gsfc.nasa.gov/

A Cooling Cosmos - CMBR 1992 COBE took a “picture” of the entire universe and its cosmic microwave background radiation In February 2003, the WMAP data showed much greater detail Source: http://map.gsfc.nasa.gov/

A Cooling Cosmos - CMB As the electromagnetic wavelength is lengthened (stretched out by an expanding universe), gamma rays from the earliest stages of the big bang would turn to X-rays, UV, visible light, IR, and ultimately microwave Source: http://map.gsfc.nasa.gov/

The Big Bang Theory Where do cosmologists get the idea that the universe originated in a Big Bang? Expanding Universe Redshift Cooling Cosmos Cosmic Microwave Background Radiation Abundance of Light Elements Hydrogen, Helium, and Lithium

Hydrogen, Helium, and Lithium are only elements assumed to be produced directly from Big Bang, all others are synthesized in stars Elements heavier than Iron (Fe) are produced in the outer envelopes of super-giant stars and in the explosion of a supernova 1. Only three elements could have formed out of the Big Bang itself: H, He, Li 2. All heavier elements up to Iron (Fe) – see red lines – are assumed to be formed through nuclear fusion within stars and then ultimately released into the universe when stars “burn out” and supernova 3. Elements heavier than Iron (27+ on the periodic table) are all created in the explosion of stars (supernova)

How the Universe was formed… The Big Bang How the Universe was formed…

A quick review of the life-cycle of stars… Makes no sense without caption in book

BIG BANG Beginning of light Nebula Star Planetary Nebula Elements #4 through 26 Beryllium Oxygen Boron Sodium Carbon Aluminum Nitrogen Argon Nebula Primordial Atom . Gravity & Nuclear Fusion Nuclear Fusion Gravity Star quarks, electrons, protons, neutrons Death Gravity Nuclear Fusion Planetary Nebula Planetary Nebula Gravity Gravity Star cooling Super-Giant ATOMS Hydrogen Helium Lithium Gravity Elements #27 and higher Nickel Zinc Copper Lead Xenon Gold Silver Cadmium Death Nuclear Fusion Gravity Planets Super Nova

Universe is 75% Hydrogen, 25% Helium Planets, Solar Systems, TODAY How long did it take? BIG BANG 1 to 3 seconds Universe is 75% Hydrogen, 25% Helium 1st Hydrogen Atoms 3 minutes 200 million yrs. 13.7 billion years Planets, Solar Systems, TODAY nebulas, stars Larger Elements black-holes, galaxies

Cosmic Background Radiation “Dark” Matter & Energy Scientist think that the universe is made up of much more “stuff” than we can detect. The “ripples” indicate there must be more than we can see… Cosmic Background Radiation

Composition of the Universe The Cosmic Background Radiation shows us that only 4% of the universe is made of “stuff” we can see. 4% Atoms 23% Dark Matter 73% Dark Energy

“Dark” Energy According to Newton’s 1st law – an object in motion, remains in motion, at a constant speed and direction Per Hubble’s law, galaxies in the universe are NOT moving at a constant motion, they are accelerating Therefore, there must be some “Dark Energy” that is pushing galaxies apart – working the opposite of gravity

Inertia (Newton’s 1st Law) explains the top galaxy’s motion – constant speed, straight line. Dark Energy is a theoretical explanation for the second galaxy's movement - acceleration.