The “Big Bang” Theory All of the matter and energy of space was contained at one point. From one central point, space and time as we know it began. Created an extremely hot plasma of protons and neutrons (plasma soup). Spread in all directions at once.

Evidence for The “Big Bang” Theory The universe is continuously expanding –Edwin Hubble first noted –Red shift. Galaxies are moving farther away from each other in every direction. –The speed is proportional to the distance away. (Balloon demo).

More Evidence for The “Big Bang” Theory Background radiation noise –Arno Penzias and Robert Wilson 1964, found “noise” came from all directions. –Background radiation left over from Big Bang. –NASA’s COBE satellite also detected background cosmic microwaves –Found fluctuations indicating cooling of plasma which started development of universe. –All this occurred in the first fractions of a second

How Old Is the Universe? If the universe is indeed finite, how long has it been in existence? –Recall v=d/t? Then also d/v = t (uses Hubble’s observations) –(distance of a particular galaxy) / (that galaxy’s velocity) = (time) 4.6 x 10^26 cm / 1 x 10^9 cm/sec = 4.6 x 10^17 sec –= approximately fifteen billion years

After The Bang Expansion and cooling (like a pressure cooker). Common particles began to form (quark soup). –photons, neutrinos, electrons and quarks –no recognizable “heavy” particles such as protons or neutrons because of the still too intense heat cooled to about 3000 billion degrees Kelvin –Protons and neutrons form After one to three minutes, protons and neutrons react to form deuterium, an isotope of hydrogen

Galaxies Powers of 10: Relative Size/ Relative time

Our Galaxy You are here

Formation of the Solar System

Solar System Formation

Our Solar System 8 or 9 planets? Inner planets and outer planets, very different Pluto different still /astronomy/ /astronomy/

Terrestrial Planets Closest to Sun Rocky cores –(iron, nickel, silicate minerals) Density relatively high Mercury Venus Earth Mars

Jovian Planets Farthest from Sun icy cores, lots of gas Density relatively low, Size very large, so overall very massive Jupiter Saturn Uranus Neptune