1. ORIGINS …

2. LEARNING GOALS I WILL BE ABLE TO EXPLAIN THE THEORY FOR THE FORMATION OF OUR SOLAR SYSTEM. I WILL BE ABLE TO EXPLAIN THE BIG BANG THEORY.

3. OUR EXPANDING UNIVERSE UNTIL 1920S, ASTRONOMERS THOUGHT THE MILKY WAY WAS THE ENTIRE UNIVERSE. THEY THOUGHT DISTANT NEBULAS WERE ONLY GAS AND DUST. (NO LUMINOUS BODIES) EDWIN HUBBLE IDENTIFIED INDIVIDUAL STARS INSIDE THE ANDROMEDA GALAXY AND REALIZED IT WAS A COMPLETELY DIFFERENT GALAXY FROM OURS. ALSO NOTICED MORE DISTANT GALAXIES THAT WERE MOVING FURTHER AWAY.

4. RED SHIFT EACH GALAXY EMITS ITS OWN DISTINCT SPECTRUM OF LIGHT. LIGHT SPECTRA SHIFT, DEPENDING ON WHETHER THE LIGHT SOURCE IS MOVING OR STATIONARY. HUBBLE NOTICED A RED SHIFT – THE LIGHT FROM THE GALAXIES SHIFTED TOWARD THE RED END OF THE SPECTRUM. THIS MEANT THE GALAXY WAS MOVING AWAY. TODAY, USED AS EVIDENCE THAT THE UNIVERSE IS EXPANDING.

5. DARK MATTER & ENERGY STARS TRAVEL AT IMMENSE SPEEDS INSIDE A GALAXY BASED ON THE MASS OF THE GALAXY ITSELF. STARS MOVED FASTER THAN ORIGINALLY EXPECTED LEADING TO BELIEVE THAT THERE WAS INVISIBLE MASS CAUSING THIS SPEED. THEY CONCLUDED THAT THERE MUST BE 10X MORE MASS IN THE GALAXY THAT WE COULD SEE WITH TELESCOPES.

6. IT IS THE GRAVITY OF THIS MASS THAT IS HOLDING THE GALAXIES TOGETHER. THEY CALL THIS MATTER DARK MATTER (DOES NOT EMIT OR ABSORB LIGHT). IN 1998 SCIENTISTS DISCOVERED THAT NOT ONLY IS THE UNIVERSE EXPANDING, BUT THAT THE RATE OF EXPANSION IS INCREASING. DARK ENERGY: THE “STRANGE” FORM OF ENERGY WORKING AGAINST GRAVITY TO CAUSE UNIVERSE EXPANSION.

7. THE BIG BANG THEORY “THE UNIVERSE BEGAN IN AN INCREDIBLY HOT, DENSE, EXPANSION APPROXIMATELY 13.7 BILLION YEARS AGO”. FIRST DESCRIBED BY BELGIAN PRIEST AND ASTROPHYSICIST GEORGES LEMAITRE. OVER HUNDREDS OF MILLIONS OF YEARS THIS MATTER EXPANDED AND FORMED CLUMPS WHICH EVENTUALLY FORMED THE GALAXIES AND STARS WE SEE TODAY. MOST WIDELY ACCEPTED EXPLANATION OF OUR UNIVERSE.

8. BIG BANG THEORY BIG BANG THEORY EVIDENCE 1965: PHYSICISTS CONDUCTED EXPERIMENTS USING HIGHLY SENSITIVE ANTENNA. IT WAS THOUGHT THAT RADIATION LEFT FROM BIG BANG WAS CAUSING INTERFERENCE. 1989: COBE SATELLITE DETECTS TEMPERATURE VARIATIONS IN UNIVERSE >> SIMILAR TO FOSSIL RECORDS ON EARTH. 2001: WMAP SATELLITE PROVIDES MORE DETAILED MEASUREMENTS THAN COBE. FOUND EVIDENCE THAT THE FIRST STARS SHONE 200-300 MILLION YEARS AFTER BIG BANG.

9. FUTURE OF THE UNIVERSE? IN 2006, ASTRONOMERS CONFIRMED THAT THE EXPANSION RATE OF THE UNIVERSE BEGAN SPEEDING UP ABOUT 5 TO 6 BILLION YEARS AGO. OVER TIME, THE EFFECT OF THE DARK ENERGY WILL INCREASE PULLING APART GALAXIES AND LEAVING THE UNIVERSE FILLED WITH EVEN MORE COLD EMPTY SPACE.

10. SOLAR NEBULA THEORY ACCORDING TO THE SOLAR NEBULA THEORY THE SOLAR SYSTEM WAS FORMED APPROX. 5 BILLION YEARS AGO FROM A MASSIVE CLOUD OF GAS AND DUST (SOLAR NEBULA). ƒ THE COLLAPSING NEBULA STARTED A SPINNING MOTION – THIS IS WHY EARTH ORBITS THE SUN.

11. LEARNING GOALS REVISITED I WILL BE ABLE TO EXPLAIN THE THEORY FOR THE FORMATION OF OUR SOLAR SYSTEM. I WILL BE ABLE TO EXPLAIN THE BIG BANG THEORY.

12. YOUR TURN … PG. 397 # 1, 4, 5.