Natural Selection

• A theory proposed by Darwin which states:

1. Variation of inheritable characteristics must exist in the population.
2. Environmental change happens that selects for the best suited characteristics that enable an organism to survive.
3. Organisms that survive need to reproduce and pass the characteristics onto their young.
4. These favourable characteristics increase in the population.

Example 1: “I am Legend”

1. Will Smith’s character has immunity to the virus.
2. Virus/cancer cure introduced.
3. Will Smith saves the mother and child.
4. If the mother meets another surviving male they may produce children with immunity.

Example 2: X-Men

1. The X-Men all have mutations.
2. Magneto tries to turn the humans into mutants.
3. Mutants and Humans survive and they can reproduce.
4. If the Mutants mate with other Mutants, eventually they will overrun the humans all everyone on Earth will become part mutant.

Conclusion:Th…

 

Conclusion:

The further away a galaxy is from Earth (x) the faster the galaxy expands away from us.

The Expanding Universe – Continued

Pitch- Highness or lowness of a sound

Wavelength- Distance between two successive crests or troughs of a wave

Spectrum- A range (of similar radiations)

Red Shift- An above-normal proportion of red wavelengths in light from a star

“Scientists inferred that theses stars must be moving away from us”- Inferred

“From this he deduced that they must be receding (or moving away) from Earth shows red shift”- Moving away

Coalesce- Joined together

 

2.

A source of waves is moving away from an observer- Decrease in wavelength

A sound is rising in pitch- Towards the observer

A source of white light is moving away from an observer- an above-normal proportion of red light

The spectral lines of a star are shifted towards the violet end of the visible light spectrum- Away from our Solar System

 

3. Hubble Rap

Evidence of the Big Bang

Questions:

1. What problems with radio signals were the Bell scientists trying to solve in the early 20th century?

2. What did they find was causing their problem?

3. How did their findings help scientists learn more about the universe?

4. What caused the universe to be flooded with gamma rays and X-rays after the Big Bang?

5. What changes occurred in this radiation as the universe cooled?

6. What was the source of the long-wavelength radiation that scientists predicted should still exist?

7. What problem were the Bell scientists trying to solve in 1965?

8. What was causing their problem?

9. What did the radiation causing their problem turn out to be?

10. Which two forms of electromagnetic radiation provided significant new information about the universe in the 20th century?

11. Why is the discovery of residual radiation left over from the Big Bang considered such convincing evidence?

12. What inescapable conclusion did scientists reach as a result of the accumulated evidence?

 

Answers:

1. They were trying to stop the radio waves from the sun interfering with their radio signals.

2. The interfering emissions from the Sun, Stars and Galaxies throughout the universe.

3. They learned that there were more Stars and Galaxies throughout the universe that were, too far to emit light so we can see them, but we could see them by observing their radio signals.

4. The resulting temperature after the Big Bang.

5. As the universe cooled, the radiation gradually lost its energy and moved down the electromagnetic spectrum.

6. It was spread out throughout the entire galaxy.

7. There was an unwanted static that was interfering with satellite signals.

8. It was caused by microwaves that seemed to be arriving with uniform intensity from all directions in space.

9. It was Penzias’ and Wilson’s unwanted static.

10. The Unwanted Static and the Remnant heat predicted to be left over from the Big Bang.

11. Because it showed evidence of the Big Bang.

12. That a titanic explosion occurred 15 billion years ago.