Origin of the Universe

Question 0

Scientific method

Answer 0

1) Develop an idea to explain an observation
2) Test the idea with new observation or by making predictions
3) If new observations do not agree with the idea or its predictions, modify the idea or develop a new one

Question 1

Science

Answer 1

Human search for natural explanation of what the universe is; how it is constructed and how it came to be

Question 2

Scientific theories must be…

Answer 2

Testable and their conclusions must be falsifiable

Question 3

Truth in science

Answer 3

On science, an baser stood that has been repeatedly confirmed and for all practical purposes is accepted as “true.” However, truth in science is never final and what is accepted today may be modified or even discarded tomorrow.

Question 4

Hypothesis

Answer 4

A tentative statement about the natural world leading to deductions that can be tested

Can be used to build more complex inferences and explanations.

Question 5

How can one become more certain about a hypothesis?

Answer 5

If the deductions are verified

Question 6

How can one become less certain about a hypothesis?

Answer 6

If the deduction is incorrect.

Question 7

Law

Answer 7

A descriptive generalization about how some aspect if the natural world behaves under states circumstances.

Question 8

Theory

Answer 8

1) A well-substantiated explanation if some aspect of the natural world that can incorporate facts, laws, inferences, and tested hypotheses.
2) Do not turn into facts through the accumulation of evidence
3) The end point of science; they explain facts.
4) the understanding that develops from extensive observation, experimentation, and creative reflection.
5) Incorporate large body of facts, laws, tested hypotheses, and logical inferences

Question 9

Pythagoras ~580-500 BC

Answer 9

Spherical rotating earth with a fire at the center (heliocentric); magic numbers

Question 10

Plato ~427-367 BC

Answer 10

Planets circling stationary Earth (geocentric).

Observing mars and its retrograde motion disproves this theory.

Question 11

Eudoxus ~408-355 BC

Answer 11

Math model with 33 spheres within sphere motions; clever attempt to reproduce retrograde motion.

Question 12

Aristotle ~384-322 BC

Answer 12

Working model with 55 spheres (here, the theory becomes overly complex and unwieldy).

Question 13

Aristarchus ~280 BC

Answer 13

Heliocentric system; was correct but ignored due to its overly radical nature.

Question 14

Ptolemy 140 AD

Answer 14

Brightness problems; geocentric theory where each planet moved in a small circle/epicycles around the sun, which in turn circled earth

Question 15

Copernicus (1473-1543)

Answer 15

Sun centered theory with circular orbits

Question 16

Kepler (1571-1630)

Answer 16

Elliptical orbits

Question 17

Galileo 1564-1642

Answer 17

Using a telescope to observe the phases of Venus, confirms heliocentric theory. Denounced by the Catholic church’s inquisition in 1633 and forced to recant his ideas

Question 18

Newton 1643-1726

Answer 18

Force of gravity; rational basis for planetary motion

Question 19

Herschel 1738-1822

Answer 19

1) Confirms gravity is universal
2) Discovers Nebulae outside Milky Way
3) Estimating distance to stars

Question 20

Parallax of a planet

Answer 20

Distance to a planet (ex: Mars) can be measured using parallax angle. Angle depends on separation of the observatories and the distance to the planet.

Question 21

Parallax of nearby stars

Answer 21

By observing a star at 6 month intervals, the Earth’s orbit is now the separation of the observatories (ex: Alpha Centauri is 4 light years from Earth).

Question 22

Using brightness to estimate distance

Answer 22

Identify star types in Milky Way where we know the distance; use absolute brightness of the same star type in other galaxies to estimate distance (Doppler effect applies to light as well as sound)

Question 23

Supernova explosion

Answer 23

1) As a large star’s hydrogen runs out it begins to collapse, temperature goes up, and the star explodes.
2) ~10 seconds long
3) All elements heavier than iron formed in this way

Question 24

Fate of the universe

Answer 24

The Big Bang could expand the universe forever or gravity could cause it to collapse back in on itself; it all depends on the universe’s mass