Week 2: Science and the Earth

Question 1

What is science? What is the overall assumption we have when we practice science?

Answer 1

is a process (it is not just a body of facts) to find answers to questions; science is the method by which we learn about the world around us, generate common understanding, and apply that understanding towards various goals. Science generates series of increasingly precise approximations to explain the natural world

Built-in Assumption: the universe is orderly, reasonable, and testable. (i.e.: the laws of nature are the same everywhere in the universe)

Question 2

What are some of the “hallmarks” of science?

Answer 2

Hallmarks:
Consistent: the results of repeated observations and experiments regarding a given natural phenomenon are, within some agreed range of answers

Observable: the phenomenon you are trying to explain must be observable, either through controlled creation of the event in a lab or by observing nature

A Natural Mechanism: to be considered science, a natural mechanism must be invoked to explain the cause of some phenomenon

Testable Predictions: any explanation for a phenomenon must predict something that can be observed/measured

Question 3

What are some of the foundational principles of science?

Answer 3

We change our minds when new data demands it

Scientific explanations are always subject to revision and correction if new evidence or understanding arises

Everything must be debated by multiple scientists

Question 4

Understand what the scientific method is, and how it is put into practice.

Answer 4

Scientific Method: helps to maintain all results that come from the process, and meet the requirements of science,

1. Recognize the Problem or Unknown: Simply, the understanding that there is a lack of knowledge to begin with
2. Gather Data
3. Hypothesis:
   - A hypothesis is an educated guess that is testable, based on all the knowledge in the field so far

-You understand there’s an unknown, you understand the context of the unknown, and now you’re putting forward an idea that could explain reason for the unknown

4. Test Hypothesis (Experiment)
   - In order to validate your hypothesis, you need to observe and to experiment
5. Does the New Data Agree?
   - Did the results of the experiments back-up your hypothesis? Do you need to change your hypothesis or do you need to change your experiment? Do you need more data?

General Theory

Question 5

What’s the difference between a hypothesis and a theory?

Answer 5

Hypothesis: is an educated guess that is testable.

-You understand there’s an unknown, you understand the context of the unknown, and now you’re putting forward an idea that could explain the reason for the unknown

Theory: is a hypothesis that has been repeatedly tested in multiple ways by multiple scientists, and has a general consensus to be our best understanding of the nature

Question 6

What are two components of a measurement?

Answer 6

Measurements must have two components: a value and a unit

Value (number): 25
Unit: Celsius

Question 7

What is astronomy? What is matter? What is radiation?

Answer 7

Astronomy: the study of matter and radiation beyond the Earth’s atmosphere

Matter: anything that has mass

Radiation: energy that is transmitted at the speed of light in the form of waves or particles

Question 8

How does planetary science differ from astronomy?

Answer 8

Planetary Science: the study of planets, moons, planetary system, their geology, chemistry, formation, and evolution

Astronomy: the study of matter and radiation beyond the Earth’s atmosphere

Question 9

What is temperature? When you measure the temperature of a room, what are you physically measuring?

Answer 9

1. Temperature: a measurement of the amount of energy the particles have that makes up the object or environment you are measuring.

When you measure the temperature of a room, you are measuring how fast or slow the energy of the particles moves in the environment.

Fast moving particles = warmer temperature
Slow moving particles = colder temperature

Question 10

Scale Properties?

Answer 10

1. Fahrenheit (F): based on air
   - Absolute Zero: -459.67 F
   - Water Freezes: 32 F
   - Water Boils: 212 F
2. Celsius or Centigrade (C): based on water
   - Absolute Zero: -273.15 C
   - Water Freezes: 0 C
   - Water Boils: 100 C
3. Kelvin (K): based on how much energy atoms have
   -Absolute Zero: 0 K
   Measured from absolute zero, and therefore has no negative temperatures. Absolute zero: occurs when molecular motion stops because the energy of an atom is zero
   -Water Freezes: 273.15 K
   -Water Boils: 373.15 K
   -Mostly used in astronomy

We have these different scales because:
Fahrenheit is asking humans how hot it feels
Celsius is asking water how hot it feels
Kelvin is asking atoms how hot it feels

Question 11

What causes the Sun to rise in the east and set in the west each day?

Answer 11

the Sun rising in the East and setting in the West is a result of the Earth spinning West to East

Question 12

Describe the Sun’s height and approximate direction (N, S, E, or W) in the sky at noon, sunset, and sunrise, as seen from both the northern and southern hemispheres.

Answer 12

N-hemisphere: at noon, the sun is primarily visible in the southern sky, facing directly south
S-hemisphere: at noon, the northern half of the sky is mostly visible
Sunrise/Sunset: perpendicular to your location
Midnight: the location is opposite of noon and faces away from the sun

Question 13

What does the word solstice mean? How does it describe what happens to the Sun’s rising and setting positions on the summer and winter solstices?

Answer 13

Solstice: the point where the Sun reaches its highest or lowest point in the sky for the year.

Question 14

Which day is the longest day of the year? Which day is the shortest day of the year?

Answer 14

-Longest Day: Summer Solstice -June 21, 2022

In the summer months, the Sun gets higher in the sky, and it stays longer above the horizon

-Shortest Day: Winter Solstice - December 21, 2022

In the winter months, the Sun does not get high in the sky, and it stays above the horizon for a shorter period of time

Question 15

Describe the difference between the Sun’s path in the sky on these days. Use this to explain the two reasons that summertime is warmer than wintertime.

Answer 15

Summer solstice: The furthest North the Sun will rise + set.

Winter solstice: The furthest South the Sun will rise + and set.

Summertime is warmer because the Sun is highest in the sky + stays in the sky for longer (the day is longer).

Question 16

What are the lengths of daytime and nighttime on the equinoxes?

Answer 16

Equal times of day and night.

Question 17

What causes the seasons? Describe the orientation of the Earth relative to the Sun on the solstices and equinoxes.

Answer 17

Earth’s N-S axis is tilted (23.5), which changes each hemisphere’s amount of direct light throughout a 365 day period. Between the winter and summer solstices, daylight increases as Earth continues its orbit around our Sun.

During the equinoxes, sunlight strikes perpendicular to the surface at Earth’s equator. All locations on Earth, regardless of latitude, experience 12 hours of daylight and 12 hours of darkness.

Question 18

Why does direct light feel warmer than indirect light?

Answer 18

Direct sunlight is more concentrated heat, which tends to be warmer but also covers a smaller surface area as compared to indirect light which is more spread out over a larger surface area.

Question 19

What does the southern hemisphere experience during northern winter, and why?

Answer 19

Summer. This is because during summer or winter, one part of the planet is more directly exposed to the rays of the Sun than the other, and this exposure alternates as the Earth revolves in its orbit.

Question 20

What is the latitude of the equator? What is the latitude of the north and south pole?

Answer 20

Latitude of Equator: 0 degrees
Latitude of North Pole: 90 Degrees N
Latitude of South Pole: 90 Degrees S

Question 21

Within what latitude can an observer see the Sun directly overhead? How did these latitudes get their names?

Answer 21

Tropic of Capricorn = 23.5 degrees S.

• The Tropic of Cancer was named because at the time of its naming, the sun was positioned in the Cancer constellation during the June solstice.
• the Tropic of Capricorn was named because the sun was in the constellation Capricorn during the December solstice.

Question 22

What are polar nights and polar days? Within what latitudes do these occur?

Answer 22

• Polar Night is when you experience 24 hours of nighttime and a Polar Day is when you experience 24 hours of Daytime.
• Polar nights occur 18 degrees north of the Arctic Circle and 18 degrees the south of the Antarctic circle

Question 23

What is the habitable zone?

Answer 23

habitable zone, the orbital region around a star in which an Earth-like planet can possess liquid water on its surface and possibly support life.

Liquid water is essential to all life on Earth, and so the definition of a habitable zone is based on the hypothesis that extraterrestrial life would share this requirement.

Question 24

Why does distance from the sun have nothing to do with our seasons?

Answer 24

Distance from the Sun has nothing to do with our seasons because its effect is small compared to the tilt of our Earth which changes each hemisphere’s amount of direct light throughout a 365 day period.

Question 25

What are the two reasons why it feels warmer during the summer?

Answer 25

There are two effects we need to consider. When we lean into the Sun, sunlight hits us at a more direct angle and is more effective at heating Earth’s surface. The second effect has to do with the length of time the Sun spends above the horizon.

Even if you’ve never thought about astronomy before, we’re sure you have observed that the hours of daylight increase in summer and decrease in winter.