PHYS 101 Test 1

Distance of Earth to the Moon

110 times the diameter of the moon.

Aristarchus

Greek scientist: first to suggest Earth spins on its axis once a day. Calculated the Moon's diameter and its distance from Earth. Determined it by watching an eclipse. Calculated Earth-sun distance.

Order of magnitude

Mega: 1000000 Kilo: 1000 Centi: 100 Milli: .001 Micro: .000001

Copernicus

Polish astronomer who proposed that the Earth revolves around the Sun.

How many seconds in one year?

o 1 year = 375 days = 365 x 24 hours = 8760 hours = 8760 x 60 min = 525600 min = 525600 x 60 sec = 31536000 sec = 3.1536 x 10^7 seconds o In 3 significant numbers: 3.15 x 10^7 seconds

How many inches are there in 5 miles?

o 5 miles = 5 x 63360 inches = 316800 inches = 3.168 x 10^5 inches o With 3 significant digits: 3.167 x 10^5 inches

How many mm are there in 5 km?

o Length: meter o 1,000 mm in 1 meter o Km: 3 orders up o Mm: 3 orders down. o 5km = 5 x 100 m = 5--- m = 5000 x 1000 mm = 5000000 mm = 5 x 10^6 mm

Unit of time

seconds

Kelvin introduced

the temperature scale.

How many km are there in 5 miles?

5 miles = 5 x 1.609 km = 8.047 km

Principle

A general hypothesis or statement about the relationship of natural quantities that has been tested over and over again and has not been contradicted. Also known as law.

Scientific Method

Principles and procedures for the systematic pursuit of knowledge involving the recognition and formulation of a problem, the collection of data through observation and experiment, and the formulation and testing of hypotheses.

Scientific Attitude

The scientific method inclined toward inquiry, integrity, and humanity.

Is this theory falsifiable? A possible theory: Cell phones cause cancer The test: * Compare cancer rates between users and non users. * See if cell phone radiation can cause cell damage. The result: No difference in cancer rates, no cell damage

Yes, it can be tested.

Is this theory falsifiable? A possible theory: Extra gov't spending (a stimulus) is necessary to get the economy out of a recession. The test: $800 billion stimulus in 2009 The result: The economy is still in recession in 2013 The response: We needed a bigger stimulus

Yes, it can be tested.

Unit of mass

kilogram

Unit of length

meter

Which of these are falsifiable hypotheses of theories? 1 = falsifiable 2 = not falsifiable * Complex creatures evolved from simpler ones. * All dropped objects fall at the same rate (in the absence of air resistance) * The path of light rays can be bent by gravity * Intelligent life exists somewhere in the universe * Space is permeated with an undetectable essence

• Complex creatures: 1 • All dropped objects: 1 • The path of light rays: 1 • Intelligent life: 2 - currently. If technology advances - 1. • Space is permeated: 2

A theory is falsifiable if

1. The theory makes a prediction 2. You can test the prediction 3. The theory needs to be thrown out if the prediction fails.

Law

A general hypothesis or statement about the relationship of natural quantities that has been tested over and over again and has not been contradicted. Also known as principle.

Fact

A statement about the world that competent observers who have made a series of observations agree on.

Theory

A synthesis of a large body of information that encompasses well-tested and verified hypotheses about certain aspects of the natural world.

Physics

It's about the nature of basic things such as motion, forces, energy, matter, heat, sound, light, and the structure of atoms.

Galileo

Italian physicist who popularized Copernican theory and who had his own astronomical discoveries.

What is science?

Once called natural philosophy, encompasses the study of living things and nonliving things, the life sciences and the physical sciences.

What is the test for whether a hypothesis is scientific or not?

a. A hypothesis is scientific if it can be written as an equation. b. A hypothesis is scientific if it is possible to prove it wrong. c. A hypothesis is scientific if it is possible to prove it right. d. A hypothesis is scientific if the appropriate scientific body says it is.

Which of these is a scientific hypothesis?

a. Atoms are the smallest particles of matter that exist. b. Space is permeated with an essence that is undetectable. c. Albert Einstein was the greatest physicist of the 20th century.

Which of the following are scientific hypotheses? Check all that apply.

a. Earth rotates about its axis because living things need an alternation of light and darkness. b. Tides are caused by the Moon. c. Chlorophyll makes grass green.

What are steps of the scientific method.

a. Reasoning and derivation from axioms. b. Assembling and organizing facts and checking them against dogma. c. Using Occam's razor to eliminate excess facts. d. Hypothesis, predictions, and experimental findings.

Relative sizes of objects in the solar system:

• Hold a dime just far enough from your eye that it obscures a full moon. o Distance earth to moon = 110 x diameter of moon Coin diameter/ coin distance = Moon diameter / moon distance = 1/10

There are 3 basic quantities the first 10 chapters are based on: Each quantity must have a unit. Seconds is the only unit that everyone is using.

1. Time: Unit is seconds. 2. Mass: how much of something. Unit is kilogram. 3. Length: distance. Unit is meter

Which of these is not a scientific hypothesis?

A. Protons carry an electric charge. B. Undetectable particles are some of nature's secrets. - Not just undetectable today, but undetectable forever. C. All of the above are scientific hypotheses.

Hypothesis

An educated guess; a reasonable explanation of an observation or experimental result that is not fully accepted as factual until tested over and over again by experiment.

If you walk from here to California, how many steps will you take?

Estimate your steps. 2 steps in one meter. 3700 x 1000 m = 3700000 m = 3700000 m x 2 (steps/meter) = 7400000 steps = 7.4 x 10^6 steps (Straight line distance 3700 km)

Pseudoscience

Fake science that pretends to be real science.

Eratosthenes

Greek mathematician, nicknamed "beta. One of the early librarians in Alexandria, Egypt. Found prime numbers, accurately measured the tilt of the Earth's axis, wrote a book "Geography": math basis for geography, treat Earth as globe, divide into lats and longs, frigid, temperate, and torrid zones. Remembered for his remarkably accurate calculation of the Earth's size.

Aristotle

Greek philosopher who claimed that an object falls at a speed proportional to its weight. He was proven wrong by Galileo by testing it at the Leaning Tower of Pisa.

Briefly, what is science?

a. Science describes the order in nature and the causes of that order. b. Science is a way of knowing about the world and making sense of it. c. Science creates testable laws and theories. d. All of the above.

Clearly distinguish between science and technology.

a. Technology solves problems, whereas science creates them. b. Technology can be helpful or harmful, while science is only helpful. c. Science is applied technology. d. Science gathers the knowledge that technology uses for practical purposes.

Which of the following activities involves the utmost human expression of passion, talent, and intelligence?

a. painting and sculpture b. literature c. music d. religion e. science