chapter1 Flashcards
The Greek mathematician Eratosthenes made measurements to show the size of
earth
When the Sun was directly overhead in Syene, why wasn’t it directly overhead in Alexandria?
earth is a sphere
Earth, like everything else illuminated by the Sun, casts a shadow. Why does this shadow taper?
The Sun is much larger than the Earth
How does the Moon’s diameter compare with the distance between Earth and the Moon?
The Moon’s diameter is 1/110 the distance between Earth and the Moon
How does the Sun’s diameter compare with the distance between Earth and the Sun?
The Sun’s diameter is 1/110 the distance between Earth and the Sun.
What are the circular spots of light seen on the ground beneath a tree on a sunny day?
These are pinhole images of the Sun
What is the role of equations in this book?
Equations are guides to thinking and show connections between concepts.
Equations in Conceptual Physics are used mainly _______.
guides to thinking
Distinguish between a hypothesis and a theory
A hypothesis is an educated guess, whereas a theory encompasses well tested and verified hypotheses.
In daily life, people are often praised for maintaining some particular point of view, for the “courage of their convictions.” A change of mind is seen as a sign of weakness. How is this different in science?
When a scientist finds evidence that contradicts a law, then the law must be abandoned
What is the test for whether a hypothesis is scientific or not?
A hypothesis is scientific if it is possible to prove it wrong
In daily life, we see many cases of people who are caught misrepresenting things and who soon thereafter are excused and accepted by their contemporaries. How is this different in science?
A scientist who lies in a scientific publication will suffer professional excommunication.
Must people choose between science and religion?
No, there is no contradiction in being scientific and religious in one’s thinking.
Psychological comfort is a benefit of having solid answers to religious questions. What benefit accompanies a position of not knowing the answers?
Not knowing answers opens the mind to a lifetime of exploring.
A theory in science is ______.
a synthesis of well-tested ideas
A fact in science is ______.
an agreement between trained investigators
A scientific hypothesis deemed valid must have a test for proving it ______.
wrong
Clearly distinguish between science and technology.
Science gathers the knowledge that technology uses for practical purposes.
Religion is concerned mainly with the ______.
spiritual world
Why is physics considered to be the basic science?
Because all other sciences can be shown to be derived from it.
Science is a body of knowledge that
- is an ongoing human activity.
- condenses knowledge into testable laws.
- describes order in nature
To a fair approximation, Early Greeks knew the
- size of Earth.
- Earth-Moon distance.
- size of the Moon
When the Sun shines on the Moon, the Moon casts a shadow
- at all times.
- that is tapered.
- that sometimes falls on Earth.
Spots of sunlight on the ground cast through openings between leaves in trees above are actually
images of the Sun
