Conceptual Physical Science Final Exam: Chapter 28: The Structure of Space and Time

According to calculations made by modern astronomers, the age of the universe is close to

14 billion years

Rank the following in order of increasing abundance in the universe: (a) dark matter, (b) ordinary matter, (c) dark energy.

B; A; C

Rank these elements in order of increasing abundance in the universe: (a) helium, (b) hydrogen, (c) carbon.

C; A; B

Rank the following in order of increasing duration: one minute on the surface of (a) Earth, (b) Mercury, and (c) the Moon.

C; B; A

The Big Bang explains __________________.

Dark Sky Elemental Abundances Cosmic Microwave Background Red Shifts Large Scale Structure

What is probably the major constituent of our universe?

Dark energy

When we speak of time dilation, we mean that time

stretches with speed.

Edwin Hubble discovered that the farther away a galaxy is the

faster it is receding from us.

Suppose you have a compressed gas, like that in a piston in a car engine. As the piston moves so that the gas expands, what happens to the gas temperature?

it cools as it expands

Is dark matter found mostly within a galaxy or just outside a galaxy?

just outside a galaxy

Dark matter is not affected by _______.

light

The Big Bang....

marked the beginning of space and time.

What type of matter is visible?

ordinary/ normal matter

Cosmic Microwave Background (CMB)

the electromagnetic radiation left over from the formation of the universe

In his special theory of relativity, Einstein stated that the laws of physics are

the same in all uniformly moving frames of reference.

Several billion years in the future our Sun will grow in size to become a red giant, whose surface will extend to the present orbit of Earth. After this happens, will the slowing of time on the Sun's surface be more or less pronounced than it is today?

the slowing of time will be less than it is today

Consider Object 1 with temperature 10 K and Object 2 with temperature 20 K. According to the laws of thermal radiation __________.

the spectrum of Object 2 has a shorter peak wavelength than the spectrum of Object 1

Cosmology is the study of the overall structure and evolution of

the universe.

Dark energy ______.

would be considered to be the opposite of gravity. is energy that exerts an outward pressure, causing spacetime to expand. is the phenomenon responsible for the acceleration of the universe.

Space and time are ________

Bound together

Which is more abundant: dark matter or ordinary matter?

Dark matter is six times more abundant than ordinary matter.

General Relativity

Gravitational attraction between masses is a result of the nearby masses; gravity has waves

How is it possible that today's diverse universe was able to arise from that which was very homogeneous at its first moments?

Inflation magnified ultrasmall quantum variations in position and momenta.

Does it necessarily take a minimum of 25,000 years to travel a distance of 25,000 light-years?

No, for a person in a spacecraft traveling near the speed of light much less time will pass.

If the Sun suddenly became less massive, what would happen to Earth's orbit?

Spacetime around the Sun would become flatter, and the Earth, with its current momentum, would exit its orbit around the Sun.

What happens to starlight as it passes close to the Sun?

Starlight is deflected toward the Sun

What was Einstein's cosmological constant?

The cosmological constant was a hypothesis that there was a repulsive force to balance gravitational attraction to keep the universe static.

Distant galaxies are _________.

accelerating away from each other.

Cosmic Inflation refers to

an extremely rapid expansion of the early universe that occurred in an extremely brief period of time.