Exam 18: Relativity and Black Holes

Muons are elementary particles that decay into other particles in about 2.2 microseconds.They are formed in the upper atmosphere of Earth from high-energy cosmic rays and can be detected on the ground even though they could travel only a few hundred meters before decaying, according to Newtonian physics.How does relativity explain that we can detect them on the ground? Explain both in our reference frame and in the frame of the muon.

What are gravitational waves? Have they been detected?

What is the Lorentz factor for an object moving at 0.85c?

The phenomenon pictured in the figure below is an example of

The equivalence principle states that the gravitational mass is equal to the

________ is the result of mass distorting the fabric of spacetime.

What is the equivalence principle? Describe a consequence of the equivalence principle for astronauts orbiting in the International Space Station.

What is the meaning of the equation E=mc²?

What will observers in different inertial frames of reference always agree on?

Three identical photons are emitted by the three different stars shown in the figure below.Explain why an observer will ultimately see each photon as having a different wavelength.

We still use Newton's law of gravitation, even though Einstein's relativity is more correct, because

One consequence of Einstein's ideas about the speed of light is that

Hawking radiation is emitted by a black hole when

In the figure below, the astronaut cannot tell the difference between the two situations due to

What is the difference between the singularity and the event horizon of a black hole?

Which of the following are the only observable properties of black holes?

If the Sun were to be instantly replaced by a 1 M_SUN black hole, the gravitational pull of the black hole on Earth would be

Assume that a group of explorers traveled to the Orion Nebula, which is the nearest star-forming cloud and is at a distance of 1,300 light-years, using revolutionary technology that allowed them to travel at a speed of 0.99c.Observers back on Earth using Earth-bound clocks would say it took the explorers ________ to get there, but the explorers with their moving clocks would say it took them only ________ to get there.

Explain how mass and compactness (that is, size and density) would affect the way an object distorts the fabric of spacetime.

What does singularity mean in the context of black holes?