Understanding Einstein's General Relativity and the Expanding Universe

The video discusses Einstein's 1915 equation, which relates mass, energy, and gravity, replacing Newton's law of gravitation. It explains the complexity of the equation and Einstein's attempt to model the universe as static, leading to the introduction of the cosmological constant. Friedmann's dynamic universe model, which did not assume a static universe, is also covered. Observational evidence later showed the universe is expanding, validating Friedmann's model and suggesting a role for Einstein's constant. The video concludes with a sponsorship message from Brilliant.org.

What did Einstein's equation of general relativity replace?

• Newton's law of motion

• Newton's law of gravitation

• Maxwell's equations

• Pythagorean theorem

What does the 'T' in Einstein's equation represent?

• Time

• Motion of mass and energy

• Temperature

• Tension

How many partial differential equations are represented by Einstein's equation?

• Five

• Ten

• Twenty

• Fifteen

What was Einstein's solution to the problem of a static universe?

• Introducing a new term in his equations

• Assuming the universe is expanding

• Ignoring the problem

• Using Newton's laws

What assumption did Friedmann challenge in Einstein's equations?

• The universe is static

• The universe is contracting

• The universe is infinite

• The universe is flat

What did Friedmann's equations suggest about the universe's density and size?

• Density increases as size increases

• Density is unrelated to size

• Density decreases as size increases

• Density remains constant

What did astronomers discover about the universe's expansion in 1998?

• It is slowing down

• It is constant

• It has stopped

• It is accelerating

What did Einstein reportedly call the extra term he added to his equations?

• His biggest blunder

• A brilliant insight

• A necessary addition

• A minor adjustment

What role does Einstein's constant play in modern cosmology?

• It explains the universe's contraction

• It is irrelevant

• It helps describe the universe's accelerating expansion

• It predicts the universe's end

What is the main focus of the Brilliant.org course mentioned in the video?

• General relativity

• Quantum mechanics

• Cosmology

• Classical physics