Hubble's Law and Cosmic Expansion

The video tutorial discusses Hubble's Law, which states that the recession speed of a galaxy is directly proportional to its distance from Earth. Edwin Hubble's work in the 1920s led to the discovery of this linear relationship, represented mathematically with Hubble's Constant. The tutorial explains the implications of this law, including the concept that the universe is expanding, and introduces the idea of the Big Bang. The video also covers the units of Hubble's Constant and hints at calculating the age of the universe in the next video.

Who was the scientist responsible for formulating the law that describes the relationship between the speed and distance of galaxies?

• Albert Einstein

• Galileo Galilei

• Isaac Newton

• Edwin Hubble

What kind of relationship does Hubble's Law describe between the velocity of a galaxy and its distance from Earth?

• Exponential

• Linear

• Quadratic

• Logarithmic

In the context of Hubble's Law, what does the symbol 'H₀' represent?

• Hubble's constant

• The gravitational constant

• The speed of light

• The Planck constant

Why is it important to specify 'galaxy' when discussing Hubble's Law in exams?

• Because it only applies to nearby objects

• Because it only applies to stars

• Because it applies to distant galaxies and clusters

• Because it applies to planets

According to Hubble's Law, what happens to the speed of a galaxy as its distance from Earth increases?

• It fluctuates

• It increases

• It remains constant

• It decreases

What does the gradient of a velocity versus distance graph represent in Hubble's Law?

• The mass of the galaxy

• Hubble's constant

• The speed of light

• The age of the universe

What does Hubble's Law suggest about the movement of galaxies relative to each other?

• They are moving away from each other

• They are stationary

• They are moving towards each other

• They are orbiting each other

What significant concept about the universe's origin is introduced by extrapolating Hubble's Law backwards in time?

• The Oscillating Universe Theory

• The Steady State Theory

• The Big Bang Theory

• The Multiverse Theory

What is the significance of the time 't' in the equation H₀ = 1/t?

• The time it takes for light to travel one parsec

• The age of the universe

• The time it takes for a galaxy to reach Earth

• The time it takes for a galaxy to double its speed

What are the SI units of Hubble's constant?

• Meters per second

• Kilometers per hour

• Seconds to the power of minus one

• Parsecs per year