The Cosmic Ladder That Lets Us Map the Universe

The video explains how astronomers measure cosmic distances using various methods, starting with parallax and trigonometry for nearby objects, and moving to standard candles like Cepheid variables for more distant ones. It highlights the cosmic distance ladder, a series of techniques that overlap to ensure accuracy, allowing astronomers to map distances from the Moon to the edge of the universe.

What is the cosmic distance ladder used for?

• Predicting solar eclipses

• Determining distances to cosmic objects

• Calculating the speed of light

• Measuring distances within the Earth's atmosphere

How did Hipparchus estimate the distance to the Moon?

• Using a pendulum

• By measuring the Moon's brightness

• Through the method of parallax

• By using a telescope

What is the main limitation of using parallax for measuring star distances?

• It is inaccurate for nearby stars

• It only works for stars within 3000 light years

• It can only be used during a solar eclipse

• It requires a telescope

What makes Cepheid variable stars useful for measuring cosmic distances?

• They emit radio waves

• They are the closest stars to Earth

• Their brightness fluctuates predictably

• Their size is constant

Who used Cepheid variables to show that the Milky Way is not the entire universe?

• Isaac Newton

• Edwin Hubble

• Albert Einstein

• Henrietta Swan Leavitt

Which of the following can be used as a standard candle besides Cepheid variables?

• Asteroids

• Supernovas

• Comets

• Black holes

What ensures the reliability of the cosmic distance ladder?

• Each step overlaps with the previous one

• It uses only one method

• It is based on ancient techniques

• Each step is independent