Question

Why are telescopes sometimes called ""time machines""?

A) because the author, H.G. Wells, used the term to describe telescopes in a book
B) because some of the oldest telescopes are still in use today
C) because observations of distant objects reveal them as they were in the past
D) because astronomers can use telescopes to see the Milky Way as it was when it was much younger
E) It's a journalistic misnomer: you cannot travel into the past or the future

Answer 1

Telescopes are called "time machines" because they allow astronomers to view distant celestial objects as they existed in the past, taking advantage of the finite speed of light to see deep into the history of the universe. Correct option is C.

Step-by-step explanation:

Telescopes are sometimes referred to as "time machines" because observations of distant objects reveal them as they were in the past, due to the finite speed of light. When we look at galaxies whose light has taken more than 13 billion years to reach us, we are essentially looking back in time, observing the universe as it was not long after the Big Bang.

This allows us to understand how galaxies have formed and evolved. Furthermore, larger telescopes enable the collection of more light which allows astronomers to observe fainter and more distant objects, providing us with a look back into periods of time even deeper in the past, such as those only accessible through instruments like the Hubble Space Telescope and the Very Large Telescope.