Question

How long does it take to travel to the nearest star at the speed of light?

Answer 1

Approximately `4.2` years

Explanation:

The nearest star (apart from the Sun) is currently Proxima Centauri, which is about `4.2` light years away. (The Sun is a mere `500` light seconds or so from the Earth)

That means that the light we currently see from Proxima Centauri started its journey about `4.2` years ago.

If an astronaut were able to travel close to the speed of light, then from the perspective of observers at home, the journey would take at least `4.2` years.

Note however, that the astronaut would experience somewhat less time, depending on how close to the speed of light they were travelling.