Question

There are two twins. One twin wants to explore the planet near Proxima Centauri and leaves on a spaceship traveling at 90% of the speed of light, while the other twin stays home on Earth. How much does the twin on Earth age while the other twin travels to Proxima Centauri?

Answer 1

4.7 years

Explanation:

Answer 2

4.7 years

Explanation:

Distance of planet from Earth = 1.3 parsec

We know that 1 parsec = 3.26 light years

And a light year is the distance traveled by light in time period of 1 year.

So, Distance of planet from Earth = 1.3
`*` 3.26 = 4.24 light years

Given that, the person travels at a speed equal to 90% of the light speed.

To travel to the planet from Earth, Light takes 4.24 years.

To travel the distance
`D`, at a speed
`s` light takes time of 4.24 years.

To travel the distance
`D`, at a speed
`0.90s`, the person takes time:

`(4.24)/(0.90) = \bold{4.7\ years}`

So, the twin on Earth ages by 4.7 years.