Hai pf, yesterday i asked a question to my friend that "I had heared that people who were travelling to space may have a slight age difference is it true??? assume if i and my friend are of age 30. i got a chance to travel to space. and i was returning to earth after 5 years. then my friend who lived at earth has an age of 35 and i have an age of moreorless 32. is those lines were true? who replied me the below mentioned answer in your case. You travel from earth, you get older 2 year and your friend 5 year. Let's say γ=52=2.5 How fast should you go? What is V, so that √(11−v2)=2.5? 2.5∗√(1−v2)=1 √(1−v2)=0.4 1−v2=0.16 v2=1−0.16=0.84 v=√(0.84) You have to travel at about 2,750,000 km per second. here my question is does the travelling speed or velocity affects agening?