Well if there's immortality I think then there should be a law to promote contraceptives so that nobody will procreate in order to control the population or we could let some people sleep for 10 years by injecting them with chemicals whiles others live to sleep when their time is due... lol
If there is immortality in this life, new people won't have to keep on becoming scientists to take the place of scientists who die. A scientist who has lived 200 years will develop great inventions, because he will have a long time to concentrate. He will develop Star-Trek-style space warps. We will leave earth, and populate the infinite number of planets out there. There will never be population that can outgrow colonizing the stars.