The argument/idea that we should concentrate resources on preventing old age (and therefore age-associated diseases that kill) thereby dramatically increasing the human life span with an eye toward increasing it indefinitely is not a scientific concept.
Agreed, that's more of a moral/political argument. But it is only one aspect of the topic "defeating death". For example: "aging can be cured" and "cryonics can delay death" are legitimate scientific concepts.
Ars Technica are holding a competition for people to make a science video up to 3 minutes long "to explain a scientific concept in terms that a high school science class would not only understand, but actually be interested in watching". Prizes in three categories: biology, physics, and mathematics. Deadline is December 25. More details here.
Anyone want to have a go at Bayes' theorem? Cognitive bias? Defeating death? Invisible purple dragons?