Five Science Fiction Movies That Get the Science Right
However, as the procedure gets underway, he realises that he wants to keep the memories after all, and begins to resist.
This sort of selective memory erasure is well beyond our current technology, but there are good reasons to think it may not be impossible. Several forms of dementia affect particular types of memory – for instance semantic dementia, which targets only factual knowledge about the world, and not "personal" life memories.
Sensibly, the film depicts memory as essentially a network of links. In its frenetic second half, Joel is asleep while the technicians "operate" on his mind. We follow as he careens from recent memories of his relationship to those of his earliest childhood.
As he encounters each memory, it is identified by the technicians and erased, leading to spectacular sequences of him running through bookshops while books disappear from the shelves and escaping from a house that is disappearing one wall at a time.
Alien (1979)
"I can't lie to you about your chances, but you have my sympathies."
This sci-fi horror has a number of realistic touches, such as the use of suspended animation to keep the spaceship's crew alive during decades-long interstellar travel (no implausible faster-than-light travel for these astronauts).
It makes the list, though, for the vicious creature the crew encounters, in particular for the finer details of its life cycle.
The alien goes through three stages over the course of the film. It begins as an egg, which produces a kind of head-sized spider, equipped with a strong tail and a vaguely reptilian appearance. This attaches itself to the nearest living body and, while clamped over the face, implants an embryo into its victim's stomach. It then falls off and dies. The embryo survives by feeding on the victim's digested food. Eventually it breaks out (in the least pleasant way possible) and runs amok on the ship.
Every element of the life cycle can be found in nature, variously in parasites, robber wasps and social insects. Much of the film's suspense comes from the filmmakers' decision to let events unfold without too much explanation – the viewer has to piece the life cycle together for themselves.
Do you have more information about this topic? If so, please click here to contact the editors of ABC News.
