Question: can there ever be the possibility of living for ever or bringing back the dead

Kevin Arbuckle answered on 10 Mar 2014:

Oddly enough, some animals do seem able to live forever (at least until something eats them!), such as some jellyfish, some flatworms, and some hydras (which look a little bit like sea anemones). Of course, it could be that they live for a very long time instead of forever, but as far as we know they don’t die of old age and there are some ways in which we think they are able to do this. The only problem is that the way these animals are thought to live forever is related to the way they grow (and their cells divide), which we can’t change in humans, so It’s probably not possible for humans to ever achieve immortality (the ability to live forever).

Bringing back the dead could have two meanings. The first is what I think you mean – to bring the body of someone who has died back to life as they are. This is actually possible, and a regular occurrence in hospitals, if it is shortly after a person dies. Someone is regarded as dead by doctors when their heart stops and they stop breathing, but they can often be brought back to life as long as this is done soon after death (called resuscitation). Unfortunately, after a short amount of time has passed the brain has suffered too much damage from the lack of oxygen (because the person isn’t breathing) to be brought back. Because of this, it is unlikely people will ever be brought back from the dead long after they have died.

On the other hand, you might think that being ‘brought back from the dead’ could be a bit like Jurassic Park – where we could take DNA from a dead person and clone them to create a new person (or animal). Of course, the person wouldn’t be exactly the same or have any memories, but would have to start life again. This has actually been suggested for some recently extinct species such as mammoths and woolly rhinoceros, but we don’t really agree on whether we should be doing this. It is not possible quite yet, but may well be in the near future for some species. Like in Jurassic Park, the biggest question, once we can answer yes to ‘can we’, will be ‘should we’?