"It is possible to keep someone alive indefinitely these days if you hook them up to enough machines."
We are not discussing what is presently available. Does it ever occur to you to actually do a search for scientific/medical back up to Mr Hockey's comments? Probably not, so entrenched is your determination to rubbish anything from your disliked side of the political fence.
If you do a google search for "medical and/or scientific evidence for possibility of life extending to 150" you will find dozens of links to just such research.
Here is one to go on with:
http://www.wsj.com/articles/SB10001424053111904875404576528841080315246
Of course no one would consider extension of life purely on the basis of mechanised support to be valid or desirable. If you were more aware of the progress of stem cell research, the potential for recreating essential organs and body parts, you would understand that what is possible is almost infinite.
As someone else has pointed out above, any such life extension would need to be accompanied by similar mental agility for life to be worth having. There is ongoing research into the dementias and we can reasonably hope that eventually a treatment or prevention for dementia will emerge.
