Advances in diet, medicine and the cleanliness of water have massively boosted human life expectancy in the last century. It is now increasing by three months per decade in the affluent west. Is the life expectancy of our pets increasing at a similar rate, proportionally speaking?

Andrew Franklin, London, UK

Given that we can already replace the heart with an artificial pump, filter toxins from the blood with dialysis, and nutrify the blood with IV drips; could a human be kept alive indefinitely with these interventions?

:Edit:

To clarify, I'm talking about future versions of current technology, which could miniaturized, which perform all of the above functions, and enable a person to continue living indefinitely.

Would the actual cells just stop replicating after time and the human fall apart, or would the continual supply of nutrified, oxygenated and cleansed blood be sufficient to keep someone alive?

I washed some apples and served them on a hand-carved soapstone platter (see photo). When we began to eat them, we noticed the apples had left blue stains on the plate. What could have caused this?

Tony Wills, London, UK

Changing as few as possible of the laws of physics, what would be the effect on life on earth - particularly human life - if there was no such thing as snow?

 Is it the reason we exist at all? Because atoms can be in more than one place at any time it is not until an atom is measured or viewed that it then takes up the position that it does, so without anything to view it an atom is in many places at the same time, do our thoughts cause this three dimensional universe we live in to exist, to be, to happen? without some sort of consciousness, a viewer, be it human or any other life form this universe would not be here, I would not be writing this and you would not be reading it. Is life just thought? And so does it gives us the ability to live in a physical form in a three dimensional world? 

What if your living on earth since 23 years and if you don't know what to do !

And dont have purpose in life ! What would you do ? Are we here for some reason or is this a just conincidence ?

If there is no heart in humans or animals there is no blood supply through veins to minds and other things, but if there is no veins there will be no blood supply...ect.

Nature's is also like that. Why?

I have heard of animal that eat plants, and I have heard of animals that eat animals, and I have heard of plants the eat animals, but are there any plants that eat other plants?

Gurvinder Bhandal,

15,  Daventry, UK

We assume that life possibly came to Earth through the landing of a relatively large body of mass from somewhere else in the cosmos.  Could the inverse happen?  Could a large volcano (or any other natural means such as storm pressures or atmospheric disruptions), have sufficient energy and force to eject material from our planet (no matter how small a fragment, but sufficient to contain and protect bacteria) to send life onto somewhere else (no matter how improbable)?  Could Earth be a staging post in life's spread further across the universe?

Is it possible to make a simple life form from standard chemicals e.g. a virus or protozoa