Damien

We know these are emotions and while we cannot explain everything about the brain we can measure emotional reaction and watch sections of the brain react to such measures. I.E We can measure the brain reacting when you mention to someone the name of the person they love. Also the bond between a parent and child is an observable reaction in humanity and other animals - from an evolutionary perspective these emotions are key to the development of most species.

Ghosts are not physically possible. They both float though walls and let can make items move. Therefore they must be composed of some magical elements which can both be pretty much nothing and yet exert physical force. Not a small trick.

There is no proof. As I mentioned above you might as well be arguing for the existence of vampires or shapeshifting lizards.

And yes, just because something can't be measured in the lab doesn't mean it does exist. Science isn't just about lab work. It's about removing human bias from a theory in order to learn something new about the Universe. We could conduct other experiments to at least lend some evidence for ghosts. We could go to a location famed for it's ghosts and see if there is a lot of unexplained stuff happening.

If ghosts exist and are actually having a physical effect on the world then we could certainly find out about it.