CAN science completely explain the universe? And can it explain love?

The answer to the first question, from science itself, is “No”.

An Austrian mathematician named Kurt Godel wrote two “incompleteness theorems” in 1931, when he was just 25, that proved, in the same way that two plus two equals four, that no logical system could produce every true statement possible.

At the heart of his work was the concept of paradox, such as this famous statement: “A male barber shaves all and only those men who do not shave themselves. Does he shave himself?”

Trying to answer this takes you through an endless series of “yes, therefore no, which means yes”, and so on.

A visual representation of this was created by the Belgian surrealist artist Rene’ Magritte in his oil painting Ceci n’est pas une pipe, which translates from French as This is not a pipe.

It’s a picture of the artist’s tobacco pipe. But the title, written below the image, makes you think that it’s just oil on canvas. If so, however, then the words in the title are also just paint, without meaning, so you can see the picture as a pipe again.

Whether they’ve heard of Godel or not, most people suspect that science has limits. When I was growing up, this was most often expressed in the statement: “Science can’t explain love.”

It was hard to argue with this, certainly not with logic. Love was the territory of poets, and any scientist who ventured into the realm would surely end up floundering.

Not so any more. Pioneering work by Dr Helen Fisher, a biological anthropologist at Rutgers University in New Jersey, has discovered the scientific basis for love.

It’s an addiction.

Specifically, it’s an addiction to a brain chemical called dopamine.

Fisher has spent the past few years putting people in love into functional magnetic resonance imaging (fMRI) scanners. These devices are able to detect changes to blood flow in the brain, essentially revealing which areas are active depending on what the brain is doing.

People in love, discovered Fisher, show increased activity in an area called the Ventral Tegmental Area (VTA), a tiny part of the brain inherited from what scentists say are our reptilian ancestors.

The main thing the VTA does is produce dopamine, a neurotransmitter that carries signals from one brain cell to another.

Other fMRI experiments have shown that the VTA is also active in the brains of drug addicts and people with obsessive behaviour disorders. But its natural purpose is as part of the brain’s reward system.

It’s the system that makes us take huge risks, when there are huge gains to be had.

This is perhaps most clearly seen when people take drugs such as Prozac which boost seratonin, another neurotransmitter. A side effect of these drugs is that they suppress the dopamine system, reducing sex drive and also romantic feelings.

“Romantic love is one of the most addictive substances on Earth,” says Fisher.

She also showed that people who had recently been dumped had even more activity in the VTA. Just when you want to forget about your former partner, your brain won’t let you.

Encouragingly, though, she also found that the system is still active in people who have been in love with each other for decades.

There are other chemicals involved in love, notably oxytocin, a hormone which is important in sexual arousal, pair bonding and maternal attachment, and scientists have not yet finished exploring this area of human behaviour. Dr Fisher is now looking at why people focus their love on one particular person, and not all their potential partners.

But it’s already clear that while there are areas that science can’t explain, love isn’t one of them.