10 mysteries that refuse to yield their secrets to science

Science has been described as the single most successful endeavour aimed at understanding the physical world. Researchers use long-established reductionist methods to break things down and see how they work. However, there are questions that seem too complex to yield to this process, and there are questions that have proven to be beyond the limits of the scientific process, at least so far: questions for which science has no response.

Here are the questions that scientists would dearly like to answer:

1 The origins of life

How did life arise on an overheated young planet in what for us would have been a poisonous atmosphere and toxic oceans? Theories abound: self-replicating chains of molecules, organic chemicals zapped from above by lightning, an information-rich double helix bound up in an early form of the genetic molecule RNA? Scientists believe they know what the conditions were like 3.8 billion years ago, but being able to say how life spontaneously arose is a huge challenge.

2 The mind and consciousness

How the mind emerges from that chemical factory – the brain – ranks as one of the biggest questions in biology. This is no small feat: a material object running on chemical-induced signalling and relying on trillions of cross-links to produce something immaterial: thought. Scientists use scanning to watch the brain at work, but they can’t make the jump between what the brain is doing physically and the thoughts or ideas that result from the brain’s biochemistry.

3 Curing cancer

Great scientific advances have been made in the treatment and control of cancer. Some cancers that previously resulted in death can now be cured, and laboratories around the world are striving to make this applicable to all cancers. Yet the disease continues to arise, with one in four of us having to deal with it at some stage in our lives. The more scientists unravel the complex biochemistry behind cancer, the more they realise just how complicated this disease can be.

4 The stuff of the universe

We can observe planets millions of light years away, study galaxies born soon after the Big Bang, and look at objects on the edge of the universe. Yet most of the universe is invisible to us. The stuff we can see – planets, stars and galaxies – only accounts for about 5 per cent of the total. The rest is described as "dark": either dark matter, probably solid stuff but not visible to us and making up an estimated 27 per cent; or dark energy, a force that may be causing our universe to expand outwards at high speed and making up 68 per cent of the total. Scientists would dearly love to know more about the dark stuff.

5 Making fusion work

Access to safe, sustainable energy is becoming an increasing challenge. We have oil, natural gas and coal, but burning them has drastic environmental implications, especially climate change. Fusion energy – joining hydrogen atoms to release huge amounts of energy – is how the sun works, but our attempts to copy this process haven’t delivered after decades of trying. Even so, scientists remain optimistic that a fusion reactor will eventually be built.

And here are the questions that seem unlikely to ever be answered by science, no matter how hard it tries:

1 Why do we fall in love?

What a strange mix of the insubstantial mind and the physical body. We meet the person of our dreams, and they make our hearts race and give us goosebumps. Brain scans can track brain activity while we experience “love”, but don’t ask the scan to explain it or find reasons why we fall in love with one person and not another.

2 What was there before the Big Bang?

All of the observations and modelling done by astronomers, physicists and cosmologists repeatedly show that the Big Bang that created the universe was real. Big atom smashers, such as at Cern, also provide insights into what was going on milliseconds after the thing went bang. But what was there before this giant firework? And who or what lit the fuse?

3 Proof of the supernatural

Many people claim to have seen ghosts or say they have had contact with the supernatural, but for all the claims there has never been objective proof. There has been no proven communication across the divide, even on Halloween, just in case you want to try again tomorrow night. By the same token, the existence of God also has to be taken on faith alone.

4 The nature of time

We all know what time it is, and we all know that time runs out and that time can speed up or slow down depending on whether we are waiting in the dentist's office or out with a loved one. But was time always there? Was it there before the Big Bang or was there a time without time? And does the arrow of time always have to point forward? Can time run backwards and is there a way to traverse time in the way we drive up and down the road? You'll be waiting on that one for a while.

5 Frozen for the future

If you have enough money, there are companies willing to freeze your deceased body in liquid nitrogen and store you on a shelf for decades and, presumably, centuries. People invest in the hope that in the future a cure will be found for whatever disease might have ended their lives. Don’t count on waking up any time soon, however. Human sperm, eggs and even fertilised eggs can be suspended in time this way, but the more complex the organism, the harder it is to thaw it out without damage.

What question would you most like to see answered by scientists? Send your top questions to science@irishtimes.com