20 Unsolved Scientific Puzzles

[BURNING MAN]

1. MOST OF THE UNIVERSE IS MISSING

We can only account for 4 per cent of the cosmos

If you’re wondering what the LHC might do for you, how’s this: it might just find a whole quarter of the universe. The collider is hoping to create some particles of what physicists call “dark matter”, an enigma that is thought to make up roughly 25 per cent of the universe. Then there is the “dark energy”, a mysterious force that seems to be ripping space and time apart. In total, a whopping 96 per cent of the universe has gone AWOL. Unless, that is, we’ve got our maths all wrong.


2. THE PIONEER ANOMALY

Two spacecraft are flouting the laws of physics

In the 1970s NASA launched two space probes that have caused no end of headaches. About 10 years into the missions of Pioneer 10 and 11, the mission head admitted that they had drifted off course. In every year of travel, the probes veer 8000 miles further away from their intended trajectory. It is not much when you consider that they cover 219 million miles a year; the drift is around 10 billion times weaker than the Earth’s pull on your feet. Nonetheless, it is there, and decades of analysis have failed to find a straightforward reason for it.


3. VARYING CONSTANTS

Destabilising our view of the universe

A decade ago, we discovered that the fundamental constants of physics might not be so constant after all. These are the numbers that describe just how strong the forces of nature are, and make the laws of physics work when we use them to describe the processes of nature. Light that has travelled across the universe from distant stars tells us those laws might have been different in the past. Though the physical laws and constants have helped us define and tame the natural world, they might be an illusion.


4. COLD FUSION

Nuclear energy without the drama

In 1989, the world was rocked by claims that you could release nuclear energy without a catastrophic explosion. Various failures to replicate or explain these results soon ended the careers of the scientists involved. But, despite what you might have heard, “cold fusion” never really went away. Over a 10-year period from 1989, US navy labs ran more than 200 experiments to investigate whether nuclear reactions generating more energy than they consume - supposedly only possible inside stars - can occur at room temperature. Numerous researchers have since pronounced themselves believers. With controllable cold fusion, many of the world's energy problems would melt away: no wonder the US Department of Energy is interested again.


5. LIFE

Are you more than just a bag of chemicals?

Are you more than the sum of the inanimate chemicals that make up your body? What turns a living tree into a lifeless piece of wood? No one knows. Researchers have even given up trying to define what life is. But they are still trying to understand it – by making it from scratch. In labs across the world, people are taking the raw materials of living things and trying to put them together in a way that makes them come alive. In an effort to resolve the anomalous nature of life, the idea of scientists playing God has taken a whole new turn.


6. METHANE FROM MARTIANS

NASA scientists found evidence for life on Mars. Then they changed their minds

On July 20, 1976, the Viking landers scooped up some Martian soil and mixed it with radioactive nutrients. The mission's scientists all agreed that if radioactive methane was released from the soil, something must be eating the nutrients – and there must be life on Mars. The experiment gave a positive result, but NASA denied an official detection of Martian life. Today, there is even more evidence that something is creating methane on Mars. Is it life? The Viking experiment suggests it was. Martin Rees, England’s astronomer royal, calls the search for extraterrestrial life the most important scientific endeavour of our time. But have we already found it?


7. THE WOW! SIGNAL

Has ET already been in touch?

It was an electromagnetic pulse that came from the direction of the Sagittarius constellation. It lasted 37 seconds and had exactly the characteristics predicted for an alien signal. Maybe that’s why, on 15 August 1977 it caused astronomer Jerry Ehman to scrawl "Wow!" on the printout from Big Ear, Ohio State University's radio telescope in Delaware. The nearest star in that direction is 220 light years away. If that really is where is came from, it would have had to be a pretty powerful astronomical event - or an advanced alien civilisation using an astonishingly large and powerful transmitter. More than 30 years later, its origin remains a mystery.


8. A GIANT VIRUS

It’s a freak that could rewrite the story of life

Mimivirus is sitting in a freezer in Marseille. Around thirty times bigger than the rhinovirus that gives you a common cold, it is by far the biggest virus known to science. But this virus’s biggest impact won’t be on the healthcare systems of the globe. It will be, most likely, on the history of life on Earth. Mimivirus doesn’t fit with the established story of how life on Earth got going. Mimi has a genome that, in parts, looks like yours. Mimivirus seems to be part of the story of life on Earth. It may even make us rewrite it.


9. DEATH

Evolution’s problem with self-destruction

Why must we die? It is a question that splits biologists, and over the years, theories have been batted back and forth as new evidence comes to light. One answer is that death is simply necessary – to avoid overcrowding, for instance. But evolution doesn’t – can’t – select for a “death switch” because evolution is supposed to be all about the individual. And yet there does seem to be a death switch: researchers have managed to locate genetic switches that massively extend the lifespan of some nematode worms. Can we solve the riddle of death?


10. SEX

There are better ways to reproduce

Sex is everywhere, but no one knows why. It is a question that “better scientists than I have spent book after book failing to answer,” says Richard Dawkins. To Charles Darwin, the reason for the prevalence of sexual reproduction was “hidden in darkness”. All the arguments in favour of sexual reproduction are countered by stronger arguments in favour of self-cloning: asexual reproduction, where an organism produces a copy of itself, is a much more efficient way to pass your genes down to the next generation. There’s no proof that sex makes a species more resilient, or better placed to cope with change. Why is it still around?


11. FREE WILL

Your decisions are not your own

Our gut instinct, our experience, is that we make the decisions to move, to think, to eat, to steal, to lie, to punch and kick. We have constructed the entire edifice of our civilisation on this idea. But science says this free will is a delusion. According to the world’s best neuroscientists, we are brain-machines. Our brains create the sense that somewhere within them is the “you” that makes decisions. But it is an illusion; there is no ghost in the machine. What does this mean for our sense of self? And for our morality – can we prosecute people for acts over which they had no conscious control?


12. THE PLACEBO EFFECT

Who’s being deceived?

The placebo effect used to be thought of as just a manipulation, a mind-trick. Doctors wore white coats, spoke in soothing tones, exuding confidence and medical know-how, and if they told you a pill would make you better, it would. By the time you found out it was just a sugar pill, you were feeling great, so who cares? Well, lots of people, actually, because our new understanding of placebo is messing up medicine. Some prescription drugs that were judged to perform “better than placebo” in clinical trials don’t work unless you know you’re taking them. All in all, the gold standard of medicine, the placebo-controlled clinical trial, is looking a little peaky.


13. HOMEOPATHY

It’s patently absurd, so why won’t it go away?

Homeopathy’s claim is that you can take a substance of dubious properties, dilute it to the point where there are no molecules of the original substance left in the sample you have, and still use it to heal sickness. Sir John Forbes, the physician to Queen Victoria’s household, called it “an outrage to human reason.” There is no justification in all of science for this idea -- and yet there remains some slim evidence that homeopathy works. How can this be?


14. The flyby problem

When scientists send their spacecraft across the universe, they save fuel by performing “slingshot fly-bys”. This is where, rather than firing up the thrusters, the craft changes its trajectory by harnessing the enormous gravitational pull of a planet. However, this trick has had an unexpected side-effect: it seems to produce a change in speed that no one can account for. In 1998, for example, NASA's NEAR Shoemaker spacecraft had its speed boosted by an additional 13.5 millimetres per second. There are many examples of this, but no explanation – which raises the tantalising possibility that it could be a sign that a whole new branch of physics is waiting to be discovered.


15. Morgellons Disease

Morgellon’s disease report extreme tiredness, itches and rashes, and fibres growing out from their skin. The official line is that this is a mental illness, however: the medical literature has Morgellons down as “unexplained dermopathy” or "delusional parasitosis". Though it was described by an English doctor 300 years ago, there were no documented cases until one 2002. Since then, however, reportings of the disease have boomed. Many researchers put this down to hypochondriacs reading about the disease on the internet.


16. The lithium anomaly

Cosmologists are getting a little depressed about lithium. They have good theories to explain which atoms were created when, and in what quantities , but lithium doesn’t fit. The universe’s entire stock of lithium atoms, some of which are sitting inside your mobile phone battery, were made in the first five minutes after the big bang. But the scientists’ stock check has thrown up an anomaly. The amount of hydrogen and helium is bang on, but lithium is way off. Lithium exists in various forms, known as isotopes, and it turns out that the universe contains only about one-third of the lithium-7 isotopes that should be out there. Even worse, there is 1000 times too much lithium-6. The bottom line? The history of the universe may require a re-write.


17. The bloop

During the cold war, the US government littered the world’s oceans with an array of underwater microphones, or hydrophones, to detect submarines. The hydrophones are still working, and have picked up some worrying noises. One sounded like it might have been made by an animal, but analysis of the acoustics revealed that the animal would have had to be far bigger than the biggest whale. The US National Oceanic and Atmospheric Administration call this unexplained sound “The Bloop” . There are hundreds of unexplained noises from the ocean, it turns out. If you go down to the depths today, be sure of a big surprise.


18. Axis of evil

The universe is meant to be “isotropic”, which means it looks pretty much the same whichever way you are facing. Unfortunately, the cosmic microwave background radiation, which fills all of space, didn’t get the memo. Its hot and cold spots are meant to be randomly distributed, but there seems to be a pattern that could be used to give the universe a “this way” and “that way” characteristic, just as a piece of wood has a grain. This is bad because we don’t yet have the mathematical skill to deal with a universe where one direction is different to another. No wonder cosmologists refer to this cosmic alignment as the “axis of evil”.


19. Hybrid creatures

The starfish Luidia sarsi lives an odd life. First it’s a larva with a tiny starfish inside. Then the starfish grows, and leaves the larva: one life has become two. The sea squirt genome shows it is the result of a fusion of two completely different creatures, defying all the usual tenets of biology. It seems that evolution has been trying out a few things. Underwater, eggs and sperm often get squirted out and carried away from where they are supposed to be, leaving them free to try conception with the “wrong” partner. Despite the fact that evolution says this isn’t meant to work, it seems that, occasionally, it does. It’s not just in the ocean, either: at least ten per cent of plant species came from similar processes. Biologists now have a whole new mess to clear up.


20. Dark flow

There’s something huge out there in space, and it is taking our stars away. Clusters of galaxies are moving at 1000 km/h towards a patch of sky between the Centaurus and Vela constellations. The best explanation for this “dark flow” is the gravitational attraction of a massive structure beyond the edge of the visible universe. This is another blow to our view of things – everything is meant to be roughly the same everywhere, so why haven’t we got something this big in our patch?

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[Truthed]

Hard to wrap your mind around some of those