Top 10 weird science discoveries

SWEET SCENT: Popcorn makes the cut as one of just 10 smell categories.
SWEET SCENT: Popcorn makes the cut as one of just 10 smell categories.

Not all scientific discoveries fall into either the "dull" or "truly groundbreaking" categories. Some are plain weird. Below is a list of the year's 10 weirdest science advacnes; they will make you laugh - then think.

1. There are 10 smells, and popcorn is one

We know there are five basic tastes, but what about smells? According to research released in September, there are 10 basic categories of odour - and popcorn is one of them. The other odours that made the cut were fragrant, woody/resinous, fruity (non-citrus), chemical, minty/peppermint, sweet, lemon, pungent and decayed.

2. "Better out than in" when farting on a plane

To fart or not to fart? That was the question a team of Danish and British gastroenterologists discussed in February. The research examined the trade-offs that have plagued frequent flyers, whether to hold back on farting - and therefore face significant discomfort and physical symptoms - or to release the fart and risk being shunned.

But even on a plane, scientists say it's better out than in.

As for getting away with it? Researchers recommend walking up and down the aisle so that the odour is distributed over a larger area. The future frequent flyer, however, could look forward to charcoal-lined underwear, which is meant to absorb odours from intestinal gases.

3. Penis size matters after all

In April, Australian researchers found that when it comes to attractiveness, penis size does matter. Researchers used a series of life-sized, computer-generated images and found women rated men more attractive as penis size increased.

There was also good news for tall men who were not so well endowed. Scientists found height had a positive effect almost equivalent to penis size. The research supports the hypothesis that female mate choice could have driven the evolution of larger penises in men.

4. Clapping is infectious

If you've found yourself clapping after bearing witness to something truly dull or terrible, it's probably because you've just caved in to peer pressure. Scientists in Sweden say it's not the quality of the performance but social pressure that affects clapping.

5. Moths get behind the wheel

In February, Japanese researchers developed a two-wheeled robot driven by a male silkmoth. The robot moves when the moth, spurred by the smell of enticing female sex pheromones, begins a mating dance of repeated zigzags. Scientists hope to develop a robot with its own smelling activities to track certain smells.

6. Sea slug sex: From detachable penises to traumatic mating rituals

Sea slugs are truly strange creatures. In February, scientists discovered the sea slug, Chromodoris reticulata, is able to dispose of its penis after sex and grow a new one within 24 hours - not just once, but at least three times.

In November, scientists also found that a Great Barrier Reef species stabs its sexual partner through the head while mating, shooting prostate gland secretions into each other's central nervous system.

7. Scientists unlock secrets of the unconscious mind

For Japanese researchers, being able to read dreams is no longer the stuff of fiction. In April, scientists scanned people's brains using magnetic resonance imaging (MRI) and then asked participants to describe images they had seen while asleep.

The answers were matched to the brain maps produced by the MRI, allowing researchers to later predict with 70 per cent accuracy which images people had dreamt.

8. Szechuan pepper tingles like a touch to the skin

Anyone who's had a bite of food containing Szechuan pepper will know that it can make the mouth tingle. In September, British scientists after examining signals sent to the brain in response to eating a Szechuan peppercorn showed that this tingle is equivalent to 50 light taps on the skin every second.

9. Is this my finger?

In September, a study by Australian researchers showed that our brain did not need touch or sight to decide which body parts are ours. They tricked the brain into believing a fake finger was the real thing using only sensory inputs from muscles. Researchers say it unearths a new category of mental illusions.

10. Dogs can tell left from right

It's well known that you can tell a happy dog from a sad one by their wagging tails. But research released in November suggested dogs recognise and respond differently to dogs that wag to the right rather than the left. It suggests dogs, like humans, have a sense of left and right, and asymmetrically organised brains.

Sydney Morning Herald