Wednesday, 14 September 2011

Study reveals laughter really is the best medicine

People feel less pain after a good laugh, because it may cause the body to release chemicals that act as a natural painkiller, research has suggested.

The researchers at the University of Oxford also think the ability to belly laugh was unique to early humans.

This, they believe, enabled our ancestors to form much larger tribal groupings than the ape-like species that lived alongside them.

The research is published in the Proceedings of the Royal Society B.

The experimenters first tested the pain thresholds of volunteers.

They were then split into two groups, with one being shown 15 minutes of comedy videos, while the other was shown material the researchers deemed boring - such as golfing programmes.

The researchers found that those subjects that had recently experienced belly laughs were able to withstand up to 10% more pain than they had done before watching the videos.

To their surprise, the scientists also found that the other group was less able to bear pain after watching 15 minutes of the "boring" programmes.

Situation comedies

The type of laughter was also important. Tittering and giggling did not elicit any physiological effect; only a good guffaw did the job.

Professor Robin Dunbar of Oxford University, who led the research, believes that uncontrollable laughter releases chemicals called endorphins into the body which, as well as generating mild euphoria, also dull pain.

"It's the emptying of the lungs that causes [this effect]," he told BBC News.

"It's exactly what happens when we say 'I laughed until it hurt'. It seems to be extremely painful and it's that pain that produces the endorphin effect."

However, not all the comedy programmes were able to hit the spot, according to Prof Dunbar.

Slapstick humour seemed to score highly whereas clever stand-up comedy routines, though found to be enjoyable, had no effect on raising pain thresholds.

"I hesitate to say this but we did have one series with [British stand-up comic] Michael McIntyre and we thought he'd go down really well - but it seemed like his humour was too cerebral to produce serious guffaws," Prof Dunbar explained.

"Things that worked very well were slapstick comedies such as Mr Bean.

"Situation comedies such as Friends also seemed to be particularly successful."

Spinal Tap

The researchers were not able to measure endorphin levels directly because that would have involved extracting fluid from the volunteers' spines using a long needle - a process which, Prof Dunbar concedes, would quickly take the smile off their faces and possibly influence the results.

Instead, the researchers took what they referred to as a proxy measurement, which tested the pain threshold for each volunteer.

This involved, for example, placing a bag of ice on their arms to see how long they could withstand it.

The greater the increase in pain threshold, the greater the amount of endorphins produced.

The aim of Prof Dunbar's study is not to develop a new treatment.

Instead, it is to explore the role of laughter in the establishment of human societies two million years ago.

All apes are capable of laughter, but it is only humans that are able to belly laugh and so release endorphins.

Prof Dunbar's theory is that as well as dulling pain, endorphins also make people more susceptible to developing bonds.

"Laughter struck us as such an odd thing," he said.

"We spend so much of our time in conversations trying to elicit laughter and laughing ourselves [so] it looked like the first port of call.

"At this point what we're trying to show is, yes you do get endorphin activation.

"The next stage will be to see whether laughing really allows groups to bond together and work as a group better and act more generously towards each other."

If that is the case, then it may explain why some two million years ago, the first humans were able to form large tribal communities of up to 100 - whereas other apes and ape-like creatures that existed at the time were only able to form communities of up to 50.

This theory creates the scenario of our ancestors sharing laughter around the fire, possibly the emergence of the first clowns, clubbing each other for comic effect.

Monday, 29 August 2011

LHC results put supersymmetry theory 'on the spot'

Results from the Large Hadron Collider (LHC) have all but killed the simplest version of an enticing theory of sub-atomic physics.

Researchers failed to find evidence of so-called "supersymmetric" particles, which many physicists had hoped would plug holes in the current theory.

Theorists working in the field have told BBC News that they may have to come up with a completely new idea.

Data were presented at the Lepton Photon science meeting in Mumbai.

They come from the LHC Beauty (LHCb) experiment, one of the four main detectors situated around the collider ring at the European Organisation for Nuclear Research (Cern) on the Swiss-French border.

According to Dr Tara Shears of Liverpool University, a spokesman for the LHCb experiment: "It does rather put supersymmetry on the spot".

The experiment looked at the decay of particles called "B-mesons" in hitherto unprecedented detail.

If supersymmetric particles exist, B-mesons ought to decay far more often than if they do not exist.

There also ought to be a greater difference in the way matter and antimatter versions of these particles decay.

The results had been eagerly awaited following hints from earlier results, most notably from the Tevatron particle accelerator in the US, that the decay of B-mesons was influenced by supersymmetric particles.

LHCb's more detailed analysis however has failed to find this effect.

Bitten the dust

This failure to find indirect evidence of supersymmetry, coupled with the fact that two of the collider's other main experiments have not yet detected supersymmetic particles, means that the simplest version of the theory has in effect bitten the dust.

The theory of supersymmetry in its simplest form is that as well as the subatomic particles we know about, there are "super-particles" that are similar, but have slightly different characteristics.

The theory, which was developed 20 years ago, can help to explain why there is more material in the Universe than we can detect - so-called "dark matter".

According to Professor Jordan Nash of Imperial College London, who is working on one of the LHC's experiments, researchers could have seen some evidence of supersymmetry by now.

"The fact that we haven't seen any evidence of it tells us that either our understanding of it is incomplete, or it's a little different to what we thought - or maybe it doesn't exist at all," he said.

Disappointed

The timing of the announcement could not be worse for advocates of supersymmetry, who begin their annual international meeting at Fermilab, near Chicago, this weekend.

Dr Joseph Lykken of Fermilab, who is among the conference organisers, says he and others working in the field are "disappointed" by the results - or rather, the lack of them.

"There's a certain amount of worry that's creeping into our discussions," he told BBC News.

The worry is that the basic idea of supersymmetry might be wrong.

"It's a beautiful idea. It explains dark matter, it explains the Higgs boson, it explains some aspects of cosmology; but that doesn't mean it's right.

"It could be that this whole framework has some fundamental flaws and we have to start over again and figure out a new direction," he said.

Down the drain

Experimental physicists working at the LHC, such as Professor Nash, say the results are forcing their theoretical colleagues to think again.

"For the last 20 years or so, theorists have been a step ahead in that they've had ideas and said 'now you need to go and look for it'.

"Now we've done that, and they need to go scratch their heads," he said.

That is not to say that it is all over for supersymmetry. There are many other, albeit more complex, versions of the theory that have not been ruled out by the LHC results.

These more complex versions suggest that super-particles might be harder to find and could take years to detect.

Some old ideas that emerged around the same time as supersymmetry are being resurrected now there is a prospect that supersymmetry may be on the wane.

One has the whimsical name of "Technicolor".

According to Dr Lykken, some younger theoretical physicists are beginning to develop completely novel ideas because they believe supersymmetry to be "old hat" .

"Young theorists especially would love to see supersymmetry go down the drain, because it means that the real thing is something they could invent - not something that was invented by the older generation," he said.

And the new generation has the backing of an old hand - Professor George Smoot, Nobel prizewinner for his work on the cosmic microwave background and one of the world's most respected physicists.

"Supersymmetry is an extremely beautiful model," he said.

"It's got symmetry, it's super and it's been taught in Europe for decades as the correct model because it is so beautiful; but there's no experimental data to say that it is correct."