Could we be hastening the demise of the universe just by looking at it?

The curiosity of quantum scientists could accidentally trigger the end of the world, it is claimed.

Astronomers may have hastened the demise of the universe - just by looking at it, according to a new theory.

Two U.S. scientists have come to the startling conclusion that the mere act of observing the cosmos too closely might bring it to an end.

By daring to measure dark energy, the mysterious force that is driving galaxies apart, astronomers may have begun the countdown to Armageddon.

The Lagoon Nebula is just one of the many matters in the universe studied by astronomers

It relates to a strange property of quantum systems which govern the fate of subatomic particles and possibly the whole universe.

Quantum systems can shift their energy state at random, as occurs when a radioactive atom decays.

Generally the probability of an energy shift occurring increases as time passes. But if a system lasts long enough without one, a point is reached where the chances of it happening plummet dramatically.

Some scientists think the universe is overdue for a quantum energy shift that would cause everything to cease to exist. A shift is not thought to be likely though, because the universe has lasted for such a long time and is still here.

But U.S. physicist Professor Lawrence Krauss, from Case Western Reserve University in Cleveland, Ohio, and colleague James Dent, from Vanderbilt University, Nashville, fear that in the last 10 years astronomers may inadvertently have nudged the cosmos into a more dangerous state.

The reason has to do with the odd way quantum states are affected by observation. In the famous Schrodinger's cat thought experiment, a cat in a box whose fate is decided by subatomic particles is both alive and dead until someone lifts the lid and observes it.

Only then is the cat discovered to be either "alive" or "dead".

According to a law known as the "quantum Zeno effect", whenever we observe or measure something at the quantum level we set its decay clock back to zero.

If looks could kill: Gazing at galaxies in the universe could be speeding up its decline

The physicists calculated that observing the effects of dark energy may have reset the universe's decay clock.

In 1998, astronomers measured light from exploding stars to provide the first observed evidence of dark energy, a force which is still not understood but thought to emerge from the vacuum of space.

As a result, say Dr Krauss and Mr Dent, the chances of a random energy shift destroying the universe may now be higher than it was before.

"Incredible as it seems, our detection of the dark energy may have reduced the life expectancy of the universe," Dr Krauss told New Scientist magazine.

"In short, we may have snatched away the possibility of long-term survival for our universe and made it more likely that it will decay."

Other experts are sceptical. Dr Max Tegmark, from the Massachusetts Institute of Technology in the US, points out that the quantum Zeno effect does not require humans to make observations of light.

Galaxies had "observed" dark energy long before humans evolved by being affected by it and encoding information about it, he said.

"When we humans in turn observe the light from these galaxies, it changes nothing except our own knowledge," Dr Tegmark added.