Here are two reports from the Department of the Really Weird.
Initially, a series of experiments showed that measurements an observer makes can influence events that have already happened in the past.
One experiment, reported by the Science Journal in 2007, confirmed that flipping a switch could retroactively change a result that had happened before the switch was flipped:
Even weirder still, the choice to allow the waves to recombine or not can be made even after the photon passes the fork where it should have split–or not.
Equally weird, the Journal Nature reports:
A team of scientists has succeeded in putting an object large enough to be visible to the naked eye into a mixed quantum state of moving and not moving.
Through a phenomenon known as ‘superposition’ a particle can be moving and stationary at the same time — at least until an outside force acts on it. Then it instantly chooses one of the two contradictory positions.
But although the rules of quantum mechanics seem to apply at small scales, nobody has seen evidence of them on a large scale, where outside influences can more easily destroy fragile quantum states. “No one has shown to date that if you take a big object, with trillions of atoms in it, that quantum mechanics applies to its motion,” Cleland says.
There is no obvious reason why the rules of quantum mechanics shouldn’t apply to large objects.
Note: Science and Nature are two of the most reputable mainstream science journals.