And new observations show that the arcs are still hanging around, when by some rights they should be long gone.

But the new observations, which are reported in the current issue of Nature, create problems for the theory.

As our knowledge of space has grown, the models have been changed to account for the new observations.

But what that dark matter may be seems more puzzling then ever in light of new observations.

The new observations are still difficult to reconcile with those from earlier experiments, he said.

This last telescope produced a flood of new observations and information.

"When we first make new observations, we don't understand what they mean."

In each drawing, a new observation is recorded from the same subject.

Just as in the case of an experienced scientist, once a new observation is made, it must then be explained.

"We need new observations to understand its nature," Huélamo said.