In the late 1940s and 1950s some theorists thought flying saucers might be space animals.

"All theorists think so, but this would be a way of checking and learning even more about this phenomenon."

Faced with these results, many theorists think that Nature is trying to tell us something fundamental.

For the first time, educational theorists and practitioners were thinking in terms of developmental psychology.

Some theorists think they have an answer, namely that the world is made up of tiny vibrating strings.

Most theorists think that is it, but there could possibly be even heavier ones we have no knowledge of as yet.

But some theorists thought the mathematics of strings was too beautiful to die.

But some theorists think that has to change.

If the giant is a planet, it is larger than theorists thought possible.

Some theorists thought that the total punch of a nucleus was the key.