alternative future n.

It had happened too quickly for wonder—he was not even thinking as he opened his eyes and looked into the cube where Marta’s gaze had met him a moment before. And then a great tide of awe and wonder came washing up into his consciousness, and he knew that Ashley had been right. There was an alternative future. There comes a point beyond which bewilderment and shock no longer affect the human brain, and Bill was outside wondering now, or groping for logical explanations. He only knew that he stood here staring into the cube from which Marta’s eyes had smiled at him so short an instant ago— They were still Marta’s eyes, deep-colored in a boy face almost Bill’s own, feature for feature, under a cap of blue steel. Somehow that other future had come to him, too.

A man enters a house and wonders whether to go upstairs or downstairs. He doesn’t know it, but if he goes up he'll meet a girl whom he'll marry and if he goes down he'll meet a man who'll murder him. Now at the moment he enters the house and wonders which to do, there are two alternatively possible futures awaiting him—murder or marriage. His choice decides which of those futures he shall enter and make real for himself, although in theory each alternative future may coexist and be real unto itself.

An alternative future must arise from the moment we change your past, giving new trends of development to your planet from that moment.

I'm talking about something that could be possible, in some alternative future, if you see what I mean.