Accelerating Expanding Universe

[Old_Geezer]

I just know this will have an obvious explanation and I'll be here with egg all over my face, but there's something I've been pondering for a while, and not thought of the explanation yet, so maybe someone here knows.

We accept that the universe seems to be expanding at an ever increasing rate, and explanations such as dark power (whatever that is) have been suggested to explain it. But surely we should expect this accelerating expansion anyway.

As I understand it, the principle cause (or at least one cause) of expansion is that between any two distant points new space is being created, so the measured separation distance between those points increases regardless of any "real" movement. Have a long enough reference distance and the ends can rush from each other faster than light speed.

So consider, for a distance D, over a corresponding time period P, D is found to have doubled. The new situation is that there is now twice the distance/length creating new space along it at correspondingly twice the rate it did at the start. Monitor for a second period P and the distance has doubled again. And so on.

That isn't linear, that's rushing faster and faster apart. So why doesn't this account for the accelerating expansion phenomenon without resorting to further explanation ? (Bet it's got something to do with time frames and some reason why the situation isn't valid.)

Just asking.

[trt]

The mind boggles!!!!