# Metric expansion of space - past, present and future

Scientists say that out universe is expanding faster and faster. This was detected via the red-shift effect. Farther galaxies are moving from us faster than those that are more closely.

But how can scientists tell this is happening now? They can see what WAS in the past. As I understood red-shift shows to us what was 10+ million years ago if the distance between us and the other galaxy is 10+ million light-years.

Closer galaxies move away more slowly. But this WAS, lets say, 5 million years ago if the distance between us and that galaxy is 5 million light-years.

The distance between us and Andromeda is 2.5 million light-years and it is moving towards us (or we are moving towards it).

As I understand the speed of expansion gets slower and slower in time. And Andromeda shows that 2.5 million years ago the direction switched to compression. Why do scientists say that expansion becomes faster and faster with time?

So we have a theory that gives the correct predictions for what a galaxy $x$ billion light years away was doing $x$ billion light years ago, and since the theory was correct then we assume it's still correct today. That's why we feel confident in saying what distant galaxies are doing right now, even though we can't see them doing it.